NZ612733B2 - Pump for sterilisation apparatus - Google Patents
Pump for sterilisation apparatus Download PDFInfo
- Publication number
- NZ612733B2 NZ612733B2 NZ612733A NZ61273312A NZ612733B2 NZ 612733 B2 NZ612733 B2 NZ 612733B2 NZ 612733 A NZ612733 A NZ 612733A NZ 61273312 A NZ61273312 A NZ 61273312A NZ 612733 B2 NZ612733 B2 NZ 612733B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- pump
- hose
- endoscope
- pump hose
- fluid
- Prior art date
Links
- 238000004659 sterilization and disinfection Methods 0.000 title claims abstract description 93
- 239000012530 fluid Substances 0.000 claims abstract description 113
- 239000007788 liquid Substances 0.000 claims abstract description 22
- 230000001954 sterilising Effects 0.000 claims abstract description 22
- 230000002572 peristaltic Effects 0.000 claims abstract description 11
- 238000005086 pumping Methods 0.000 claims description 17
- 230000011664 signaling Effects 0.000 claims 2
- 241000223221 Fusarium oxysporum Species 0.000 claims 1
- 238000007654 immersion Methods 0.000 claims 1
- 238000004140 cleaning Methods 0.000 abstract description 9
- 230000000249 desinfective Effects 0.000 description 108
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 42
- 238000010926 purge Methods 0.000 description 24
- 238000001514 detection method Methods 0.000 description 22
- 238000000034 method Methods 0.000 description 18
- 238000004891 communication Methods 0.000 description 7
- 230000001808 coupling Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 230000002829 reduced Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 241000153282 Theope Species 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 4
- 238000005859 coupling reaction Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 239000010935 stainless steel Substances 0.000 description 4
- 239000008399 tap water Substances 0.000 description 4
- 235000020679 tap water Nutrition 0.000 description 4
- KENZYIHFBRWMOD-UHFFFAOYSA-N 1,2-dichloro-4-(2,5-dichlorophenyl)benzene Chemical compound ClC1=CC=C(Cl)C(C=2C=C(Cl)C(Cl)=CC=2)=C1 KENZYIHFBRWMOD-UHFFFAOYSA-N 0.000 description 3
- 239000012141 concentrate Substances 0.000 description 3
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229920002574 CR-39 Polymers 0.000 description 2
- OSVXSBDYLRYLIG-UHFFFAOYSA-N Chlorine dioxide Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 2
- 230000005355 Hall effect Effects 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 230000003247 decreasing Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000008233 hard water Substances 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 239000008234 soft water Substances 0.000 description 2
- 238000010200 validation analysis Methods 0.000 description 2
- 101700051609 ADC2 Proteins 0.000 description 1
- 239000004155 Chlorine dioxide Substances 0.000 description 1
- 241000862969 Stella Species 0.000 description 1
- 210000001138 Tears Anatomy 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 235000019398 chlorine dioxide Nutrition 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000000875 corresponding Effects 0.000 description 1
- 230000001419 dependent Effects 0.000 description 1
- 230000001809 detectable Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 description 1
- 150000008040 ionic compounds Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006011 modification reaction Methods 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 230000036961 partial Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 235000015108 pies Nutrition 0.000 description 1
- 150000003071 polychlorinated biphenyls Chemical class 0.000 description 1
- 230000000717 retained Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 239000008223 sterile water Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001960 triggered Effects 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
- A61B90/70—Cleaning devices specially adapted for surgical instruments
- A61B2090/701—Cleaning devices specially adapted for surgical instruments for flexible tubular instruments, e.g. endoscopes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
- A61L2/16—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using chemical substances
- A61L2/18—Liquid substances or solutions comprising solids or dissolved gases
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L2202/00—Aspects relating to methods or apparatus for disinfecting or sterilising materials or objects
- A61L2202/10—Apparatus features
- A61L2202/15—Biocide distribution means, e.g. nozzles, pumps, manifolds, fans, baffles, sprayers
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L2202/00—Aspects relating to methods or apparatus for disinfecting or sterilising materials or objects
- A61L2202/20—Targets to be treated
- A61L2202/24—Medical instruments, e.g. endoscopes, catheters, sharps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/0009—Special features
- F04B43/0081—Special features systems, control, safety measures
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/0009—Special features
- F04B43/0081—Special features systems, control, safety measures
- F04B43/009—Special features systems, control, safety measures leakage control; pump systems with two flexible members; between the actuating element and the pumped fluid
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
- F04B43/1238—Machines, pumps, or pumping installations having flexible working members having peristaltic action using only one roller as the squeezing element, the roller moving on an arc of a circle during squeezing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
- F04B43/1253—Machines, pumps, or pumping installations having flexible working members having peristaltic action by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
- F04B43/1253—Machines, pumps, or pumping installations having flexible working members having peristaltic action by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing
- F04B43/1261—Machines, pumps, or pumping installations having flexible working members having peristaltic action by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing the rollers being placed at the outside of the tubular flexible member
Abstract
Disclosed are a peristaltic pump (2); sterilisation apparatus and method of using the sterilisation apparatus. The present peristaltic pump (2) ensures that a medical instrument such as an endoscope is sufficiently sterilised and not damaged whilst being cleaned unsupervised. The peristaltic pump (2) is suitable for use in sterilising the lumen of an endoscope in a sterilisation compartment of a sterilisation apparatus. The pump (2) comprises a flexible pump hose (44); a motor-driven impeller (46); first and second electrodes (52a, 52b); means for applying a voltage across the first and second electrodes (52a, 52b); and means for measuring an electrical property between the conductive fittings (53a, 53b). The flexible hose (44) includes an outlet end and an inlet end. The electrically conductive fittings (53a, 53b) are disposed at each end and are in contact with fluid in the pump hose (44). The motor-driven impeller (46) is disposed in relation to the pump hose (44) such that when the impeller (46) is driven it will intermittently bear against the pump hose (44) so as to bring the internal walls of the pump hose (44) together. The first (52a) and second (52b) electrodes are in contact with the conductive fittings (53a, 53b) at, respectively, the outlet and inlet ends of the pump hose (44). The outlet end of the pump hose (44) is connected to one end of an endoscope having a lumen to be sterilised and immersed in a conductive sterilant liquid in the sterilisation compartment. The inlet end of the pump hose (44) is in fluid connection with the sterilant liquid in the sterilisation compartment. The only conductive path, apart from via the pump hose (44), that will exist between the first (52a) and second (53b) electrodes when the pump hose (44) is operated will be via the lumen of the endoscope. ) is suitable for use in sterilising the lumen of an endoscope in a sterilisation compartment of a sterilisation apparatus. The pump (2) comprises a flexible pump hose (44); a motor-driven impeller (46); first and second electrodes (52a, 52b); means for applying a voltage across the first and second electrodes (52a, 52b); and means for measuring an electrical property between the conductive fittings (53a, 53b). The flexible hose (44) includes an outlet end and an inlet end. The electrically conductive fittings (53a, 53b) are disposed at each end and are in contact with fluid in the pump hose (44). The motor-driven impeller (46) is disposed in relation to the pump hose (44) such that when the impeller (46) is driven it will intermittently bear against the pump hose (44) so as to bring the internal walls of the pump hose (44) together. The first (52a) and second (52b) electrodes are in contact with the conductive fittings (53a, 53b) at, respectively, the outlet and inlet ends of the pump hose (44). The outlet end of the pump hose (44) is connected to one end of an endoscope having a lumen to be sterilised and immersed in a conductive sterilant liquid in the sterilisation compartment. The inlet end of the pump hose (44) is in fluid connection with the sterilant liquid in the sterilisation compartment. The only conductive path, apart from via the pump hose (44), that will exist between the first (52a) and second (53b) electrodes when the pump hose (44) is operated will be via the lumen of the endoscope.
Description
PUMP FOR STERILISATION APPARATUS
The present invention relates to a pump for a sterilisation apparatus, sterilisation
apparatus including the pump, and a method of use of the apparatus. The
tus is particularly for use in ising medical ments such as
endoscopes.
Endoscopes must be thoroughly d and sterilised after use on one patient,
before use on another patient. A number of washer-disinfectors are known for
carrying out such cleaning and sterilising procedures.
discloses isation apparatus which includes a tray for
receiving an item to be sterilised, and a drain having a valve which is operated by
an electronic controller. The controller is configured to operate opening and
closing of the drain valve to control exposure time of equipment to sterilisation fluid
in the tray. The controller can also keep a log of various parameters relating to
sterilisation cycles, including sterilisation times and dates, and details of
equipment and operators.
For endoscopes which have a lumen, ie, an internal cavity running along the
length of the endoscope, the tus may e a pump for pumping sterilising
fluid into one end of the lumen, through the ope, and out the other end so
as to sterilise internal surfaces in addition to external surfaces. Insufficient
sterilisation may result if the lumen is blocked, or if the pump fails to cycle the
sterilising fluid through the lumen for any other reason.
Examples of prior art peristaltic pumps are described in EP 0 745 400 and
US 2004/0265154.
Y OF THE INVENTION
Aspects of the invention are specified in the independent claims. Preferred
_ 2 _
(followed by page 2a)
features are specified in the dependent claims.
