WO2021217248A1

WO2021217248A1 - Portable ozone sterilization chamber and methods associated therewith

Info

Publication number: WO2021217248A1
Application number: PCT/CA2021/050566
Authority: WO
Inventors: Adam Bott; James J. Ferri; Ryan BAERG; Jeffrey Richard F. Domenchini; Ghanshyam MALI
Original assignee: Puro Canada Inc.
Priority date: 2020-05-01
Filing date: 2021-04-26
Publication date: 2021-11-04

Abstract

In an aspect, a sterilization unit is provided, and includes a housing, an ozone generator and a seal arrangement. The housing defines a sterilization chamber and has an aperture therein that extends from an external environment to the sterilization chamber. The aperture has a first end with a cross-sectional dimension. The ozone generator generates ozone and provides the ozone to the sterilization chamber. The seal arrangement includes a plug having a plug body that extends into the aperture, and a plug head having a head dimension that is larger than the cross-sectional dimension of the first end of the aperture. The cover member is adhered to a surface of the housing surrounding the plug and which engages the plug head to hold the plug in engagement with the housing to seal against leakage of gas between the sterilization chamber and the external environment of the sterilization unit.

Description

PORTABLE OZONE STERILIZATION CHAMBER AND METHODS

ASSOCIATED THEREWITH

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of US provisional application no. 63/019,168, filed May 1 , 2020, and US provisional application no. 62/130,314, filed December 23, 2020.

FIELD

[0002] The specification relates generally to portable ozone sterilization chambers and methods of using same.

BACKGROUND OF THE DISCLOSURE

[0003] The COVID-19 pandemic has illustrated a need for personal protective equipment (PPE) such as masks, face shields, goggles, and gowns to be readily available. Disposable PPE can be subject to supply chain disruptions to acquire and restock PPE, require significant storage space, and generate considerable waste because they should be discarded after a single use.

[0004] Although reusable PPE generates less waste and is less impacted than disposable PPE by supply chain disruptions to acquire and restock it, sanitizing reusable PPE after each use can be expensive and inconvenient. For example, reusable PPE such as gowns are generally sent to a different floor from their field site of use to be sanitized for reuse, or even sent completely off-site to a commercial cleaning/disinfecting service retained by a medical facility. These commercial cleaning/disinfecting services use appliance-size or even large industrial size chambers for cleaning PPE such as an industrial washing machine for cloth reusable gowns or sterilizing closet or room-size sterilization chambers. Sending reusable PPE away from their field of use site can also present localized supply disruption. [0005] A need exists for the ability to conveniently sanitize either type of PPE (e.g., reusable PPE, and certain disposable PPE) in the field, that is, at their field site of use or as close to their field site as possible in order to be readily available to PPE users.

[0006] Ozone (03) is a triatomic inorganic molecule made up of three atoms of oxygen. Due to its potent oxidizing power, ozone has many industrial, commercial and medical applications such as the application of ozone gas to break down macromolecular compounds constituting the integrity of viruses in addition to bacteria, protozoa, fungi, molds, pesticides, heavy metals, nitrates, nitrites and other potentially harmful substances. Ozone, for example, is very effective in sterilizing or decontaminating nonporous surfaces exposed to it.

[0007] Ozone gas has been proven to kill the SARS coronavirus and since the structure of the new 2019-nCoV coronavirus is almost identical to that of the SARS coronavirus, it is relatively safe to assume that ozone will also work on the new 2019-nCoV coronavirus. [0008] All materials react differently when exposed to ozone. Ozone is an oxidizing agent, and excessive exposure to ozone can cause some materials to deteriorate or degrade overtime. Natural materials (such as natural rubber, leather, or silk) or unprotected metals could see negative effects after multiple cycles of ozone exposure. As such, use of ozone or other sterilization gases comprising ozone on some items such as porous items (e.g., masks, gowns) and items comprising elastic, rubber or similar material needs to be limited to avoid degradation and therefore added expense of more frequent replacement costs.

[0009] A need exists for the ability to conveniently sanitize PPE, including reusable and certain disposable PPE, using ozone without degradation of materials in the PPE from ozone exposure. Further, a need exists for a portable, convenient device and method of using same to provide sanitization of items such as PPE in real-time at, or close to, the field sites of their use (e.g., hospital unit which can be a mobile, temporary hospital) that minimizes degradation. SUMMARY OF THE DISCLOSURE

[0010] The above and other problems are overcome, and additional advantages are realized, by illustrative embodiments.

[0011] It is an aspect of illustrative embodiments to provide a method of sterilizing one or more items in a sterilization gas atmosphere, comprising: placing a selected quantity of items that are to be subjected to sterilization in a sterilization chamber, the items corresponding to a material load; sealing the sterilization chamber; supplying sterilization gas to the sterilization chamber for a treatment cycle having a designated treatment period, the sterilization gas comprising at least ozone and the supplying comprising generating ozone and supplying the ozone to the sterilization chamber; matching the generated amount of ozone to the material load by generating ozone to reach a designated ozone concentration level that is greater than a minimum treatment threshold level to achieve a designated sterility acceptance rate for the material load and less than a maximum treatment threshold level to prevent degradation of the items from exposure to the generated amount of ozone; and determining when the treatment period for selected item is complete.

[0012] In accordance with aspects of an illustrative embodiment, the designated treatment period is a predetermined fixed period oftime.

[0013] In accordance with aspects of an illustrative embodiment, the material load is characterized by material load parameters comprising a predetermined item type and a predetermined quantity of items selected to achieve the designated ozone concentration level.

[0014] In accordance with aspects of an illustrative embodiment, the material load parameters further comprise at least one of a make/model of items to be treated, an upper number limit of items in the material load for a treatment cycle, a level of contamination of the items, and a permeability factor for the items and/or components thereof. [0015] In accordance with aspects of an illustrative embodiment, items to be treated in the sterilization chamber are degradable by the sterilization gas after subjected to a degradation condition chosen from prolonged cumulative exposure to the sterilization gas beyond an upper limit exposure time threshold, and number of treatment cycles exceeding an upper limit treatment cycle count.

[0016] In accordance with aspects of an illustrative embodiment, the method further comprises: repeating a treatment cycle of the items in the material load a selected number of times; and limiting the selected number to less than the upper limit treatment cycle count to prevent degradation of the items from exposure to the generated amount of ozone.

[0017] In accordance with aspects of an illustrative embodiment, the supplying further comprises: detecting concentration of ozone in the sterilization chamber using an ozone sensor; and selectively operating an ozone generator to supply the ozone at the designated ozone concentration level using detected ozone concentration data from the ozone sensor until the treatment period expires.

[0018] In accordance with aspects of an illustrative embodiment, the selectively operating comprises using detected ozone concentration data from the ozone sensor to selectively terminate and resume generating ozone to maintain the designated ozone concentration level.

[0019] In accordance with aspects of an illustrative embodiment, the treatment period is a predetermined fixed period of time.

[0020] In accordance with aspects of an illustrative embodiment, the method further comprises generating an indication to a user of the sterilization chamber to reduce the selected quantity of items when the detected ozone concentration data from the ozone sensor indicates that the designated ozone concentration level is not reached within a time limit chosen from the treatment period and a selected time interval within the treatment period. [0021] In accordance with aspects of an illustrative embodiment, determining when the treatment period for selected item is complete comprises: totaling the durations of detection intervals of the ozone sensor that indicate an ozone concentration level in the sterilization chamber being at least the designated ozone concentration level; and determining when the total durations of the detection intervals corresponds to the designated treatment period.

[0022] In accordance with aspects of an illustrative embodiment, the method further comprises generating an indication to a user of the sterilization chamber to reduce the selected quantity of items when the detected ozone concentration data from the ozone sensor indicates that the designated ozone concentration level is not reached within a selected time limit.

[0023] In accordance with aspects of an illustrative embodiment, the method further comprises neutralizing the ozone in the sterilization chamber when the treatment period for the items is complete.

[0024] In accordance with aspects of an illustrative embodiment, the method further comprises providing an indicator within the material load as confirmation the surfaces of material load were actually treated, the indicator being configured to change a state thereof in response to exposure to ozone.

[0025] In accordance with aspects of an illustrative embodiment, the method further comprises placing the indicator in a designated representative location among the items in the material load to provide confirmation that the surface areas of the items in the material load were treated.

[0026] In accordance with aspects of an illustrative embodiment, the method further comprises running a second treatment cycle if the indicator does not change its state after the current treatment cycle.

[0027] In accordance with aspects of an illustrative embodiment, the method further comprises servicing the unit if the indicator does not change its state after the second treatment cycle. [0028] In accordance with aspects of an illustrative embodiment, the method further comprises placing a rack within the chamber during a treatment cycle, the rack comprising a selected number and arrangement of features chosen from protrusions, grooves, depressions, separators, troughs, and apertures that correspond to a selected form factor of the item, the selected number corresponding to the designated number of items in a material load to assists the user with inserting the designated material load into the chamber for a treatment cycle.

[0029] In accordance with aspects of an illustrative embodiment, a sterilization unit is provided that comprises: a sealable sterilization chamber configured to receive a selected quantity of items that are to be subjected to sterilization in the sterilization chamber, the items corresponding to a material load; an ozone generator for generating ozone and providing the ozone to the sterilization chamber; an ozone sensor; and a controller configured to match the generated amount of ozone to the material load by generating ozone to reach a designated ozone concentration level that is greater than a minimum treatment threshold level to achieve a designated sterility acceptance rate for the material load and less than a maximum treatment threshold level to prevent degradation of the items from exposure to the generated amount of ozone, and determining when the treatment period for selected item is complete.

[0030] In accordance with aspects of an illustrative embodiment, the controller is configured to match the generated amount of ozone to the material load by detecting the concentration of ozone in the sterilization chamber using the ozone sensor, and selectively operate the ozone generator to supply the ozone at the designated ozone concentration level using detected ozone concentration data from the ozone sensor until the treatment period expires.

[0031] In accordance with aspects of an illustrative embodiment, the controller is further configured to selectively operate the ozone generator by using the detected ozone concentration data to selectively terminate and resume operating the ozone generator to maintain the designated ozone concentration level. [0032] In accordance with aspects of an illustrative embodiment, the treatment period is a predetermined fixed period of time.

[0033] In accordance with aspects of an illustrative embodiment, the sterilization unit further comprises an indicator, and wherein the controller is further configured to generate an indication via the indicator to a user of the sterilization chamber to reduce the selected quantity of items when the detected ozone concentration data from the ozone sensor indicates that the designated ozone concentration level is not reached within a time limit chosen from the treatment period and a selected time interval within the treatment period.

[0034] In accordance with aspects of an illustrative embodiment, the controller is further configured to determine when the treatment period for the selected items is complete by totaling the durations of detection intervals of the ozone sensor that indicate an ozone concentration level in the sterilization chamber being at least the designated ozone concentration level, and determining when the total durations of the detection intervals corresponds to the designated treatment period.

[0035] In accordance with aspects of an illustrative embodiment, the sterilization unit further comprises an indicator, and wherein the controller is further configured to generate an indication via the indicator to a user of the sterilization chamber to reduce the selected quantity of items when the detected ozone concentration data from the ozone sensor indicates that the designated ozone concentration level is not reached within a selected time limit.

[0036] In accordance with aspects of an illustrative embodiment, the sterilization unit further comprises at least one fan, and the controller is configured to selectively operate the at least one fan during a neutralization process to reduce ozone in the sterilization chamber to less than a selected ozone concentration level using detected ozone concentration data from the ozone sensor.

[0037] In accordance with aspects of an illustrative embodiment, the sterilization unit further comprises a lock assembly for a lid to the sealable sterilization chamber, the controller being configured to maintain the lock assembly in a locked mode to keep the lid closed during an ozone generation process, and to unlock the lock assembly and allow opening the lid after a neutralization process is completed by determining when ozone in the sterilization chamber is reduced to less than a selected ozone concentration level using detected ozone concentration data from the ozone sensor. [0038] In accordance with aspects of an illustrative embodiment, a sterilization unit is provided that comprises: a sealable sterilization chamber configured to receive a selected quantity of items that are to be subjected to sterilization in the sterilization chamber, the items corresponding to a material load; an ozone generator for generating ozone and providing the ozone to the sterilization chamber; a controller configured to match the generated amount of ozone to the material load by generating ozone to reach a designated ozone concentration level that is greater than a minimum treatment threshold level to achieve a designated sterility acceptance rate for the material load and less than a maximum treatment threshold level to prevent degradation of the items from exposure to the generated amount of ozone, and determining when the treatment period for selected item is complete; and a rack configured to be placed within the sterilization chamber during a treatment cycle, the rack comprising a selected number and arrangement of features chosen from protrusions, grooves, depressions, separators, troughs, and apertures that correspond to a selected form factor of the item to match the generated amount of ozone to the material load and reach the designated ozone concentration level by guiding the user with placement of the selected quantity of items into the sterilization chamber for a treatment cycle.

[0039] In accordance with aspects of an illustrative embodiment, the rack is made from an ozone-compatible material that can be sanitized.

[0040] In accordance with aspects of an illustrative embodiment, the rack comprises a plurality of stackable shelves, and each shelf has a selected number and arrangement of features chosen from protrusions, grooves, depressions, separators, troughs, and apertures that correspond to a selected form factor of the item to match the generated amount of ozone to the material load and reach the designated ozone concentration level.

[0041] In accordance with aspects of an illustrative embodiment, the sterilization unit further comprises an indicator placed among the items of the material load as confirmation that surfaces of material load are actually treated after a treatment cycle is completed, the indicator being configured to change a state thereof in response to exposure to ozone.

[0042] In accordance with aspects of an illustrative embodiment, the indicator is portable, and disposable or reusable.

[0043] Additional and/or other aspects and advantages of illustrative embodiments will be set forth in the description that follows, or will be apparent from the description, or may be learned by practice of the illustrative embodiments. The illustrative embodiments may comprise apparatuses and methods for operating same having one or more of the above aspects, and/or one or more of the features and combinations thereof. The illustrative embodiments may comprise one or more of the features and/or combinations of the above aspects as recited, for example, in the attached claims. [0044] In another aspect, a sterilization unit is provided, and includes a housing, an ozone generator and a seal arrangement. The housing defines a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization. The housing has an aperture therein that extends from an external environment of the sterilization unit to the sterilization chamber. The aperture has a first end with a cross-sectional dimension. The ozone generator is for generating ozone and providing the ozone to the sterilization chamber. The seal arrangement includes a plug having a plug body that extends into the aperture, and a plug head having a head dimension that is larger than the cross-sectional dimension of the first end of the aperture. The cover member is adhered to a surface of the housing surrounding the plug and which engages the plug head to hold the plug in engagement with the housing to seal against leakage of gas between the sterilization chamber and the external environment of the sterilization unit. [0045] In another aspect, a method of assembling and testing a sterilization unit is provided, and includes:

[0046] a) assembling a housing and an ozone generator together, wherein the housing defines a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, wherein the housing has an aperture therein that extends from an external environment to the sterilization chamber, and wherein the ozone generator is configured for generating ozone and providing the ozone to the sterilization chamber; [0047] b) fluidically connecting an ozone sensor to the sterilization chamber through the aperture;

[0048] c) operating the ozone generator in order to generate the ozone in the sterilization chamber;

[0049] d) drawing gas from inside the sterilization chamber to the ozone sensor and measuring how much ozone is present in the gas; and [0050] e) sealing the aperture.

[0051] In yet another aspect, a sterilization unit is provided and includes a housing, and an ozone generator. The housing defines a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization. The housing has a bottom portion and a lid, wherein the lid has a lid hinge wall and the bottom portion has a bottom portion hinge wall. The lid hinge wall and the bottom portion hinge wall are movably connected to one another by a hinge arrangement that includes at least one hinge defining a pivot axis for the hinge arrangement. The ozone generator is for generating ozone and providing the ozone to the sterilization chamber. When the housing is at an ambient pressure, the hinge arrangement is positioned in a first hinge position in which the pivot axis extends along a linear path, and wherein the hinge arrangement is movable to a second hinge position in which the pivot axis along an arcuate path so as to accommodate flexing of the lid hinge wall and the bottom portion hinge wall during evacuation of the housing to a selected amount of pressure below the ambient pressure. [0052] In yet another aspect, a sterilization unit is provided and includes a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization. The housing has an aperture therein that extends from an external environment of the sterilization unit to the sterilization chamber. The aperture has a first end with a cross-sectional dimension. The ozone generator is for generating ozone and providing the ozone to the sterilization chamber. A controller that controls current from a power source to the ozone generator. The controller receives signals from a temperature sensor that are indicative of a temperature. When signals from the temperature sensor are indicative that the temperature is below a selected threshold temperature, the controller is configured to: a) measure current flow at each of a first plurality of frequencies over a selected range of frequencies; b) determine which of the current flows measured in step a) was a first lowest current flow; and c) transmit current to the ozone generator at a first transmission frequency that is selected based on whichever frequency of the first plurality of frequencies is associated with the first lowest current flow determined in step b).

[0053] When signals from the temperature sensor are indicative that the temperature is above the selected threshold temperature, the controller is configured to: d) measure current flow at each of a second plurality of frequencies over the selected range of frequencies, e) determine which of the current flows measured in step d) was a second lowest current flow, and f) transmit current to the ozone generator at a second transmission frequency that is selected based on whichever frequency of the second plurality of frequencies is associated with the second lowest current flow determined in step e).

[0054] In yet another aspect, an ozone cleaner for cleaning one or more items is provided and includes an ozone generator for generating ozone, a housing defining a cleaning chamber that is configured to receive the one or more items and the generated ozone, a power source to supply power to the ozone generator, a first sensor for sensing an undesired operating temperature of the ozone cleaner and a second sensor for sensing the power supplied to the ozone generator. The ozone cleaner includes an operating mode wherein the ozone cleaner is adapted to supply power to the ozone generator at an operating frequency, and a frequency setting mode wherein the ozone cleaner is adapted to supply power to the ozone generator over a set of frequencies in response to the first sensor sensing the undesired operating temperature to determine a set frequency from the set of frequencies selected based upon the sensed amount of supplied power at the set frequency during the frequency setting mode.

[0055] In another aspect, a method of operating an ozone cleaner for cleaning one or more items, the ozone cleaning comprising an ozone generator for generating ozone is provided. The method includes: supplying power to the ozone generator; sensing an undesired operating condition of the ozone cleaner; varying an operating frequency of the supplied power over a range of given frequencies in response to sensing the undesired operating condition; sensing the amount of supplied power at the given frequencies during varying the frequency of the power supply; and supplying power at a selected frequency from the given frequencies based upon the sensed amount of supplied power at the given frequencies.

[0056] In another aspect, an ozone cleaner for cleaning one or more items is provided and includes an ozone generator for generating ozone, a housing defining a cleaning chamber that is configured to receive the one or more items and generated ozone from the ozone generator, a power supply to supply power to the ozone generator; and a first sensor for sensing an undesired operating condition of the ozone cleaner. The ozone generator and the power supply form a resonance circuit. In response to the first sensor sensing the undesired operating condition the ozone cleaner enters a frequency setting mode in which the ozone cleaner is adapted to power the resonance circuit over a set of frequencies, sense the amount of supplied power at each frequency in the set of frequencies, and set the frequency of the supplied power to a set frequency from the set of frequencies selected based upon the sensed amount of supplied power at the set frequency during the frequency setting mode.

[0057] In another aspect, a sterilization unit is provided and includes a housing and an ozone generator. The housing defines a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization. The housing has a bottom portion and a lid. The ozone generator is configured for generating ozone and providing the ozone to the sterilization chamber. When the housing is at an ambient pressure, the housing is in a first position, such that the sterilization chamber occupies a first volume, and wherein, during evacuation of the housing to a selected amount of pressure below the ambient pressure, at least a portion of the housing is movable to an evacuation position in which the sterilization chamber occupies a second volume that is smaller than the first volume.

