U.S. patent application number 09/867047 was filed with the patent office on 2003-11-06 for reverse flow cleaning and sterilizing device and method.
Invention is credited to Stanley, Patricia M..
Application Number | 20030206826 09/867047 |
Document ID | / |
Family ID | 27379388 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030206826 |
Kind Code |
A1 |
Stanley, Patricia M. |
November 6, 2003 |
Reverse flow cleaning and sterilizing device and method
Abstract
A device and method for cleaning and sterilizing tubular
structures particularly, long, narrow tubular structures such as
lumens of a medical device such as an endoscope by reversing the
flow of fluid in interconnected tubular structures. The device
comprises a first and second valve in fluid communication with a
first and second tubular structure. The valves selectively switch
between a first and second position causing a first and second flow
path within the tubular structures, at least a part of the second
flow path opposite the first flow path.
Inventors: |
Stanley, Patricia M.;
(Minneapolis, MN) |
Correspondence
Address: |
MINNTECH CORPORATION
14605 28TH AVENUE NORTH
MINNEAPOLIS
MN
55447
|
Family ID: |
27379388 |
Appl. No.: |
09/867047 |
Filed: |
May 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09867047 |
May 29, 2001 |
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09409101 |
Sep 30, 1999 |
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6286527 |
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Current U.S.
Class: |
422/28 ;
134/166C; 134/166R; 134/22.12; 134/22.18; 422/33 |
Current CPC
Class: |
A01N 2300/00 20130101;
A01N 2300/00 20130101; C23F 11/08 20130101; A61B 2090/701 20160201;
A61B 1/123 20130101; A61L 2202/14 20130101; A61L 2202/24 20130101;
C23F 11/04 20130101; A01N 37/16 20130101; A61B 1/125 20130101; A01N
59/00 20130101; A61L 2202/17 20130101; A01N 37/16 20130101; A61L
2/16 20130101; A61B 90/70 20160201; C23F 11/10 20130101; A61B
1/00057 20130101; A61L 2202/122 20130101; A01N 59/00 20130101; A61L
2/186 20130101; A61L 2/24 20130101 |
Class at
Publication: |
422/28 ;
134/166.00R; 134/166.00C; 134/22.12; 134/22.18; 422/33 |
International
Class: |
B08B 009/032 |
Claims
I claim:
1. A device for sterilizing or cleaning tubular structures
comprising: a) a first valve and a second valve; b) said first and
second valves in fluid communication with a fluid supply maintained
at a positive pressure; c) said first valve in fluid communication
with a first tubular structure, the first tubular structure having
a proximal end and a distal end, said first valve in fluid
communication with the proximal end; d) said second valve in fluid
communication with a second tubular structure, the second tubular
structure having a proximal end and a distal end, said second valve
in fluid communication with the proximal end; e) the first tubular
structure in fluid communication with the second tubular structure;
f) said first and second valves selectively switchable between a
first position and a second position, g) said first position
causing a first fluid flow path and said second position causing a
second fluid flow path, wherein at least a part of said second
fluid flow path is opposite said first fluid flow path; h) wherein
in said first position said first valve is open to the fluid supply
and said second valve is closed to the fluid supply, and i) wherein
in said second position said second valve is open to the fluid
supply and said first valve is closed to the fluid supply.
2. The device of claim 1 wherein the distal end of at least one of
the tubular structures is open to a drain at about atmospheric
pressure.
3. The device of claim 1 wherein at least one of said valves is
open to a drain line when said valve is closed to the fluid
supply.
4. The device of claim 3 wherein in said first position said second
valve is open to the drain line and in said second position said
first valve is open to the drain line.
5. The device of claim 1 wherein the fluid supply is below about 20
psi.
6. The device of claim 5 wherein the fluid supply has a flow from
about 50 cm/sec to about 500 cm/sec for about 1 minute to about 20
minutes.
7. The device of claim 1 wherein the fluid supply has a flow from
about 100 ml/min to about 1400 ml/min and below about 20 psi.
8. The device of claim 1 wherein the tubular structures are lumens
in a medical device.
9. The device of claim 8 wherein one of said fluid flow paths
starts in a control head of the medical device.
10. The device of claim 8 wherein one of the tubular structures is
a CO.sub.2 lumen of an endoscope.
11. The device of claim 8 wherein the proximal end of the first
tubular structure and the proximal end of the second tubular
structure are located in one end of the medical device.
12. The device of claim 11 wherein said first fluid flow path is
downstream except for upstream through a control air channel,
upstream through an air/water cylinder, upstream through an
umbilical air channel, upstream through an air/water supply port,
upstream through said second valve, and upstream through an
umbilical water channel; and said second fluid flow path is
downstream except for upstream through a control CO.sub.2 channel,
upstream through a CO.sub.2 cylinder, upstream through an umbilical
CO.sub.2 channel, upstream through a CO.sub.2 supply port, and
upstream through said first valve.
13. The device of claim 1 further comprising a third and a fourth
valve, a third and a fourth tubular structure, and a third and a
fourth position.
14. An automatic reprocessing device comprising the device of claim
1 wherein positioning of said valves is controlled by a central
processor.
15. The device of claim 1 wherein the tubular structure is long and
narrow.
16. The device of claim 1 wherein the tubular structure has a
length and a diameter, the length from about 200 to about 8000
times the diameter.
17. The device of claim 1 wherein the fluid supply is a liquid.
18. A method of sterilizing a tubular structure comprising: a)
providing a tubular structure; b) providing a sterilizing fluid; c)
causing said sterilizing fluid to flow at a positive pressure
through said tubular structure in a first fluid flow path; and d)
causing said sterilizing fluid to reverse flow at a positive
pressure through said tubular structure in a second fluid flow
path, wherein at least part of said second fluid flow path is
opposite said first fluid flow path.
19. The method of claim 18 wherein said sterilizing fluid is below
about 50 degrees C. and said sterilizing fluid is provided from
about 1 minute to about 20 minutes.
