WO2002015771A9

WO2002015771A9 - Disposable protective covering for medical instruments

Info

Publication number: WO2002015771A9
Application number: PCT/US2001/026655
Authority: WO
Inventors: Richard G Nadeau Jr; Ernel O Simpson
Original assignee: Rheologics Inc; Cytometrics Llc; Richard G Nadeau Jr; Ernel O Simpson
Priority date: 2000-08-25
Filing date: 2001-08-27
Publication date: 2003-05-01
Also published as: AU2001288426A1; WO2002015771A2; WO2002015771A3

Abstract

A protective covering and method for using the same to shield and protect a spectral imaging apparatus, including its probe, from bodily fluids or other contaminates in both operating and non-operating room environments. In one embodiment, the protective covering includes a cap and a drape. The cap protects the probe from direct contact with a subject's tissues. The cap is hollow and elongated to cover the probe, and has an open end and a closed end. At the closed end, the cap has an optically transparent face. This permits light to be transmitted from the probe through the closed end of the cap with minimal optical distortion. At the open end, the cap has a securing mechanism, such as a Luer lock, that fastens the cap to the spectral imaging apparatus. The drap covers the remainder of the spectral imaging apparatus, including its handle and connecting cable. In another embodiment, the protective covering includes a cap and shield. The body of the shield projects over the spectral imaging apparatus to protect it from liquids spilled or splattered in non-operating room environments.

Description

Disposable Protective Covering for Medical Instruments

Background of the Invention

1. Field of the Invention

This invention relates to protective coverings for medical instruments, such as endoscopes and other probing devices. More particularly, the invention relates to disposable protective coverings for use on spectral imaging devices.

2. Related Art

An important aspect of diagnosing health problems is the ability to analyze and test a subject's tissue and blood. Non-invasive analysis of a subject's tissue and blood is advantageous because it does not involve a high risk of injury caused by the testing procedure itself. For example, non-invasive analyses typically avoid puncturing body parts or changing bodily functions, e.g. blood flow, infection levels, vital signs, and the like.

Typically, a spectral imaging apparatus is used for non-invasive analysis of a subject's tissue and blood. The spectral imaging apparatus has a probe with a polarized light source. The probe is used to project an illumination pattern within a region of interest and beneath a surface of the region of interest. A spectral imaging apparatus of this type can be used for measuring and testing. For example, hemoglobin levels can be measured using the spectral imaging apparatus to aid in diagnosing anemia and other diseases involving abnormal red blood cell count. The spectral imaging apparatus can also be used for analysis based solely upon imaging the region of interest. For example, the apparatus can be used to obtain images of tissues to be analyzed by an expert. The expert can use these images to determine the presence of cancerous cells within a particular region. Using a spectral imaging apparatus to probe a variety of subjects requires the use of a probe cover. The cover, or probe cap, must not block or interfere with the illumination pattern which the probe projects. In order to avoid interference with the illumination pattern, the cap has a window at its end which transmits light. The window is said to have a low birefringence. Low birefringence of the window ensures that the optical properties of the probe will be substantially unaffected by the cap.

In health care environments, in particular surgical environments, the spectral imaging apparatus must be appropriately sterilized and protected from contaminates. As such, it is of critical importance that a cap be used to cover the probe portion of the spectral imaging apparatus. Moreover, the remaining parts of the spectral imaging apparatus must also be covered and protected from the environment. The same spectral imaging apparatus is typically used on a variety of subjects. Protective coverings reduce the likelihood of spreading contagious diseases from one patient to the next. Without the protective coverings, the spectral imaging apparatus could contact dangerous viruses and other infectious materials in one subject and transmit them to another subject. For that reason, it is important that the cap be made for disposable use. Beyond the risk of transmitting disease, inaccurate results based erroneously on a different subject's blood or tissues could dangerously lead to the wrong diagnosis.

What is needed, therefore, is a disposable protective covering that is easy to install and remove.