In accordance with a first aspect of the t invention, there is provided a
peristaltic pump for use in sterilising the lumen of an endoscope in a sterilisation
compartment of a sterilisation apparatus, the pump comprising: a flexible pump
hose having an outlet end and an inlet end, and an electrically tive fitting at
each end in contact with fluid in the pump hose; a motor-driven impeller disposed
in relation to the pump hose such that when the impeller is driven it will
intermittently bear against the pump hose so as to bring the al walls of the
pump hose together; a first ode in contact with the conductive fitting at the
outlet end of the pump hose, and a second electrode in contact with the
conductive fitting at the inlet end of the pump hose; means for applying a voltage
across the first and second electrodes; and means for measuring an electrical
property between the conductive fittings; n when the outlet end of the pump
hose is connected to one end of an endoscope having a lumen to be ised and
immersed in a conductive sterilant liquid in the sterilisation tment, and the
inlet end of the pump hose is in connection with the sterilant liquid in the
isation compartment, the only conductive path that will exist between the first
electrode and the second electrode when the pump is operated, apart from via the
pump hose, will be via the lumen of the endoscope.
The term ‘comprising’ as used in this specification and claims means ‘consisting at
least in part of’. When interpreting statements in this specification and claims
which include the term ‘comprising’, other features s the features prefaced
by this term in each statement can also be present. Related terms such as
‘comprise’ and ‘comprised’ are to be interpreted in a similar manner.
In accordance with a second aspect of the present invention, there is provided a
sterilisation apparatus comprising a container having a sterilisation compartment
for receiving an item to be sterilised, and a peristaltic pump of the first aspect,
for pumping a sterilant liquid to and from the sterilisation compartment.
_ 2a _
(followed by page 3)
In accordance with a third aspect of the present invention, there is provided a
method of using the apparatus of the second aspect for sterilising an ope
having a lumen, the method including the steps of: placing the endoscope in the
sterilisation compartment; connecting the outlet end of the pump hose to one end
of the endoscope to establish a fluid connection between the pump hose and the
lumen; g the sterilisation compartment with sterilising liquid; providing the inlet
end of the pump hose with an inlet hose, and disposing the free end of the inlet
hose in the sterilising liquid within the isation compartment; operating the
pump so that the impeller causes fluid to be pumped through the lumen of the
endoscope and causes fluid to be drawn into the free end of the inlet hose; and
measuring an electrical ty n the conductive fittings of the pump hose.
The invention provides a pump that enables a sterilisation process to be carried
out correctly unsupervised, so that sterilised medical instruments are not damaged
and are fully sterilised safe for use, or which will signal an error condition in the
event of a blockage or other malfunction1.
In prior art peristaltic pumps, at least one roller is always pinching the pump hose,
and at the mid—point of the rotor’s rotation the pump hose is pinched at two places.
In an ment of the present invention, there is at least one point during the
rotation of the rotor when the pump hose is not substantially pinched so that a fluid
path exists through the pump hose from the inlet end to the outlet end.
1 This advantage and other stated advantages
are advantages of at least preferred embodiments of the invention. It is not
necessary for every embodiment of the invention to meet each stated advantage.
W0 2012/110313
_ 3 _
BRIEF PTION OF THE GS
The invention will now be further described, by way of e only, with
reference to the following drawings in which:
Figure 1 shows apparatus in accordance with an embodiment of the
invention;
Figure 2 is a front view of the pump shown in Figure 1, with lid open;
Figure 3 is a rear view of the pump of Figure 2 with lid closed;
Figure 4 is a top view of the apparatus of Figure 1 with the pump lid open;
Figures 5 and 6 are top views of the pump of Figure 2 at different stages of
the pumping process;
Figure 7 is a sectional view of the pump of Figure 5 along the line A—A;
Figure 8 is an inside rear view of the pump of Figure 1;
Figure 9 is a graph of variation in motor load current under different
operating conditions;
Figure 10 is a view of the pcb of Figure 8;
Figures 11-13 are graphs showing electrical signals for an embodiment of
the invention under different conditions;
Figure 14 is a tic view of apparatus in accordance with another
embodiment of the invention;
WO 10313
_ 4 _
Figure 15 shows an equivalent electrical circuit for the apparatus of Figure
14;and
Figures 16—33 are graphs showing various aspects in accordance with
operation of embodiments of the invention;
Figure 34 shows an embodiment of an outlet tube for use in an embodiment
of the invention;
’IO Figures 35-36 are graphs illustrating waveform and conductivity values for
sterilant s in accordance with aspects of the invention; and
Figure 37 shows an alternative hose set for use in an embodiment of the
invention.
DETAILED DESCRIPTION
Sterilisation apparatus 10, shown in Figure 1, comprises a tray 6, an electronic
controller 4 and a peristaltic pump 2. The tray 6 and details of the operation of the
controller 4 are described in . In addition to the features of the
prior art controller, the present ller is ured to control the pump 2 and
receive data from it.
The tray 6 includes a sterilisation compartment 8 defined between an inner wall 7
and an island 14. In use, the sterilisation compartment 8 receives an item to be
sterilised, for example an endoscope 16. The sterilisation compartment 8 is
surrounded by an overflow compartment 12 which enables the sterilisation
compartment 8 to be completely filled with ising fluid without the fluid ng
out of the tray 6. The sterilisation compartment 8 is ted to a drain outlet 28
via a valve (not shown) in the controller (4), which can be programmed to operate
the valve after a pre—set time to allow drainage of sterilising fluid from the
sterilisation compartment. The controller 4 has program buttons 32 to input
W0 2012/110313
_ 5 _
instructions and a display 30 for displaying information about the sterilisation
process or prompting user input.
The pump 2 has a lid 24, an outlet hose 18 and an inlet hose 20. The term ‘hose
set’ will be used herein to refer to the outlet hose 18, inlet hose 20 and any
associated fittings or couplings. In this example, the outlet hose 18 is ted to
an endoscope 16 via a tor 22. The endoscope 16 has a central lumen, and
there is an open fluid path between the outlet hose 18 and the lumen of the
endoscope 16. The outlet hose 18 and inlet hose 20 are disposed through a cable
opening 28 in an external wall of the tray 6. The free end of the inlet hose 20 lies
on or adjacent to the bottom of the sterilisation compartment 8, so that, in use,
sterilising fluid will be drawn into the inlet hose 20 by operation of the pump 2,
while fluid is pumped through the lumen of the endoscope 16. Each of the outlet
hose 18 and inlet hose 20 may optionally be provided with a filter (not shown) to
remove particulates from the circulating fluid.
Referring now to Figure 2, the pump 2 includes a pump hose 44, in this example
made of a flexible silicone rubber material, provided with electrically conductive
fittings or couplings 53 at each end. In this embodiment, the fittings 53 are made of
stainless steel and e conductive hose barbs which are a push-fit for the ends
of the pump hose. The fitting 53a at the outlet end of the pump hose 44 is ed
with a female connector 50 and the fitting 53b at the inlet end of the pump hose 44
is provided with a male connector 48. The connectors 50, 48 are connected,
respectively, to the outlet hose 18 and the inlet hose 20. The conductive fitting 53a
at the outlet end of the hose pump 44 is in electrical contact with a first electrode
contact clip 52a, and the conductive fitting 53b at the inlet end of the hose pump
44 is in electrical contact with a second electrode contact clip 52b. It will be
understood that it is not ary that the conductive part of the fitting be in direct
t with the end of the hose. Providing that the conductive part is in contact
with fluid passing through the hose, it could be located within or on a non—
conductiver part of the fitting which is fitted to the hose.
W0 2012/110313
_ 5 _
A motor—driven impeller 46, which in this e is a rotor (‘pump ’), is
disposed in relation to the pump hose 44 such that when it is driven it will
intermittently bear against the pump hose 44 at at least one point so as to bring
the al walls of the pump hose together, as will be described in more detail
with reference to Figures 5 and 6.
The pump 2 may have one or more control buttons and one or more display
means for ing information about the state of the pump. In this embodiment,
the pump 2 has a standby button 36, a power LED 38, a Bluetooth LED 40, and a
pump/fault LED 42. This embodiment of the pump 2 also es e 3) a
reset switch 54, a USB socket 56 for firmware updates, and a powerjack 58.
As shown in Figure 4, clockwise rotation of the impeller 46 drives fluid out of the
pump hose 44 through the outlet hose 18 and the lumen of the endoscope 16 in
the sterilisation compartment 8. At the same time, fluid is drawn into the free end
of the inlet hose 20 and through the pump hose 44.
Referring now to Figure 5, when the impeller 46 is turned about its spindle 60 it
intermittently bears against the pump hose 44 at a re point 62 so as to bring
together the internal walls of the pump hose. In a preferred embodiment, the
internal walls are brought together so as to form a substantially fluid-tight seal. It
will be understood that it is not essential that intermittently there is no fluid
ication between either side of the pressure point 62. It is sufficient that an
electrical property is substantially changed when the impeller 46 squeezes the
internal walls of the pump hose 44 together. The ical property may for
example be resistance, impedance, voltage or current when the pump hose 44
contains an electrically conductive fluid, which aqueous sterilising fluids typically
are. Referring to Figure 6, further rotation of the impeller 46 moves it away from
the pressure point 62, and permits the resilient walls of the pump hose 44 to revert
to an open configuration wherein fluid at the outlet end is in fluid communication
with fluid at the inlet end within the pump hose 44.