20. The method of claim 18 wherein said tubular structure has a
diameter of less than about 6 mm and wherein said flow and said
reverse flow are from about 50 cm/second to about 500 cm/second and
below about 20 psi.
21. The method of claim 18 wherein said flow and said reverse flow
are from about 100 ml/min to about 1400 ml/min and below about 20
psi.
22. The method of claim 18 wherein said tubular structure is a
lumen of a medical device.
23. The method of claim 22 wherein one of said fluid flow paths
starts in a control head of said medical device.
24. The method of claim 22 wherein said first fluid flow path and
said second fluid flow path start in one end of said medical
device.
25. The method of claim 24 wherein said first fluid flow path is
downstream except for upstream through a control air channel,
upstream through an air/water cylinder, upstream through an
umbilical air channel, upstream through an air/water supply port,
upstream through said second valve, and upstream through an
umbilical water channel; and said second fluid flow path is
downstream except for upstream through a control CO.sub.2 channel,
upstream through a CO.sub.2 cylinder, upstream through an umbilical
CO.sub.2 channel, upstream through a CO.sub.2 supply port, and
upstream through said first valve.
26. The method of claim 18 further comprising providing the device
of claim 1.
27. The method of claim 18 wherein said flow and said reverse flow
are controlled by a central processor.
28. The method of claim 18 wherein said tubular structure is long
and narrow.
29. The method of claim 18 wherein said tubular structure has a
length and a diameter, said length from about 200 to about 8000
times said diameter.
30. The method of claim 18 wherein said sterilizing fluid is a
liquid.
31. A method of cleaning the lumens of a medical device comprising:
a) providing a medical device with a first lumen and a second
lumen, said first and second lumens each having a proximal end and
a distal end, and said distal end of at least one of said lumens
open to a drain at about atmospheric pressure; b) providing a
cleaning fluid; c) causing said cleaning fluid to flow at a
positive pressure through said first and second lumens in a first
fluid flow path, said first fluid flow path starting at said
proximal end of said first lumen; and d) causing said cleaning
fluid to reverse flow at a positive pressure through said first and
second lumens in a second fluid flow path, said second fluid flow
path starting at said proximal end of said second lumen, wherein at
least part of said second fluid flow path is opposite said first
fluid flow path.
32. The method of claim 31 wherein said proximal end of said first
lumen and said proximal end of said second lumen are located in one
end of said medical device.
33. The method of claim 31 wherein one of said fluid flow paths
starts in a control head of said medical device.
34. The method of claim 31 wherein said first fluid flow path
drains through said proximal end of said second lumen and said
second fluid flow path drains through said proximal end of said
first lumen.
35. The method of claim 31 wherein said flowing and said reverse
flowing are from about 100 ml/min to about 1400 ml/min and below
about 20 psi.
36. The method of claim 31 wherein said flowing and said reverse
flowing are from about 50 cm/sec to about 500 cm/sec.
37. The method of claim 31 wherein said first fluid flow path is
downstream except for upstream through a control air channel,
upstream through an air/water cylinder, upstream through a
umbilical air channel, upstream through an air/water supply port,
upstream through said second valve, and upstream through a
umbilical water channel; and said second fluid flow path is
downstream except for upstream through a control CO.sub.2 channel,
upstream through a CO.sub.2 cylinder, upstream through a umbilical
CO.sub.2 channel, upstream through a CO.sub.2 supply port, and
upstream through said first valve.
38. The method of claim 31 further comprising providing the device
of claim 1.
39. The method of claim 31 wherein said flowing and said reverse
flowing are controlled by a central processor.
40. The method of claim 31 wherein said tubular structure is long
and narrow.
41. The method of claim 31 wherein said tubular structure has a
length and a diameter, said length from about 200 to about 8000
times said diameter.
42. The method of claim 31 wherein said cleaning fluid is a liquid.
Description
[0001] This application claims the benefit of U.S. Provisional
application No. 60/102,663, filed Oct. 1, 1998; U.S. Provisional
application No. 60/102,664, filed Oct. 1, 1998; and U.S.
Provisional application No. 60/117,401 filed Jan. 27, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to the field of sterilizing
and cleaning tubular structures including long, narrow, tubular
structures. In particular, it relates to a device and method for
cleaning and sterilizing medical devices with lumens.
[0004] 2. Description of the Related Art
[0005] Many tubular structures, in particular flexible fiber
endoscopes, define long tortuous lumens. These lumens are typically
from about 1 m to about 4 m long with inside diameters from about
0.5 mm to about 6 mm and frequently contain crevices, bends,
connections, restrictions, and irregularities. These instruments
are frequently used in diagnostic medicine, requiring penetration
into the human body or other contact with the human bloodstream. It
is, therefore, desirable that they are cleaned, rinsed, sterilized,
disinfected, or otherwise treated with fluid chemical disinfectants
or sterilants to prevent the cross contamination and transmission
of pathogenic organisms from patient to patient. In order for fluid
chemical sterilization to be effective, the chemical must reach all
internal and external surfaces. Efficaciousness, therefore, is
severely limited by the inherent irregularities present in the
long, narrow, lumens of flexible fiber endoscopes making effective
cleaning and sterilization difficult.
[0006] Consistently and quickly cleaning, disinfecting, and
sterilizing medical devices is an important part of providing
quality healthcare. Failure to consistently clean and sterilize
medical instruments leads to unwanted transmission of bacteria,
viruses, and other organisms to and from patients. Improper
handling of medical instruments allows unwanted organisms access
inside the body where they may cause infection and disease.
[0007] Although the terms "sterilization" and "disinfection" are
sometimes used imprecisely, the medical industry and regulatory
agencies have more precisely defined the following terms including
subdividing disinfection into high, intermediate, and low level
disinfection.
[0008] Sterilization is generally defined as the destruction or
elimination of all microbial life forms. Operationally, a
sterilizing process is one that destroys all microbes on a device
that has been contaminated with 10.sup.6 bacterial endospores.
[0009] High level disinfection is generally defined as the
destruction or elimination of all microbial life forms except
microbial spores. High level disinfectants however, must show a
capability of destroying bacterial spores over an extended period
of time.