[0058] In another aspect, a sterilization unit is provided and includes a housing, an ozone generator and a latch. The housing defines a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization. The housing has a bottom portion and a lid. The ozone generator is configured for generating ozone and providing the ozone to the sterilization chamber. The latch is positioned to lock the lid and the bottom portion together, wherein the latch includes a striker, a ratchet and a pawl. The striker is mounted to one of the lid and the bottom portion, and the ratchet is mounted to the other of the lid and the bottom portion. The ratchet is pivotable between an open position in which the ratchet does not capture the striker, and a closed position in which the ratchet captures the striker, so as to lock the housing closed. A ratchet biasing member urges the ratchet towards the open position. The pawl is movable between a ratchet locking position in which the pawl holds the ratchet in the closed position, and a ratchet release position in which the pawl permits the ratchet to move to the open position. The latch includes a pawl biasing member that urges the pawl towards the ratchet locking position. When the ratchet is in the closed position the ratchet permits movement of the pawl to the ratchet locking position by the pawl biasing member. The striker is movably mounted to said one of the lid and the bottom portion for movement between a retracted position and an extended position. When the striker is in the retracted position, the striker does not cause pivoting of the ratchet to the closed position. Movement of the striker to the extended position drives the ratchet to pivot to the closed position. The latch further includes a striker biasing member that urges the striker towards the retracted position. The latch further includes an external actuator that is accessible from outside the housing and is actuatable by a user to overcome the striker biasing member and drive the striker to the extended position so as to drive the ratchet to the closed position so as to capture the striker and lock the housing closed.

[0059] In another aspect, the present disclosure is directed to a method of operating a sterilization unit that includes a housing defining a sterilization chamber for holding at least one item for sterilization of the at least one item, an ozone generator positioned for generating ozone in the sterilization chamber, the method comprising: a) determining data that relates to power consumption of the ozone generator; b) determining a threshold ramp up time for reaching at least a threshold ozone concentration level, based on the data determined in step a); c) operating the ozone generator in a ramp-up mode for a first selected period of time that is based on the threshold ramp up time; d) determining a selected duty cycle to operate the ozone generator at, in order to ensure that the sterilization chamber is maintained at at least the threshold ozone concentration level; e) operating the ozone generator in a sterilization mode at the selected duty cycle for a second selected period of time; and f) operating the ozone generator in a neutralization mode for a third selected period of time to neutralize ozone contained in the sterilization chamber from step e).

[0060] In another aspect, a sterilization unit is provided, including a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, where the housing has a bottom portion and a lid, an ozone generator for generating ozone and providing the ozone to the sterilization chamber, a rack system configured to support the quantity of items when received within the sterilization chamber, where the bottom portion and the lid both each define a space that together define the sterilization chamber such that when the lid is in a closed position with the bottom portion the rack system is received within both of the spaces defined by the lid and the bottom portion.

[0061] In another aspect, a sterilization unit is provided, including a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, where the housing has a bottom portion and a lid, and an ozone generator for generating ozone and providing the ozone to the sterilization chamber, where the bottom portion includes a floor for supporting the weight of the quantity of items and the floor includes one or more legs positioned inwards the outer perimeter of the floor for transferring the weight of the items supported by the floor to a underlying support structure.

[0062] In accordance with aspects of an illustrative embodiment, the present disclosures is directed to a decontamination unit, comprising: a housing defining a treatment chamber that is shaped to receive a quantity of items that are to be subjected to decontamination, wherein the housing has an aperture therein that extends from an external environment of the decontamination unit to the treatment chamber, wherein the aperture has a first end with a cross-sectional dimension; an ozone generator for generating ozone and providing the ozone to the treatment chamber; and a seal arrangement including a plug having a plug body that extends into the aperture, and a plug head having a head dimension that is larger than the cross-sectional dimension of the first end of the aperture; and a cover member that is adhered to a surface of the housing surrounding the plug and which engages the plug head to hold the plug in engagement with the housing to seal against leakage of gas between the treatment chamber and the external environment of the decontamination unit.

[0063] In accordance with aspects of an illustrative embodiment, the housing includes a bottom portion and a lid, and wherein the aperture is in the lid.

[0064] In accordance with aspects of an illustrative embodiment, the cover member has a first side and a second side and is adhered to the surface of the housing on the first side, and wherein the decontamination unit further comprises a logo member adhered to the second side of the cover member, wherein the logo member is more rigid than the cover member.

[0065] In accordance with aspects of an illustrative embodiment, the cover member is made from a flexible sheet. [0066] In accordance with aspects of an illustrative embodiment, the aperture is generally circular in cross-section, and has an aperture diameter at the first end, and the plug head is generally circular and has a head diameter that is larger than the aperture diameter at the first end.

[0067] In accordance with aspects of an illustrative embodiment, the plug body has a proximal end that is proximate to the plug head and a distal end, wherein the plug body tapers inwardly towards the distal end.

[0068] In accordance with aspects of an illustrative embodiment, the plug has a blind aperture extending through the plug head into the plug body.

[0069] In accordance with aspects of an illustrative embodiment, the plug head is outside of the housing.

[0070] In accordance with aspects of an illustrative embodiment, a decontamination unit comprises a housing defining a treatment chamber that is shaped to receive a quantity of items that are to be subjected to decontamination, wherein the housing has a bottom portion and a lid; an ozone generator for generating ozone and providing the ozone to the treatment chamber, wherein, when the housing is at an ambient pressure, the housing is in a first position, such that the treatment chamber occupies a first volume, and wherein, during evacuation of the housing to a selected amount of pressure below the ambient pressure, at least a portion of the housing is movable to an evacuation position in which the treatment chamber occupies a second volume that is smaller than the first volume.

[0071] In accordance with aspects of an illustrative embodiment, the lid has a lid hinge wall and the bottom portion has a bottom portion hinge wall, wherein the lid hinge wall and the bottom portion hinge wall are movably connected to one another by a hinge arrangement that includes at least one hinge defining a pivot axis for the hinge arrangement, and wherein, when the housing is at the ambient pressure, the hinge arrangement is positioned in a first hinge position in which the pivot axis extends along a linear path, and wherein the hinge arrangement is movable to a second hinge position in which the pivot axis extends along an arcuate path so as to accommodate flexing of the lid hinge wall and the bottom portion hinge wall during evacuation of the housing to the selected amount of pressure below the ambient pressure.

[0072] In accordance with aspects of an illustrative embodiment, the housing has an aperture therein that extends from an external environment to the treatment chamber, wherein the treatment chamber is connectable to a vacuum source so as to generate the selected amount of pressure below the ambient pressure.

[0073] In accordance with aspects of an illustrative embodiment, the at least one hinge is a single hinge that includes a first plurality of hinge knuckles mounted to the bottom portion hinge wall, a second plurality of hinge knuckles mounted to the lid hinge wall and which are positioned in gaps between the first hinge knuckles, and a hinge pin that extends through the first plurality of hinge knuckles and the second plurality of hinge knuckles, wherein the hinge pin is sufficiently flexible and the first and second hinge knuckles have a sufficient amount of play therebetween, so as to permit movement of the hinge arrangement between the first hinge position and the second hinge position.

[0074] In accordance with aspects of an illustrative embodiment, the hinge pin is made from a material having a selected yield stress, and is shaped to incur stress below the elastic yield stress during movement of the hinge arrangement from the first hinge position to the second hinge position.

[0075] In accordance with aspects of an illustrative embodiment, the lid has a lid lip and the bottom portion has a bottom portion lip, and wherein at least one of the lid lip and the bottom portion lip has a projection thereon, and the other of the lid lip and the bottom portion lip has a compressible member captured thereon, wherein the compressible member has an inside edge that faces inwardly towards the volume contained by the housing, and an outer edge that faces outwardly away from the volume contained by the housing, and closure of the lid on the bottom portion brings the projection into sealing engagement with the compressible member, such that the projection compresses the compressible member between the outside edge and the inside edge and is spaced from the compressible member at the outside edge and the inside edge. [0076] In accordance with aspects of an illustrative embodiment, the projection has a cross-sectional shape that is a V-shape.

[0077] In accordance with aspects of an illustrative embodiment, the projection has an inward surface that faces at least partially inwardly towards the treatment chamber, and an outward surface that faces at least partially outwardly away from the treatment chamber, wherein at least a portion of the inward surface and at least a portion of the outward surface are engaged with the compressible member upon closure of the lid on the bottom portion. [0078] In accordance with aspects of an illustrative embodiment, the compressible member has a projection engagement face that is engaged by the projection, wherein the projection engagement face is planar.

[0079] In accordance with aspects of an illustrative embodiment, the projection is on the bottom portion lip and the compressible member is captured on the lid lip.

[0080] In accordance with aspects of an illustrative embodiment, there is provided a decontamination unit, comprising: a housing defining a treatment chamber that is shaped to receive a quantity of items that are to be subjected to decontamination, wherein the housing has a bottom portion and a lid; an ozone generator for generating ozone and providing the ozone to the treatment chamber; and a latch positioned to lock the lid and the bottom portion together, wherein the latch includes a striker, a ratchet and a pawl, wherein the striker is mounted to one of the lid and the bottom portion, and wherein the ratchet is mounted to the other of the lid and the bottom portion, wherein the ratchet is pivotable between an open position in which the ratchet does not capture the striker, and a closed position in which the ratchet captures the striker so as to lock the housing closed, wherein a ratchet biasing member urges the ratchet towards the open position, wherein the pawl is movable between a ratchet locking position in which the pawl holds the ratchet in the closed position, and a ratchet release position in which the pawl permits the ratchet to move to the open position, wherein the latch includes a pawl biasing member that urges the pawl towards the ratchet locking position, and wherein when the ratchet is in the closed position the ratchet permits movement of the pawl to the ratchet locking position by the pawl biasing member, wherein the striker is movably mounted to said one of the lid and the bottom portion for movement between a retracted position and an extended position, wherein, when the striker is in the retracted position, the striker does not cause pivoting of the ratchet to the closed position, wherein movement of the striker to the extended position drives the ratchet to pivot to the closed position, wherein the latch further includes a striker biasing member that urges the striker towards the retracted position, and wherein the latch further includes an external actuator that is accessible from outside the housing and is actuatable by a user to overcome the striker biasing member and drive the striker to the extended position so as to drive the ratchet to the closed position so as to capture the striker and lock the housing closed. [0081] In accordance with aspects of an illustrative embodiment, the striker is on the lid and the ratchet and the pawl are on the bottom portion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0082] The above and/or other aspects and advantages of embodiments of the illustrative embodiments will be more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings, of which:

[0083] Figs. 1A and 1 B are perspective views of a sterilization unit constructed in accordance with an example embodiment and showing the lid in a closed position and open position, respectively.

[0084] Figs. 2A and 2B, are cross-section views of a treatment chamber in a sterilization unit constructed in accordance with an example embodiment.

[0085] Figs. 2C and 2D are perspective views of a catalyst drawer used in a sterilization unit constructed in accordance with an example embodiment.

[0086] Fig. 2E is a cross-section view of a treatment chamber in a sterilization unit constructed in accordance with another example embodiment.

[0087] Figs. 3A and 3B are perspective views of a sterilization unit constructed in accordance with an example embodiment and showing a rack system disposed in the treatment chamber thereof and with the lid in an open position and a closed position, respectively.

[0088] Fig. 4 is a perspective view of a rack system for use in a sterilization unit and constructed in accordance with an example embodiment.

[0089] Figs. 5A and 5B depict a rack system for use in a sterilization unit and constructed in accordance with an example embodiment.

[0090] Fig. 6 is a graph depicting how 03 concentration (ppm) rises when repeating 25 minute ozone generation cycles on the same set of clean masks in a sterilization unit. [0091] Fig. 7 is graph depicting how 03 concentration (ppm) varies as between two trial cycles in a sterilization unit.

[0092] Fig. 8 is graph depicting how 03 concentration (ppm) rises during a 25 minute ozone generation cycle in a sterilization unit.

[0093] Fig. 9 is a graph depicting a baseline treatment curve for determining material load parameters for a sterilization unit in accordance with an illustrative embodiment.

[0094] Fig. 10 is a graph depicting an optimized curve to achieve a desired sterility acceptance rate for PPE treated in a sterilization unit in accordance with an illustrative embodiment.

[0095] Fig. 11 depicts example cleaning operations of a sterilization unit in accordance with a first illustrative embodiment.

[0096] Fig. 12 illustrates the occurrence of example cleaning cycle processes with respect to the optimized curve in Fig. 10 in accordance with an illustrative embodiment. [0097] Fig. 13 depicts example cleaning operations of a sterilization unit in accordance with a second illustrative embodiment.

[0098] Fig. 14 depicts example cleaning operations of a sterilization unit in accordance with a third illustrative embodiment.

[0099] Fig. 15 is a block diagram of electronic components in a sterilization unit constructed in accordance with an illustrative embodiment. [0100] Fig.16 is a diagram depicting a user interface for a sterilization unit constructed in accordance with an illustrative embodiment.

[0101] Fig. 17 depicts an ozone concentration sensor printed circuit board (PCB) module disposed in the ozone generation cell section of a sterilization unit constructed in accordance with an illustrative embodiment.

[0102] Figs. 18A and 18B illustrate, respectively, front and rear perspective views of a sensor PCB module constructed in accordance with an embodiment.

[0103] Fig. 18C is an exploded view of the sensor PCB module in Figs. 18A and 18B.

[0104] Fig. 18D is a rear cross-section view of the sensor PCB module in Figs. 18A and

18B.

[0105] Fig. 18E is a top view of the sensor PCB module in Figs. 18A and 18B.

[0106] Fig. 18F is a side, partial cross-section view of the sensor PCB module in Figs.

18A and 18B.

[0107] Fig. 19A is a front perspective view of an example ozone concentration sensor PCB constructed in accordance with an illustrative embodiment.

[0108] Fig. 19B is rear perspective view of the sensor PCB in Fig. 19A.

[0109] Fig. 20 is an exploded view of a sensor PCB module constructed in accordance with another embodiment.

[0110] Fig. 21 is a diagram depicting a user interface for a sterilization unit constructed in accordance with an illustrative embodiment.

[0111] Fig. 22 is a perspective exploded view of the sterilization unit with an optional aperture and an optional seal arrangement in accordance with another embodiment.

[0112] Fig. 23 is a perspective view of the sterilization unit shown in Fig. 22 being performance-tested.

[0113] Fig. 24 is a magnified sectional view of a portion of the sterilization unit shown in Fig. 22, showing the aperture and the seal arrangement.

[0114] Fig. 25 is a flow diagram of a method of assembling and testing a sterilization unit in accordance with another embodiment. [0115] Fig. 26 is a plan view of the sterilization unit with an optional hinge arrangement in accordance with another embodiment.

[0116] Fig. 27 is a perspective view of the sterilization unit shown in Fig. 26, while a partial vacuum is drawn inside the sterilization unit.

[0117] Figs. 28A-28E are schematic diagrams of portions of electronic components of an ozone cleaner in accordance with another embodiment of progressively increasing detail. [0118] Figs. 29A and 29B are schematic diagrams of portions of electronic components of the ozone cleaner in further increasing detail in relation to Fig 28E.

[0119] Fig. 30A is a flow diagram of a method for controlling current to an ozone generator using the portions of the control system shown in Figs. 28A-28E, and 29A and 29B.

[0120] Fig. 30B is another flow diagram of a method for controlling current to an ozone generator using the portions of the control system shown in Figs. 28A-28E, and 29A and 29B.

[0121] Figs. 31 and 32 together make up a flow diagram of another method for controlling current to an ozone generator in accordance with an embodiment of the present disclosure. [0122] Fig. 33 is a set of related graphs illustrating PWM operating frequency, average current and temperature in relation to time for the ozone cleaner containing the components shown in any of Figs. 28A-28E, and 29A and 29B.

[0123] Fig. 34 is a perspective view of a portion of the lid and the bottom portion from the housing shown in Fig. 2A, with an option seal structure, when the lid is open.

[0124] Fig. 35 is a sectional view of the portion of the lid and bottom portion shown in Fig. 34, when the lid is closed.

[0125] Fig. 36 is a perspective view of a portion of an underside of the bottom portion of the housing shown in Fig. 2A, with an optional functional elements chamber.

[0126] Fig. 37 is another perspective view of the underside of the bottom portion of the housing shown in Fig. 2A, with a floor member covering the functional elements chamber. [0127] Fig. 38 is a magnified front elevation view of a latch that is optionally provided on the sterilization unit shown in Fig. 2A, in a closed position and with a striker of the latch in an extended position.

[0128] Fig. 39 is a magnified front elevation view of the latch shown in Fig. 38, in an open position, with a striker in a retracted position and with the lid of the housing partially open. [0129] Fig. 40 is a magnified front elevation view of the latch shown in Fig. 38, in a position in which the latch is not in a closed position, as the striker is in a retracted position. [0130] Fig. 41 is an exploded perspective view of the latch shown in Figs. 38-40.

[0131] Fig. 42 is a perspective view of the striker from the latch shown in Figs. 38-40, in the retracted position.

[0132] Fig. 43 is a perspective view of the striker from the latch shown in Figs. 38-40, in the extended position.

[0133] Fig. 44 is a perspective view of the sterilization unit shown in Fig. 1A, highlighting a feature that act as a handle.

[0134] Fig. 45 is a sectional elevation view of a portion of the sterilization unit, showing the feature that acts as a handle.

[0135] Fig. 46 is a perspective, exploded view of the sterilization unit shown in Fig. 1 A, with an optional lid-limiting feature.

[0136] Fig. 47 is a perspective, unexploded view of the sterilization unit shown in Fig. 1A, with an optional lid-limiting feature, shown with the lid in an open position.

[0137] Fig. 48 is a flow diagram illustrating a method of operating a sterilization unit.

[0138] Fig. 49 is an example of certain steps in further detail of the method illustrated in

Fig. 48.

[0139] Fig. 50 is a graph of ozone concentration over time for a plurality of sterilization units operated using the method illustrated in Fig. 48.

[0140] Throughout the drawing figures, like reference numbers will be understood to refer to like elements, features and structures. DETAILED DESCRIPTION

[0141] For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiment or embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. It should be understood at the outset that, although exemplary embodiments are illustrated in the figures and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the drawings and described below.

[0142] Various terms used throughout the present description may be read and understood as follows, unless the context indicates otherwise: “or” as used throughout is inclusive, as though written “and/or”; singular articles and pronouns as used throughout include their plural forms, and vice versa; similarly, gendered pronouns include their counterpart pronouns so that pronouns should not be understood as limiting anything described herein to use, implementation, performance, etc. by a single gender; “exemplary” should be understood as “illustrative” or “exemplifying” and not necessarily as “preferred” over other embodiments. Further definitions for terms may be set out herein; these may apply to prior and subsequent instances of those terms, as will be understood from a reading of the present description. It will also be noted that the use of the term “a” will be understood to denote “at least one” in all instances unless explicitly stated otherwise or unless it would be understood to be obvious that it must mean “one”.

[0143] Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, the components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components and the methods described may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, “each” refers to each member of a set or each member of a subset of a set.

[0144] Reference will now be made in detail to illustrative embodiments, which are depicted in the accompanying drawings. The embodiments described herein exemplify, but do not limit, the illustrative embodiments by referring to the drawings.