W0 2012/110313
_ 7 _
By determining (within a ied tolerance level) whether and to what extent a
tive path exists between the electrode clips 52a, 52b, it can be determined
whether a conductive sterilising fluid is being cycled through the outlet hose 18
and inlet hose 20, for example via a lumen of an endoscope 16. During normal
pumping, a conductive path will exist between the electrodes 52 via sterilising fluid
in the outlet hose 18, in the lumen of the endoscope 16, in the sterilising
compartment 8, and in the inlet hose 20. in this example, the tor 22 is non—
conductive so that when connected to the endoscope, the only conductive path
between the inside of the outlet hose 18 and the inlet hose 2O (apart from via the
1O pump hose 44) is via the lumen of the endoscope 16. An electrical property
measured between the electrodes 52 will have a substantially constant value.
However if this conductive path is interrupted, for example by a blockage in the
lumen or by the free end of the inlet hose 20 being above the level of ising
fluid in the sterilisation tment 8 so that air is sucked in, the only major
conductive path will be via the pump hose 44. In this event, the electrical property
that is measured between the tive fittings b will be affected by the
internal fluid path within the pump hose 44. If, for example, a voltage is applied to
the electrodes 52a,52b, and resistance is the measured electrical property, its
value will increase as the impeller 46 squeezes together the internal walls at
pressure point 62. if the pressure is such as to e a complete internal seal,
the ed resistance will intermittently rise ntially. If current is
measured, its value will intermittently fall substantially. It will be understood that
various electrical measurements may be made to determine whether the only
major conductive path is via the fluid within the pump hose 44. In a preferred
embodiment, the circuit used for the sensing is an oscillator function as opposed to
a direct DC resistance function to avoid electrolysis occurring at the conductive
fittings 53. if a DC resistance is used then over time one of the stainless steel
fittings 53 is liable to h and may build up an insulating oxide layer.
it the measured electrical property is determined to be fluctuating beyond a
specified range or limit, the apparatus may be programmed to signal an error
condition. Various operating modes and error situations are summarised below.
Normal Operation
As the rotor s and when connected to the isation compartment filled with
sterilant solution, the conductivity across the two conductive gs 53 alternates
between two states. A short flow (low resistance) within the pump hose 44 and a
long path (high resistance) out through the tion via the lumen of the
endoscope 16 and h the solution within the sterilisation compartment 8. The
frequency of this state change allows determination of the pump speed as the
“IO controller 4 knows the state will change twice in each full rotation. in addition, loss
of conductivity through either the long path or the short path tells the controller 4
where solution is present in the system.
No Solution
if no solution is present, either because the pump (due to a blocked inlet hose 20)
or within the sterilisation compartment 8 se it has not be adequately filled)
one of the states will register an open circuit.
Disconnected instrument
At the start of the cycle, the pump operates, the initial state is with air throughout
the tube set, endoscope and pump hose, so there is no conductivity within a full
rotation. As the pump primes solution enters the tube set and the pump enters a
state where there is no conductivity when the rotor is not in the mid—point position
(Figure 6). The number of rotations is now counted until there is conductivity
across the sterilisation compartment at which point the controller has determined
that solution has reached the conductive lumen connector on the endoscope. At
this point the controller reverses the pump and counts the rotations back until the
conductivity across the sterilisation compartment is lost. This should happen
ately as the lumen at this point is full of air which will be drawn into the tube
set. If conductivity is not lost then the controller has determined that solution is
W0 2012/110313
_ 9 _
being drawn in from the lumen connector and therefore it must be nected
from the endoscope.
Blocked Instrument
In the event of a blocked instrument (endoscope) there are two methods that the
controller can use to detect failure. In the case of a full blockage the pump will not
be able to release the trapped air within the tube set. Solution will never reach the
lumen connector and therefore the controller will never measure conductivity
across the sterilisation tment.
in the event of a partial block it is possible that enough air will be pushed past the
blockage and the pump will be able to pump solution up to the lumen connector.
However, once solution reaches the blockage the loads on the pump will increase
significantly as the pump tries to counter the pressure build-up in the tube set.
Once a cut—off pressure is d (for example 172 kPa) the t load on the
pump motor will have increased to a pre-set old within the controller. The
controller can then determine that the pump pressure is beyond the limits set by
endoscope manufacturers and abort the cycle.
Pump Failure
In the event of a pump failure the conductivity measured between the two
conductive unions will remain constant. At the start of a cycle, if the pump fails to
operate, the controller will see no conductivity because the tube set is full of air. If
the pump fails mid-cycle the controller will see either conductivity across the
solution in the pump tube or the tivity across the solution in the isation
compartment but they will not be alternating. This remains true of either electrical
or mechanical failure of the pump.
WO 10313
_ 10 _
Excessive Wear in the Pump Components
Peristaltic pumps have a finite pump hose life. The materials used over time lose
their y to return to shape after the rotor has passed. This reduces pump
efficiency as the volume of solution pumped in each pump rotation drops. In
extreme cases the pump hose can fracture or split, resulting in total pump failure.
The controller has a number of methods to determine and predict these failures.
ed Pump Hose Lifetime
In the present example the pump has a maximum pump hose lifetime of about 100
hours (approximately 3000 cycles as the pump only operates for approximately
two minutes per . At this point a warning will be shown to the operator at the
start of each cycle. For the next 10 cycles it is possible to clear the warning and
’15 continue with the cycle. However, at the 11‘“ operation, further cycles will not be
le until the pump hose is replaced and a specific alarm reset procedure
documented with the replacement parts is med.
Pump Hose Wear Detection
The controller can determine wear in the pump hose through a combination of
events. As the pump hose wears, the pump efficiency diminishes. At the start of a
cycle, when the pump is purging air to draw in on, the duration of pump
operation before conductivity between the two conductive fittings will increase.
As the material memory of the pump tube diminishes the tube tends to flatten and
remain at its compressed shape even when not in contact with the ends of the
pump rotor. The effort required by the motor to rotate the rotor drops, resulting in a
current load drop on the motor controller.
By monitoring these variables and counting pump error states it is possible to
t pump hose failure even in the event that it happens before the preset hose
_ 11 -
operation lifetime is exceeded.
Pump Hose Failure Detection
If the pump hose fails completely (rupture or split) then the controller will see one
of two possible error ios. If the tube fails near or at the inlet union then air
rather than liquid will be drawn into the pump; then at the start of the cycle the
ller will not register any conductivity across the conductive fittings; this
will generate a no solution error. The documented troubleshooting steps for this
error will include a check of the pump hose for damage.
If the pump hose fails at any point beyond the inlet union then the pump will be
able to draw liquid but it will end up pumping this into a sump created within the
bottom of the pump body rather than to the outlet connection. This sump will
create a path of conductivity across the pump unions which will lack the pump
frequency as seen in normal pump operation. The controller can determine that
the pump rotor is still rotating by monitoring the current load. This event will r
a pump failure mode.
Failure to Drain
At the end of a sterilisation cycle the pump resumes operation to purge the
instrument's lumen of solution. By monitoring conductivity across the pump unions
the ller can monitor the air being pumped into the pump hose. If the
sterilisation compartment is empty then the long path of conductivity in the pump
cycle will already be open.
As the pump draws air from the sterilisation compartment pickup the pump hose
will become empty and the controller will have lost conductivity through both the
long and short paths of the pump cycle.
By monitoring current load to ensure the pump is still ing, the controller can
_ 12 _
operate for a pre-set time threshold to confirm that air has been pumped through
the lumen channel and therefore that the endoscope has been purged of solution.
The tive result of these detectable events is that the controller can provide
full cycle validation within the system. tivity of the solution is always
d, even in the case of high purity water,
The steriliant, for example Fuse for Instruments adds ionic compounds which
result in a high level of tivity regardless of water supply, as will be
discussed in more detail later. Fuse is a trade mark of Tristel PLC.
In one embodiment, the lid 24 is provided with a magnet 34, and a Hall effect
sensor (not shown) is provided on the PCB 70. When the lid 24 is lifted or
removed for maintenance of the pump tube or for other s, the Hall effect
sensor cannot detect the magnet 34 and will not allow the pump head to rotate,
providing a kill switch function.
Referring now to Figures 7, 8 and 10, internal details of the embodiment of the
pump 2 are illustrated. The pump 2 has a s 74 on which is mounted a cap
member 64 and a base member 76 housing a battery pack 78. A motor 72 drives
the impeller rotor 46 within a pump chamber 66 via a gearhead 68. A PCB 70
includes circuitry for applying a voltage to the electrodes 52 and measuring an
electrical ty. The PCB 70 has mounted on it the reset switch 54, USB socket
56 and powerjack socket 58. The rechargeable battery pack 78 is located in a
recessed portion 82 of the PCB. A Bluetooth module 80 enables automatic
communication with the controller 4.
Example Operation
When the controller and pump are used together using a Bluetooth communication
link, with the controller operating as the master unit, once communication is
established the system is ready to commence a disinfection cycle as ded
from the controller.
W0 2012/110313
_ 13 -
There will be various operation ses depending on the type of disinfectant
used, which will require different firmware. Disinfectant is first pumped through the
opic device using the pump for a given period of time, for example 1
minute. At the completion of the cycle water nally sterile water) and air will be
used to flush out any disinfectant e.