Summary of the Invention

The present invention is directed towards a protective covering and method for using a protective covering to shield and protect a spectral imaging apparatus; including its probe, from bodily fluids or other contaminates in both operating and non-operating room environments. hi one embodiment, the protective covering includes a cap and a drape. The cap protects the probe from direct contact with a subject's tissues. The cap is hollow and elongated to cover the probe, and has an open end and a closed end. At the closed end, the cap has an optically transparent face. This permits light to be transmitted from the probe through the closed end of the cap with minimal optical distortion. At the open end, the cap has a securing mechanism, such as a Luer lock, that fastens the cap to the spectral imaging apparatus.

The drape covers the remainder of the spectral imaging apparatus, including its handle and connecting cable. The drape and cap can be formed as a single unit or as two separate components that are subsequently assembled prior to use.

In another embodiment, the protective covering includes a cap and shield. The body of the shield projects over the spectral imaging apparatus to protect it from liquids spilled or splattered in non-operating room environments. The cap and shield can also be formed as a single unit or as separate components.

Brief Description of the Figures

The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears.

FIG. 1 illustrates a protective covering for a spectral imaging apparatus according to an embodiment of the present invention. FIG. 2 illustrates a cap for covering a probe connected to a spectral imaging apparatus, according to an embodiment of the present invention.

FIG. 3 illustrates a focusing assembly according to an embodiment of the present invention. FIG. 4 illustrates a pre-assembled protective covering according to an embodiment of the present invention.

FIG. 4a illustrates an assembled protective covering according to an embodiment of the present invention.

FIG. 5 illustrates a protective covering for a spectral imaging apparatus according to another embodiment of the present invention.

FIG 5 a illustrates a protective covering prior to being secured to a spectral imaging apparatus, according to an embodiment of the present invention.

FIG 5b illustrates a protective covering after being secured to a spectral imaging apparatus, according to an embodiment of the present invention. FIG. 6 illustrates a pouch for storing a protective covering, according to an embodiment of the present invention.

FIG 6a illustrates a pouch containing an alternative embodiment of a protective covering, according to an embodiment of the present invention.

FIG. 7 illustrates a protective covering for a spectral imaging apparatus used in non-operating applications, according to an embodiment of the present invention

Detailed Description of the Preferred Embodiments

FIG. 1 illustrates an exemplary spectral imaging apparatus 100, including a handle 110, a connecting cable 112 and a probe 120. Spectral imaging apparatus 100 is preferably, but not necessarily, of the type described in commonly assigned

U.S. Patent No. 5,983,120, issued November 9, 1999, in the names of Warren

Groner and Richard G. Nadeau, and entitled "Method and Apparatus for Reflected Imaging Analysis" (hereinafter referred to as "the '120 patent"), or in commonly assigned U.S. Patent No. 6,104,939, issued August 15, 2000, in the names of Warren Groner and Richard G. Nadeau, and entitled "Method and Apparatus for Reflected Imaging Analysis" (hereinafter referred to as "the '939 patent"). The disclosure of the '120 patent and the '939 patent are incorporated herein by reference as though set forth in its entirety. It will be apparent to those skilled in the relevant arts that spectral imaging apparatus 100 contains many other components, including a housing, a light source for illuminating a region of interest, etc. These elements are not shown for convenience of description of the inventive features.

FIG. 1 also shows a cap 130 and drape 140. Cap 130 and drape 140 represent one example of a protective covering according to the present invention. Cap 130 and drape 140, collectively, serve to shield and protect spectral imaging apparatus 100 from bodily fluids or other contaminates, and promotes a sterile operating environment for spectral imaging apparatus 100. Cap 130 is formed to securely fit over probe 120.

FIG. 2 illustrates a closer view of cap 130. As shown, cap 130 includes a closed end portion 210 and an open end portion 230. The central region or window (not shown) of closed end portion 210 is optically transparent to permit light to be transmitted with minimal optical distortion. In a preferred embodiment, optical distortion is abated by adjusting the following properties for the optically transparent window: transmittance, flatness, polarization distortion, and glare. Transmittance is measured as a ratio of the light intensity measured by spectral imaging apparatus 100 with cap 130 installed thereon to the light intensity measured by spectral imaging apparatus 100 without cap 130.