[0145] An example decontamination unit 10, also referred to as sterilization unit 10, has a space-conscious, portable and lightweight design that is specially designed to hold large, hard-to-clean household, medical or other items for decontamination which may include the items’ sanitation (e.g., such as the reduction of harmful bacteria, viruses and other pathogens), the items’ disinfection (e.g., such as the almost elimination of harmful bacteria, viruses and other pathogens) or their sterilization (e.g., such as the elimination of harmful bacteria, viruses and other pathogens) (e.g., such as the almost elimination of harmful bacteria, viruses and other pathogens), via ozone purification. Preferably the decontamination unit 10 may be configured to sterilize the items as a sterilization unit 10, however depending on the decontamination unit’s 10 configuration, such the ozone generated levels of the unit 10 and time periods of exposure of the ozone to the items by the unit 10, the decontamination unit 10 may be configured to sanitize or disinfect or clean the items as non-limiting examples. Other configurations of the unit 10 for decontaminating the items to different levels of efficacy are possible. The sterilization unit 10 uses ozone to purify items, and this energized form of oxygen is able to inactivate viruses and other pathogens, and may therefore also be referred to as an ozone cleaner 10. The sterilization unit 10 operates a fan to circulate the ozone within a sealed enclosure to penetrate deep into items placed with in it. The sterilization unit 10 uses two main processes during each type of cleaning cycle. The first process is ozone generation for purification or sterilization, and the second process is ozone neutralization. Because ozone at certain concentration levels can be harmful if inhaled, ozone neutralization is important to limit exposure to unhealthy ozone levels that could occur after ozone generation process or the ozone purification process.

[0146] During the ozone generation process, ozone is produced by adding energy to oxygen molecules (02), which causes the oxygen atoms to part ways and temporarily recombine with other 02 molecules creating ozone (03). A corona discharge method is used by the sterilization unit 10 and the enclosure air is circulated with a fan. It is to be understood that other ozone generation methods can be used with the sterilization unit 10 such as an ozone generator that employs ultraviolet (UV) light.

[0147] During the ozone neutralization process, ozone will naturally decay to form oxygen gas (02); however, this process can be slow. After generating enough ozone to purify the items within, the sterilization unit 10 will begin ozone neutralization. This process uses a custom designed filter to quickly remove the ozone from the air inside the unit and allow items to be safely removed from the enclosure.

[0148] With reference to Figs. 1A and 1 B, an example sterilization unit 10 comprises a housing 11 that includes a bottom portion 12 and a lid 14 that is connected to the bottom portion by hinge(s) 26 on one side thereof and by a lid latch/lock assembly 20 on the other side thereof. The bottom portion 12 defines a treatment chamber 16 dimensioned to receive items to be purified. In addition, the lid 14 may also in part define the treatment chamber 16. It can, more generally be stated that the housing 11 defines the treatment chamber 16 that is shaped to receive a quantity of items that are to be subjected to sterilization.

[0149] The treatment chamber 16 may alternatively be referred to as the sterilization chamber 16, or, for convenience, may simply be referred to as the chamber 16.

[0150] The sterilization unit 10 is dimensioned to be portable and therefore convenient to use at basically any field of use site such as in specific wards or on the respective floors of medical facilities, and at sites external to conventional medical facilities such as at temporary field hospitals, homes, offices, businesses, sports venues, educational institutes as examples. An example unit 10 is shown closed in Fig. 1A and opened in Fig. 1 B. The example unit 10 can have dimensions on the order of 730mm length (L) by 442mm width (W) by 514mm height (FI) when closed, and 730mm (L) by 651 mm (W) by 744mm (FI) when opened.

[0151] With reference to Figs. 2A, 2B, 2C and 2D, interior cross-section views of the sterilization unit 10 are shown. The sterilization unit 10 has a treated item chamber or section 16, an ozone generator cell section 30 and a neutralization section 50. The ozone generation cell section 30 and the neutralization section 50 are placed along the bottom and sides of the chamber 16 to maximize the volume of the treated item section 16 and to maximize efficiency of air flow to and from the ozone generation cell section and a neutralization section. As described in further detail below, the walls defining the ozone generation cell section and the neutralization section as well as the treatment section 16 are made from a material selected to withstand degradation by ozone exposure.

[0152] The ozone generation cell section 30 has an inlet grill 40 in its cover 32 for intake of gases from the treatment section 16, an optional ozone sensor 164 (see Fig. 17), an ozone fan 38, an ozone generation cell 34, and an outlet grill 42 in its cover for supplying generated ozone into the treatment chamber 16. For example, the ozone generation cell 34 can be a Model YD- 05FI167 commercially available from Yui Da Electrics Co., Ltd., or an equivalent thereof. Thus the ozone generation cell 34 may be said to be configured for generating ozone and providing the ozone to the sterilization chamber 16.

[0153] The ozone generation cell 34 may alternatively be referred to as the ozone generator 34, or, for convenience, as the cell 34.

[0154] The neutralization section 50 has an inlet grill 56 for intake of gases from the treatment section 16, an optional catalyst drawer 60 for receiving a replaceable catalyst material or filter, a neutralization fan 54, and an outlet grill 58 for promoting neutralization of the ozone gases in the air of the treatment chamber 16. The ozone fan 38 circulates air across the ozone generation cell 34, and the neutralization fan 54 circulates air through catalyst material. [0155] Arrows 48 and 62 indicate airflow direction in the respective ozone generation cell section and the neutralization section. With reference to Fig. 2E, in another possible configuration, the direction of flow indicated by arrow 62 may be reversed as compared to the direction shown in Fig. 2A as now indicated by reference numeral 62’, where an inlet 56’ is provided adjacent the floor 752, and illustratively formed within the floor 752. Illustratively, inlet 56’ is provided adjacent the outlet grill 42, both located about a middle section of the floor 752. Illustratively the outlet grill 42 and the inlet 56’ are formed at raised sections 752’ of the floor 752 which extends, slightly, into the chamber 16 and above the floor 752. The flow 62’ exits the neutralization section 50 at outlet 58’ at a position raised above the floor 752. Raised ribs 753 may also be provided on the floor 752 to support items thereon to facilitate air flow beneath the items. The neutralization fan 54 remains off until the neutralization process in a treatment cycle begins. Although optional, an ozone PCB sensor module 44 can be placed as shown in Fig. 2A in the ozone generation cell section 30 to measure circulated air at all times during a treatment cycle.

[0156] Fig. 2B is a partial cross-section view of the ozone generation cell section 30 showing air flow from the fan 38, over a corona discharge element of the ozone generation cell 34, and out through the outlet grill 42. When the ozone generation cell is powered ON” by electronics described below, the ozone generation cell is provided with 7kV at a fixed frequency from a high voltage transformer. During the ozone generation process, the cell is toggled between ON and the above voltage, and OFF, at a rate to generate sufficient ozone while keeping the cell cool. Air is forced across the corona discharge element through a small channel that is not accessible to the user. The inlet and outlet grills 40, 42 are each made of a wire mesh material or other permeable surface that allows airflow in/out of the channel without allowing treated items 84 to come in contact with the cell 34. When the cell 34 is OFF”, the ozone fan 38 remains powered to circulate air. As the outlet 42 is located adjacent the floor 752, the outlet 42 may be formed as part of a raised section of the floor 752 to avoid covering and blocking of the outlet 42 and flow of ozone therethrough by items placed and resting on the floor 752. [0157] The neutralizing gaseous fluid could be, but is not required to be ozone. For example, hydrogen peroxide is used in medical application to neutralize bacteria. It is also known to use a combination of hydrogen peroxide gas followed by ozone as discussed in patents of TS03.

[0158] The sterilization unit 10 generates ozone for the chamber 16 after the lid 14 has been closed, for example for using an ozone generator in communication with the chamber 16, and illustratively using an ozone generator provided as part of or within the bottom portion 12 and therefore does not require gas tanks or other components to be connected to the unit to supply ozone.

[0159] It is to be understood that the sterilization gas used in the chamber can be ozone by itself, or ozone mixed with other gases such as hydrogen peroxide gas.

[0160] In accordance with example embodiments, the sterilization unit 10 is modified to receive a removable, multi-piece rack system 70 to maximize its effectiveness at sanitizing medical items or PPE such as disposable masks. For example, to ensure proper cleaning performance by the sterilization unit 10, a user should be placing the masks in a controlled fashion, to ensure that: (1 ): the masks receive sufficient airflow and therefore ozone sanitation treatment; (2) the masks are not able to block critical areas like air intake or exhaust ports for circulating fans in the sterilization unit 10; and (3) the internal volume of the chamber is used to maximum efficiency (i.e. , the sterilization unit 10’s chamber holds as many masks as possible). In accordance with example embodiments, a rack system 70 is provided that achieves these objectives. For example, the rack system 70 is dimensioned to fit within the chamber 16 and, when loaded with items 84, maximize use of the internal volume of the chamber 16, as illustrated in Figs. 3A and 3B. As viewed in Fig. 3A, the rack system 30 may be received within an interior space 13a defined by the walls of the bottom portion 12 and extend out of the space 13a and above the upper end 12a of the bottom portion 12 to within an interior space 13b defined by the walls of the lid 14 when the lid 14 is closed 14. The rack system 70 is lightweight and easy to be placed within and removed from the chamber. The rack system 70 may be configured to rest upon the floor 752 or may be supported by other parts of the housing 11 , such as by the inner wall(s) of the bottom portion 12. Providing a lid 14 defining in part the chamber 16 when the lid 14 is closed allows the top of the rack system 70 to protrude from the opening at the upper end 12a of the bottom portion 12 when received within the bottom portion 12, as shown in Fig. 3A, to be exposed and accessible when the lid 12 is opened, for example from the side of the unit 10, for providing ease of access to a user when the unit 10 is raised off of the ground, such as when the unit 10 is supported on a table, shelf, or desk, or other raised structure. Since the user therefore does not have to reach into the bottom portion 12 to extract or insert the rack system 70, ease of use of the rack system 70 with the unit 10 results, as well as the possibility of placement of the unit 10 on elevated intervening structures between the ground and the unit 10. The rack system 70 can comprise a modular design comprising plural stages or shelves 72, as shown in Figs. 4 and 5A, that can each be configured to be removably stacked on top of each other for convenient and safe loading and unloading of the stages with respect to the chamber, and convenient loading and unloading of PPE or treated items to and from the respective shelves or stages 72.

[0161] The rack system’s components (e.g., shelves 72, spacers 74, and the like) are made from an ozone-compatible material that will not degrade from exposure to ozone in the chamber 16, and will be easy to clean and sanitize. Fig. 4 shows an example rack system comprising stainless steel wire shelves 72 that are stacked in a similar fashion for each shelf. For example, each shelf 72 has an integrated or snap-on spacer 74 that contacts another shelf 72 at a distal end thereof. The distal end of the spacer 74 can be configured to simply rest against a surface of the next shelf, or snap-on to a wire on the next shelf, or fit within a corresponding groove in the next shelf. This wire mesh design maximizes airflow since there is very little surface contact between treated items such as masks and the rack system components. The modular design of each shelf or tray 72 creates a modular rack system 70 that provides a user the ability to conveniently add and remove wire mesh shelves as needed. [0162] Fig. 5A shows a rack system comprising polycarbonate shelves 72 with airflow holes 80. The perimeter or shape of each of the shelves 72 can be configured to provide handles 82 to facilitate removing each rack individually. For example, the handles 82 may, when the rack system 70 is received within space 13a, in one possible configuration, be positioned above the upper end 12a of the bottom portion 12 for ease of access when the lid 14 is in the opened position. Each shelf 72 can be provided with a lip 76 along the edge of the shelf (e.g., along the perimeter entirely or at least partially) to keep treated items such as masks 84 in place at the edges of the shelf. The shelves 72 can also be provided with markers or posts 78 (shown in Figs. 3A and 5B) to guide the placement of items 84 on each shelf to optimize the exposure of their surfaces to ozone as well as the number of items 84 that can be placed on each shelf and still achieve that desired exposure. The markers can be physical (e.g., the posts 78) or implemented using indicia on the shelf.

[0163] With continued reference to Figs. 3A, 3B, 4, 5A and 5B, the rack system 70 and shelves 72 can be modified depending on the type of treated item 84 used thereon such as different brands of N95 respirators, or other medical equipment like gloves, face-shields, etc. For example, Fig. 5B shows example spacing shelves 72 configured to hold N95 Masks for purification by the sterilization unit 10. Fig. 5B depicts an example rack system 70 with an example material load of masks. The rack comprises a displaceable shelving system that can be placed within and removed from the interior of the chamber 16 and is dimensioned to fit within chamber 16. The rack may be dimensioned to project above the bottom portion 14, for example when resting on the floor 752 or when supported by some other support surface (e.g. notches in the side walls of the bottom portion 12) of the sterilization unit 10, to extend and fit within the space 13b defined by the lid 14 when the lid 14 is in the closed position. The rack system 70 is made from lightweight non-permeable material such as plastic and can be a unitary piece, or composed of pieces (e.g., shelves and leg/shelf separators) that can be pressure-fitted or snap-fit or otherwise constructed for assembly. The shelves’ dimensional area and spacing are selected to guide user to place 50 masks within the chamber 16, e.g., 10 masks per shelf without overlapping them for optimal exposure to ozone. The masks shown in the material load are N95 respirators available from Sobmex.

[0164] In accordance with embodiments of the present disclosure, a material load parameter is defined to achieve a minimum 03 concentration required for effective sanitizing of treated items while reducing excessive ozone generation and degradation of the treated items due to generated ozone exposure.

[0165] As stated above, ozone is an oxidizing agent that is highly effective at sanitizing surfaces exposed to it; however, excessive exposure to ozone can cause some materials such as rubberized materials, elastics and porous materials to deteriorate or degrade over time. The present disclosure is advantageous because it runs a cycle in the chamber of the sterilization unit 10 having an ozone generation process based on a material load parameter that is empirically determined and defined to ensure a selected number and type of treated PPE items is exposed to a sufficient ozone concentration level for sanitization while minimizing degradation of the treated PPE items as a result of the generated ozone exposure.

[0166] The present disclosure overcomes a number of problems associated with sanitizing items with porous surfaces such as PPE (e.g., masks, face shields and gowns). Example problems overcome by embodiments of the present disclosure include, but are not limited to: (a) significant variation in ozone concentration levels due to differences in materials in the treated PPE items; (b) differences in degree of ozone absorption exhibited by the treated PPE items that have undergone repeated treatment cycles; and (c) demonstrated degradation of certain PPE items when exposed to repeated treatment cycles at unnecessarily high ozone concentration levels. Managing treatment cycles to minimize degradation of treated PPE items, while successfully sanitizing them, is a significant advantage of embodiments of the present disclosure because it allows sanitization and reuse of PPE, including potential reuse of certain types of disposable PPE, while maximizing their end-of- life (EOL) period, minimizing waste, reducing PPE replacement cost, and increasing PPE availability to PPE users. [0167] For example, Fig. 6 is a graph depicting how 03 concentration (ppm) rises when repeating 25 minute ozone generation cycles on the same set of clean masks. The sterilization unit 10 was loaded with same 50 Sobmex brand masks for each of 5 trial cycles. The graph indicates not only a rise in 03 concentration level over time during an individual cycle, but also a rise in 03 concentration level with each of the 5 trial cycles as the mask material absorbs more ozone with each cycle but reacts with fewer impurities. Thus, with each subsequent cycle, the ozone in the chamber declines more slowly.

[0168] Fig. 7 is a graph depicting how 03 concentration (ppm) varies as between two trial cycles of the sterilization unit 10. The treated items in one of the trial cycles were 50 Sobmex brand N95 masks, whereas the treated items in other one of the trial cycles were 503M brand N95 masks. The sterilization unit 10 was operated with the same settings with respect to a target ozone concentration level and treatment period (e.g., 25 minute treatment period or duration of the ozone generation process). Further, the two trial cycles of the sterilization unit 10 did not employ any ozone sensor feedback. In other words, the sterilization unit 10 was operated in an open loop with respect to controlling the ozone generation cell to reach the same inputted target concentration level, but did not use ozone sensor feedback to maintain the target concentration level throughout the cycle. As the graph indicates, the ozone concentration levels compared between the two trial cycles indicates significant variation between the mask brands. Different factors can account for the ozone concentration level variation such as mask materials, mask construction (e.g., material thickness), size and therefore surface area exposed to ozone, and so on.

[0169] In addition, the sterilization unit 10 was loaded with 50 3M brand masks and operated for repeated cycles wherein the masks were exposed to high concentrations of ozone (e.g., 254 ppm over a 25 minute treatment period as indicated in Fig. 8). The elastic material in the 3M masks was observed to breakdown after exposure to such high ozone concentration levels.

[0170] In accordance with an example first embodiment of the present disclosure, a sterilization unit 10 is provided which does not necessarily have an ozone concentration sensor or closed control loop that employs ozone concentration sensor feedback. Instead, the sterilization unit 10 is operated in an open loop and uses designated material load parameters to match a generated amount of ozone to a material load (e.g., a selected number of items placed in the chamber 16 for a cleaning cycle) by generating ozone to reach a designated ozone concentration level that is greater than a minimum treatment threshold level to achieve a designated sterility acceptance rate for the material load (e.g., a desired sterility acceptance rate for PPE) and less than a maximum treatment threshold level to prevent degradation of the items from exposure to the generated amount of ozone. Material load parameters can correspond to selected items that are to be subjected to sterilization in the sterilization chamber and are characterized by a predetermined item type and a predetermined quantity of items. A designated treatment period of exposure of the selected items to a sterilizing gas in the sterilization chamber at the designated ozone concentration level us used.

[0171] Material load parameters can be empirically determined parameters in accordance with an example embodiment to successfully treat items in a material load while avoiding degradation of permeable items in that load. A baseline treatment curve defined by ozone concentration (e.g., in ppm units) relative to time (e.g., minutes) or duration of treatment or cumulative exposure to the sterilization gas(es) is provided in Fig. 9. Fig. 10 illustrates an optimized curve to achieve a desired sterility acceptance rate for PPE treated by the sterilization unit 10. Empirical data suggests that treated items need to be subjected to an ozone concentration level of at least 13.75 ppm for 25 minutes to be sterilized sufficiently. A minimum target threshold for ozone concentration level is 20 ppm for 25 minutes. In accordance with an aspect of example embodiments, the designated ozone concentration level for a treatment threshold level is selected to be 30-32 ppm to allow for fluctuations in ozone concentration levels while ensuring the minimum target threshold of 20 ppm is met during a 20 minute treatment period. Also, the designated ozone concentration level of 30-32 ppm is also selected to be sufficiently low to minimize degradation of the treated items over repeated cycles and maximize efficiency of the ozone generation cell to prevent overheating and reduce wasted energy. In addition, the material load parameters can comprise a selected number of PPE items and brand of PPE item that is loaded into the sterilization unit 10 during a cycle.

[0172] The following Table 1 comprises example material load parameters:

[0173] Fig. 11 is a flow chart of example operations of the sterilization unit 10 during a cleaning cycle in accordance with the first embodiment wherein unit 10 is operated using designated material load parameters and in an open loop without ozone sensor feedback for ozone generation control during an ozone generation process. The user interface mechanism to select and/or initiate a cleaning cycle or otherwise operate the sterilization unit 10 is described below in connection with the electronics depicted in Fig. 15 and the example user interface depicted in Figs. 16 and 21. A cleaning cycle comprises multiple processes comprising at least an ozone generation process for sterilization and an ozone neutralization process, and can also include a diagnostic process. As described in connection with Figs. 13 and 14, ozone generation process can include a ramp up process and a control loop process. Fig. 12 illustrates the following example cleaning cycle processes with respect to a diagram of ozone concentration level (ppm) over time (min.): (1 ) a diagnostic process; (2) a ramp up process; (3) a control loop process; and (4) a neutralization process. For clarity, the flow diagrams in Figs. 11 , 13 and 14 omit particular user settings and assume that a user has placed items to be treated in the chamber, closed the lid, and initiated a cleaning cycle.