[0010] Intermediate disinfection is generally defined as the
destruction of all microbial life forms except bacterial spores and
some viruses. However, intermediate disinfection requires the
destruction or elimination of Mycobacterium tuberculosis var.
bovis, which is a relatively difficult bacterium to destroy.
[0011] Low level disinfection is generally defined as the
destruction of vegetative forms of bacteria (such as salmonellae
and staphylococci), most fungi, medium sized or lipid containing
viruses (such as Herpes simplex virus, hepatitis B virus, and HIV),
but not bacterial endospores, mycobacteria, or small or non-lipid
viruses (such as poliovirus and rhinovirus).
[0012] The level of disinfection or sterilization desired for a
particular piece of equipment generally depends on the degree of
exposure the equipment poses to the patient. For example,
sterilization is generally necessary for equipment that is
introduced directly into the human body, either in contact with the
blood stream, or in contact with normally sterile areas of the
body. High level disinfection is generally required for equipment
that contacts mucus membranes, but does not penetrate bodily
surfaces. Low and intermediate disinfection is generally required
for equipment that contacts unbroken skin.
[0013] Endoscopes, which are used to probe internal passages of the
body, are an exception to the general rule of sterilizing equipment
that is introduced directly into the human body. Ideally, all
endoscopes should be cleaned and sterilized between uses. However,
due to their delicate optical equipment, endoscopes remain an
exception to the sterilization rule. The delicate optical equipment
and lenses in these devices do not allow conventional methods of
sterilization such as autoclaving, ethylene oxide gassing, or
soaking for several hours in liquid sterilants. Autoclaving
requires high temperatures for sterilization, which damages the
optical lenses of the endoscopes. Ethylene oxide gas equipment is
expensive and requires several hours to complete the sterilization
and degassing process. Repeated soaking in liquid sterilants may
also damage some endoscopes. In addition, the high cost of these
specialized pieces of equipment demands efficient utilization of
the instruments, requiring use of the same endoscope on as many
patients in as little time as feasible. Therefore, soaking in
liquid sterilants or sterilization by ethylene oxide gas is not
economically feasible because of the long time period required. The
demand for rapid reuse results in pressure to shorten or eliminate
cleaning, disinfection, and sterilization practices. As a
compromise to all of these considerations, high level disinfection
for endoscopes is conventionally accepted in lieu of
sterilization.
[0014] Although high level disinfection has been conventionally
acceptable, it does not provide the level of safety of
sterilization. The conventional rationale for accepting the reduced
level of safety is that endoscopes contact mucus membrane and do
not provide access to the blood stream. However, endoscopes are
routinely used to find lesions in mucus membrane areas that may
provide access to the blood stream. In addition, many endoscopes
provide biopsy forceps that are miniature scalpels used to cut
biopsy samples from the mucus membrane tissue. These common
practices provide access to the bloodstream and a potential pathway
for unwanted organisms to access all parts of the body. In addition
to providing a direct path to the bloodstream, many endoscopes such
as duodenoscopes are used in normally sterile parts of the body.
Introducing contaminated equipment into these areas has been shown
to cause infection.
[0015] The lumens of medical devices have conventionally been
difficult to clean, disinfect, and sterilize. Some larger lumens
may be cleaned with brushes. However, lumens that are too small for
brushes are generally limited to cleaning by flushing with fluids
such as water or air. As noted previously, the lumens also contain
crevices, bends, connections, restrictions, and irregularities that
restrict flow and hold residual material making cleaning difficult.
Before a piece of equipment is disinfected or sterilized, it is
preferably first cleaned. Failure to completely clean residual
material from the equipment potentially leaves microorganisms
within and beneath the residual material not easily accessible to
the disinfectant or sterilant.
[0016] Some conventional devices have used special attachments or
caps to direct flow into different passages of endoscopes. However,
these attachments create additional attachment points. The
unexposed surfaces between the attachment and the medical device
may not receive complete cleaning or sterilization.
[0017] Typically, conventional devices and methods of cleaning have
used unidirectional flow to clean long narrow devices with lumens.
It is believed that irregularities and restrictions in the passages
create air pockets or sheltered areas along the passages. For
example, as the fluid flows around corners, the fluid tends to flow
to the outside of the corner, leaving an air pocket or undisturbed
liquid or material on the inside edge. Fluid flow is also reduced
on the downstream side of any restriction.
[0018] Some devices, such as those disclosed in Ishii 4,526,623,
use suction from a syringe to draw residual fluid in the lumens or
to draw fluid from an additional fluid container. However, the use
of suction may collapse lumens, introduce additional air pockets in
the lumen, and create the need for additional attachments. Suction
may also require the use of check valves to properly control the
removal of fluid and reduce the amount of air introduced into the
medical device. Check valves may also reduce or eliminate complete
removal of the fluid. Cleaning by suction only removes liquid from
multiple lumens until one lumen contains air. Once a single lumen
contains air, only air is drawn through the device because air
flows more easily than liquid. The relative differences in the size
of the lumens would also cause certain lumens to drain more
quickly, leaving liquid in the remaining lumens. Lastly, the
syringe method and device of Ishii is not easily automated.
[0019] Sterilization methods have also included immersion or
soaking of medical devices in liquid sterilant. Sterilization by
soaking typically requires several hours and air bubbles may become
trapped inside the lumens, causing inconsistent results.
[0020] A new and useful device and method is needed that overcomes
the problems associated with conventional methods of cleaning and
sterilizing tubular structures, including long, narrow, tubular
structures, particularly medical devices with lumens, by providing
a device and method that provides a reverse flow through the
tubular structures.
SUMMARY OF THE INVENTION
[0021] It is an object of the reverse flow cleaning and sterilizing
device and method in accordance with the present invention to solve
the problems outlined above that have heretofore inhibited the
successful cleaning and sterilization of tubular structures, in
particular, long, narrow, tubular structures.
[0022] More particularly, the apparatus and method of the reverse
flow cleaning and sterilizing device in accordance with the present
invention provides for the cleaning and sterilization of medical
devices with lumens, particularly endoscope lumens.