Transmittance through the optically transparent window should be equal to or greater than ninety percent from 500 nanometers (nm) to 650 nm.

Optical flatness for the window surface should be equal to or less than six fringes, as measured interferometrically, at 635 nm. For example, if the diameter of cap 130 is approximately five millimeters (mm), the optical flatness should be less than two microns in surface variation across the five mm diameter, assuming the optical flatness is measured interferometrically by reflection across the surface.

Polarization distortion is considered by measuring a change in degree of polarization (DOP), a change in degree of linear polarization (DOLP) and a change in degree of circular polarization (DOCP), due to cap 130. These three parameters identify any degradation of linear polarization purity on passage of polarized light through cap 130. At 635 nm in a preferred embodiment, neither DOP nor DOLP should exceed two percent, and DOCP should not exceed six percent.

The glare parameters are based on a cap glare count and cap glare ratio. To determine cap glare count, one must measure the "light-on dark levels." The light-on dark levels are detector light intensity levels when probe 120, with a light source on, is placed in a dark container or room. The light-on dark level is measured with cap 130 installed and designated as I_ldc. The light-on dark level is also measured without cap 130 and designated as I_ld. The difference between I_]dc and I_ld represents the cap glare count. Preferably, the cap glare count should not exceed seventy five. Ideally both I_ldc and I_]d should be equivalent to I_d, which represents the detector dark or zero level when the light source is off for probe 120. However, due to internal light reflections and light scatter inside probe 120, in the case of I_ld, and due to additional light reflections and scatter from cap 130, in the case of I_ldc, these intensity levels are always greater than the detector zero level.

The cap glare ratio is a measured ratio of additional light glare due to the presence of cap 130 over the light glare due to probe 120, or [I_Idc - I_ld]/[I_ld - LJ.

Preferably, the cap glare ratio should not exceed five.

In an embodiment, cap 130, including both closed end portion 210 and open end portion 230, is formed in one piece from clear plastic. Materials, such as acrylics, polycarbonate, clear polyesters, clear ABS, clear PNC, Cyclic-Olefin polymers or other clear plastic material, can be used for this purpose. A clear plastic material with a low birefringence having a light transmission of at least 90% between 350 nm and 750 nm can be used.

In another embodiment, cap 130 can also be formed in two pieces. In this embodiment, the open end portion 230 of cap 130 is formed from a rubber modified polymer. However, the optically transparent region of closed end portion 210 is made from a clear plastic material. In an embodiment, the optically transparent region is an anti-reflective coated glass.

As shown, located near open end portion 230 of cap 130 is a ribbed portion 240. Ribbed portion 240 is designed to improve an individual' s ability to grip and hold cap 130. Ribbed portion 240 facilitates manipulating cap 130 so that it can be securely fastened to spectral imaging apparatus 100. Ribbed portion 240 can be a pin-like structure, as shown in FIG 1, or similar contoured structures that facilitate gripping.

Cap 130 also includes securing mechanism 250a-250b for attaching cap 130 to spectral imaging apparatus 100. Securing mechanism 250a-250b is aLuer lock that fits a threaded region located between probe 120 and spectral imaging apparatus 100. The threaded region aligns cap 130 such that the optically transparent region of closed end portion 210 is concentric to the objective window (not shown) of probe 120. The threaded region is part of a focusing mechanism that is used to move either cap 130 or probe 120 towards or away from the subject.

FIG.3 illustrates an exploded view of a focusing assembly for the present invention. More specifically, FIG. 3 shows the relationship of a focusing mechanism 310 to cap 130 and probe 120, according to an embodiment of the present invention. As shown, focus mechanism 310 fits over the objective lens of probe 120 and attaches to a base containing a stepper motor 320 and an encoder 330. As described above, cap 130 fits over probe 120, and securing mechanism 250a-250b fits (shown in FIG. 3 as securing mechanism 250a) into a threaded region 340. The entire focusing assembly (namely, focusing mechanism 310, stepper motor 320, encoder 330) are housed within spectral imaging apparatus 100.