[0174] With reference to Fig. 11 , ozone generation is not measured, for example, not measured using an ozone concentration sensor. Instead, the sterilization unit 10 can be configured to use a timer designed to achieve a target ozone concentration for a specific application. Cycle phase or process times shown in Fig. 11 are for example purposes only and may be adjusted based on application. During a diagnostic process (block 100) of 1 minute in length during a cleaning cycle, the sterilization unit 10 is controlled to perform diagnostic tests on various components before turning on the ozone generation cell such as ensuring the ozone generation fan and the neutralizing fan are operational and that the power supply draw is acceptable. During an ozone generation process that is at least 20 minutes in length during a cleaning cycle (block 102), the sterilization unit 10 is controlled to set a target ozone generation cell pulse width modulation (PWM) set point based on an intended application to continuously generate ozone until a generation time is met using the timer. The target PWM set point is selected to achieve the designated ozone concentration level of 30-32 ppm, for example. As explained below, a controller in the sterilization unit 10 can monitor current of the ozone generation cell to determine or search for the optimum operating frequency or duty cycle of the ozone generator cell for switching between the supply and load. During an ozone neutralization process that is 25 minutes in length during a cleaning cycle (block 104), for example, the sterilization unit 10 is controlled to turn off the ozone generation cell, and maintain the 03 generation fan and the neutralizing fan ON or in a running state to circulate air through the catalyst. The target neutralization process length can be set to ensure air within the sterilization unit 10 and the treated items are sufficiently neutralized before the cleaning cycle ends. When the cleaning cycle ends (block 106), the sterilization unit 10 is controlled to operate a user interface to indicate that the cleaning cycle is complete, and to unlock the sterilization unit 10 to allow a user to open the lid and to remove the treated items.

[0175] Fig. 13 is a flow chart of example operations of the sterilization unit 10 in accordance with a second embodiment wherein unit 10 uses an integrated ozone concentration sensor to monitor ozone concentration level throughout a cleaning cycle. This sensor feedback is used during the ozone generation process to meet a target concentration for as long as possible. [0176] The ozone generation control time is fixed in duration using a timer, for example. Cycle phase or process times shown in Fig. 13 are for example purposes only and may be adjusted based on application.

[0177] With reference to Fig. 13, during a diagnostic process (block 110) of 1 minute in length during a cleaning cycle, the sterilization unit 10 is controlled to perform diagnostic tests on various components before turning on the ozone generation cell such as ensuring the 03 generation fan and the neutralizing fan are operational and that the power supply draw is acceptable. The sterilization unit 10 is controlled to implement an ozone generation ramp up process (block 112) wherein the sterilization unit 10 powers the ozone generation cell with maximum safe PWM to generate and increase the ozone concentration level in the chamber until 80% of a target ozone concentration level (e.g., the designated ozone concentration level of 30-32 ppm) is measured by the integrated ozone concentration sensor. If the detected ozone concentration level does not reach 80% of the target ozone concentration level within 1 minute (block 114), the sterilization unit 10 ends the cleaning cycle and generates an error indication (block 118) for the user and optionally a message on a display such as a suggestion to reduce the material load by removing some of the items to be treated from the chamber.

[0178] With continued reference to Fig. 13, the sterilization unit 10 initiates an ozone generation control loop process when the process ozone generation ramp up process is successfully completed. During an ozone generation control loop process (block 116), the sterilization unit 10 is controlled to use feedback from the sensor to maintain the ozone concentration level in the chamber at a set point for the desired application (e.g., the designated ozone concentration level of 30-32 ppm). When the sensor indicates ozone concentration level under the set point, the sterilization unit 10 toggles the ozone generation cell ON to generate ozone. When the sensor indicates ozone concentration level above the set point, the sterilization unit 10 turns the ozone generation cell OFF and waits for the ozone in the chamber to decay. To minimize overshoot of the set point, the neutralizing fan can also be operated, along with the ozone generation fan, to lower ozone concentration level faster. The ozone generator output (e.g. reference numeral 42) positioned adjacent the ozone neutralizer input (e.g. reference numeral 56’) as shown in Fig. 2E illustratively assists with minimizing overshoot as ozone generated can be drawn into the neutralization conduits without having to flow through the chamber 16. The sterilization unit 10 remains in the ozone generation control loop process until a timer expires. This timer is set for a designated amount of time for an intended application (e.g., 20 minutes to correspond to the designated 20 minute treatment period of the material load parameters) and cannot be adjusted. During an ozone neutralization process that is 25 minutes in length during a cleaning cycle (block 120), for example, the sterilization unit 10 is controlled to turn off the ozone generation cell, and maintain the 03 generation fan and the neutralizing fan ON or in a running state to circulate air through the catalyst. The target neutralization process length can be set to ensure air within the sterilization unit 10 and the treated items are sufficiently neutralized before the cleaning cycle ends. When the cleaning cycle ends (block 122), the sterilization unit 10 is controlled to operate a user interface to indicate that the cleaning cycle is complete, and to unlock the sterilization unit 10 to allow a user to open the lid and to remove the treated items.

[0179] Fig. 14 is a flow chart of example operations of the sterilization unit 10 in accordance with a third embodiment wherein unit 10 uses an integrated ozone concentration sensor to monitor ozone concentration level throughout a cleaning cycle, to control cycle timing to ensure a sufficient ozone concentration level is met for the required amount of time, and to ensure the sterilization unit 10 has neutralized long enough that it is safe to open. The ozone generation control time can therefore vary in duration unlike the example embodiment in Fig. 13. Cycle phase or process times shown in Fig. 14 are for example purposes only and may be adjusted based on application.

[0180] With reference to Fig. 14, during a diagnostic process (block 130) of 1 minute in length during a cleaning cycle, the sterilization unit 10 is controlled to perform diagnostic tests on various components before turning on the ozone generation cell such as ensuring the 03 generation fan and the neutralizing fan are operational and that the power supply draw is acceptable. The sterilization unit 10 is controlled to implement an ozone generation ramp up process (block 132) wherein the sterilization unit 10 powers the ozone generation cell with maximum safe PWM to generate and increase the ozone concentration level in the chamber until 80% of a target ozone concentration level (e.g., the designated ozone concentration level of 30-32 ppm) is measured by the integrated ozone concentration sensor. If the detected ozone concentration level does not reach 80% of the target ozone concentration level within 1 minute (block 134), the sterilization unit 10 ends the cleaning cycle and generates an error indication (block 138) for the user and optionally a message on a display such as a suggestion to reduce the material load by removing some of the items to be treated from the chamber.

[0181] With continued reference to Fig. 14, the sterilization unit 10 initiates an ozone generation control loop process when the process ozone generation ramp up process is successfully completed. During an ozone generation control loop process (block 136), the sterilization unit 10 is controlled to use feedback from the sensor to maintain the ozone concentration level in the chamber at a set point for the desired application (e.g., the designated ozone concentration level of 30-32 ppm). When the sensor indicates ozone concentration level under the set point, the sterilization unit 10 toggles the ozone generation cell ON to generate ozone. When the sensor indicates ozone concentration level above the set point, the sterilization unit 10 turns the ozone generation cell OFF and waits for the ozone in the chamber to decay. To minimize overshoot of the set point, the neutralizing fan can also be operated, along with the ozone generation fan, to lower ozone concentration level faster. During this ozone generation control loop process (block 136), the sterilization unit 10 monitors ozone concentration levels in the chamber via the sensor, and counts on a timer for every 1 -second interval wherein the concentration level is above a target level (e.g., the designated ozone concentration level of 30-32 ppm). When the desired time above the target ozone concentration level (e.g., 30 ppm for 20 minutes) is achieved, the sterilization unit 10 proceed to the ozone neutralization process. Thus, the total amount time the sterilization unit 10 is in the ozone generation control loop process may exceed the designated 20 minute treatment period of the material load parameters, for example, if the sterilization unit 10 determines that the designated ozone concentration level of 30 ppm was not being consistently achieved. With continued reference to Fig. 14, the ozone neutralization process duration can also be variable, unlike the embodiment in Fig. 13. For example, during an ozone neutralization process of a cleaning cycle (block 140), the sterilization unit 10 is controlled to turn off the ozone generation cell, and maintain the 03 generation fan and the neutralizing fan ON or in a running state to circulate air through the catalyst. The sterilization unit 10 continues the ozone neutralization process until the ozone concentration sensor has measured below a target concentration (e.g., 0.05 ppm) for a set interval of time (e.g., 1 minute). When the cleaning cycle ends (block 142), the sterilization unit 10 is controlled to operate a user interface to indicate that the cleaning cycle is complete, and to unlock the sterilization unit 10 to allow a user to open the lid and to remove the treated items. The sterilization unit 10 also generates an indication via a user interface that the required time and ozone concentration level parameters have been met.

[0182] Figs. 15 and 16 provide, respectively, a block diagram of example electronics and an example user interface for a sterilization unit 10 in accordance with illustrative embodiments. It is to be understood that components in Fig. 15 need not be located on the same printed circuit board (PCB) or implemented in the same physical area in the sterilization unit 10.

[0183] For example, for reasons described below, a sensor PCB in sensor PCB module can be provided with an optional ozone concentration sensor that is used for controlling the ozone generation cell. The sensor PCB is located in an ozone generation cell section of the sterilization unit 10 along with the ozone generation fan and therefore is physically separate from another main PCB having a controller (e.g., located on the bottom of the unit and outside of the chamber) that can set cleaning cycle operation parameters, and control a user interface (e.g., the interface of Figs. 16 and 21 ) and the lid lock assembly of the sterilization unit 10. [0184] With reference to Fig. 15, the unit 10 comprises a controller 150 and a power supply 152 electrically connected to a first current sensor amplifier 154. In an embodiment, the power supply 152 is a 12V power supply and the first current sensor amplifier 154 monitors current to ensure components within the ozone generation cell 34 do not draw too much current for preventing damage to the power supply 152. The first current sensor amplifier 154 is electrically connected to a High Voltage (HV) amplifier 156 which is electrically connected to a High Voltage (HV) transformer 158. In an embodiment, the HV amplifier 156 applies voltage for FET's, and the HV transformer 158 steps up the voltage for the ozone generator cell 34 from 12 Volts to 7,000 Volts. The HV transformer 158 is electrically connected to the ozone generation cell 34 which is used to create ozone within the cleaning space or chamber, preferably through a corona discharge effect. The ozone generation cell 34 is then electrically connected to a second current sensor amplifier 162 which measures current being used by the ozone generation cell 34. The second current sensor amplifier 162 is electrically connected to the controller 150 and feeds the current being used by the ozone generation cell 34 to an analog to digital converter (ADC) disposed within the controller 150.

[0185] As further shown in Fig. 15, the controller 150 is electrically connected to the HV amplifier 156 and has a pulse width modulating (PWM) hardware module to control the operating frequency of the ozone generation cell 34. The controller 150 monitors the current of the ozone generation cell 34 to determine/search for the optimum operating frequency of the ozone generation cell 34. As will be understood from the entirety of the subject disclosure, the controller 150 controls the ozone generation and neutralization cycles, controls the electronic lock operation, senses ozone concentration levels within the cleaning space, auto-tunes the ozone cell, and detects the lid position.

[0186] An example user interface (Ul) in Figs. 16 and 21 is implemented by a Ul PCB disposed near the lid lock assembly 20 on the bottom portion 12 of the sterilization unit 10. The Ul PCB can have buttons that, when depressed by a user, activate associated switches to provide inputs to the controlled on the main PCB via wire harnesses and wires connecting the Ul PCB and main PCB. The buttons can include, but are not limited to, a cycle select button 170. For example, the Ul PCB can have a single button to initiate a single-type of cleaning cycle having designated parameters related to a designated ozone concentration and treatment period. Alternatively, the Ul PCB can allow a user to pick between two cycles via buttons 170a, 170b for light or heavy cleaning as described in commonly owned U.S. Patent. No. 10,391 ,527 and shown in Figs. 16 and 21 (i.e. , 25 or 45 minute cycle). In accordance with yet another alternative embodiment, the Ul PCB can allow a user to pick from among more than two different types of cleaning cycles (e.g., deodorize, clean, and sterilize, each with an increasing level of ozone concentration used during the ozone generation process). The Ul PCB can provide an OPEN or STOP button 174 to allow a user to indicate that he or she wishes to terminate the cleaning process and open the lid. The controller, however, can electronically override or delay the manual opening until the ozone neutralization process lowers the ozone concentration level to an acceptable safe level. [0187] With continued reference to Figs. 16 and 21 , the Ul PCB can provide various indicators also. For example, the controller on the main PCB can determine when the catalyst needs to be replaced and generate an indication 172 via the Ul PCB. The controller can also generation an indication 176 whether an ozone generation or neutralization process is currently in effect within the chamber, or an indication 178 of when the cleaning cycle is complete. The indicators can be via light emitting diodes (LEDs) or graphical screen display 180 that can display alphanumeric messages for a user such as current ozone concentration level in the chamber, or error message (e.g., diagnostic result, or recommendation to remove items from the chamber to reduce material mode when a ramp up process fails to reach a desired target concentration level within a minute of ozone generation cell operation). The sterilization unit 10 is configured with a user interface and cycle selection button (e.g., a push button, or a touchscreen input button) single clean cycle operation, or multiple types of clean cycles.

[0188] Regardless of the number of preset types of clean cycles offered by the unit, the sterilization unit 10 is configured to run each clean cycle with sufficient ozone concentration and sufficient minimum cycle duration to sanitize (e.g., eliminate pathogens such as COVID- 19 or other viruses) a designated material load provided into the chamber of the unit for that cleaning cycle.

[0189] Also, concentration and cycle time are optimized to sanitize a designated material load. Particularly useful for PPE such as masks and gowns. Reusable and porous and degradable. Unit 10 optimization cleans a designated material load while minimizing degradation or damage to porous materials or other degradable materials of the treated items in the designated material load.

[0190] Fig. 17 illustrates an ozone concentration sensor PCB module 44 disposed in the ozone generation cell section 30 of the sterilization unit 10 under a circulating fan cover 32. The placement of the sensor PCB module 44 in the ozone generation cell section 30 in Fig. 17 realizes a number of advantages. For example, the ozone concentration sensor 164 is not seen by a user and cannot be damaged by items placed inside the sterilization unit 10, or casually tampered with. On the other hand, the sensor PCB module 44 is a potentially serviceable component and convenient access to it is provided via two Torx screws for removable attachment of the sensor PCB module 44 within the sterilization unit 10. Also, the air being sampled by the sensor PCB module 44 is circulated throughout the sterilization unit 10 to maximize the accuracy of the sensor measurements. A large area is available on the sensor PCB 200 for high airflow and multiple airflow deflector designs. As described below, the sensor PCB module 44 has two standoff legs 202 that provide 12V power from a common power terminal.

[0191] Figs. 18A and 18B illustrate, respectively, front and rear perspective views of a sensor PCB module 44 constructed in accordance with an embodiment to provide the sensor PCB 200 with a cover 204 and standoff legs 202 that provide 12V power from a common power terminal. Fig. 18C is an exploded view of the sensor PCB module 44. The standoff legs 202 each have an M3 clearance hole 208 for a terminal and a punched cut out 206 for a front cover clip 210, and can bend to apply pressure to outer wall of unit 10. The PCB 200 has a saw tooth shape on each side at the top thereof to create teeth 212 for a press-fit into the cover, and spade connectors 214 at the bottom thereof. The cover 204 is made from PC-ABS or similar ozone-compatible plastic. The cover 204 has slots 216 to engage the teeth 212 on the PCB, and two clips to retain a standoff connection to the PCB. [0192] Fig. 18D is a rear cross-section view of the sensor PCB module 44 showing how the cover slots 216 engage the teeth 212 from cut-outs in the sensor PCB 200. Fig. 18E is a top view of the sensor PCB module 44 showing how the sensor PCB 200 sides engage respective rails 220 in the cover to control the sensor PCB 200 position within the sensor PCB module 44. Fig. 18F is a side, partial cross-section view of the sensor PCB module 44 showing how cover clips 210 press into holes 206 in the standoff legs 202 to secure them to the PCB 200. Cut-outs in cover provide flexible sections for clips to be installed over components.

[0193] Fig. 19A is a front perspective view of an example ozone concentration sensor PCB 200 constructed in accordance with an illustrative embodiment of the present disclosure. Fig. 19B is rear perspective view of the sensor PCB 200. The sensor PCB 200 can be connected to a main system controller 150 located on another PCB in the sterilization unit 10, for example. The sensor PCB 200 provides ozone concentration measurements to the controller

[0194] 150. The controller 150, in turn, can set control loop parameters as described in connection with the second and third process control embodiments shown in Figs. 13 and 14, as well as control all functions during the different processes of a cleaning cycle described in connection with Figs. 11 , 13 and 14.

[0195] The sensor PCB 200 has an air sampling area 166 coincident with the ozone concentration sensor 164. Fig. 19B shows the air sampling area 166. The sensor PCB 200 has cut-outs 212 to be press-fit into the cover 204. The sensor PCB has 2x4 pin programming headers 224 for wired connection to the controller 150, a protection subassembly 226 for wired communication, and an optional Bluetooth Low Energy (BLE) module 228 for wireless communication with the controller 150 on the main PCB, or an optional external component of the sterilization unit 10 (e.g., a mobile phone with unit 10 maintenance app that receives unit 10 status or operational data). The sensor PCB 200 uses a non-reactive material for a grommet that can be used for data transfer from ozone concentration sensor 164 to the main PCB (e.g., located on the bottom of unit 10 and exterior to the chamber). The sensor PCB 200 also has power spade connectors 214 to connect the sensor PCB 200 to a power source 152 in the sterilization unit 10.

[0196] In accordance with another embodiment, the sensor PCB module 44’ can be constructed as shown in the exploded view of Fig. 20. The sensor PCB module 44’ in Fig. 20 has an injection molded cover 204’ made from an ozone-compatible injection material like that of the sensor PCB module 44 in Fig. 19. Also, the covers 204, 204’ of the embodiments shown in Figs. 19 and 20 can each have its side profile changed to adjust the amount of airflow to and from the sensor. The PCB 200’ has two or more ozone concentration sensors 164a, 164b for redundancy, or to make use of varied sensor properties. The legs 202’ have a retention feature 206’ stamped therein to engage corresponding standoffs 234 on the cover 204’ to lock the legs 202’ in place with screws 232 (e.g., two self-tapping PT screws). The unit uses two fans 38 and 54, that is, one to circulate air over the ozone generation cell and the other to move air through the ozone neutralizing catalyst. These fans can be brushed or brushless, although the sterilization unit 10 uses brushless fans similar to those is used to cool computers. These fans 38 and 54 control their motor with integrated electronic control units (ECUs) that need to be conformably coated because they are directly exposed to the ozone in unit 10. Although brushed fans can be used in the sterilization unit 10, they are more complicated in assembly, require more space in the chamber 16 and will eventually show effects of corrosion. The fans 38 and 54 are wrapped in foam to retain their positions in the sterilization unit 10 and to isolate the fan noise. An advantage was realized by wrapping the fans 38 and 54 because the foam acted improve the air flow. Adding the foam seals each of the fans 38 and 54 to the cover 32 and 52 and the base 12 and eliminates air from flowing backwards and just circulating around the fan, which pushes more air flow through the catalyst 60 and over the ozone generation cell 34. [0197] To ensure there is a seal between the inside chamber 16 and external environment of the sterilization unit 10, the fans 38 and 54 connect to the outside (e.g., to a main PCB on the bottom of the sterilization unit 10 and outside the sterilization chamber 16) through fixed/sealed terminals. These terminals are also used to connect the cell to the electrical sources outside of the unit. The terminals are designed to nest an O-ring (e.g., made of silicone) that is resistant to ozone and compliant to create a seal. The seals for the fans 38 and 54 are placed under the sterilization unit 10 outside of the ozone chamber 16 in an electrical section that houses a main PCB with the controller 150. This allows a visual inspection to ensure that the seals for the terminals are installed while reducing exposure of the user to ozone. The terminals are designed to also have a hard stop on the plastic to limit compression of the seal but also to have a secondary seal surface where the metal terminal is in contact with the plastic base. The terminals are made from stainless steel to resist corrosion.