The power status LED 38 nt to the power button will indicate the following:
0 Power ON Green - constant
1O 0 Battery Low Green - off intermittently
0 Charge Battery Yellow/Orange - flashing on and off
0 Battery on charge Yellow/Orange — momentarily flashing Green
0 Battery Full on charge Green — constant
0 Product shutdown OFF
The Bluetooth Status LED 40 will indicate the status of the Bluetooth
communication link:
0 Bluetooth search mode Blue — flashing (Waiting for controller to link to pump)
0 Bluetooth link established Blue — Constant (controller ication with pump)
0 No Bluetooth activity OFF - No communication link
The pump Status LED 42 will indicate the pump operation and pending automatic
control:
0 pump operating Green — constant
0 pump ready in standby mode Green — flashing momentarily
0 pump e Red — flashing
0 System Failure Red — Constant
o No automatic mode OFF
Bluetooth Pairing
A Bluetooth communication pairing mechanism for the controller and pump will
operate. This is achieved by first switching on the pump 2 and then switching on
_ 14 _
the controller 4 and pressing the ‘ON’ button again, holding it for 3 seconds to
initiate the pairing process. Should the pump 2 need servicing then an
alternative pump may be paired with the controller.
Selecting controller operating mode
Press the controller ‘On’ button twice to te the select menu;
Option 1 - controller (Standalone operating mode)
Option 2 - controller + pump (Paired operation with controller and pump)
Option3 - Bluetooth Download (Download ller Event file to PC using
oth com’s)
Press ‘ON’ button to scroll down to the desired option ‘StellaCONTROLLER +
pump’.
Either option 1 and 2 will be saved to memory as the default when the controller is
switched on.
To change this default repeat Stage 1.
Wait 8 seconds and the controller will ce into the chosen mode of
operation.
Standard operation
Press the controller ‘ON’ button once to switch it on.
Press the pump ‘Standby’ button 36 to switch it on.
The pump Green Power LED 38 will glow.
The controller will display the StellaTM Logo for 1 second.
The Bluetooth icon will appear while the controller 4 searches for the paired pump
2.
The pump blue LED 40 will flash during Bluetooth search mode.
When the Bluetooth com link is established “Read Instructions” icon will appear for
3 seconds.
The pump blue LED 40 will glow ntly.
The controller ball valve will close, preventing drainage of fluid from the
sterilisation tment 8. Allow 1 minute, after the valve has opened from the
last cycle, for fluid to drain before proceeding with the next disinfection cycle.
_ 15 _
An animated graphic with “ADD CLEANED lNSTRUMENT” will appear for 3
seconds.
The pump Motor green LED 42 will start flashing to indicate automatic pump
control.
An animated jug pouring graphic with “ADD DISINFECTANT” will appear.
If moisture is detected in the fluid sensor as valve is closed, then “START CYCLE”
will also appear to prompt the user to manually activate the disinfection cycle by
pressing the ON button once the sterilisation tment is full.
“IO Disinfection
The operator adds disinfectant (sterilising fluid) into the isation compartment
When the sterilisation compartment has filled with ectant the controller Fluid
Sensor (not shown) is triggered.
The disinfectant timer starts. A typical timing is 5 minutes, but times may be varied
according to the nature of the sterilising fluid and the item of equipment to be
sterilised.
A pie graphic appears to count down and “DISINFECTING” on the controller
display 30.
The pump 2 operates for 1 minute g disinfectant through the ope
The pump Motor LED 42 will glow constant green.
The pump monitors disinfectant pumped through the endoscope.
An animated circulating arrow s on the top right corner of the controller
display 30 to indicate that the pump is operating.
When the pump stops the animated arrow remains stationary.
Drain Cycle
The ection cycle expires:
The CONTROLLER valve automatically opens to drain the fluid.
After 10 seconds the pump operates, pumping air into the endoscope to expel
disinfectant residue.
_ 15 _
The pump verifies that air is pumped through the endoscope for 1 minute.
An ed circulating arrow s on the top right corner of the controller
display while the pump is operating.
When the pump stops the animated arrow halts.
After 1 minute the controller sounds a beep every 30 seconds.
The pump stops.
The Motor LED 42 stops glowing.
A text prompt appears “COMPLETE” with a tick graphic ating with text
“CONFIRM REMOVAL OF INSTRUMENT”.
’10 The operator presses the “ON” Button to acknowledge removal of the instrument.
If the valve fails to open then the display 30 displays “REMOVE lNSTRUMENT”
and a constant harsh sound will continue until the controller is shut down.
Shutdown
’15 The operator presses the “OFF” button or the auto shutdown occurs after 15
minutes.
The controller ball valve stays open.
The pump shuts down.
The controller switches off powering down.
Various e modes may be displayed in the event of failure of the pump or the
controller, and various y charge modes may be displayed.
The load current of the pump motor 72 can be monitored by the pump system to
ascertain overload conditions. Such conditions may occur when the pump is in use
as a result of a blockage in the hose or in the endoscope. The base load current
will be reasonably consistent while air is pumped through the hose initially;
whether the hose is clear or blocked the load current is typically the same, with
slightly higher peak t.
When disinfectant is present in the hose and there is a blockage t in the
outlet hose 18 or endoscope 16 the pump motor current will increase (see
_ 17 _
Figure 9). This waveform is measured at the Control Board Micro ADC2 Analogue
Input (PF2). The motor typically draws a load t of about 250 mA (1V Avg)
when pumping air or sterilising fluid through the ope. When a ge
occurs the current increases to approximately 850 mA (1.4V Avg). Under severe
conditions the pump will almost stall.
With a stalled pump a Hardware Current Limit will limit the current to 450 mA
(1.8V).
Failure modes:
1O - A stalled pump motor load current will result in a flat signal level of 1.8V (450mA)
- In the event of a blocked instrument or hose the motor current signal level will be
1.4V average (350 mA)
. With typical ion while air is being pumped or water is g freely the
pump motor current signal is 1V on average (250 mA).
- The current load old for blockage failure sets the trip after 3 seconds for
300 mA load (1.2V Average).
- The current load threshold for a stalled motor sets the trip level after 2 seconds
for 400mA load (1.6V).
2O Referring now to Figure 14, an alternative embodiment of the invention uses a
conductive Luer—lock tor 22 to connect the free end of the outlet hose 18 to
the Luer inlet of the endoscope 16. The inlet hose 20 is provided with an inlet
fitting 118 which includes a strainer to remove particulates. The strainer may be
made of metal, notably stainless steel. In one embodiment, the strainer includes a
metal (preferably stainless steel) weight to ensure that it is submerged correctly.
The system can detect that the connector 22 has correctly ted to the Luer
fitting on the endoscope 16 or has not unconnected. This is done by pumping
liquid, at the beginning of a cycle, through the tube set until it reaches the
connector 22. At this point the current 116 is detected via the inlet hose 20 via
fitting 118 and the outlet hose connector 22. Once this current 116 is detected, the
pump reverses, ng the pump turns that it used to reach the endoscope 16.
When the pump turns have been counted the pump should encounter air sucked
W0 2012/110313
—18-
out of the dry lumen of the endoscope 16. This air can be detected by loss of
current, thus determining that the lumen is connected and present. If, at the end of
the counted pump turns, the current is still present then liquid has entered the tube
set which could only have come from a loose or disconnected Luer look. This
would indicate an UNHOOK and register a fail. An equivalent electrical circuit is
rated in Figure 15 for a voltage source X-Y applied via the ode contact
clips 52. An ative current path 114 through the pump hose 44 is intermittently
interrupted by closure of the pump hose by the rotor 46, allowing the current 116
to be distinguished.
A r ment of the hose set is shown in Figure 37. Here, the outlet hose
18 is in two parts, 18a and 18b, which are ted by a conductive joint 120.
This arrangement ensures that the conductive path in the sterilisation
compartment is closed slightly prior to the liquid ng the lumen of the
connected endoscope or other instrument. This compensates for inertia-induced
overrun of the rotor 46 of the pump 2. In addition it provides a conductive path
from the liquid in the tube set to the liquid in the sterilisation compartment in the
event that the lumen connection on the instrument is made of a non—conductive
material.
An example of the fluid signal is shown in Figure 11. The peak signal 112
represents the conductive path through the pump hose 44, which is about 8% of
the rm duty cycle. The duty cycle time is estimated A = (3.15/V - 0.03)
seconds, where V motor is the applied pump motor terminal voltage. The pump
rotor speed is estimated (n = 12.5 x V motor) rpm. Different liquids will have
different electrical property values. For example, for Stella FuseTM sterilising fluid,
the peak value 112 is about 1V, and the base value for the conductive path 116 is
about 0.38 V. Corresponding values for water are respectively 0.6 V and 0.2 V.
The trough portion of this rm represents the conductive path though the
hose—set, starting from the metal outlet hose coupling (X), then through the metal
hose coupling 22 on the endoscope 16, through the fluid in the sterilisation
_ 1g _
compartment 8 then through the intake filter 118 to the metal intake hose coupling
(Y). The minimum level (0.08V) is the measured level for no fluid, a circuit design
feature that can be used by the system to m the fluid sensor circuit is
operating.