[0023] The unique sterilization and cleaning device in accordance
with the present invention broadly includes a first valve and a
second valve. The first and second valves are each in fluid
communication with a fluid supply at a positive pressure. The first
valve is in fluid communication with a first tubular structure
having a proximal end and a distal end with the first valve in
fluid communication with the proximal end. The second valve is in
fluid communication with a second tubular structure having a
proximal and a distal end with the second valve in fluid
communication with the proximal end. The first tubular structure is
in fluid communication with the second tubular structure. The first
and second valves selectively switch between a first position and a
second position. The first position causes a first fluid flow path
and the second position causes a second fluid flow path. At least
part of the second fluid flow path is opposite the first fluid flow
path. In the first position the first valve is open to the fluid
supply and the second valve is closed to the fluid supply. In the
second position the second valve is open to the fluid supply and
the first valve is closed to the fluid supply.
[0024] The device may also provide that either both fluid flow
paths start at one end of a medical device or one fluid flow path
may start in a control head or center of the medical device.
[0025] The device may also provide that the distal end of at least
one of the tubular structures is open to a drain at about
atmospheric pressure.
[0026] The device may also provide that in the first position the
second valve is open to a drain line and in the second position the
first valve is open to a drain line.
[0027] The device may also provide that the fluid supply has a flow
volume from about 100 ml/min to about 1400 ml/min and a flow
velocity from about 50 cm/sec to about 500 cm/sec and a pressure
below about 20 psi for about 1 minute to about 20 minutes.
[0028] The device may also provide a third and a fourth valve, a
third and a fourth tubular structure, and a third and a fourth
position.
[0029] The device may also be used in an automatic reprocessing
device so that a central processor controls positioning of the
valves.
[0030] The apparatus and method in accordance with the present
invention provides both a method of sterilization of tubular
structures and a method of cleaning the lumens of a medical
device.
[0031] The sterilization method broadly includes the sterilization
of the interior of a tubular structure comprising: a) providing a
tubular structure, b) providing a sterilizing fluid c) causing the
sterilizing fluid to flow at a positive pressure through the
tubular structure in a first fluid flow path, and d) causing the
sterilizing fluid to reverse flow at a positive pressure through
the tubular structure in a second fluid flow path, so that at least
part of the second fluid flow path is opposite the first fluid flow
path.
[0032] The sterilization method may also include providing the
sterilizing fluid at a temperature from about 20 degrees C. to
about 50 degrees C. and from about 1 minute to about 20
minutes.
[0033] The sterilization method may also include providing a
tubular structure having a diameter equal to or less than about 6
mm and the flowing and the reverse flowing have a flow velocity
from about 50 cm/second to about 500 cm/second, a flow volume from
about 100 ml/min to about 1400 ml/min, and a pressure below about
20 psi.
[0034] The sterilization method may also include starting the first
fluid flow path and starting the second fluid flow path in one end
of a medical device.
[0035] The device may also provide that one fluid flow path may
start in a control head or other attachment point of the medical
device.
[0036] The sterilization method may also include providing the
device of the present invention.
[0037] The sterilization method may also include controlling the
flowing and the reverse flowing by a central processor.
[0038] The present invention may also include a method of cleaning
a medical device with lumens. The cleaning method broadly includes
a method of cleaning the lumens of a medical device including a)
providing a medical device with a first lumen and a second lumen,
each lumen having a proximal end and a distal end, the first lumen
in fluid communication with the second lumen, and the second end of
at least one of the lumens open to a drain at about atmospheric
pressure; b) providing a cleaning fluid; c) causing the cleaning
fluid to flow at a positive pressure through the lumens in a first
fluid flow path starting at the proximal end of the first lumen;
and d) causing the cleaning fluid to reverse flow at a positive
pressure through the lumens in a second fluid flow path starting at
the proximal end of the second lumen, such that at least part of
the second fluid flow path is opposite the first fluid flow
path.
[0039] The cleaning method may also include providing a medical
device with the first end of each lumen located in the same end of
the medical device.
[0040] The cleaning method may also provide that either both fluid
flow paths start at one end of a medical device or one fluid flow
path may start in a control head or other attachment point of the
medical device.
[0041] The cleaning method may also include draining the first
fluid flow path through the proximal end of the second lumen and
draining the second fluid flow path through the proximal end of the
first lumen.
[0042] The cleaning method may also include providing the flowing
and the reverse flowing at a flow velocity of from about 50 cm/sec
to about 500 cm/sec, a flow volume from about 100 ml/min to about
1400 ml/min, and a pressure below about 20 psi.
[0043] The cleaning method may also include providing the device of
the present invention.
[0044] The cleaning method may also provide controlling the flowing
and the reverse flowing by a central processor.
[0045] One advantage of the present invention is improved
sterilization. The present invention provides better application of
the fluid to all parts of the interior of tubular structures.
Improved application of the fluid to the interior of the tubular
structure results in faster and more consistent sterilization.
[0046] Another advantage is that air pockets are consistently
removed. The present invention improves sterilization and cleaning
by providing better application of fluid by consistently removing
air pockets from the interior of the tubular structures. Flowing
and reverse flowing at a positive pressure provides consistent
removal of air pockets. Soaking or holding fluid in the tubular
structures does not consistently remove air pockets resulting in
inconsistent cleaning and sterilization.
[0047] Another advantage is that the fluid obtains improved access
to cracks, crevices, and restrictions. Flowing and reverse flowing
at a positive pressure forces fluid into cracks, crevices, and
restrictions from more than one direction. Flowing from one
direction or flowing at a negative pressure does not force fluid
into the cracks and crevices, especially downstream of a
restriction, causing inconsistent sterilization and cleaning.
[0048] Another advantage is that residual liquids and materials
remaining in the lumens are more adequately displaced with fluid.
Liquid, such as left over rinse water may not be completely
displaced using an unidirectional flow pattern. As a result, the
chemicals (active ingredients) in the fluid must diffuse into the
rinse water before sterilization may occur. The present invention
provides better displacement of residual materials and liquids
providing faster and more consistent sterilization and
cleaning.