[0198] Since the ozone generation cell 34 runs on AC current at high voltage, there is a risk of EMC/EMI. There are several ways the sterilization unit 10 mitigates EMC/EMI. With regard to the cell 34, the geometry of the cell 34 (i.e. , a long wire) connected through additional long wires to the high voltage transformer can function as an antenna. The high energy pulse generated by the high voltage can transmit EMI. Several measures are undertaken with regard to the construction of the sterilization unit 10 to mitigate any transmitted interference. For example, Fig. 2A shows the plastic area of the bottom portion 12 of the sterilization unit 10 where the cell 34 is installed. This plastic area is covered by an aluminum tape since aluminum has good corrosion resistance. This tape is a part of the faraday cage that will enclose the cell to collect and capture the RF transmitted energy generated (i.e., the EMI). Any interference frequency that is generated has a large enough wavelength that a metal mesh mitigates its power but still allows airflow. Also, cut-outs to allow clearance to the actual high voltage terminals that carry the power to the cell 34. In order for the faraday cage to interfere and mitigate with transmitted RF (EMI), the cage needs to cover as much of the cell 34 and the wires connecting to the cell as possible. As some of the wires are outside of the chamber in the electrical area, a connection is provided between the inner cage and the portion in the electrical area, and that connection is covered with a metal mesh. Such a connection, however, has to be done while ensuring the ozone chamber 16 remains sealed. Accordingly, another terminal is provided that pierces the tape and is electrically connected to the tape through a metal on metal connection with a nut. [0199] To further mitigate EMI, positive and negative wires enter the ozone chamber 16 as close as possible. One of the wires connects directly to the cell 34 through the terminal, and the other connects to a wire that is also captured in the Faraday cage and then connects to the other cell 34 connection. This arrangement allows as much electrical wire length to be captured in the cage as possible. The cell 34 is isolated from the cage to ensure that the cage does not become a conductive source for the electric current (e.g., such as maintaining space using foam and spacers, although another method such as an insulating coating can be used). The other portion of the cage is made from a formed wire mesh. This has sufficient holes to allow airflow over the cell providing oxygen to turn to ozone and supporting cooling. Foam is used to bias the cage down onto contact with the aluminum tape so make a completed metal cage around the cell. When the cover 32 is put on, the cover holds the foam and cage in place.

[0200] As mentioned, the cage over the cell 34 needs to allow for cell 34 connection to wires that provide the high voltage. This is done by covering the two wires with a metal mesh sleeve, which is connected by a clip attached to a terminal that goes through the plastic and contacts the aluminum tape. To ensure that the high voltage cannot have a leak path to the end user, the low voltage items such as the fan wire do not cross the high voltage wires. [0201] In accordance with another example embodiment, a portable indicator that is separate from the chamber is placed among the items of the material load in the chamber at a representative location to provide validation of ozone exposure (e.g., likelihood of treatment of all surface areas of the items in the material load). The indicator changes color or exhibits another visual change to a user’s natural eyesight or unassisted vision, depending on degree of exposure during an ozone sterilization process. The portable indicator is disposable after each cleaning cycle, but can be reusable in accordance with an alternative example embodiment if the indicator can be returned to its neutralized pre-test state after exhibiting change(s) indicating ozone exposure. The portable indicator can be, for example, a TS03 chemical indicator commercially available from TS03, Inc., Quebec, Canada. The TS03 chemical indicator looks like a small sticker of about 2 square inches in footprint area, and has a chromophore which changes color when the required sterilization parameters have been met. Another example indicator can be an ozone test strip or test stick such as Model 90736 Ozone Test Sticks commercially available from Macherey-Nagel Inc. Unlike the feedback sensor (i.e. the ozone concentration sensor 164), the indicator does not provide feedback data to the control unit, but rather serves as a validation to the user of ozone exposure of the items during the cleaning cycle. If the indicator is not changed after the cleaning cycle, the user can run an additional cleaning cycle. If the indicator does not change after an additional cleaning cycle, then the indicator serves as a notification to the user that the sterilization unit 10 needs calibration and/or repair and/or replacement.

[0202] These principles could possibly be extended to porous or permeable items beyond masks, such as gowns. A gown could be folded in a given/standard manner and a disposable indicator place in a given/standard location in the folded gown to check for a positive indication. If multiple gowns are placed in the unit then an indicator could be placed in each gown, or one indicator in a gown in a lot could serve to represent all gowns. Folded gowns could be placed on shelves of a rack to allow for required separation (and ozone flow), and lack of overlapping between gowns. This assumes that the mask fabric is porous or permeable which it would need to be in order to perform a mask function.

[0203] Not only would this provide a proxy for masks generally; but, if all the items 84 are made of the same fabric, then the proxy would be self-calibrating to that fabric. This is particularly advantageous if different mask suppliers are using different materials or different porous or permeable. If a disposable indicator strip is not visible, then the user may be required to tear off the indicator from the fabric to view the strip. Fabric can be pre-made with strips, or indicator strips can be provided to hospitals or other field sites for the sterilization unit 10 along with some fabric in bulk to allow unit 10 operators to cut their own. Also, fabric samples can be pre-cut and have a self-adhesive edge to stick to the side of the sterilization unit 10 to trap the indicator strip.

[0204] Alternatively, two pieces of fabric can be adhered together to trap the indicator strip. Alternatively, the indicator strip can be put on a larger adhesive non-porous backing and then the fabric placed over the indicator onto the backing with the sensor portion of the indicator facing the fabric (porous material). Again, the backing and the fabric and the indicator pieces could be provided separately for the hospital or field site of the sterilization unit 10 to assemble. If the resulting indicator assembly is standalone, then it could be placed on a rack shelf 72 and removable together with the rack shelf 72. The operator can then put in another rack shelf 72 and then the indicator assembly can be taken apart at a later time. [0205] Preferably the indicator assembly can be attached to a rack shelf 72 at a standard location so that this could be calibrated for testing. Also, the operator would know to look in a specific location. As well, the indicator assembly would stay with the particular lot of masks on the rack shelf 72 or rack system 70 such that an operator would not lose track of the indicator assembly for a particular lot of masks.

[0206] The indicator assembly can also be deployed over an opening for the top shelf 72 of the rack system 70 such that the operator would have to see the indicator assembly before opening the rack system 70 and removing items 84, and can assess the need to perform another cleaning cycle before items 84 are removed from the rack system 70. This could be before removing the rack, or after. Placement of the indicator assembly can also be an error proofing tool to avoid the operator losing track of which masks resulted in a positive indication active ingredients.

[0207] Reference is made to Figs. 22-24, which illustrate an optional feature of the sterilization unit 10. As can be seen in Fig. 22, the housing 11 has an aperture 300 therein that extends from an external environment (shown at 302) of the sterilization unit 10 to the sterilization chamber 16. With reference to Fig. 24, the aperture 300 has a first end 304 with a cross-sectional dimension D1 , and a second end 306 which can, but does not necessarily have to have the same cross-sectional dimension D1. In an example, D1 may be about 0.25 inches, or any other suitable dimension.

[0208] In the embodiment shown, the aperture 300 is provided on the lid 14. However, it will be noted that the aperture 300 could alternatively be provided on the bottom portion 12, or on any other part of the housing 11 in embodiments where there are other parts of the housing 11 present.

[0209] The sterilization unit 10 in Figs. 22-24 further includes a seal arrangement that includes a plug 308 and a cover member 310. The plug 308 has a plug body 312 that extends into the aperture, and a plug head 314. The plug head 314 has a head dimension D2. As can be seen in Fig. 24, the plug head dimension D2 is larger than the cross-sectional dimension D1 of the first end 304 of the aperture 300. For example, the head dimension D2 may be 16mm (0.63 inches), or any other suitable dimension.

[0210] The aperture 300 may be generally circular in cross-section (as seen in Fig. 22), in which case, the cross-sectional dimension D1 is an aperture diameter. Similarly, the plug head 314 may be generally circular, in which case, the head dimension D2 is a head diameter.

[0211] The plug body 312 has a proximal end 316 that is proximate to the plug head 314 and a distal end 318. In the embodiment shown in Fig. 24, the transition between the plug body 312 and the plug head 314 is a step-wise transition. In another embodiment however, the transition could be gradual, such that whatever portion of the plug 308 is too large to fit in the aperture 300 could be referred to as the plug head 314.

[0212] In the embodiment shown in Fig. 24, the plug body 312 tapers inwardly towards the distal end 318. This tapering may be provided all the way from the proximal end 316, as shown in Fig. 24, or alternatively the tapering may be provided only along a portion of the length of the plug body 312.

[0213] The plug 308 may be made from any suitable material such as, for example, an elastomeric material, such as EPR (ethylene propylene rubber). [0214] The cover member 310 is adhered to a surface 320 of the housing 11 surrounding the plug 308. As a result, the cover member 310 engages the plug head 314 to hold the plug 308 in sealing engagement with the housing 11 to seal against leakage of gas between the sterilization chamber 16 and the external environment 302 of the sterilization unit 10. [0215] The sealing against leakage of gas may be provided by engagement of the plug head 314 with the surface 320 of the housing 11 , and/or by engagement of the plug body 312 with the wall of the aperture 300. In the embodiment shown, sealing against leakage of gas is at least in part by engagement of the plug body 312 with the wall of the aperture 300, as the proximal end 318 of the plug body 312 has a diameter of about 0.256 inches, and is therefore slightly larger in diameter than the diameter of the aperture 300.

[0216] Optionally, the plug 308 may include a blind aperture 321 that extends through the plug head 314 into the plug body 312. The blind aperture 321 may facilitate injection molding of the plug 308, by permitting a relatively consistent wall thickness.

[0217] The cover member 310 may be any suitable type of member. For example, in the embodiment shown in Fig. 24, the cover member 310 is a flexible sheet (e.g. a polymeric sheet) with adhesive thereon and is sufficiently flexible to accommodate the plug head 314 while remaining adhered to the surface 320, even though the plug head 314 stands proud of the surface 320 in the example embodiment shown. Other types of connections or additional connections of the cover member 310 with the lid 14 are possible, such as a snap fit connection as one example.

[0218] In the embodiment shown the plug head 314 is outside of the housing 11 . Thus, the plug 308 is inserted into the aperture 300 from outside of the housing 11. It is alternatively possible for the plug 308 to be inserted into the aperture 300 from inside of the housing 11.

[0219] The cover member 310 has a first side 322 and a second side 324 and is adhered to the surface 320 of the housing 11 on the first side 322. In some embodiments, the sterilization unit 10 may include a top member 326 that is adhered to the second side 324 of the cover member 310. In such embodiments, the cover member 310 may be a flexible sheet with adhesive on both the first side 322 and the second side 324. The top member 326 may itself be a sheet (e.g. a polymeric sheet), that is flexible but is more rigid than the cover member 310 so as to hide the presence of a bump caused by the projection of the plug head 314 from the surface 320, wherein the bump might otherwise have been visible through the flexible cover member 310.

[0220] In some embodiments, however, the cover member 310 itself may be sufficiently rigid so as to hide the bump, while still being flexible enough to remain adhered to the surface 320 all around the plug 308, thereby precluding the need for a top member.

[0221] An example of a purpose for the aperture 300 is described hereinbelow, with reference to Figs. 23 and 25. The aperture 300 may be used for end-of-line testing of the sterilization unit 10, as part of the method 400 shown in Fig. 25. The method 400 is a method of assembling and testing the sterilization unit 10. The method 400 includes a step 402, which is assembling the housing 11 and the ozone generator 34 together. Step 404 includes fluidically connecting an ozone sensor 330 (shown schematically as a simple dashed rectangle in Fig. 23) to the sterilization chamber 16 through the aperture 300. In the example shown in Fig. 23, this fluidic connection is achieved by connecting a test conduit 332 (e.g. a flexible tubular conduit) between a vacuum source 334 and the sterilization chamber 16 and by mounting the ozone sensor 330 so as to be exposed to the flow of gas from the test conduit 332. Step 406 includes operating the ozone generator 34 in order to generate the ozone in the sterilization chamber 16. Step 408 includes drawing gas from inside the sterilization chamber 16 to the ozone sensor 330 and measuring how much ozone is present in the gas. It will be noted that the ozone sensor 332 and the vacuum source 334 are shown schematically in Fig. 23, however, it will be well understood by a person skilled in the art as to suitable examples of these components that could be used. Step 410 includes sealing the aperture 300 after having measured the amount of ozone is present in the gas. In some embodiments, the method 400 further includes repairing the sterilization unit 10 if the ozone sensor 330 detects an ozone level that is below a selected threshold ozone level. Upon repairing the sterilization unit 10, steps 404, 406 and 408 may be repeated to check if the ozone level in the gas is above the threshold ozone level. If the ozone level is above the threshold ozone level, then step 410 may be carried out, and the sterilization unit 10 may continue to be assembled or packaged as needed. It is optionally possible that step 410 may itself include a step 412, which is to provide the plug 308, a step 414, which is to provide the cover member 310, a step 416, which is to insert the plug 308 into the aperture 300, and a step 418 which is to adhere the cover member 310 to the surface 320 engaging the plug head 314 with the cover member 310 to urge the plug 308 into sealing engagement with the housing 11 to seal against leakage of gas between the sterilization chamber 16 and the external environment 302.

[0222] Optionally, the method 400 further includes adhering the top member 326 to the cover member 310.

[0223] Reference is made to Figs. 17, 26 and 27 which illustrates another optional feature for the sterilization unit 10. As shown in Fig. 17, the lid 14 has a lid hinge wall 500 and the bottom portion 12 has a bottom portion hinge wall 502. The lid hinge wall 500 and the bottom portion hinge wall 502 are movably connected to one another by a hinge arrangement 504 that includes at least one hinge 506 defining a pivot axis Ah (Fig. 26) for the hinge arrangement 504.

[0224] When the housing 11 is at an ambient pressure, the hinge arrangement 504 is positioned in a first hinge position in which the pivot axis Ah extends along a linear path (represented by Ah1 in Fig. 26). The hinge arrangement 504 is movable to a second hinge position in which the pivot axis Ah along an arcuate path (represented by Ah2 in Figs. 26 and 27) so as to accommodate flexing of the lid hinge wall 500 and the bottom portion hinge wall 502 during evacuation of the housing 11 to a selected amount of pressure below the ambient pressure. The lid hinge wall 500 and the bottom portion hinge wall 502 are shown flexed while the housing 11 is at the selected amount of pressure below the ambient pressure in Fig. 27. The housing 11 reaches the selected amount of pressure below the ambient pressure during the aforementioned testing of the ozone generator 34 after assembly of the sterilization unit 10, by connecting the test conduit 332 between the vacuum source 334 and the sterilization chamber 16.

[0225] In the embodiment shown in Figs. 26 and 27, it can be seen that the at least one hinge 506 is a single hinge 506. The single hinge 506 includes a first plurality of hinge knuckles 508 mounted to the bottom portion hinge wall 502, a second plurality of hinge knuckles 510 mounted to the lid hinge wall 500 and which are positioned in gaps 512 between the first hinge knuckles 508, and a hinge pin 514 that extends through the first plurality of hinge knuckles 508 and the second plurality of hinge knuckles 510. The hinge pin 514 is sufficiently flexible and the first and second hinge knuckles 508 and 510 have a sufficient amount of play therebetween, so as to permit movement of the hinge arrangement 504 between the first hinge position (Fig. 26) and the second hinge position (Fig. 27). [0226] In some embodiments, the hinge pin 514 may be made from a material having a selected yield stress, and is shaped to incur stress below the elastic yield stress during movement of the hinge arrangement from the first hinge position to the second hinge position.

[0227] In an alternative embodiment, the at least one hinge 506 may include a plurality of hinges 506 that are spaced apart from one another sufficiently to permit flexure of the lid hinge wall 500 and the bottom portion hinge wall 502 and therefore to permit movement of the hinge arrangement from the first hinge position to the second hinge position.

[0228] In an alternative embodiment, the at least one hinge 506 may be at least one living hinge. A living hinge does not include a hinge pin and hinge knuckles but instead includes a flexible flap that extends between the lid hinge wall 500 and the bottom portion hinge wall 502.

[0229] When the housing 11 is at ambient pressure, the housing 11 is in the position shown in Figure 26, which may be said to be a first position. When the housing 11 is in this first position, the sterilization chamber occupies a first volume. By contrast, during evacuation of the housing 11 to the selected amount of pressure below the ambient pressure (i.e. to a selected negative pressure), as shown in Figure 27, at least a portion of the housing 11 is movable to an evacuation position in which the sterilization chamber 16 occupies a second volume that is smaller than the first volume. As can be seen, in Figure 27, the portion of the housing 11 that is movable to the evacuation position may include the bottom portion hinge wall 502 and the lid hinge wall 500, which flex inwardly (i.e. which flex inwardly towards the sterilization chamber 16) during the evacuation, preferably without any plastic deformation of the housing 11 (i.e. preferably incurring stress that is below the elastic yield stress for the housing 11 ). A target pressure difference between the start of an evacuation test detected using a pressure sensor 335, and a threshold pressure that ensures there is no leaks from the unit 10 is ascertained. A properly sealed unit 10 shows a pressure decrease of approximately 40mbar after 15 minutes. Depending on manufacturing rate such a 15 minute testing period monitoring for the 40-50mbar decrease can be used, or a rate of pressure decrease in a shorter period can be monitored.

[0230] Reference is made to Figs. 28A-32, which illustrate another optional feature of the sterilization unit 10. The feature illustrated in these figures relates to tuning the frequency at which the ozone generator 34 operates, based on the temperature sensed at the ozone generator 34. Figs. 28A-28E illustrate a control system to progressively increasing levels of detail, each level of detail representing an example embodiment in relation to an earlier figure. Fig. 29A is a schematic diagram illustrating a further level of detail in an example embodiment in relation to Fig. 28E. Fig. 29B is a schematic diagram illustrating a further level of detail in the example embodiment shown in Figure 28A.

[0231] Referring to Fig. 28A, a schematic representation of an embodiment of the ozone cleaner is provided. The ozone cleaner 10 may include the ozone generator 34, a first sensor 560, which is configured for sensing an undesired operating condition of the ozone cleaner 10, and a power supply 554 to supply power to the ozone generator 34. Additionally, the ozone cleaner 10 includes the housing 11 , which defines a cleaning chamber 16 that is configured to receive the one or more items and generated ozone from the ozone generator 34. [0232] The ozone generator 34 and the power supply 554 form a resonance circuit. In an embodiment, in response to the first sensor 560 sensing the undesired operating condition, the ozone cleaner 10 may enter a frequency setting mode wherein the ozone cleaner 10 is adapted to power the resonance circuit over a set of frequencies, sense the amount of supplied power at each frequency in the set of frequencies, and set the frequency of the supplied power to a set frequency from the set of frequencies selected based upon the sensed amount of supplied power at the set frequency during the frequency setting mode. Examples of the frequency setting mode are described further below.