With the pump hose filled with water the peak signal, the t path through the
pump-hose, measures ~ 0.6V (A — Figure 13) and the trough signal level, the
conductive path 116 through the hose—set, measures ~ 0.2V (B — Figure 13). V\fith
no disinfectant present, while the tray is empty or air pocket is present in the
1O hose—set, the trough signal level is typically 0.08V (C — Figure 13). For Stella Fuse
disinfectant the pump-hose peak measures ~1V and the and hose-set measures
~O.38V. These levels will also depend on mineral content in the water and
alternative disinfectant such as Cidex OPA.
Minimum Pump Speed @ 5Vdc (5O — 60rpm)
The waveform illustrated in Figure 12 is at the m minimum pump speed
(5V) with water pumped through the hose-set. The or each roller 46 opens the
pump hose at a duty cycle ~ 600ms. With two rollers 46 the peak will appear twice
for each pump head revolution, which is ~ 52 - 60rpm @ 5Vdc. This is the
2O minimum speed ement to ensure the pump hose 44 will be primed with fluid,
at 3Vdc the pump may not prime should it be elevated more than 100mm above
the intake filter fluid level. This is the result of air back-feeding through the pump
hose 44 as it is momentarily opened when monitoring the conductive path 114
through the pump hose.
Prime pump speed @ 7Vdc (80— 85 rpm)
To ensure the pump hose 44 is well primed the optimum pump speed needs to
operate a margin above minimum pump speed and in this ment it is
recommended to operate the pump at 7Vdc (~80 - .
Figure 13 illustrates a signal when the sterilising compartment is beginning to drain
empty after 200ms, g the conductive path 116 through the endoscope
_ 20 _
ng and intake filter. The peak signal (A) will continue to appear for
approximately 2 to 3 pump revolutions (4 to 5 peaks in the fluid sensor waveform)
before air begins to pump though the intake hose and purge out residue from
inside the endoscope.
Nominal Pump speed @ 12Vdc (140 -150rpm)
The nominal ing speed of the pump is 12Vdc, which provides a good margin
above minimum disinfectant flow rate. For an endoscope of small Luer Channel
size, eg $0.5mm this speed may reduce to 7 — 8Vdc.
Maximum Pump speed @ 24Vdc (270 - BOOrpm)
To purge the endoscope clear of disinfectant the pump momentarily operates at
maximum speed to create maximum air drag and remove large al
disinfectant droplets. Once this is achieved the air speed can be reduced, (nominal
speed of 12Vdc) to dry out any further moisture and condensation. In this
example, maximum speed is achieved with applied motor voltage 24Vdc, which is
~27O - 310rpm.
Waveform monitoring
Retained in the system memory are several base line parameters used to help
monitor and process the fluid signal waveform. These points include an average
value for the peak signal Figure 13(A), for the fluid path through the pump hose,
the average value of the fluid path through the hose-set (B) and the average value
for the base level for no fluid t (C).
The conductive properties of disinfectant and water differ therefore two base line
parameters are required for both the disinfectant and rinse water for signal levels
(A) and (B), as a result five base line parameters are required. These levels will
begin as default values in firmware when installed and will slowly integrate towards
the e levels over the product me, ng for slight wear and tear of the
pump mechanism and water chemical composition.
_ 21 _
These five base line parameters include;
The Peak value when Disinfectant is g through the pump hose (DP)
Figure 16 (A)
The Peak value when Rinse water is passing through the pump hose (RP)
Figure 16 (A)
The Average value for Disinfectant passing through the hose-set (DA)
Figure 16 (B)
The Average value when Rinse water is passing through the hose—set (RA)
Figure 16 (B)
1O The Average value when No fluid is passing through the hose-set (NA)
Figure 16 (C)
Waveform thresholds
To enable the system to monitor when the fluid sensor waveform has reached the
required levels various threshold levels are required, which are margins set above
and below the base line ters. These thresholds are fixed into memory but
may differ depending on the ectant chemistry. The firmware will not be
required to adjust the threshold levels. The Peak old is used to detect the
fluid signal (A) through the pump—hose, the Upper and Lower disinfectant threshold
levels used to detect the conductive path (B) through the hose—set and endoscope
intake filter (B).
Base Line Parameters — Figure 16
A Peak signal Fluid tive path through Pump— hose
Disinfectant peak trend (DP)
Rinse water peak trend (RP)
B Disinfectant/ Rinse Fluid conductive path h hose—set
Disinfectant Average Trend (DA)
Rinse Water Average Trend (RA)
C No fluid All of the hose-set or a large portion is vacant of fluid
'No Fluid' Average Trend ).08V (NA)
D Air pocket in hose A small portion of the hose-set is vacant of fluid
_ 22 _
Threshold Parameters — Figure 16
E Disinfectant Peak Threshold (DPT)/Rinse water Peak old (RPT)
F Disinfectant Upper Threshold (DUT)/Rinse water Upper Threshold (RUT)
G Disinfectant Lower Threshold (DLT)/Rinse water Lower old (RLT)
H No Fluid Upper Threshold (NUT),
I No Fluid Lower Threshold (NLT)
The system will track the average trend for fluid conduction over time and update
the base line parameters accordingly with sampled es recorded within
these threshold margins.
Four old levels are required, which include :
1x Peak threshold Figure 16— E
1x Upper and 1x Lower threshold for disinfectant in the hose-set F & G
1x Upper and 1x Lower threshold for rinse water hose-set path F & G
1x upper and 1x lower old level for No—Fluid H & I
1. The peak threshold (PT) is 70%; Percentage Figure 16-
Disinfectant Peak Threshold (DPT) = DP x PT (70%) E
Rinse Peak Threshold (RPT) = DP x PT (70%) E
2. The hose—set fluid conduction path Upper Threshold (UT) is 150%
Disinfectant Upper Threshold (DUT) = DA x UT (150%) F
Rinse Upper Threshold (RUT) = RA x UT (150%) F
3. The hose—set fluid conduction path Lower Threshold (LT) is 80%;
Disinfectant Lower Threshold (DLT) = DA x LT (80%) G
Rinse Lower Threshold (RLT) = RA x LT (80%) G
This upper nce may be higher to allow for mechanical noise caused by roller
wear and slight deformation in the pump chamber. See Figures 13 and 16 for
signal noise.
4. The No fluid Threshold (NT) is Upper threshold is 150% and lower threshold
level 50%.
No fluid Upper Threshold (NUT) = NA x (150%) H
No fluid Lower Threshold (NLT ) = NA x ( 50%) I
This signal is used to determine if the fluid sensor system is functioning. If this
signal is not present, the operator will be prompted to check that the relevant port
is set LOW to activate the fluid sensor circuit.
During the endoscope detection phase 3 the thresholds DLT and RLT (G) and
NUT (H) are used for detecting air sucked back from inside the endoscope.
1O e:
The following parameters would be calculated for the illustrating in Figure 13
waveform:
Disinfectant peak value DP = 1.0V
ectant Peak Threshold DPT = 1.0V x 70% = 0.7V
Disinfectant value DA = 0.38V (B)
Disinfectant Upper Threshold DUT = 0.38V x 150% = 0.57V
Disinfectant Lower Threshold DLT = 0.38V x 80% = 0.3V
Rinse water peak value DP = 0.6V
Disinfectant Peak Threshold DPT = 0.6V x 70% = 0.42V
(G)
Rinse value RA = 0.2V
Rinse Upper old DUT = 0.2V x 150% = 0.3V
Rinse Lower Threshold DLT = 0.2V x 80% = 0.16V
No fluid value NA = 0.08V
No fluid Upper Threshold NUT = 0.08 x 150% = 0.12V
No fluid Lower Threshold NLT = 0.08 x 50% = 0.04V
Production suite parameters list
The Production Suite will provide access to the five base line parameters DP, RP,
DA, RA, NA, the four tolerance parameters PT, LT, UT and NT and the Motor
1O speed threshold level described in the following section. These parameters may
be different for each disinfectant chemistry type firmware t and may be
adjusted as experienced is gained with ent chemistries and range of sizes for
ope Luer channels.
Disinfection and drain cycle process
The fluid sensor rm rated in Figure 17 would be typical during a
disinfection cycle and drain cycle process, excluding any rinse cycles.
Disinfection clean cycle phases
2O The Disinfection clean cycle for the exemplified embodiment is managed in eight
phases:
Phase 1 Purge residue from hose-set and endoscope while
Controller displays: Add Disinfectant
When tray is full with disinfectant the controller begins the
disinfection cycle
Phase 2 Pump priming - fill the hose-set with disinfectant
Phase 3 Pre-Cycle Endoscope detection
Phase 4 Disinfecting Luer Channel
Phase 5 Pump stops — ciose pump hose
Drain cycle (Disinfection timer expires)
Phase 6 Post—Cycle Endoscope detection
Phase 7 Purge ope of residue
Dry Endoscope from condensation
Phase 8 Cycle Complete - Confirm Removal of Instrument
The Pre—Cycle and Post—Cycle Endoscope detection is confirmation the
endoscope is connected during the entire disinfection process and inform the
operator should the endoscope fail to be detected.
This process may only be performed at the cle and ycle phases
should multiple Rinse cycles take place between. The cle and post- cycle
’IO endoscope detection phases are performed differently, where information from the
pump priming phase is used to for the post-cycle endoscope detection phase,
Each phase of an exemplary disinfection process is described below.