[0049] Another advantage is that soaking is not required. The
present invention is not limited by the use of large volumes of
sterilizing fluid needed to immerse the entire tubular structure,
saving sterilization fluid.
[0050] Another advantage is that sterilization can be accomplished
more quickly. Long soaking times of hours required for immersion
sterilization may be reduced to about minutes for the present
invention. Quicker sterilization results in better utilization of
medical equipment.
[0051] Another advantage is that sterilization can be accomplished
more consistently.
[0052] Flowing sterilizing fluid from more than one direction and
forcing the sterilizing fluid into cracks and crevices with
positive pressure reaches the interior surfaces of tubular
structures more consistently. More consistent application of the
sterilizing fluid to the interior surfaces provides more consistent
sterilization.
[0053] Another advantage is that the present invention can be
attached to the supply ports of the endoscope. The present
invention may be attached to one end of a medical device such as an
endoscope without any attachments to the distal end or insertion
section of the medical device. Other methods using suction pressure
require the attachment of a fluid source in addition to the suction
source requiring additional attachments. A device that connects to
one end of the medical device provides an easier and more
centralized attachment and eliminates the need for additional
attachments.
[0054] Another advantage is that the present invention provides an
alternative method of attachment to the air/water channel,
particularly if the device does not have a gas or CO.sub.2 channel.
The present invention may provide for attachment to the air/water
channel at the air/water control cylinder.
[0055] Another advantage is that the present invention reduces the
number of attachments that cause additional contamination points.
Each additional attachment creates an area between the attachment
and the medical device that is difficult to reach with fluid. The
more attachments the greater the inconsistency of cleaning and
sterilization.
[0056] Another advantage is that the present invention uses
positive pressure flow. In addition to the improved penetration
capabilities previously described, positive pressure flow is easier
to provide. Positive pressure provides a greater range of pressures
and can be more easily provided through a greater variety of
positive pressure pumps. Positive pressure flow provides both the
pressure source and the fluid source at one location, simplifying
connections and automation. Positive pressure is also safer because
contaminates cannot be drawn into the device through leaks in the
system.
[0057] Another advantage of the present invention is that it may be
operated at temperatures less than 50 degrees C. Operating at
temperatures below 50 degrees C. prolongs the life of medical
devices and reduces burn hazards.
[0058] Another advantage is that the present invention may be
easily automated. The use of valves controlled by a central
processor may be easily automated, particularly in an automatic
reprocessing device. The elimination of manually operated equipment
and methods such as syringes provides for automation.
[0059] These and other objects and advantages of the present
invention will become apparent during the course of the following
detailed description and appended claims. The invention may best be
understood with reference to the accompanying drawings, wherein an
illustrative embodiment is shown.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 is a schematic drawing of the device in a first flow
position.
[0061] FIG. 2 is a schematic drawing of the device in a second flow
position.
[0062] FIG. 3 is a side cross sectional view of an endoscope
connected to the device showing a first and a third fluid flow
path.
[0063] FIG. 4 is a side cross sectional view of an endoscope
connected to the device showing a second and fourth fluid flow
path.
[0064] FIG. 5 is a schematic drawing of the device in an alternate
second flow position.
[0065] FIG. 6 is a schematic drawing of the device in an alternate
first flow position.
[0066] FIG. 7 is a side cross sectional view of an endoscope
connected to the device showing an alternate first fluid flow
path.
[0067] FIG. 8 is a side cross sectional view of an endoscope
connected to the device showing an alternate second fluid flow
path.
[0068] FIG. 9 is a schematic drawing of the device incorporated
into an automatic endoscope reprocessing machine controlled by a
central processor.
[0069] FIG. 10 is a schematic drawing of the device incorporated
into an alternate embodiment of an automatic endoscope reprocessing
machine controlled by a central processor.
[0070] FIG. 11 shows an exterior perspective view of a medical
instrument reprocessing device having one of a pair of chemical
supply drawer access doors in an open position and one of a pair of
reprocessing bay cabinet access doors in an open position.
[0071] FIG. 12 shows a perspective view of the major components of
a medical instrument reprocessing device in one possible
arrangement relative to each other and positioned in a
representation of the compartmentalization provided by an exterior
housing. Two reprocessing bays are represented in the reprocessing
bay cabinet of the housing; one configured with a reprocessing bay
door in the open position and the other, presented in broken lines,
configured without the necessary reprocessing bay door.
[0072] FIG. 13 shows a perspective view of two reprocessing bays,
without access panels, of a medical instrument reprocessing device.
One reprocessing bay is shown in a partial sectional view
disclosing an exterior pressure washing assembly.
[0073] FIG. 14 shows a perspective sectional view of a heater
assembly of a medical instrument reprocessing device invention.
[0074] FIG. 15 shows a front elevational view of the movable
cassette assembly of a medical instrument reprocessing device.
[0075] FIG. 16 shows a schematic representation of the hydraulic
system and pneumatic system of a medical instrument reprocessing
device.
DETAILED DESCRIPTION OF THE INVENTION
[0076] General Assembly
[0077] Referring to FIGS. 1, 2, 5, 6, 9, and 10, the device 10 in
accordance with the present invention broadly includes a first
valve 80 and a second valve 82. However, additional valves for
additional tubular structures may be provided. The first and second
valves 80,82 are each in fluid communication with to a fluid supply
84 at a positive pressure. The first valve 80 is in fluid
communication with a first tubular structure 94, the first tubular
structure 94 having a proximal end 98 and a distal end 100, the
first valve 80 is in fluid communication with the proximal end 98.