[0233] In an embodiment the ozone cleaner 10 includes an operating mode in which the ozone cleaner 10 is adapted to power the resonance circuit at an operating frequency during the operating mode, wherein the operating frequency is the set frequency from the frequency setting mode.

[0234] In an embodiment, the ozone cleaner 10 is configured to enter the frequency setting mode from the operating mode in response to the first sensor 560 sensing the undesired operating condition and return to the operating mode using the set frequency as the operating frequency.

[0235] The first sensor 560 may be a temperature sensor, as shown in Figure 28B. The temperature sensor 560 may be positioned to sense a temperature from the power supply 554 or from a component that receives current from the power supply 554. An example of such sensing using the temperature sensor 560 is described further below. In other embodiments, the first sensor 560 may be some other type of sensor, such as a current sensor. As the temperature rises, the current from the power supply 554 may change (i.e. may increase). Accordingly, by sensing the current, and entering the frequency setting mode based on the sensed current, particularly when the ozone cleaner 10 is in the operating mode, the temperature of the components of the ozone cleaner 10 can be controlled.

[0236] Figure 28B shows an example, more-detailed embodiment of the ozone cleaner 10 shown in Figure 28A. In the embodiment shown in Figure 28B, the power supply 554 includes a power source 702 and a power driver circuit 704. The power source 702 may be any suitable power source such as an electrical conduit that connects to an AC outlet in a home or building. The power supply 554 may be configured to generate DC current from the incoming AC current at any suitable voltage, such as 12VDC.

[0237] Figure 28C shows an example, more-detailed embodiment of the ozone cleaner 10 shown in Figure 28B. As can be seen in Figure 28C, the power source may further include a switch 706 that is controlled by a controller 552. The controller 552 may include a processor 552a (Fig. 29B) and a memory (Fig. 29B), as described further below. The controller 552 is configured to control whether the switch is open or closed and therefore controls whether current is transmitted to the power driver circuit 704 for powering the ozone generator 34 or not.

[0238] Figure 28D shows an example, more-detailed embodiment of the ozone cleaner 10 shown in Figure 28C. As can be seen in Figure 28D, the power driver circuit 704 may include an impedance matching circuit 708 (an example of which is shown in Fig. 29A) and a transformer 558. The transformer 558 may be similar to the transformer 158 (Fig. 15) and may step the voltage from the power source 702 up to about 7kV. The transformer 558 may be, for example, a flyback transformer.

[0239] Figure 28E shows an example, more-detailed embodiment of the ozone cleaner 10 shown in Figure 28D. As can be seen in Figure 28D, the impedance matching circuit 708, the transformer 558, and optionally, the switch 706, and optionally the temperature sensor 560 may be mounted to a printed circuit board 564. The printed circuit board 564 may be referred to as a high-voltage circuit board since high voltage electronics are present on this board. The controller 552 and a second sensor, such as a current sensor 556 may be provided on a printed circuit board which may be referred to as a low-voltage circuit board, since only low voltage electronics are present on that board.

[0240] Fig. 29A illustrates example embodiments of circuits and components represented in Fig. 28E in greater detail. Fig. 29B illustrates example embodiments of circuits and components on the low voltage circuit board 562. As can be seen, the low voltage circuit board 562 may have a high voltage board interface 566 for electrical communication with the high voltage circuit board 564. The high voltage circuit board 564 has a main board interface 568 for electrical communication with the main board 562. The high voltage circuit board 564 further includes an ozone generator interface 572 that connects power to the ozone generator 34 via suitable electrical conduits 574. Suitable electrical conduits 570 electrically connect the high voltage board interface 566 with the main board interface 568.

[0241] In some embodiments, the undesirable operating condition is a temperature of the power driver circuit 708 above a predetermined temperature (also referred to as a selected threshold temperature).

[0242] In some embodiments, the power source 702 is adapted to vary the frequency of the power supplied to the ozone generator 34 over another set of frequencies in response to the temperature sensor sensing again the temperature above the predetermined threshold temperature.

[0243] The optionally provided current sensor 556 may be configured to sense the current supplied at each frequency in the set of frequencies, as is described further below. Furthermore, the ozone cleaner 10 may be adapted to select the set frequency corresponding to the lowest sensed amount of current over the set of frequencies during use in the frequency setting mode.

[0244] Where the controller 552 is provided, and is coupled to the first sensor 560 and to the power source 702, the controller 552 may be configured, in response to the first sensor 560 sensing the undesired operating condition, to enter the frequency setting mode to control the power source 702 to vary the frequency of a voltage supplied to the ozone generator 34 over the set of frequencies.

[0245] A second sensor (e.g. the current sensor 556) may be provided for sensing the amount of supplied power at each frequency in the set of frequencies during use in the frequency setting mode. [0246] With reference to Fig. 29B, the power source 702 may include a transistor. The controller 552 may be coupled to the transistor for controlling a switching frequency of the transistor, to vary the operating frequency of the voltage supplied to the ozone generator 34.

[0247] As described further below, it will be noted that the controller 552 may be configured to operate the transistor with a fixed duty cycle while varying the operating frequency of the voltage.

[0248] In some embodiments, the controller 552 may be adapted to control the power source 702 to vary the frequency of the voltage supplied to the ozone generator 34 over another set of frequencies in response to the temperature sensor sensing again the temperature above the predetermined threshold temperature.

[0249] Now referring to Fig. 30B, there is illustrated a method of operating an ozone cleaner (such as the ozone cleaner 10). The method may be illustratively performed by controller 552 for example. The controller 552 during an initialization mode 1000, which may be performed prior to delivery of the ozone cleaning system to a consumer, or at each power up of the ozone cleaner. Since the ozone cell may have different characteristic impedances to the power supply, such as for example with respective high voltage amplifier, the initialization mode will self-adjust the ozone optimization process by operating the ozone generator and the power supply at an operating frequency to place the circuit formed by the power supply and the ozone circuit in resonance to ensure maximum power transfer from the power supply to the ozone generator. As part of the initialization process, the controller determines if the frequency is at an optimum setting, and if it is not, the controller will adjust the power supply operating frequency to increase or decrease the operating frequency as required. The optimum operating frequency may be determined by monitoring the current, keeping in mind that the operational current has to be kept below the power supply maximum output current. In more detail, since the ozone cell impedance tolerance varies by up to 10%, the controller may gradually ramp up the frequency from approximately 14 kFIz to 16 kFIz. While this is happening, the current flowing to the ozone generator is monitored. When the operating frequency is at the resonant frequency the current dips, and thus this is the dip that the controller is monitoring. The controller records this dip and sets the initial operational frequency of the ozone cell to the now known resonant frequency. Once this optimum frequency setting has been established by the controller, the ozone cleaner may be operated in a normal operating mode whereby ozone may be generated following the user selecting a clean cycle to begin producing ozone within the cleaning space 16 using the ozone generator 50. During the normal operating mode, not only may the ozone cell impedance tolerance vary, but also components forming part of the power supply may also vary as a result of temperature changes of the ozone cleaner, causing impedance mismatch between the power supply and the ozone generator and the resonant circuit formed by the ozone generator and the power supply to not operate in resonance even if the operating frequency has be set during the initialization mode was previously determined to be a resonant frequency. As a result of an impedance unbalance between the ozone generator and the power supply, current flow from the power supply may increase and cause damage to the power source components either as a result of a current flow above a safe threshold, or as a result of the increase current further causing a corresponding increase in temperature which may eventually lead to a thermal overload condition above which a temperature of the power supply may cause damage to its components, and possibly the ozone cells. During the normal mode of the ozone cleaner the controller may further be configured for performing the steps as shown in Fig. 30B. In response to a detection of an undesired operating condition of the ozone cleaner, such as a temperature spike in the power supply above a predetermined threshold which may provide an indication that a mismatch in impedance as a result of operating the ozone cleaner in the normal mode has occurred, the controller may perform a test of the circuit formed by the ozone generator and the power supply by energizing the circuit over a range of frequencies to determine a frequency at which the new mismatched circuit operates as a resonant circuit at which current and temperature may return to a level such that the ozone cleaner operates in desired operating condition, which may include operating at a lower current flow, and/or at a lower operating temperature. Should the undesired operating condition occur again at a subsequent time indicating for example a mismatch in the circuit has occurred again, the controller may return to again perform a test of the circuit at the same, or a different frequency range, and for example at a higher frequency range. A higher operating frequency range may assist with reducing current flowing through the circuit to prevent a thermal overload condition of the circuit by operating the inductors at a higher frequency tending increase the impedance of the series inductor and/or transformer to reduce current flow. The controller may proceed to enter into a thermal overload mode in the event the testing and setting of the operating frequencies described herein above does not decrease the temperature and/or current of the circuit. The thermal overload mode will operate the power supply to stop a powering of the ozone generator. A temperature sensor may be monitored and at a predetermined temperature level the controller may return to operate the ozone cleaner in the normal mode again.

[0250] Fig. 33 shows the temperature, the duty cycle, and the sensed current in relation to time, during use of the ozone cleaner 10 in accordance with some of the algorithms described and shown herein.

[0251] In some embodiments, the controller 552 controls the frequency and the duty cycle of the current that is sent to the ozone generator 34. In some embodiments, the controller 552 controls the frequency in accordance with a method of controlling current shown at 600 in Fig. 30A. The method 600 may be stored as executable code in the memory 552b and executed by the processor 552a as described below. As can be seen in Fig. 30A, the method 600 by which the controller 552 controls the current may be as follows:

[0252] When signals from the temperature sensor 560 are indicative that the temperature is below a selected threshold temperature, the controller 552 may be configured to carry out the following steps: at step 602, the current flow is measured at each of a first plurality of frequencies over a selected range of frequencies. This measuring may be carried out using the current sensor 556, which sends signals to the processor 552a, which in turn stores the current flows in the memory 552b. At step 604, the processor 552a determines which of the current flows measured in step 602 was a first lowest current flow. At step 606, the controller 552 transmits current to the ozone generator at a first transmission frequency that is selected based on whichever frequency of the first plurality of frequencies is associated with the first lowest current flow determined in step 604. In an example, the controller 552 may, at step 602, take current measurements starting at an initial frequency of 14000 Hz and at every increment of 100 Hz through to 16600 Hz inclusive, and may determine at step 604 that the lowest current flow occurred at a frequency of 14700 Hz. The controller 552 may then at step 606 transmit current at a first selected frequency of 14700 Hz or at some other first selected frequency that is selected based on the frequency of 14700 Hz.

[0253] When signals from the temperature sensor 560 are indicative that the temperature is above the selected threshold temperature, the controller 552 may be configured to carry out the following steps: at step 608, the current flow is measured at each of a second plurality of frequencies over the selected range of frequencies. This measuring may be carried out using the current sensor 556, which sends signals to the processor 552a, which in turn stores the current flows in the memory 552b. At step 610, the processor 552a determines which of the current flows measured in step 608 was a second lowest current flow (i.e. the lower current flow of the current flows measured in step 608). At step 612, the controller 552 transmits current to the ozone generator 34 at a second transmission frequency that is selected based on whichever frequency of the second plurality of frequencies is associated with the second lowest current flow determined in step 610. In an example, the controller 552 may determine that the lowest current flow measured during step 608 is when operating at a frequency of 15300 Hz. The controller 552 may then at step 612 transmit current at a second selected frequency of 15300 Hz or at some other second selected frequency that is selected based on the frequency of 15300 Hz.

[0254] The selected threshold temperature may be any suitable temperature, such as, for example, about 35 degrees Celsius. It has been found that, by carrying out steps 608, 610 and 612 when the temperature measured exceeds the selected threshold temperature, new frequencies are found to have the lowest current flow. As a result, energy savings are achieved by operating at the second transmission frequency, instead of continuing to operate at the first transmission frequency. A reason for this is that, as the temperature of the transformer 558 and of other components of the control system, and of the ozone generator 34 increase, the impedance associated with these components changes (generally increases). As a result, the frequency at which the lowest current flow is measured can change.

[0255] Figs. 31 and 32 are together another flow diagram that illustrate a method that can be said to carry out the steps shown in Fig. 30A.

[0256] In some embodiments, the selected threshold temperature is a first selected threshold temperature, and the controller 552 may be configured to carry out steps similar to 602, 604 and 606 to look for a lowest current flow over a range of frequencies, when operating above a second selected threshold temperature.

[0257] In some embodiments, the selected threshold temperature is a first selected threshold temperature and there is a second selected threshold temperature, which is higher than the first selected threshold temperature. The controller 552 in such embodiments further controls a duty cycle of the current transmitted to the ozone generator 34, in addition to controlling the frequency of the current. Upon receiving signals from the temperature sensor 560 that are indicative that the temperature is above the second selected threshold temperature, the controller 552 is configured to reduce the duty cycle of the current transmitted to the ozone generator 34, in order to reduce the temperature of the components of the ozone generator 34 and the high-voltage circuit board 564. The second selected threshold temperature may be any suitable temperature such as, for example, 90 degrees Celsius.

[0258] In an example embodiment, the duty cycle of the current transmitted to the ozone generator 34 may be about 98% when the temperature measured at the temperature sensor 560 is less than the second selected temperature, and is reduced to about 49% when the temperature measured at the temperature sensor 560 is greater than the second selected temperature.

[0259] In some embodiments, the controller 552 controls a duty cycle of the current transmitted to the ozone generator 34 based on the current measured by the current sensor 556. Upon receiving signals from the current sensor 556 that are indicative that the current is above a selected current threshold, such as, for example, 2A, the controller 552 is configured to reduce the duty cycle of the current transmitted to the ozone generator 34, in order to reduce the temperature of the components of the ozone generator 34 and the high- voltage circuit board 564.

[0260] Reference is made to Figs. 34-35, which show a number of optional features for the sterilization unit 10. Referring to Figs. 34 and 35, the lid 14 has a lid lip 700 and the bottom portion 12 has a bottom portion lip 702. At least one of the lid lip 700 and the bottom portion lip 702 has a projection 704 thereon, and the other of the lid lip 700 and the bottom portion lip 702 has a compressible member 706 captured thereon. In the example embodiment shown in Figs. 34 and 35, the projection 704 is on the bottom portion lip 702 and the compressible member 706 is on the lid lip 700.

[0261] The projection 704 and the compressible member 706 extend all the way around the perimeter of the bottom portion lip 702 and the lid lip 700 respectively, so as to form a seal along the entire periphery of the bottom portion lip 702 and the lid lip 700.

[0262] The projection 704 may have a cross-sectional shape that is a V-shape as shown. Optionally, the V-shape may be symmetric about an axis of symmetry shown at 708.

[0263] The compressible member 706 may be made from any suitable material. Preferably, the compressible member 706 is made from a material that is resistant to degradation from contact with ozone, since at least some portion of the compressible member 706 may be exposed to ozone during sterilization of items in the sterilization chamber 16 of the housing 11. For example, the compressible member 706 may be made from a suitable foam polymeric material such as Neoprene, or some other suitable elastomer. [0264] The compressible member 706 may be positioned in a seal channel 710 in the lid lip 700. The seal channel 710 may be sufficiently wide that, when the compressible member 706 is uncompressed (as shown in Fig. 34), there is clearance between an inside edge shown at 712 of the compressible member 706 and an inside wall 714 of the seal channel 710, and clearance between an outside edge shown at 716 of the compressible member 706 and an outside wall 718 of the seal channel 710. The compressible member 706 may be kept in the seal channel 710 by an adhesive or by any other suitable means. For greater clarity, the inside edge 712 of the compressible member 706 is the edge of the compressible member 706 that faces inwardly (i.e. generally towards the sterilization chamber 16 defined by the housing 11), and the outside edge 716 of the compressible member 706 is the edge that faces outwardly (i.e. generally away from the sterilization chamber 16 defined by the housing 11 ). In the example shown, the inside edge 712 and the outside edge 716 are surfaces that are planar. In other examples (not shown), where the compressible member 706 does not have a generally rectangular cross-sectional shape, but instead has, for example, an elliptical cross-sectional shape, one or both of the inside edge 712 and the outside edge 716 may be an inner peripheral line or an outer peripheral line, as the case may be, as opposed to a surface.

[0265] Closure of the lid 14 on the bottom portion 12 brings the projection 704 into sealing engagement with the lid (as seen in Fig. 35), such that the projection 704 compresses the compressible member 706 between the outside edge 716 and the inside edge 712 (i.e. engaging a projection receiving surface 719 of the compressible member 706 that extends between the inside and outside edges 712 and 716 and faces the projection 704), and is spaced from the compressible member at the outside edge 716 and the inside edge 712. As can be seen in Fig. 35, this arrangement permits essentially the same amount of sealing performance between the lid 14 and the bottom portion 12, even if the projection 704 is not centered on the compressible member 706 due to tolerances in the manufacture of the sterilization unit 10. [0266] It will further be noted that the aforementioned V-shape of the projection 704 means that the projection 704 has an inward surface 720 and an outward surface 722. The inward surface 720 faces at least partially inwardly towards the sterilization chamber 16. For example, in the embodiment shown in Figs. 34 and 35, the inward surface 720 faces inwardly towards the sterilization chamber 16 and also faces upwardly. The outward surface 722 faces at least partially outwardly away from the sterilization chamber 16. For example, in the embodiment shown in Figs. 34 and 35, the outward surface 720 faces outwardly away from the sterilization chamber 16 and also faces upwardly. At least a portion of the inward surface and at least a portion of the outward surface are engaged with the compressible member upon closure of the lid on the bottom portion. In a situation in which there is a positive pressure in the sterilization chamber 16, the compressible member 706 is urged into stronger engagement with the inward surface 720, thereby increasing the seal force therebetween, so as to better resist leakage of gas from the sterilization chamber 16. In a situation in which there is a negative pressure in the sterilization chamber 16, the compressible member 706 is urged into stronger engagement with the outward surface 722, thereby increasing the seal force therebetween, so as to better resist leakage of gas into the sterilization chamber 16.

[0267] Another optional feature that may be provided for the sterilization unit 10 is shown in Figs. 2A, 36 and 37. As can be seen in Fig. 2A, many of the functional elements of the sterilization unit 10 are mounted in a functional elements chamber shown at 750 that is underneath a floor 752 of the sterilization chamber 16. For example, the ozone generator 34, the neutralization fan 54, the ozone fan 38 may all be positioned in the functional elements chamber 750. In Fig. 2A, at least the ozone generator 34, the neutralization fan 54 and the ozone fan 38 are all shown in the functional elements chamber 750. Functional chamber 750 is shown as fluidly isolated from chamber 16 to prevent ozone from being exposed to various electronics housed within chamber 750. Chamber 750 is not sealed relative to the external environment. Optionally, other functional elements such as the power supply 554, and the controller 552 are also positioned in the functional elements chamber 750.

[0268] The functional elements chamber 750 is shown more clearly in Fig. 36. By positioning these functional elements in the functional elements chamber 750 beneath the floor 752 of the sterilization chamber 16 the center of mass of the unit 10 is moved closer towards the lower portion of the unit 10 and the sterilization unit 10 is less likely to tip over if inadvertently impacted.

[0269] In order to protect the functional elements in the functional elements chamber 750 from being damaged from the weight of the housing 11 , and for example from the weight of any items and/or a rack system placed on the floor 752, which may also cause flexing and deformation of the floor 752, which may, in turn, lead to cracks in the floor 752 allowing undesirable leakage of ozone from the chamber 16, the floor 752 of the sterilization chamber 16 may have a plurality of legs shown at 754 that extend down from an underside 757 of the floor 752 pass through the functional elements chamber 750 and extend through apertures 755 in a floor member shown at 756 of the functional elements chamber 750 so as extend below the floor member 756 of the functional elements chamber 750. As a result, the legs 754 will contact the ground (or whatever other underlying support surface the sterilization unit 10 will be placed on), to support the sterilization unit 10 thereon, thereby preventing the floor member 756 from supporting the sterilization unit 10 on the ground or other support surface. Floor member 756 is supported against deflection at various positions within the outer perimeter of the floor member 756 via the legs 754, and may in addition be supported about its perimeter in engagement with the housing 11 by downwardly extending skirt 15 connected to the outer perimeter of floor 752.