In a preferred embodiment, focusing mechanism 310 is configured to traverse cap 130withrespect to probe 120. Holding probe 120 in a fixed position, focusing mechanism 310 moves cap 130 inward and outward to adjust the focus of optical images captured by spectral imaging apparatus 100. Focus mechanism 310 uses stepper motor 320 and encoder 330 in a closed loop controller system to position cap 130 to any depth in a specified range. In addition, focus mechanism 310 is integrated with securing mechanism 250a-250b (e.g., Luer lock connector) that holds cap 130. In operation, stepper motor 320 turns a spur gear that translates securing mechanism 250a-250b along the optical axis of probe 120, via a lead screw mechanism. Simultaneously, the spur gear turns the shaft of encoder 330 allowing precise location of cap 130. In an embodiment, focusing mechanism 310 moves in step sizes of less than or equal to three microns Focusing mechanism 310 also functions to minimize the birefringence angle. The negative range of motion is the distance traveled inward. The negative range of motion should be sufficient to guarantee that the closed end portion 210 of cap 130 touches probe 120. Focusing mechanism 310 has the capability to report the position of cap 130 with respect to probe 120. Therefore, an operator of spectral imaging apparatus 100 can measure the distance between the closed end portion 210 and probe 120, as well as instruct spectral imaging apparatus 100 to locate cap 130 to a specified distance.

FIG. 4 illustrates an embodiment of the present invention where cap 130 is assembled to drape 140 prior to being placed over spectral imaging apparatus 100. Drape 140 consists of a collar 442 and a sleeve 444. Collar 442 has a opening 446 through which cap 130 fits. Sleeve 444 is formed to fit spectral imaging device 100, including any cable 112 connected to handle 110 of spectral imaging apparatus 100. FIG.4a illustrates cap 130 after it has been fitted through collar 442. When assembled, cap 130 and drape 140 can be placed over probe 120 and spectral imaging apparatus 100 to completely cover spectral imaging apparatus 100, including connecting cable 112 (as shown in FIG. 1). Cap 130 and drape 140 are attached to each other by ultrasonic welding. Alternatively, a medical grade adhesive is used to attach the two parts.

FIG. 5 illustrates another embodiment of the present invention where cap 130 is fitted over probe 120 prior to being inserted into drape 140. As shown, drape 140 is inverted to insert cap 130 through collar 442. FIG 5a shows drape 140 after it has been placed and secured onto cap 130. FIG 5b shows drape 140 after it has been placed over the remainder of spectral imaging apparatus 100, including handle 110 and connecting cable 112. In this embodiment, both tape 510 and tie downs 512 are provided to secure sleeve 444 of drape 140 onto spectral imaging apparatus 100. In another embodiment, either tape 510 or tie downs 512 can be used for this purpose. In yet another embodiment, the inner side of drape 140 includes an adhesive layer that enables drape 140 to temporarily adhere to spectral imaging apparatus 100. Thus, as shown in FIG. 4 and FIG. 5, cap 130 and drape 140 can be two separate pieces or they can be formed as a single unit that is later attached to each other. When attaching cap 130 to collar 442 of drape 140, a medical grade adhesive can be used.

Drape 140 may be a terminally sterilized clear plastic covering that fits over spectral imaging apparatus 100 and the length of cablel 12. Drape 140 may be made from a low density polyethylene (LDPE) film. Drape 140 typically is about three to five mm in thickness. Collar 442 is composed of material comparable to drape 140 to promote bonding and adhesiveness. Typically, collar 442 is a polyethylene socket to which the polyethylene sleeve 444 is attached. Collar 442 and sleeve 444 may be attached to each other by ultrasonic welding.

In another embodiment, a medical grade adhesive is used to attached the two components. Collar 442 is approximately 0.020 inches in thickness.

FIG. 6 shows a pouch 600 used for storing drape 140. Pouch 600 may be apoly-mylar/Tyvek pouch. FIG. 6 shows pouch 600 with only drape 140. FIG 6a shows pouch 600 containing drape 140 and cap 130 assembled together, as discussed above.