The tubular structures typically have a length that is about 200 to
about 8,000 times the inside diameter. The second valve 82 is in
fluid communication with a second tubular structure 96, the second
tubular structure 96 having a proximal end 102 and a distal end
104, the second valve 82 is in fluid communication with the
proximal end 102. The first tubular structure 94 is in fluid
communication with the second tubular structure 96. The first and
second valves 80, 82 selectively switch between a first position
106 and a second position 108. In the first position 106, the first
valve 80 is open to the fluid supply 84 and the second valve 82 is
closed to the fluid supply 84. In the second position 108 the
second valve 82 is open to the fluid supply 84 and the first valve
80 is closed to the fluid supply 84. The first position 106 causes
a first fluid flow path 110 and the second position 108 causes a
second fluid flow path 112. At least a part of the second fluid
flow path 112 is opposite the first fluid flow path 110.
[0078] The device 10 may also provide that the distal end 100, 104
of at least one of the tubular structures 94, 96 is open to a drain
114 at about atmospheric pressure.
[0079] The device 10 may also provide that in the first position
106 the second valve 82 is open to the drain line 88 and in the
second position 108 the first valve 80 is open to the drain line
88.
[0080] The device 10 may also provide that the fluid supply 84 has
a flow volume from preferably about 100 ml/min to about 1400
ml/min. Preferably the flow volume is about 100 ml/min to about 250
ml/min for tubular structures of about 1 mm to about 2 mm in
diameter and about 600 ml/min to about 1400 ml/min for tubular
structures of about 3 mm to about 6 mm in diameter. The fluid
supply 84 has a flow velocity from preferably about 50 cm/sec to
about 500 cm/sec and most preferably about 50 cm/sec to about 250
cm/sec. The fluid supply 84 has a pressure preferably below about
20 psi and most preferably from about 10 psi to about 20 psi.
Pressures above about 20 psi may damage the endoscope and are not
recommended by manufacturers. The sterilizing fluid 116 is
preferably provided for about 1 minute to about 20 minutes and most
preferably about 10 minutes.
[0081] The device 10 may also provide a third and a fourth valve, a
third and a fourth tubular structure, and a third and a fourth
position.
[0082] The device 10 may also be used in an automatic reprocessing
device so that a central processor controls positioning of the
valves.
[0083] The device 10 may be used to process a medical device with
lumens such as an endoscope 12 described below. Endoscopes may be
about 1 m to about 4 m long and have lumens ranging from about 0.5
mm to about 6 mm.
[0084] As shown in FIGS. 3,4 7, and 8, endoscope 12 may have a
plurality of tubular structures or lumens 14. The lumens 14
typically consist of a water channel 16, a suction channel 18, an
air channel 20, and a CO.sub.2 channel 22. The endoscope 12
typically has an insertion section 24 extending from a control
section 26 and an umbilical section 28 also extending from the
control section 26. The lumens 14 are defined inside the endoscope
12 and extend through the endoscope 12 from the insertion section
24 and are in fluid communication with control valve cylinders 30
and extend and are in fluid communication with the lumens 14 in the
umbilical section 28. There are typically three control valve
cylinders 30 including an air/water cylinder 32, a suction cylinder
34, and a CO.sub.2 cylinder 36.
[0085] Umbilical Section
[0086] During use, the light guide or umbilical section 28 of the
endoscope 12 connects the lumens 14 of the endoscope 12 to a supply
of air, water, and CO.sub.2 via supply ports located at the distal
end 52 of the umbilical section 28. The lumens 14 include an air
channel 20, a suction channel 18, a water channel 16 and a CO.sub.2
channel 22. The umbilical section has a suction supply port 38 in
fluid communication with the suction channel 18, a CO.sub.2 supply
port 40 in fluid communication with the CO.sub.2 channel 22, an air
supply port 44 in fluid communication with the air channel 20, and
an air/water supply port 42 in fluid communication with the water
channel 16 and the air channel 20. The lumens 14 extend through the
umbilical section 28 and are in fluid communication with the
control cylinders 30 located in the control section 26.
[0087] Control Section
[0088] The control section 26 is located in the middle of the
endoscope 12 and contains the control cylinders 30 and the lens 132
for viewing though the endoscope 12. During normal operation, the
control cylinders 30 contain control valves and provide operational
control of the flow of air, water, and CO.sub.2. During processing,
cleaning, and sterilization, the control valves are removed from
the air/water control cylinder 32 and the suction cylinder 34 and
the openings are capped. The CO.sub.2 control valve in the CO.sub.2
cylinder 36 is left in the open position. The CO.sub.2 cylinder 36
is in fluid communication with both the CO.sub.2 channel 22 from
umbilical section 28 and the CO.sub.2 channel 22 that is in fluid
communication with the air channel 20 between the air/water
cylinder 32 and the insertion section 24. The air/water cylinder 32
is in fluid communication with four channels, a) the air channel 20
from the umbilical section 28, b) the water channel 16 from the
umbilical section 28, c) the air channel 20 from the insertion
section 24, and d) the water channel 16 from the insertion section
24. The insertion section 24 typically has three instead of four
lumens because the CO.sub.2 channel 22 joins and is in fluid
communication with the air channel 20 in the control section 26
downstream of the control cylinders 30.
[0089] Insertion Section
[0090] The insertion section 24 is connected to the control section
26 of the endoscope 12 and is the portion of the endoscope 12 that
is inserted into the patient during use. The insertion section 24
has an air/water nozzle 46 and a suction opening 48 located at the
distal end 54 of the insertion section 24. The water channel 16 and
air channel 20 merge in the insertion section 24 to form an
air/water channel 56. The air/water channel 56 is in fluid
communication with the air channel 20 and the water channel 16 and
with the air/water nozzle 46. The air channel 20 is in fluid
communication with the air/water cylinder 32 and with the air/water
channel 56. The water channel 16 is in fluid communication with the
air/water cylinder 32 and with the air/water channel 56. The
suction channel 18 is in fluid communication with the suction
cylinder 34 and with the suction opening 48. The endoscope may also
have a forceps or biopsy port 50 located in the control section 26.
The biopsy port 50 is in fluid communication with the suction
channel 18 between the suction cylinder 34 and the suction opening
48.