Phase 1 inary Purge
Both the controller and pump are switched on and establish communications.
During 'Add Instrument and Add Solution’ before closing the ball valve the
Controller instructs the pump to e for 6 seconds at 12Vdc to purge out any
residue from inside the hose-set and endoscope that may reside from previous
cleaning orfailed clean cycle.
Phase 2 Pump priming
The ller closes the ball valve. Once the tray is filled with disinfectant the
controller "Disinfecting" timer begins and instructs the pump unit to begin the prime
cycle.
The pump motor operating at 7Vdc will prime the pump with disinfectant until the
fluid sensor peak signal s (A) with disinfectant in the pump hose.
At this point the pump motor voltage is reduced to 5Vdc to minimum operating
speed, the trough potion of the waveform is ~ 0.08V (C).
The system counts all of peak signals A (path 114 through the ose) while
pumping disinfectant through the outlet hose and stops immediately as the
conductive path 116 is complete through the endoscope coupling and intake filter,
the trough n of the waveform (B), (0.38V), which is typically 5 - 7 peaks
(Figure 16). The number of peaks is temporarily saved to memory for the post-
W0 2012/110313
_ 25 _
cycle endoscope detection.
Phase 3 Pre-Cycle Endoscope Detection
Now the hose-set is completely filled with disinfectant; however air remains inside
the endoscope at this stage. The pump will now momentarily reverse slowly at
5Vdcjust enough and stop when the conductive path through the fluid signal has
dropped on e below the Disinfectant Lower Threshold BLT (80% DA). This
is the result of air being sucked back into the outlet hose that remained in the
endoscope (88), opening the conductive path (D). See Figures 16 and 18.
If the endoscope is not connected then disinfectant will be sucked back into the
1O outlet hose instead, ore the tive path through the hose-set will remain
steady (94), confirming the ope is not connected(B) (Figure 19).
Figure 18 ope detection confirmed
Phase 1 - Outlet hose filled in 5 peaks (84)
Phase 2 - Air sucked back opens conductive path (86)
Figure 19 Endoscope detection failure
Phase 1 - Outlet hose filled in 5 peaks (90)
Phase 2 — Fluid sucked back maintaining tion (92)
Report Failure and Purge after Drain
If the endoscope is not connected, the pump will stop and instruct the controller of
the failure code, the controller will open the ball valve and display the failure
"Instrument Unhooked".
After the 1 minute drain cycle when the tray has drained empty the pump will
operate for 10 seconds at 12Vdc to purge the hose-set from disinfectant.
Pump Motor Overload
The pump system must protect the pump from current overload and the pump
hose from pressure overload. Should the outlet hose or endoscope become
blocked at any stage the motor load current will exceed typical load current
230mA. Figure 21 illustrates an overload condition.
W0 2012/110313
_ 27 _
Pump Failure (Over—current Trip)
If the pump head is stalled, either from an oversized pump hose being fitted or
mechanical interference, the hardware current limit will only deliver 400mA
maximum. The current trip threshold is set to 380mA, if the average current level is
measurement constantly above this threshold for more than 3 seconds then the
pump will stop and instruct the controller of pump failure. The controller will open
the ball valve, record the Over—current Trip failure and display ”Pump e".
Blocked Instrument
If there is a d hose or endoscope the average load current will reach above
350mA. If this situation remains for more than 5 seconds the pump will stop and
inform the controller of the Failure Code for Blocked Instrument. The controller will
open the ball valve, record the failure and display "Blocked Instrument".
’15 Overload time-out
If the average load current reads above 230mA as a result of a small Endoscope
Luer channel, then the system will reduce the d e to decrease the
pump speed until the average load current has reduced to 230mA. If the applied
motor voltage has reached 5Vdc and the average load current s above
300mA for more than 5 s then the pump unit will stop the rotor and inform
the controller of the Pump Overload ut. The controller opens the ball valve,
records the failure code for Overload time-out and display "Blocked Instrument".
Figure 20 rates a normal load condition,
The average motor current may still remain above 230mA but below 300mA for an
endoscope with a small diameter long Luer channel. In this situation the system
continues with the disinfection cycle.
The waveform of Figure 21 illustrates that for a 0.5mm Luer channel with applied
motor voltage of 12Vdc the motor load current on average is above 300mA, 70mA
above the nominal load current 230mA. In this regard the pump system will reduce
the e on the motor until the average load current is settled at 230mA. Figure
_ 28 _
22 shows a waveform where the average load current has been reduced on
average to 230mA with an applied motor voltage of 8Vdc.
The system needs to register this condition has occurred, so that during Phase 8,
the 1 minute Purge cycle, the pump motor voltage will NOT operate the purge at
24Vdc for 15 seconds, but remain at 12Vdc for the entire 1 minute purge cycle.
Pump Pressure Overload
If an endoscope with a small diameter long Luer channel is fitted to the Pump unit
the trough portion the fluid waveform in Figure 16 (B) may appear on average
above the Upper Threshold (DUT) (2), which will be due to high pressure causing
back feed through the pump hose.
If this situation continues for more than 5 seconds the pump speed is reduced by
decreasing the motor voltage until the trough portion of the valve is on average
below the Upper Threshold.
Motor Current Overload Waveform
Referring to Figure 23 a typical load t 100 for normal pump operation is
2O about 250 mA. A waveform 96 of 350 mA for more than 3 seconds causes the unit
to stop pumping; or a waveform 98 of 300 mA for more than 5 seconds causes the
unit to stop pumping if the motor e has reached 5Vdc. If the motor speed
has dropped to the minimum (5V) and the situation still s after 5 seconds
then the pump unit will stop pumping and inform the controller of the Pump
Overpressure time-out. ing to Figure 24, the controller will open the ball
valve, record the failure code and y "Blocked Instrument". In the event of
consistent failures a ed pump hose will be ed.
Luer Channel Disinfection
After it is confirmed the endoscope is connected then proceed to operate the
pump in the forward direction at 5Vdc for 10 seconds then 12Vdc for 90 s
to complete the Luer channel disinfection. This initial reduced speed allows the
system to respond better to a potential blocked instrument or hose—set.
Phase 5 Disinfection pump cycle stops
Waveforms for exemplary ection cycles are illustrated in Figures 25 and 26.
After pumping disinfectant through the endoscope Luer channel for 1 minute the
pump stops and the disinfection process continues for the ing 4 minutes.
g the pump hose
seconds before the disinfection timer expires or the last Rinse cycle for a
‘IO specified disinfectant is completed, the pump unit must ensure the pump hose is
closed so that disinfectant or rinse water will not siphoned out during the drain
cycle before it has time to confirm the endoscope is connected. During this 5
seconds before opening the ball valve for the drain cycle the controller instructs
the pump unit to 'close pump hose'. The pump unit s 5V to the pump motor
for 5 seconds to ensure ectant is present in the endoscope and then
operates the pump motor in short bursts at 5V until the pump hose has closed.
This is confirmed by ensuring the fluid conduction signal through the hose-set is
within the disinfectant upper and lower thresholds. See Figure 16. n
threshold level (2) and (3). After this the ller proceeds to the 1 minute drain
cycle.
Leak Failure
During this phase if no fluid is detected the pump unit stops the pump and informs
the controller of Leak failure mode, the controller opens the ball valve, records the
failure and displays failure "Leak”.
Phase 6 Drain Cycle
During the Drain Cycle,(After the disinfection cycle or last rinse cycle) the
controller instructs the pump unit to perform a Post—Cycle Endoscope detection
and purge cycle to expel the e from inside the endoscope. The post
endoscope detection confirms it has not become disconnected during the
disinfection cycle or rinse cycles.
WO 10313
_ 30 _
Post-Cycle Endoscope Detection
The controller opens the ball valve to commence the drain cycle and 30 seconds
later instructs the pump unit to confirm the endoscope is connected. The pump
unit s 5V to the pump motor and stops immediately when the conductive
path through the hose—set is no longer detected, Figure 16 Peak signal (A). At this
stage disinfectant still remains in the outlet hose and the endoscope Luer channel.
The pump motor will now reverse at 5Vdc while at the same time using the fluid
sensor to count the number of peaks that appear when the disinfectant from the
outlet hose and endoscope is pumped back into the inlet hose. The pump will then
stop immediately as soon as the fluid sensor no longer detects ectant in the
pump hose.
The number of peaks represent the combined length of the outlet hose and
ope. This number has subtracted the previous value stored to memory at
Phase 2 Pump priming . If the result is r than 0 then the endoscope is found
to be connected. if the remainder is less than 0 or equal this would indicate the
endoscope is no longer connected to the et, becoming nected during
the disinfection process. The difference will vary depending on the inside diameter
and length of the Luer channel.
Valve Failed to Open
if during the reverse operation fluid is constantly detected for more than 1 minute
the pump unit stops the pump and informs the controller of failure "Valve failed to
open. The controller will again attempt to open the valve for 3 seconds, record the
failure and displays the failure: "Valve Failed to Open" and e Instrument".
Figure 27 Pre — Cycle Endoscope detection
In the illustrated waveform, 5 -6 Peaks 102 are required to fill the outlet hose.