Various embodiments of a protective covering that includes a cap 130 and drape 140 have been described. These embodiments are typically used in operating room applications. Accordingly, cap 130 and drape 140 are sterilized via Gamma sterilization to reach a Sterilization Assurance Level (SAL) of 10^"6. For non-operating room applications, the above-mentioned cap/drape protective coverings can be used. However, FIG. 7 illustrates an alternative protective covering that can be used for non-operating room applications. FIG. 7 shows an exemplary embodiment of a shield 700 that is molded to fit over the objective end of probe 120 and protects spectral imaging apparatus 100 from splattered, splashed, or spilled liquids. Shield 700 includes a tapered portion 710 and an unsecured portion 720. Tapered portion 710 is formed and fitted to attach to the base of cap 130 after cap 130 has been placed onto probe 120. Unsecured portion 720 is designed to be wider than tapered portion 710, so that the region connecting tapered portion 710 to unsecured portion 720 (referred to as the "body" of shield 700) is formed to be projected over the front of spectral imaging apparatus 100 and guard the instrument from liquids. The body of shield 700, hence, covers the open end of cap 130, when installed, to extend the moisture protection to the top of spectral imaging apparatus 100.

As described with respect to cap 130 and drape 140, shield 700 is a disposable accessory. Shield 700 may be composed of a medical grade LDPE. Shield 700 can also be packed in polyethylene pouches similar to pouch 600, and can be sterilized via Gamma Radiation. However, since shield 700 is not designed for operating room applications, the sterilization requirements do not have to meet SAL 10^"6. Shield 700 maybe a separate piece of plastic that is joined to cap 130, typically with a medical grade adhesive. Alternatively, shield 700 is the same piece of plastic used to form cap 130.

While various embodiments of the present invention have been described above, it should be understood that theyhave been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

Claims

Whatls Claimed Is:

1. A sheath for covering a medical instrument, including a probe having a proximal end and a distal end, comprising: a sleeve adapted to cover a handle connected to the probe and adapted to cover the length of a cable connected to said handle; a collar coupled to said sleeve and formed to fit said handle; and a lens formed to fit the distal end of the probe and functionally attached to said collar.

2. A sheath of claim 1 , wherein said sleeve comprises clear plastic.

3. A sheath of claim 1, wherein at least one of said sleeve and said collar conforms to sterilization assurance level 10^"6.

4. A sheath of claim 1, wherein at least one of said sleeve and said collar is composed of polyethylene.

5. A sheath of claim 1 , wherein said collar is welded ultrasonically to said sleeve.

6. A sheath of claim 1, wherein a medical grade adhesive couples said collar to said sleeve.

7. A sheath of claim 1, wherein a medical grade adhesive attaches said lens to said collar.

8. A sheath of claim 1, further comprising a pouch for storing said sleeve and said collar.

9. A sheath of claim 1 , wherein said lens comprises an open end and a closed end, wherein a Luer lock is disposed at said open end, said Luer lock configurable to be threaded into the instrument.

10. A sheath of claim 9, wherein said Luer lock is configurable to be threaded into a focusing mechanism on the instrument, said focusing mechanism operable to move said lens with regard to the probe.

11. A shield for covering a medical instrument, including a probe having a proximal end and a distal end, the distal end having an attachable cap covering a portion of the instrument from the distal end to the proximal end, said shield comprising: a tapered end attachable to the distal end of the probe; and an unsecured end formed to be projected over the front of the instrument, wherein the region between said tapered end and said unsecured end provides a covering to protect the instrument.

12. A shield of claim 11, wherein the attachable cap comprises an open end and a closed end, wherein said tapered end covers an open end of the attachable cap so as to extend moisture protection to the top of the probe.

13. A shield of claim 11, wherein the shield is composed of low density polyethylene.

14. A shield of claim 11, wherein the attachable cap comprises an open end and a closed end, wherein a Luer lock is disposed at said open end, said Luer lock configurable to be threaded into the instrument.

15. A shield of claim 14, wherein said Luer lock is configurable to be threaded into a focusing mechanism on the instrument, said focusing mechanism operable to move the attachable cap with regard to the probe.