[0270] Reference is made to Figs. 38-43, which show another optional feature of the sterilization unit 10, which is a latch shown at 760. The latch 760 is positionable to lock the lid 14 and the bottom portion 12 together, (i.e. to hold the housing 11 closed and to maintain compression of the compressible member 706). The latch 760 includes a striker 762 that is mounted to one of the lid 14 and the bottom portion 12, and a ratchet 764 that is mounted to the other of the lid 14 and the bottom portion 12. In the example shown, the striker 762 is movably mounted to the lid 14 and the ratchet 764 and the pawl 768 are mounted to the bottom portion 12.

[0271] The ratchet 764 has a mouth 767 that is sized to receive the striker 762. The ratchet 764 is pivotable about a ratchet axis 765 between an open position (Figure 39) in which the ratchet 764 permits withdrawal of the striker 762 therefrom (i.e. in which the ratchet 764 does not capture the striker 762), and a closed position (Figure 38) in which the ratchet 764 captures the striker 762. The latch 760 may further include a ratchet biasing member 766 that urges the ratchet 762 towards the open position. In other words, the ratchet 764 may be said to be biased towards the open position. The ratchet biasing member 766 may be any suitable type of biasing member, such as, for example, a torsion spring, a compression spring, or any other type of spring.

[0272] The latch 760 further includes a pawl 768, which may be positioned on whichever of the lid 14 and the bottom portion 12 that the ratchet 764 is positioned on. The pawl 768 is movable (e.g. pivotable about a pawl axis 769) between a ratchet locking position (Figure 38) in which the pawl 768 holds the ratchet 764 in the closed position, and a ratchet release position (Figure 39) in which the pawl 768 permits the ratchet 764 to move to the open position. The latch 760 may further include a pawl biasing member 770 that urges the pawl 768 towards the ratchet locking position. The pawl biasing member 770 may be any suitable type of biasing member, such as, for example, a torsion spring, a compression spring, or any other type of spring. When the ratchet 764 is in the open position, a blocking surface 772 on the ratchet 764 blocks the pawl 768, preventing the pawl 768 from moving to the ratchet locking position. When the ratchet 764 is pivoted to the closed position, the blocking surface 772 is out of the way of the pawl 768 thereby permitting the pawl 768 to move to the ratchet locking position shown in Fig. 38. A pawl limiter 771 is shown in Fig. 38, and is a fixed element that prevents the pawl 768 from overpivoting past the ratchet locking position. When the ratchet 764 is pivoted to the closed position, a switch 773 may be activated when the ratchet 772 has been moved to the latched position in response to the manually user activated extension of the striker 762 causing the ratchet 772 to pivot to the closed position. Since the switch 773 is in electrical communication with the controller 150 to signal to the controller 150 a change in state indicating to the controller 150 that the lid 14 is in a latched position with the housing 12. Even if a user has selected a clean cycle to begin producing ozone, the controller 150 will not activate the ozone generator before receiving a signal indicating that the lid 14 is latched with the bottom portion 12 via the latch 760, and for example before receiving a signal from the switch 773. Switch 773 is an example of a position sensor, and may be provided alternatively as a hall sensor and magnet configuration as another example for detecting the position of the ratchet 772. Alternatively, or additionally, a sensor may be similarly configured to detect the position of the pawl 768, and for example the controller 150 may control the generation of ozone only when the sensor detects the pawl 768 in the ratchet holding position as shown in Fig. 38. Fig. 39 shows the switch 773 in a deactivated state in accordance with an illustrative example when the ratchet 772 has moved away from engagement with the switch 773 and towards the open position. Once the ratchet 764 has been rotated to the closed position and the pawl 768 has been pivoted to the ratchet holding position as seen in Fig. 38, in a possible configuration, a manual activation of the actuator 781 , such as a user attempting to manually pull the button 780 upwards will not cause the latch 760 to release. Rather, the latch 760 may be released by the controller 150 electronically controlling a power release motor 763 acting on the pawl 768 to move the pawl 768 away from the ratchet holding position against the bias 770 of the pawl biasing member 770, for example to move the pawl in a clockwise direction. Upon the powered release of the pawl 768 from the ratchet 764, the ratchet 764 will allow the striker 762 to move upwards and the lid 14 will automatically move from the closed position to a partially opened position under influence of the ratchet bias member 766 acting to move the striker 762 upwards and/or the decompression of the seal 706 moving the lid 14 upwards and away from the bottom portion 14, and without any further manual intervention from a user, such as a handle pull or rotation, or a lifting of the lid 14. In another possible configuration, a manually activatable emergency back up mechanism, such as a hidden handle and lever system for example may be provided to act on the pawl 768 to allow a user to move the pawl 768 without the intervention of the controller 150. [0273] The striker 762 is movably mounted to said one of the lid 14 and the bottom portion 12 for movement between a retracted position (Figures 39, 40, 42) and an extended position (Figures 38 and 43). The striker 762 may be generally U-shaped and may be entirely or partially metallic, for strength.

[0274] Figure 40 illustrates the lid 14 closed on the bottom portion 12. As can be seen, the striker 762, when in the retracted position, does not cause the ratchet 764 to pivot sufficiently to bring the ratchet 764 to the closed position. In the embodiment shown, the striker 762 does cause some pivoting of the ratchet 764, but the amount of pivoting is insufficient to bring the ratchet 764 to the closed position. In some alternative embodiments, the striker 762 may not engage the ratchet 764 at all when in the retracted position, and so the ratchet 764 remains in the open position. Whether or not the striker 762 actually engages and causes some pivoting of the ratchet 764, the lid 14 is not locked closed on the bottom portion 12 when the striker 762 is in the retracted position.

[0275] In order to cause the latch 760 to close so as to lock the lid 14 closed on the bottom portion 12 (i.e. to lock the housing 11 closed), the striker 762 is moved from the retracted position to the extended position. Movement of the striker 762 to the extended position drives the ratchet 764 to pivot to the closed position in which the ratchet 764 captures the striker 762 so as to lock the housing closed. The movement of the ratchet 764 to the closed position permits the pawl 768 to move to the ratchet locking position in order to ensure that the ratchet 764 remains in the closed position.

[0276] The latch 760 further includes a striker biasing member 774, (Figure 41) that urges the striker 762 towards the retracted position. In the exploded view shown in Fig. 41 , it can be seen that the striker biasing member 774 includes a helical compression spring. In the embodiment shown, there are two striker biasing members 774, however any other suitable number and type of striker biasing member may be used. The striker 762 mounts to a plate 776 which is covered by cover member 778. The plate and the cover member 778 together make up a button 780, which may more broadly be referred to as an actuator 781 . The striker biasing members 774 urge the button 780 to a raised position, which brings the striker 762 to the retracted position. In other words, the striker biasing members 774 urge the striker 762 towards the retracted position. The actuator 781 is actuatable by a user to overcome the striker biasing members 774 and drive the striker 762 to the extended position so as to drive the ratchet 764 to the closed position so as to capture the striker 762 and lock the housing 11 closed. In the present example, actuation of the actuator 780 means pressing the button 780, however, any other type of actuator, such as a lever arm, a rotary member that engages a rack type gear, or any other suitable type of actuator may be used.

[0277] It will be noted that the actuator 781 is an external actuator, in the sense that it is accessible only from outside the housing 11. By providing a latch such as the latch 760 that cannot close unless a user actuates the actuator 781 from outside the housing 11 , a situation is prevented where, for example, a child gets into the sterilization chamber 16 and inadvertently causes the lid 14 to fall closed, triggering the latch 760 to lock the lid 14 closed. [0278] Another optional feature of the sterilization unit 10 is for the indentations shown at 790 in Figures 1A and 2A to be shaped so as to be handles for facilitating lifting and carrying of the sterilization unit 10. The indentations 790 optionally may extend both inwards laterally and upwards by some selected amount so that the fingers of the user (which are shown at 791 in Figures 44a and 45) naturally form a J-shape when holding the sterilization unit 10. Also optionally, the indentations 790 may include a rubberized coating 792 on the surfaces that the fingers 791 of the user engage to assist in maintaining grip on the sterilization unit 10 during lifting and carrying of the sterilization unit 10.

[0279] Reference is made to Figs. 46 and 47 which show an optional bracket 796 that is used to limit the angular travel of the lid 14 during opening of the lid 14. As can be seen, the bracket 796 mounts to and extends rearwardly from (or more broadly, outwardly from) the bottom portion hinge wall 502. The bracket 796 includes a lid support surface 797 that partially supports the lid 14 when the lid 14 is in the open position shown in Fig. 47. In this position the lid 14 rests against the bracket 796 such that the center of gravity of the lid 14 maintains the lid 14 in the open position. Providing the bracket 796 ensures that the lid 14 does not overrotate to a position in which the hinge 506 is overstressed, and possibly the unit 10 is caused to tip over. However, the bracket 796 extends several inches rearwardly from the bottom portion hinge wall 502. To keep the overall packaging volume required for the sterilization unit 10 relatively small, the bracket 796 may be made mountable to the bottom portion hinge wall 502 after the sterilization unit 10 has been shipped to a customer, or at least to a point of sale. In some embodiments, the bracket 796 may be removably mountable in case the sterilization unit 10 needs to be shipped somewhere after use. The bracket 796 may be mountable by way of a plurality of mechanical fasteners such as machine screws (shown at 798 in Figure 46).

[0280] Reference is made to Figure 48, which shows a method 800 in accordance with another aspect of the present disclosure. The method 800 is advantageous in that it provides the sterilization unit 10 with the capability to sterilize items relatively quickly, reliably, while accounting for variation from unit to unit, without the need to employ a dedicated ozone sensor such as the ozone sensor 164 (Fig. 15).

[0281] The method includes a step 802 in which data is determined using at least one sensor other than an ozone sensor. The sensor may be, for example, the current sensor 556 (Figure 28D). The data may be, for example, a minimum current draw from the ozone generation cell 34 (Figure 2B) at different operating frequencies. Expressed differently, step 802 may be to determine data that relates to power consumption of the ozone generator. Since current draw is related to power consumption, determining current draw of the ozone generator is an example of determining data that relates to power consumption of the ozone generator. In other examples, a temperature sensor could be provided, which would be used to determine a temperature in the ozone generator 34 or in some other suitable position in the sterilization unit 10. Temperature may be considered data that relates to the power consumption of the ozone generator 34. By contrast, directly measuring the ozone concentration in the sterilization unit 10 may be said to not be related to power consumption of the ozone generator 34 since an ozone generator may have different production rates under different conditions.

[0282] At step 804, a threshold ramp up time is determined for bringing the ozone concentration of the sterilization chamber 16 (Fig. 2A) to at least a selected threshold ozone concentration level, based on the data obtained in step 802. At step 806, the ozone generation cell 34 in the sterilization unit 10 is operated in a ramp-up mode for a first period of time that is based on the threshold ramp up time determined in step 804. In a particular embodiment, the controller 552 (Fig. 28C) references a look up table that relates ozone generation to current draw, based on experiments carried out on the make and model of the ozone generation cell 34 prior to manufacture of the sterilization unit 10. Using the look-up table, the controller 552 can determine a minimum amount of time that is needed to operate the ozone generation cell 34 in the ramp-up mode in order to reach the selected ozone concentration level. The threshold ramp-up time may be this minimum amount of time that is determined. Alternatively, the threshold ramp-up time could be based on this minimum amount of time. For example, the threshold ramp-up time could be this minimum amount of time, plus 10 seconds. When the sterilization unit 10 is operated in the ramp-up mode, the ozone generation cell 34 is operated at a selected duty cycle, that may be, for example, 95% or 98% or any other selected duty cycle. The duty cycle in the ramp-up mode may be referred to as a first duty cycle, or as a ramp-up duty cycle.

[0283] At step 808, the ozone generation cell 34 is operated in a sterilization mode for a second selected period of time at a second selected duty cycle so as to sterilize the items contained within the sterilization chamber 16. The second selected duty cycle is selected in step 807, and is selected in order to ensure that the sterilization chamber is maintained at at least a threshold ozone concentration level. The second selected duty cycle may be selected based on the data obtained in step 802. For example, the controller 552 may reference the aforementioned look-up table, which relates ozone generation to current draw, in order to determine the second selected duty cycle for the ozone generation cell 34. In some embodiments, the second selected duty cycle may be selected to maintain an approximately constant ozone concentration level, based on an assumption regarding the rate of degeneration of ozone that takes place as the ozone reacts with the items in the sterilization chamber 16. In some embodiments, the second selected duty cycle may be selected to provide a low upward ramp rate for the ozone concentration level, thereby ensuring that the ozone concentration cannot fall below the selected threshold ozone concentration level. This ‘low upward ramp rate’ strategy is used in the embodiment represented in Figure 49. In still other embodiments, the second selected duty cycle may be selected to permit a low downward ramp rate for the ozone concentration level, wherein the ramp rate that is permitted still ensures that the ozone concentration cannot fall below the selected threshold ozone concentration level. The selected period of time for the sterilization mode may be any selected period of time, such as 36 minutes, or any other suitable period of time that is determined to be sufficient.

[0284] The second selected duty cycle may also be referred to as the sterilization mode duty cycle.

[0285] When it is stated that the ozone generator 34 is operated at a selected duty cycle for a selected period of time, it will be understood that it need not be operated at that precise duty cycle at every instant of time throughout the period of time. It may be, for example, that the ozone generator 34 is operated with a duty cycle that varies up and down, but which has an average that is at least the selected duty cycle.

[0286] After step 808, step 810 is carried out, in which the sterilization unit 10 is operated in a neutralization mode for a third selected period of time in order to neutralize the ozone contained in the sterilization chamber 16, before permitting opening of the sterilization unit 10. The selected period of time in the neutralization mode may be any suitable selected period of time in order to bring the ozone concentration down to below a selected level, as described elsewhere herein.

[0287] Fig. 49 illustrates some of the steps of the method 800 broken down into further steps, in a particular embodiment. [0288] Fig. 50 is a graph that shows ozone concentration curves in the sterilization chamber 16 of a plurality of examples of the sterilization unit 10, using the method 800. To generate these curves, the method 800 was carried out on each of the plurality of examples of the sterilization unit 10, relying on the data from the current sensor 556. However, an ozone sensor was present, in order to verify whether using the method 800 (and relying on a sensor such as a current sensor) would successfully generate sufficient ozone when in the ramp-up mode, and would maintain the sterilization chamber 16 at a sufficient ozone concentration level for the duration of time in the sterilization mode.

[0289] In the curves shown in Fig. 50, the portions of the curves shown at 850 represent the ramp-up mode for the examples of the sterilization unit 10. The first inflection points on the curves represent the moment at which the ramp-up mode ended and the sterilization mode was initiated. As can be seen, two dashed lines shown at 852a and 852b pass through the first inflection points of two of the curves. As can be seen, one sterilization unit 10 (whose curve is shown at 854 was operated for about 4.2 minutes in the ramp-up mode, while another sterilization unit 10 (whose curve is shown at 856) was operated for about 5.4 minutes in the ramp-up mode. The threshold ozone concentration level that was desired to be reached or exceeded is shown at 858. The portions of the curves that represent the sterilization mode for the aforementioned examples of the sterilization unit 10, are shown at 860. In the curves shown in Fig. 50, it can be seen that a strategy was employed wherein the duty cycle for the sterilization mode was selected so that the ozone concentration in the sterilization chamber 16 increased gradually throughout operation in the sterilization mode. It should be noted that the rate at which ozone is consumed in the sterilization chamber 16 depends somewhat on the quantity and type of items that are placed in the sterilization chamber 16. The duty cycle made be selected to ensure that, for what is predicted to be a worst-case scenario in terms of the quantity and type of items being sterilized, the ozone concentration in the sterilization chamber 16 remains at or above the threshold ozone concentration level. As a result, for situations where fewer items are being sterilized or for items that do not consume as much ozone during the sterilization process, the sterilization chamber 16 will see a gradual increase in ozone concentration.

[0290] Once the sterilization mode 860 is completed, the sterilization unit 10 enters the neutralization mode, as noted above, which is represented by the regions of the curves shown at 862. The operation of the sterilization unit 10 when neutralizing the ozone present in the sterilization chamber 16 is described elsewhere in the present disclosure.

[0291] The following paragraphs summarize some aspects of the present disclosure. [0292] In an aspect, the present disclosure is directed to a sterilization unit, comprising: a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, wherein the housing has an aperture therein that extends from an external environment of the sterilization unit to the sterilization chamber, wherein the aperture has a first end with a cross-sectional dimension; an ozone generator for generating ozone and providing the ozone to the sterilization chamber; and a seal arrangement. The seal arrangement includes a plug having a plug body that extends into the aperture, and a plug head having a head dimension that is larger than the cross-sectional dimension of the first end of the aperture; and a cover member that is adhered to a surface of the housing surrounding the plug and which engages the plug head to hold the plug in engagement with the housing to seal against leakage of gas between the sterilization chamber and the external environment of the sterilization unit.

[0293] Optionally, for the sterilization unit, the housing includes a bottom portion and a lid, and wherein the aperture is in the lid.

[0294] Optionally, for the sterilization unit, the cover member has a first side and a second side and is adhered to the surface of the housing on the first side, and wherein the sterilization unit further comprises a logo member adhered to the second side of the cover member, wherein the logo member is more rigid than the cover member.

[0295] Optionally, for the sterilization unit, the cover member is made from a flexible sheet. [0296] Optionally, for the sterilization unit, the aperture is generally circular in cross- section, and has an aperture diameter at the first end, and the plug head is generally circular and has a head diameter that is larger than the aperture diameter at the first end.

[0297] Optionally, for the sterilization unit, the plug body has a proximal end that is proximate to the plug head and a distal end, wherein the plug body tapers inwardly towards the distal end.

[0298] Optionally, for the sterilization unit, the plug has a blind aperture extending through the plug head into the plug body.

[0299] Optionally, for the sterilization unit, the plug head is outside of the housing. [0300] In another aspect, the present disclosure is directed to a sterilization unit, comprising: a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, wherein the housing has a bottom portion and a lid; an ozone generator for generating ozone and providing the ozone to the sterilization chamber, wherein, when the housing is at an ambient pressure, the housing is in a first position, such that the sterilization chamber occupies a first volume, and wherein, during evacuation of the housing to a selected amount of pressure below the ambient pressure, at least a portion of the housing is movable to an evacuation position in which the sterilization chamber occupies a second volume that is smaller than the first volume.

[0301] Optionally, for the sterilization unit, the lid has a lid hinge wall and the bottom portion has a bottom portion hinge wall, wherein the lid hinge wall and the bottom portion hinge wall are movably connected to one another by a hinge arrangement that includes at least one hinge defining a pivot axis for the hinge arrangement. When the housing is at the ambient pressure, the hinge arrangement is positioned in a first hinge position in which the pivot axis extends along a linear path, and wherein the hinge arrangement is movable to a second hinge position in which the pivot axis extends along an arcuate path so as to accommodate flexing of the lid hinge wall and the bottom portion hinge wall during evacuation of the housing to the selected amount of pressure below the ambient pressure. As a further option, the at least one hinge is a single hinge that includes a first plurality of hinge knuckles mounted to the bottom portion hinge wall, a second plurality of hinge knuckles mounted to the lid hinge wall and which are positioned in gaps between the first hinge knuckles, and a hinge pin that extends through the first plurality of hinge knuckles and the second plurality of hinge knuckles, wherein the hinge pin is sufficiently flexible and the first and second hinge knuckles have a sufficient amount of play therebetween, so as to permit movement of the hinge arrangement between the first hinge position and the second hinge position. As yet a further option, the hinge pin is made from a material having a selected yield stress, and is shaped to incur stress below the elastic yield stress during movement of the hinge arrangement from the first hinge position to the second hinge position.