Figure 28 Post-Cycle Endoscope Detection.
in this waveform, 8 -9 Peaks 104 are required to empty the outlet hose as fluid is
sucked back from the outlet hose and endoscope.
Figure 29 Post-Cycle Endoscope Detection Failure.
_ 31 _
Only 5 —6 Peaks 106 are required to empty the outlet hose as fluid is sucked back
from the outlet hose and endoscope. This rm illustrates that the endoscope
has failed to be ed as only 4 to 5 peak fluid signals appear, less or equal to
those counted in Figure 28.
Report Failure and Purge after Drain
If the endoscope is not connected the pump will stop and instruct the controller of
the failure, the controller will check the ball valve is opened, record the failure and
display the failure "Instrument Unhooked".
1O After the 1 minute drain cycle the pump is operated at 12Vdc to purge the hose-set
from ectant.
Phase 7 Purge e
Purging e and drying endoscope
The pump continues in the forward direction at 5Vdc for 5 seconds to purge out
any disinfectant or rinse water residue in the hose set and endoscope. After the 5
seconds the pump speed is increased, if the pump speed during the disinfection
was not able to operate at 12Vdc (Overload Time-out) then apply 12Vdc to the
pump motor for the remaining 1 minute purge cycle.
If the pump was able to operate at 12Vdc during the disinfection cycle then apply
24V for 15 seconds, purging out any large residual particles in the hose-set and
endoscope. The speed is then decreased with 12Vdc applied to the motor for the
remaining 40 seconds, pumping air to dry out the Luer channel from condensation.
Purge Mode failure
During the purge mode if fluid is continually detected for more than 1 minute this
would indicate that the controller ball valve has failed to open.
Phase 8 Cycle te — Confirm Removal of Instrument
When the Disinfection cycle, Rinse cycle and Post-Endoscope Detection is
confirmed and the final Purge cycle is complete the pump unit informs the
ller of a successfully clean cycle. The controller will now issue a Validation
code to the operator, recording the time and tion code as per the standard
controller operating procedure.
2012/051594
_ 32 _
Perished Pump hose and replacement
Consecutive overload failures
If the pump unit has stopped the disinfection cycle 5 times utively for Motor
Over-current Trip, Pump Overload Timeout or Over-pressure timeout, this may
indicate the pump hose has perished, the wrong pump hose is fitted or some form
of ical interference.
With continuous wear the pump hose will fail and possibly rupture causing fluid to
leak into the pump chamber creating an electrical conductive path directly between
1O both hose couplings.
Should this occur the fluid signal level will appear constantly above the Peak
Threshold (1) while the pump is ing or not. in these circumstances proceed
to failure ce pump hose".
Perished hose detection
Should the operator choose to reset the ”Replace Pump Hose” alarm without
taking action to replace the pump hose, this will eventually lead to a ous
situation for the patient. The hose will become flat to the point where the pump will
no longer deliver the required disinfectant flow rate, exposing risk of cross
contamination from one t to the next. As there is no other means for
monitoring the disinfectant flow rate this situation must be well monitored and stop
further disinfection cycles and again alert the operator to replace the pump hose.
A severely flattened pump hose will have less fluid present inside, the result is the
peak signal in the fluid sensor waveform will diminish below the original level of 1V
for disinfectant and 0.6V for rinse water. See Figure 16 (A).
This information will enable the pump system to process the state of the pump
hose and take action to stop further disinfection cycles accordingly.
To manage this situation the fluid sensor waveform peak signal level is ed
with the original level when the hose was new. Separate Original Peak values for
Disinfectant and Rinse water (DPO) and (RPO) are recorded into memory when
the pump hose is new or has been replaced. This Original Peak valve (DPO)
(RPO) will be updated by a small percentage each time the hose is replaced after
_ 33 _
100 hours of pump operating time. The al peak values will integrate rapidly in
the positive direction and very slowly in the negative direction, allowing for the
aging hose effects and should the or not replace the hose before resetting
the "Replace Pump Hose" alarm.
Method for updating Original Peak values
After the pump hose has just been replaced or the first time for the pump to
operate, (eg. the operator has reset the "Replace Pump Hose" alarm), the system
will record during the next consecutive disinfection cycle and rinse cycle the
’10 average peak signal levels above the peak old (1) (DPT) and (RPT) using
the original peak value trends (DPO) and (RPO). The difference between the
average and peak levels (DP) and (RP) and the Original peak values (DPO) and
(RPO) are calculated at the end of the disinfection clean cycle. The integrator will
then update into memory with the Original peak values (DPO) and (RPO) by +20%
/-5% of the difference calculated. The integrator is ed to responding quickly
to a positive differential than a negative differential to compensate for an operator
consistently resetting the "Replace Pump Hose" alarm but does not actively
replaced the pump hose.
Pump hose expiry
The pump unit is to count the number of minutes of pump operation, After 100
hours (6000 minutes) the pump unit s the ller that the pump hose has
expired. The controller will y the warning "Replace Pump Hose" for 5
seconds once communications has established with the controller and after each
time the operator has pressed the controller 'ON' button to "Restart Cycle". The
operator will be able to continue 10 disinfection cycles before the controller will no
longer permit further disinfection cycles to begin, at which time the pump hose
must be replaced. This process allows the operator time to ue with further
disinfection cycles throughout the day and replace the pump hose at the end of the
day.
If the hose has not been replaced by this stage the pump unit will inform the
controller that no further disinfection cycles can take place, the controller will
W0 2012/110313
_ 34 _
constantly display "Replace Pump Hose" and will not proceed r beyond this
warning and auto shut down as normal.
Replacement of Pump Hose
At this stage the pump LED will flash red.
When the pump hose has been replaced the or will need to plug in the PC
USB cable or Power Adaptor into the pump unit and press the pump Standby
button for three seconds to acknowledge the pump hose has been replaced, at
which time the pump Red LED will stop flashing.
Pump speed
The Pump head rotates at about 1 revolution per second at 5Vdc.
The motor will stop within 100ms (36°) when operating at 5Vdc.
Protection of Motor Reverse Relay
When changing the direction of pump, first set the motor voltage to 0V for 300ms
before changing the relay state, then apply the motor voltage for the pump to
operate in the opposite direction. This allows enough time for the motor to come to
a complete standstill and avoid t flow and electrical arcing while changing
over the motor relay contacts, thereby providing m me of the Motor
relay.
Pump speed information
Figure 30 Pump Rotor Speed versus Applied Motor Voltage
Figures 30a-c illustrate the pump head rotation speed (a), the number of
revolutions (b) and the time (c) before the pump is standstill after power has been
removed, which is the minimum time required before changing the reverse relay
contacts over and reapplying power to the pump motor.
This detail is recorded with the pump hose fitted while pumping air, which is the
maximum expected speed and time before standstill. These levels will reduce
under load conditions when pumping disinfectant and smaller Endoscope Luer
channel diameter size.
Figure 31 graphs Flow rate over pump hose ion lifetime for an endoscope
_ 35 _
with a Luer Channel of 0.5 mm diameter and a pump motor voltage at 8 Vdc. This
is the optimum operating voltage for this size of endoscope Luer l.
Increasing the speed does not improve fluid flow rate due to back pressure
created by the size of the small Luer channel diameter. This information is based
on a model of an Endoscope that is 0.5 m long and has a 0.5 mm diameter Luer
Channel. With the hose operation lifetime limit of 100 hours the hose is sufficient
for a 1 mm diameter Luer l.
For some endoscopes it is desirable to limit the pressure, for example to a
’10 maximum of 20-24 PSI 65 kPa). Many endoscope manufacturers specify a
maximum allowable pressure of 25 PSl (172 kPa). We propose to limit the voltage
to the motor which should stall the pump at the desired pressure. Alternatively a
spring—loaded pump head roller (rotor) may be used, which releases re in
the pump hose at a desired pressure level.
Fluid Sensor Tests and Threshold Levels
The performance of fluid detection system must be consistent and reliable to
ensure this automated process runs smoothly t adverse interruptions
throughout the lifetime of the product. It is desirable:
1. To identify if there is a clear difference in the fluid signal levels for tap water,
both soft and hard water with a higher mineral content, and the ectant.
2. That the signal for the disinfectant remains consistent over a period of 170
hours of exposure time and with 50 hours ofkpump operating time.
Figure 32 shows the fluid sensor signal trend as measured over 170 hours and 50
hours pump operation for an embodiment of the invention. The ue reading
is ed by the micro; for the equivalent e reading multiply by 2.
Over 170 hours of exposure time using nine disinfectant batches the fluid sensor
signal level in the pump hose varied from 1140mV (570 on the graph) to 1210mV
(605) with an average 1188mV (594 +2%, — 4%). The tube set signal level varied
from 442mV (221) to 508mV (254) with an average 484mV (242 +5%, -
W0 2012/110313
_ 35 _
8.5%). The dips in the signal level were attributed to aging disinfectant solution,
observed about 80 hours in Figure 32, or the level of l content in the water.
The sion from these test results is that the fluid sensor signal levels will
remain reasonably consistent for over a period of 170 to 200 hours and the pump
hose for 50 to 100 hours of pump operating time. Any inconsistency after this time
may indicate it is time for the operator to replace the pump hose and tube set.