[0091] Suction Channel
[0092] The suction channel 18 is typically from about 3 mm to about
6 mm in diameter. The suction channel 18 can be subdivided into an
umbilical suction channel 18a, a control suction channel 18b and an
insertion suction channel 18c. The umbilical suction channel 18a is
the portion of the suction channel 18 from the suction supply port
38 to the suction cylinder 34. The control suction channel 18b is
the portion from the suction cylinder 34 to the biopsy port 50. The
insertion suction channel 18c is the portion from the biopsy port
50 to the suction opening 48.
[0093] Air Channel
[0094] The air channel 20 is typically from about 1 mm to about 2
mm in diameter. The air channel 20 can be subdivided into an
umbilical air channel 20a, a control air channel 20b, and an
insertion air channel 20c. The umbilical air channel 20a is the
portion from the air/water supply port 42 and the air supply port
44 to the air/water cylinder 32. The control air channel 20b is the
portion from the air/water cylinder 32 to the CO.sub.2 channel 22.
The insertion air channel 20c is the portion from the CO.sub.2
channel 22 to the air/water channel 56.
[0095] Water Channel
[0096] The water channel 16 is typically from about 1 mm to about 2
mm in diameter. The water channel 16 can be subdivided into an
umbilical water channel 16a and an insertion water channel 16c. The
umbilical water channel 16a is the portion from the air/water
supply port 42 to the air/water cylinder 32. The insertion water
channel 16c is the portion from the air/water cylinder 32 to the
air/water channel 56.
[0097] CO.sub.2Channel
[0098] The CO.sub.2 channel 22 is typically from about 0.5 to about
2 mm in diameter. The CO.sub.2 channel 22 is particularly complex
and restricted in the CO.sub.2 valve. The CO.sub.2 or gas valve
utilizes narrow passages and restrictions. The CO.sub.2 channel 22
may be subdivided into an umbilical CO.sub.2 channel 22a, and a
control CO.sub.2 channel 22b. The umbilical CO.sub.2 channel 22a is
the portion from the CO.sub.2 supply port 40 to the CO.sub.2
cylinder 36 and the control CO.sub.2 channel 22b is the portion
from the CO.sub.2 cylinder 36 to the air channel 20.
[0099] The Device
[0100] As previously described and as shown in FIGS. 1 through 10,
the device 10 broadly includes a first valve 80 and a second valve
82. The first and second valves 80, 82 are each in fluid
communication with a fluid supply 84.
[0101] In the preferred connection to an endoscope, the first valve
80 is in fluid communication with the CO.sub.2 supply port 40 and
the second valve 82 is in fluid communication with the air/water
supply port 42. The connection to the air/water supply port 42 may
also preferably include a connection to the air supply port 44
using a T-connection. In addition, either valve 80, 82 may be
connected to either the CO.sub.2 supply port 40 or the air/water
supply port 42.
[0102] In an alternative connection to an endoscope, the first
valve 80 is in fluid communication with the air/water supply port
42 and the second valve 82 is in fluid communication with the
air/water cylinder 32. The connection to the air/water supply port
42 may also include a connection to the air supply port 44 using a
T-connection. In addition, either valve 80, 82 may be connected to
either the air/water cylinder 32 or the air/water supply port
42.
[0103] The valves 80, 82 are preferably three-way valves that
provide three connections to the valve and allow flow between any
two connections. However, the valves may be two-way valves or a
combination of two-way valves. Preferably one connection is in
fluid communication with the fluid supply 84, a second connection
is connected to a first tubular structure 94, and one connection is
connected to a second tubular structure 96. The valves 80, 82 are
preferably Predyne B3314 three way valves with 1/8 inch NPT threads
and a fluid constant (Cv) of 0.11. The valves 80, 82 may be in
fluid communication with the tubular structures 94, 96 by any means
known in the art such as tubing and flexible couplings.
[0104] The connecting lines 134, including the fluid supply 84 and
the drain line 88 may be of any material used in sterilizing and
cleaning processing equipment. The connecting lines are preferably
about 1/4 inch to about 12 inch diameter plastic tubing, preferably
polyethylene.
[0105] The device 10 may also include a blocking valve 118 in the
fluid supply 84 to direct the flow of fluid to a limited number of
tubular structures. Limiting the flow to one or two lumens allows
the use of a smaller fluid supply pump. Limiting the flow to one
lumen at a time also assures that each lumen receives adequate flow
and is not affected by different lumen sizes or by blockages. The
blocking valve 118 may also be used in testing procedures to
determine if blockages exist in the lines or lumens.
[0106] The fluid may consist of a cleaning fluid 86, a sterilizing
fluid 116, or any other fluid that is desired to reach all portions
of the tubular structure 94,96. The fluid may be a liquid or a gas.
The sterilizing fluid 116 may comprise a liquid performic acid
based sterilant, as described in provisional application No.
60/102,664 entitled MULTI-PART ANTI-MICROBIAL CONCENTRATE SYSTEM
ACTIVATED FLUID, USE-DILUTION FLUID, METHOD OF MAKING SAME, AND
METHOD OF STERILIZING WITH THE USE-DILUTION FLUID, filed on Oct. 1,
1998, the disclosure of which is hereby incorporated by
reference.
[0107] The device and method of the present invention may be
incorporated into an endoscope reprocessing device, as described in
provisional application No. 60/102,663 entitled ENDOSCOPE
REPROCESSING AND STERILIZATION SYSTEM, filed on Oct. 1, 1998, the
disclosure of which is hereby incorporated by reference. FIGS.
11-16 and the following description of the medical reprocessing
device are from the above described provisional application.
[0108] Automatic Medical Instrument Reproccessing Device
[0109] Referring now to FIGS. 11-15, an endoscope reprocessing and
sterilization system is shown and generally indicated as 810. An
exterior housing 812 is provided to arrange, contain and provide
protection for the components of the reprocessing system 810. A
reprocessing bay cabinet 814 of the housing 812 is configured to
contain at least one reprocessing bay 816. The reprocessing bay
cabinet 814 is equipped with at least one cabinet access door 818.