[0302] Optionally, for the sterilization unit, the housing has an aperture therein that extends from an external environment to the sterilization chamber, wherein the sterilization chamber is connectable to a vacuum source so as to generate the selected amount of pressure below the ambient pressure.

[0303] Optionally, for the sterilization unit, the lid has a lid lip and the bottom portion has a bottom portion lip, and wherein at least one of the lid lip and the bottom portion lip has a projection thereon, and the other of the lid lip and the bottom portion lip has a compressible member captured thereon, wherein the compressible member has an inside edge that faces inwardly towards the volume contained by the housing, and an outer edge that faces outwardly away from the volume contained by the housing. Closure of the lid on the bottom portion brings the projection into sealing engagement with the compressible member, such that the projection compresses the compressible member between the outside edge and the inside edge and is spaced from the compressible member at the outside edge and the inside edge. As a further option, the projection has an inward surface that faces at least partially inwardly towards the sterilization chamber, and an outward surface that faces at least partially outwardly away from the sterilization chamber, wherein at least a portion of the inward surface and at least a portion of the outward surface are engaged with the compressible member upon closure of the lid on the bottom portion. As yet a further option, the compressible member has a projection engagement face that is engaged by the projection, wherein the projection engagement face is planar. The projection, if provided, may have a cross-sectional shape that is a V-shape. If the projection and compressible member are provided, the projection may be on the bottom portion lip and the compressible member may be captured on the lid lip.

[0304] In yet another aspect, the present disclosure is directed to a sterilization unit, comprising: a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, wherein the housing has a bottom portion and a lid; an ozone generator for generating ozone and providing the ozone to the sterilization chamber; and a latch positioned to lock the lid and the bottom portion together, wherein the latch includes a striker, a ratchet and a pawl, wherein the striker is mounted to one of the lid and the bottom portion, and wherein the ratchet is mounted to the other of the lid and the bottom portion. The ratchet is pivotable between an open position in which the ratchet does not capture the striker, and a closed position in which the ratchet captures the striker, wherein a ratchet biasing member urges the ratchet towards the open position so as to lock the housing closed. The pawl is movable between a ratchet locking position in which the pawl holds the ratchet in the closed position, and a ratchet release position in which the pawl permits the ratchet to move to the open position, wherein the latch includes a pawl biasing member that urges the pawl towards the ratchet locking position, and wherein when the ratchet is in the closed position the ratchet permits movement of the pawl to the ratchet locking position by the pawl biasing member. The striker is movably mounted to said one of the lid and the bottom portion for movement between a retracted position and an extended position, wherein, when the striker is in the retracted position, the striker does not cause pivoting of the ratchet to the closed position, wherein movement of the striker to the extended position drives the ratchet to pivot to the closed position. The latch further includes a striker biasing member that urges the striker towards the retracted position, and wherein the latch further includes an external actuator that is accessible from outside the housing and is actuatable by a user to overcome the striker biasing member and drive the striker to the extended position so as to drive the ratchet to the closed position so as to capture the striker and lock the housing closed.

[0305] Optionally, for the sterilization unit, the striker is on the lid and the ratchet and the pawl are on the bottom portion.

[0306] In yet another aspect, the present disclosure is directed to a sterilization unit, comprising: a housing defining a sterilization chamber that is shaped to receive a quantity of items that are to be subjected to sterilization, wherein the housing has a bottom portion and a lid; and an ozone generator for generating ozone and providing the ozone to the sterilization chamber. The housing defines a sterilization chamber having a floor, wherein the housing defines a functional elements chamber beneath the floor of the sterilization chamber, and has a functional elements chamber floor member that in part defines the function elements chamber and is below the floor of the sterilization chamber, wherein a plurality of legs extend down from an underside of the floor of the sterilization chamber pass through the functional elements chamber and extend through apertures in the functional elements chamber floor member so as to extend below the functional elements chamber floor member, so as to prevent the floor member from supporting the sterilization unit on a support surface.

[0307] In yet another aspect, the present disclosure is directed to an ozone cleaner for cleaning one or more items, the ozone cleaner comprising: an ozone generator for generating ozone; a housing defining a cleaning chamber that is configured to receive the one or more items and generated ozone from the ozone generator; a power supply to supply power to the ozone generator; and a first sensor for sensing an undesired operating condition of the ozone cleaner. The ozone generator and the power supply form a resonance circuit, wherein in response to the first sensor sensing the undesired operating condition the ozone cleaner enters a frequency setting mode in which the ozone cleaner is adapted to power the resonance circuit over a set of frequencies, sense the amount of supplied power at each frequency in the set of frequencies, and set the frequency of the supplied power to a set frequency from the set of frequencies selected based upon the sensed amount of supplied power at the set frequency during the frequency setting mode. [0308] Optionally, the ozone cleaner further has an operating mode in which the ozone cleaner is adapted to power the resonance circuit at an operating frequency during the operating mode, wherein the operating frequency is the set frequency from the frequency setting mode. As a further option, the ozone cleaner may be configured to enter the frequency setting mode from the operating mode in response to the first sensor sensing the undesired operating condition and return to the operating mode using the set frequency as the operating frequency.

[0309] Optionally, the first sensor may be a temperature sensor. As a further option, the power supply may include a power source and a power driver circuit coupling the power source to the ozone generator, wherein the temperature sensor is positioned to sense a temperature from the power supply or from a component that receives current from the power supply. As a yet further option, the power driver circuit comprises an impedance matching circuit, and a transformer. As a still further option, the power driver circuit and the temperature sensor may be mounted to a printed circuit board. As a still further option, the undesirable operating condition is a temperature of the power driver circuit above a predetermined temperature. As a still further option, the power source is adapted to vary the frequency of the power supplied to the ozone generator over another set of frequencies in response to the temperature sensor sensing again the temperature above the predetermined threshold temperature.

[0310] Optionally, the ozone cleaner further comprises a current sensor for sensing a supplied current at each frequency in the set of frequencies. As a further option, the ozone cleaner may be adapted to select the set frequency corresponding to the lowest sensed amount of current over the set of frequencies.

[0311] Optionally, the ozone cleaner further comprises a controller coupled to the first sensor and to the power source, the controller configured in response to the first sensor sensing the undesired operating condition to enter the frequency setting mode to control the power source to vary the frequency of a voltage supplied to the ozone generator over the set of frequencies. As a further option, the ozone cleaner further comprises a second sensor coupled to the controller for sensing the amount of supplied power at each frequency in the set of frequencies. As a further option, the power source comprises a transistor, and the controller is coupled to the transistor for controlling a switching frequency of transistor to vary operating frequency of the voltage supplied to the ozone generator. As a further option, the controller is configured to operate the transistor with a fixed duty cycle while varying the operating frequency of a voltage.

[0312] Optionally, where the controller is provided, the controller is adapted to control the power source to vary the frequency of a voltage supplied to the ozone generator over another set of frequencies in response to the temperature sensor sensing again the temperature above the predetermined threshold temperature.

[0313] Optionally, the ozone generator is configured to generate ozone using corona discharge.

[0314] In yet another aspect, the present disclosure is directed to a method of operating an ozone cleaner for cleaning one or more items, the ozone cleaning comprising an ozone generator for generating ozone, the method comprising: supplying power to the ozone generator; sensing an undesired operating condition of the ozone cleaner; varying an operating frequency of the supplied power over a range of given frequencies in response to sensing the undesired operating condition; sensing the amount of supplied power at the given frequencies during varying the frequency of the power supply; and supplying power at a selected frequency from the given frequencies based upon the sensed amount of supplied power at the given frequencies.

[0315] Optionally, the method further comprises determining another selected frequency within a second range of given frequencies based upon the sensed amount of power suppled in response to determining a subsequent undesired operating condition of the ozone cleaner. [0316] In yet another aspect, the present disclosure is directed to a ozone cleaner for cleaning one or more items, the ozone cleaner comprising: an ozone generator for generating ozone; a housing defining a cleaning chamber that is configured to receive the one or more items and the generated ozone; a power source to supply power to the ozone generator; a first sensor for sensing an undesired operating temperature of the ozone cleaner; a second sensor for sensing the power supplied to the ozone generator. The ozone cleaner comprises an operating mode wherein the ozone cleaner is adapted to supply power to the ozone generator at an operating frequency, and a frequency setting mode wherein the ozone cleaner is adapted to supply power to the ozone generator over a set of frequencies in response to the first sensor sensing the undesired operating temperature to determine a set frequency from the set of frequencies selected based upon the sensed amount of supplied power at the set frequency during the frequency setting mode.

[0317] In yet another aspect, the present disclosure is directed to a method of operating a sterilization unit that includes a housing defining a sterilization chamber for holding at least one item for sterilization of the at least one item, an ozone generator positioned for generating ozone in the sterilization chamber, the method comprising: a) determining data that relates to power consumption of the ozone generator; b) determining a threshold ramp up time for reaching at least a threshold ozone concentration level, based on the data determined in step a); c) operating the ozone generator in a ramp-up mode for a first selected period of time that is based on the threshold ramp up time; d) determining a selected duty cycle to operate the ozone generator at, in order to ensure that the sterilization chamber is maintained at at least the threshold ozone concentration level; e) operating the ozone generator in a sterilization mode at the selected duty cycle for a second selected period of time; and f) operating the ozone generator in a neutralization mode for a third selected period of time to neutralize ozone contained in the sterilization chamber from step e).

[0318] Optionally, the determination of the selected duty cycle made in step d) is made based on the data determined in step a). [0319] It will be understood by one skilled in the art that this disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the above description or illustrated in the drawings. The embodiments herein are capable of other embodiments, and capable of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms "connected," "coupled," and "mounted," and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms "connected" and "coupled" and variations thereof are not restricted to physical or mechanical connections or couplings. Further, terms such as up, down, bottom, and top are relative, and are employed to aid illustration, but are not limiting.

[0320] The components of the illustrative devices, systems and methods employed in accordance with the illustrated embodiments can be implemented, at least in part, in digital electronic circuitry, analog electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. These components can be implemented, for example, as a computer program product such as a computer program, program code or computer instructions tangibly embodied in an information carrier, or in a machine-readable storage device, for execution by, or to control the operation of, data processing apparatus such as a programmable processor, a computer, or multiple computers.

[0321] A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. Also, functional programs, codes, and code segments for accomplishing the illustrative embodiments can be easily construed as within the scope of claims exemplified by the illustrative embodiments by programmers skilled in the art to which the illustrative embodiments pertain. Method steps associated with the illustrative embodiments can be performed by one or more programmable processors executing a computer program, code or instructions to perform functions (e.g., by operating on input data and/or generating an output). Method steps can also be performed by, and apparatus of the illustrative embodiments can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), for example.

[0322] The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an ASIC, a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0323] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example, semiconductor memory devices, e.g., electrically programmable read-only memory or ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory devices, and data storage disks (e.g., magnetic disks, internal hard disks, or removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks). The processor and the memory can be supplemented by, or incorporated in special purpose logic circuitry.

[0324] Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0325] Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of claims exemplified by the illustrative embodiments. A software module may reside in random access memory (RAM), flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable disk, a CD- ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. In other words, the processor and the storage medium may reside in an integrated circuit or be implemented as discrete components. [0326] Computer-readable non-transitory media includes all types of computer readable media, including magnetic storage media, optical storage media, flash media and solid state storage media. It should be understood that software can be installed in and sold with a central processing unit (CPU) device. Alternatively, the software can be obtained and loaded into the CPU device, including obtaining the software through physical medium or distribution system, including, for example, from a server owned by the software creator or from a server not owned but used by the software creator. The software can be stored on a server for distribution over the Internet, for example.

[0327] The above-presented description and figures are intended by way of example only and are not intended to limit the illustrative embodiments in any way except as set forth in the following claims. It is particularly noted that persons skilled in the art can readily combine the various technical aspects of the various elements of the various illustrative embodiments that have been described above in numerous other ways, all of which are considered to be within the scope of the claims.

[0328] Persons skilled in the art will appreciate that there are yet more alternative implementations and modifications possible, and that the above examples are only illustrations of one or more implementations. The scope, therefore, is only to be limited by the claims appended hereto and any amendments made thereto.

Claims

CLAIMS What is claimed is:

1. A decontamination unit, comprising: a housing defining a treatment chamber that is shaped to receive a quantity of items that are to be subjected to decontamination, wherein the housing has an aperture therein that extends from an external environment of the decontamination unit to the treatment chamber, wherein the aperture has a first end with a cross-sectional dimension; an ozone generator for generating ozone and providing the ozone to the treatment chamber; and a seal arrangement including a plug having a plug body that extends into the aperture, and a plug head having a head dimension that is larger than the cross-sectional dimension of the first end of the aperture; and a cover member that is adhered to a surface of the housing surrounding the plug and which engages the plug head to hold the plug in engagement with the housing to seal against leakage of gas between the treatment chamber and the external environment of the decontamination unit.

2. A decontamination unit as claimed in claim 1 , wherein the housing includes a bottom portion and a lid, and wherein the aperture is in the lid.

3. A decontamination unit as claimed in claim 1 , wherein the cover member has a first side and a second side and is adhered to the surface of the housing on the first side, and wherein the decontamination unit further comprises a logo member adhered to the second side of the cover member, wherein the logo member is more rigid than the cover member.

4. A decontamination unit as claimed in claim 1, wherein the cover member is made from a flexible sheet.

5. A decontamination unit as claimed in claim 1, wherein the aperture is generally circular in cross-section, and has an aperture diameter at the first end, and the plug head is generally circular and has a head diameter that is larger than the aperture diameter at the first end.

6. A decontamination unit as claimed in claim 1 , wherein the plug body has a proximal end that is proximate to the plug head and a distal end, wherein the plug body tapers inwardly towards the distal end.

7. A decontamination unit as claimed in claim 1 , wherein the plug has a blind aperture extending through the plug head into the plug body.

8. A decontamination unit as claimed in claim 1, wherein the plug head is outside of the housing.

9. A decontamination unit, comprising: a housing defining a treatment chamber that is shaped to receive a quantity of items that are to be subjected to decontamination, wherein the housing has a bottom portion and a lid; an ozone generator for generating ozone and providing the ozone to the treatment chamber, wherein, when the housing is at an ambient pressure, the housing is in a first position, such that the treatment chamber occupies a first volume, and wherein, during evacuation of the housing to a selected amount of pressure below the ambient pressure, at least a portion of the housing is movable to an evacuation position in which the treatment chamber occupies a second volume that is smaller than the first volume.

10. A decontamination unit as claimed in claim 9, wherein the lid has a lid hinge wall and the bottom portion has a bottom portion hinge wall, wherein the lid hinge wall and the bottom portion hinge wall are movably connected to one another by a hinge arrangement that includes at least one hinge defining a pivot axis for the hinge arrangement, and wherein, when the housing is at the ambient pressure, the hinge arrangement is positioned in a first hinge position in which the pivot axis extends along a linear path, and wherein the hinge arrangement is movable to a second hinge position in which the pivot axis extends along an arcuate path so as to accommodate flexing of the lid hinge wall and the bottom portion hinge wall during evacuation of the housing to the selected amount of pressure below the ambient pressure.

11. A decontamination unit as claimed in claim 9, wherein the housing has an aperture therein that extends from an external environment to the treatment chamber, wherein the treatment chamber is connectable to a vacuum source so as to generate the selected amount of pressure below the ambient pressure.

12. A decontamination unit as claimed in claim 10, wherein the at least one hinge is a single hinge that includes a first plurality of hinge knuckles mounted to the bottom portion hinge wall, a second plurality of hinge knuckles mounted to the lid hinge wall and which are positioned in gaps between the first hinge knuckles, and a hinge pin that extends through the first plurality of hinge knuckles and the second plurality of hinge knuckles, wherein the hinge pin is sufficiently flexible and the first and second hinge knuckles have a sufficient amount of play therebetween, so as to permit movement of the hinge arrangement between the first hinge position and the second hinge position.

13. A decontamination unit as claimed in claim 12, wherein the hinge pin is made from a material having a selected yield stress, and is shaped to incur stress below the elastic yield stress during movement of the hinge arrangement from the first hinge position to the second hinge position.

14. A decontamination unit as claimed in claim 9, wherein the lid has a lid lip and the bottom portion has a bottom portion lip, and wherein at least one of the lid lip and the bottom portion lip has a projection thereon, and the other of the lid lip and the bottom portion lip has a compressible member captured thereon, wherein the compressible member has an inside edge that faces inwardly towards the volume contained by the housing, and an outer edge that faces outwardly away from the volume contained by the housing, and closure of the lid on the bottom portion brings the projection into sealing engagement with the compressible member, such that the projection compresses the compressible member between the outside edge and the inside edge and is spaced from the compressible member at the outside edge and the inside edge.

15. A decontamination unit as claimed in claim 14, wherein the projection has a cross- sectional shape that is a V-shape.

16. A decontamination unit as claimed in claim 14, wherein the projection has an inward surface that faces at least partially inwardly towards the treatment chamber, and an outward surface that faces at least partially outwardly away from the treatment chamber, wherein at least a portion of the inward surface and at least a portion of the outward surface are engaged with the compressible member upon closure of the lid on the bottom portion.

17. A decontamination unit as claimed in claim 16, wherein the compressible member has a projection engagement face that is engaged by the projection, wherein the projection engagement face is planar.

18. A decontamination unit as claimed in claim 14, wherein the projection is on the bottom portion lip and the compressible member is captured on the lid lip.

19. A decontamination unit, comprising: a housing defining a treatment chamber that is shaped to receive a quantity of items that are to be subjected to decontamination, wherein the housing has a bottom portion and a lid; an ozone generator for generating ozone and providing the ozone to the treatment chamber; and a latch positioned to lock the lid and the bottom portion together, wherein the latch includes a striker, a ratchet and a pawl, wherein the striker is mounted to one of the lid and the bottom portion, and wherein the ratchet is mounted to the other of the lid and the bottom portion, wherein the ratchet is pivotable between an open position in which the ratchet does not capture the striker, and a closed position in which the ratchet captures the striker so as to lock the housing closed, wherein a ratchet biasing member urges the ratchet towards the open position, wherein the pawl is movable between a ratchet locking position in which the pawl holds the ratchet in the closed position, and a ratchet release position in which the pawl permits the ratchet to move to the open position, wherein the latch includes a pawl biasing member that urges the pawl towards the ratchet locking position, and wherein when the ratchet is in the closed position the ratchet permits movement of the pawl to the ratchet locking position by the pawl biasing member, wherein the striker is movably mounted to said one of the lid and the bottom portion for movement between a retracted position and an extended position, wherein, when the striker is in the retracted position, the striker does not cause pivoting of the ratchet to the closed position, wherein movement of the striker to the extended position drives the ratchet to pivot to the closed position, wherein the latch further includes a striker biasing member that urges the striker towards the retracted position, and wherein the latch further includes an external actuator that is accessible from outside the housing and is actuatable by a user to overcome the striker biasing member and drive the striker to the extended position so as to drive the ratchet to the closed position so as to capture the striker and lock the housing closed.

20. A decontamination unit as claimed in claim 19, wherein the striker is on the lid and the ratchet and the pawl are on the bottom portion.