Measurements were recorded while the pump motor is operating at 5Vdc. The
peak signal appears on average once every 700ms: see Figure 33. The peak
1O signal level is the pump hose path and the base signal level is the tube set
conductive path. During the pre-cycle count phase the first fluid sensor peaks only
are included. The peak r is the number of half turn pump rotations it will
take to fill and empty the outlet tube. The number is rounded to four if the count is
four or less and rounded down to five if the count is five or above. This may occur
when a “Y” tube section is attached to the end of the outlet tube for dual channel
endoscopes (Figure 34). The peak counter snapshot time is set for 1 second,
ng for a 300 ms margin. Referring to Figure 34 both the inlet and outlet tube
are 430 mm in length, a combined length of 860 mm. With the Y hose outlet tube
attached, the shortest route is 540 mm, and the longest length is 600 mm.
Measured Fluid Signal Levels from Six Pump Units
The following fluid sensor signal levels were ed. The values listed below
are the decimal value measured by the micro ADC input pin. (ADC = mV/2)
PCA Sample 1 Pump Hose Tube Set
Water (pre cycle) Peak = 392 Tube set = 100
Disinfectant Peak =608 Tube set = 236
Water (post cycle) Peak = 380 Tube set =120
PCA Sample 2
Water (pre cycle) Peak = 400 Tube set = 100
Disinfectant Peak = 608 Tube set = 236
Water (post cycle) Peak = 384 Tube set =112
PCA Sample 3 '
_ 37 _
Water (pre cycle) Peak = 408 Tube set = 104
Disinfectant Peak = 620 Tube set = 236
Water (post cycle) Peak = 404 Tube set =108
PCA Sample 4
Water (pre cycle) Peak = 388 Tube set =108
Disinfectant Peak = 588 Tube set = 228
Water (post cycle) Peak = 372 Tube set =104
PCA Sample5
Water (pre cycle) Peak = 396 Tube set =108
Disinfectant Peak = 612 Tube set = 236
Water (post cycle) Peak = 384 Tube set =108
PCA Sample 6
Water (pre cycle) Peak = 388 Tube set =108
ectant Peak = 596 Tube set = 288
Water (post cycle) Peak = 380 Tube set =108
Average Levels
Water
Pump hose Peak 389 (Min 380, Max 408) Tolerance i 19 (5%) Min = 380 —- 10% (350)
Tube Set Level 108 (Min 100, Max 120) Tolerance i 12 (11%) Min = 100 —- 10% (90)
Hard Water
Pump hose Peak 456 (Min 445, Max 478) Tolerance i 22 (5%) Max = 478 + 5% (500)
Tube Set Level 160 (Min 148, Max 178) Tolerance :18 (11%) Max = 178+10% (200)
Disinfectant (Soft Water)
Pump hose Peak 605 (Min 588, Max 620) Tolerance i 5 (2.5%) Min = 588 — 10% (530)
Tube Set Peak 243 (Min 228, Max 288) Tolerance i 45 (19%) Min = 228—10% (205)
s are shown in Figure 35. Regardless of the hardness of the water,
disinfectant threshold levels are distinguishable from rinse water threshold levels.
Sensor signal levels were tested for a rt sterilant system (referred to herein
as Fuse, which is a trade mark of Tristel PLC). The sterilant solution is prepared
WO 10313
_ 38 _
by mixing together Part A and Part B to produce a chlorine dioxide solution with a
substantially greater concentration of sodium ions than tap water. ements
were d out on standard concentrations and on double concentrations which
are used in some markets, and for differing water volumes. Results are given in
Table 1 and graphed in Figure 37.
The conductivity of the double concentrate was measured 5—7% lower than the
standard concentration, a level of variation expected when ing soft and
hard tap water.
Water Volume
IIIIII108 108 108
IIIIIIFuse Part
IIIIIIFuse Part 452 148 468 160 488 176
IIIIIIFuse 616 240 652 268 700
Fuse x2 584 228
from
Standard
Table 1
From the results, we conclude that the conductive property of the double
concentrate (used in China) is within the margin of variation when comparing hard
W0 2012/110313
_ 39 _
and soft tap water (i10%). The Fuse concentration level would need to be much
greater (>200%) before the operating performance of the pump unit could be
affected. The conductive property of the standard Fuse disinfectant is the
equivalent to the conductive property of the double concentrate (Fuse x2) used in
China. The firmware fluid sensor thresholds therefore can remain the same for
both types of composition.
The invention has been described with reference to specific embodiments. lt will
be understood that various modifications may be made to the embodiments within
the scope of the claims. For example, the peristaltic pump may be a linear pump
or a rotary pump; the materials from which the hoses and gs are made may be
selected from any suitable materials that are resistant to the sterilising fluid with
which they are to be used. The electronics and means for measuring ical
properties may be selected from arrangements well known per se to those skilled
in the art of electronics. The various ary measurements, detection
methodologies, and modes of ion may be varied in accordance with specific
needs and c apparatus design and disinfectant materials.
w 40 ..
ARTICLE 34 AMENDMENTS 201330
Claims (14)
1. 5 1. A peristaltic pump for use in sterilising the lumen of an endoscope in sterilisation tment of a sterilisation apparatus, the pump comprising: a flexible pump hose having an outlet end and an inlet end, and an electrically conductive fitting at each end in contact with fluid in the pump hose; or motorrdriven impeller disposed in relation to the pump hose such that 10 when the impeller is driven it will intermittently bear against the pump hose so as to bring the internal walls of the pump hose together; a first electrode in t with the conductive fitting at the outlet end of the pump hose, and a second electrode in contact with the conductive fitting at the inlet end of the pump hose: 15 means for applying a voltage across the first and second electrodes; and means for measuring an electrical property between the conductive fittings; wherein when the outlet end of the pump hose is connected to one end of an endoscope having a lumen to be sterilised and ed in a conductive 2o sterilant liquid in the steritisatton compartment, and the inlet end of the pump hose is in connection with the sterilant liquid in the sterilisation compartment, the only conductive path that wilt exist between the first electrode and the second electrode when the pump is operated, apart from via the pump hose, will be via the lumen of the endoscope.
2. A pump according to claim 1. n the impeller is mounted for rotary motion and wherein when the er is d at least one point exists at which the pump hose is incompletely occluded so that a fluid path exists through the pump hose from the inlet end to the outlet end.
3. A pump according to claim 1 or claim 2, wherein the impeller is arranged and adapted intermittently to bring the internal Walls of the pump hose together to n 41 . make a substantially fluid-tight seal.
4. A pump according to any preceding claim , r comprising means for signalling an error condition if the measured electrical property is outside a specified value range.
5, A pump according to any preceding claim, further comprising means for measuring the load current of the motor and means for determining whether a blockage is present depending on the ed load current.
6. A pump according to any preceding claim. further comprising an outlet hose for connecting the outlet end of the pump hose to an instrument to be sterilised; wherein the outlet hosts is in two parts connected er by an electrically conductive connector.
7. A pump according to any preceding claim. further comprising an inlet hose connected to the inlet end of the pump hose, for immersion in a source of ant ; the inlet hose being provided with an electrically conductive fitting at its free end.
8. Sterliisation apparatus comprising a container having a sterilisation Compartment for receiving an item to be sterilised, and a altic pump as claimed in any preceding claim, for pumping a sterllant liquid to and from the isation compartment.
9. Apparatus according to claim 8. further comprising an electronic controller for operating a drainage valve to allow fluid to drain from the sterilisation compartment after a predetermined time period; the controller being linked to the pump in a manner which permits the ller to control one or more operating 30 modes of the pump.
10. Apparatus according to claim 9, wherein the controller is arranged and adapted to receive data from the pump.
11. A method of using the apparatus of any of claims 8-10 for sterilislng an endoscope having a lumen, the method including the steps of: placing the endoscope in the sterilisation compartment; connecting the outlet end of the pump hose to one end of the endoscope to establish a fluid connection betWeen the pump hose and the lumen; filling the sterilisation compartment with a sterilant liquid; providing the inlet end of the pump hose with an inlet hose. and disposing 10 the free end of the inlet hose in the ant liquid within the sterilisation compartment; ing the pump so that the impeller causes fluid to be pumped through the lumen of the endoscope and causes fluid to be drawn into the free end of the inlet hose: and 15 ing an electrical property between the conductive fittings of the pump hose.
12. A method according to claim it, further sing the steps of: comparing the measured electrical property with a predetermined value 20 range; and signalling an error condition it the measured property is outside the value range.
13. A method according to claim 11 or claim 12, r comprising ing 25 the load current of the motor and determining from the measured value whether: (i) the pump is operating normally, or (ii) a blockage is present within the endoscope or one of the hoses; or (iii) the motor has stalled. 30
14. A method according to claim 13. further comprising triggering an alarm or error signal it a blockage is detected or ii the motor has stalled, _ 43
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1102609.3 | 2011-02-15 | ||
GBGB1102609.3A GB201102609D0 (en) | 2011-02-15 | 2011-02-15 | Pump for sterilisation apparatus |
PCT/EP2012/051594 WO2012110313A1 (en) | 2011-02-15 | 2012-01-31 | Pump for sterilisation apparatus |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ612733A NZ612733A (en) | 2014-12-24 |
NZ612733B2 true NZ612733B2 (en) | 2015-03-25 |
Family
ID=
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