The embodiment shown in FIG. 11 is configured to have two cabinet
access doors 818a, 818b which are shown with one cabinet access
door 818a in the open position allowing access to the at least one
reprocessing bay 816 and the other cabinet access door 818b in the
closed position. The preferred embodiment shown in FIGS. 11-12 is
configured to have two independently operated reprocessing bays
816a, 816b, although it is not limited to two independently
operated reprocessing bays 816.
[0110] A chemical supply drawer 820, which is configured to contain
support components, generally indicated at 822, is equipped with at
least one drawer access door 824.
[0111] The embodiment shown in FIG. 11 is configured to have two
chemical supply drawer access doors 824a, 824b which are shown with
one drawer access door 824a in the open position allowing access to
the support components 822 and the other drawer 820 access door
824b in the closed position. The support components 822, contained
within the chemical supply drawer 820, can include a soap container
826, a plurality of chemical sterilant component containers 828,
830, a water heater 832, a hot water tank 834, a reaction chamber
836, a load sensor 838, an electric motor and pump 840, an air
compressor 842, and a compressed air tank 844. The preferred
embodiment shown in FIG. 12 is configured with two chemical
sterilant component containers 828, 830 which serve to contain the
two components of a multi-component concentrate system. The
reprocessing system 810 may include a greater or lesser number of
chemical sterilant component containers depending upon the number
of components required for the sterilant used. In the preferred
embodiment, each of the two reprocessing bays 816a, 816b is
independently operated. To support such independent operation, the
device 810, as shown in FIG. 12, is equipped with an independently
operated electric motor and pump 840a, 840b, one for each
reprocessing bay 816a, 816b.
[0112] Hydraulic and pneumatic connections between each of the
components contained within the chemical supply drawer 820 and the
reprocessing bays 816a, 816b contained within the reprocessing bay
cabinet 814 are shown only in FIG. 16 to simplify presentation of
the major components shown in FIGS. 11-15.
[0113] The reprocessing bays 816a, 816b are identically configured
and independently operated. Detail discussion of the reprocessing
bay components and operations will, for demonstration purposes, be
limited to descriptions of reprocessing bay 816a.
[0114] The reprocessing bay 816a is equipped with a reprocessing
bay door 846, which serves to seal the reprocessing bay during
operation. The reprocessing bay door 846 can be constructed so as
to provide thermal and sound proofing features. The vertical side
walls 848a, 848b, back wall 850, ceiling member 852, and floor
member 854 can also be formed to provide thermal and sound proofing
features. The thermal and sound proofing features can be provided
by manufacturing the side walls 848a, 848b, back wall 850, ceiling
852, floor 854, and door 846 structures of materials such as, for
example, plastics, steel, glass, and the like.
[0115] The reprocessing bay 816a is equipped with at least one and
preferably two identical rotating arm members 856. In the preferred
embodiment, the two rotating arm members 856a, 856b are separately
rotatably mounted on a central portion of opposing side walls 848a,
848b. The following detailed description applies to all rotating
arm members 856 but reference is limited to rotating arm member
856a, which is best shown in FIG. 13. The rotating arm member 856a
includes a central hub sleeve 858 rotatably connected around a
rotating arm hub member 860 which extends outwardly at about a
right angle from the central portion of side wall 848a At least two
counterbalanced spray arms 862a and 862b are connected on
approximate opposing sides of the central hub sleeve 858. Each
spray arm 862a, 862b defines a spray arm lumen 864a, 864b (shown in
part with broken lines). The spray arm lumen 864a, 864b extends at
least a portion of the length of the spray arm 862a, 862b and
serves to operatively connect a hub sleeve lumen 866 defined within
the central hub sleeve 858 with a plurality of spray jets 868
defined in the wall of the spray arms 862a, 862b. Together the
interconnected hub sleeve lumen 866, spray arm lumens 864a, 864b
and spray jets 868 provide a conduit for the pressurized flow of
washing, rinsing and sterilizing fluids from a rotating fluid
connector 870, defined within the hub member 860, to the interior
of the reprocessing bay 816a. The washing, rinsing and sterilizing
fluids are provided to the rotating fluid connector 870 by tubular
conduits as shown in FIG. 16. Optionally, one or more of the side
walls 848a, 848b, back wall 850, ceiling 852, floor 854 and door
846 members walls of the reprocessing bay can be provided with wall
spray jets 869 which are fluidly connected to the rotating fluid
connector 870 or, alternatively, to a separate fluid inlet
connector. Tubular conduits used in the present invention can be
formed of metal, plastic, glass and the like as is well known in
the art.
[0116] At the each distal end 872a, 872b of spray arms 862a, 862b
is a spray nozzle 874a, 874b, which is configured with a plurality
of spray openings 876. The spray openings 876 are operatively
connected to the spray arm lumens 864a, 864b and together with the
spray jets 868 direct sterilant and rinse fluids into the central
portion of the reprocessing bay 816a. Spray nozzles 874a, 874b may
also rotate about the longitudinal axis of spray arms 862a, 862b.
In addition to the fluid directing function for sterilizing and
rinsing, the spray openings 876 and spray jets 868 direct the
pressurized flow of fluid out of the spray nozzle 874a, 874b and
spray arms 862a, 862b in such a manner as to effect aggregate
impulse which produces a reactive rotational force of the spray
arms 862a, 862b around the central hub 860.
[0117] The reprocessing bay 816a can have at least one cassette
guide 878 which serves to guide a cassette 880 from a loading
position outside of the reprocessing bay 816a to an operational
position inside the reprocessing bay 816a. Preferably the
reprocessing bay 816a is equipped with two cassette guides, an
upper cassette guide 878a and a lower cassette guide 878b. The
upper cassette guide 878a can be secured to the ceiling 852 or
alternatively to the upper portion of the back wall 850 of
reprocessing bay 816a. The lower cassette guide 878b can be secured
to the floor 852 or alternatively the lower portion of the back
wall 850 of reprocessing bay 816a. The interior surface of the door
846 of reprocessing bay 816a can be configured to have a door guide
882 which aligns with the lower cassette guide 878b to facilitate
the positioning of the cassette 880 into or out of the reprocessing
bay 816a.
[0118] The cassette 880 is configured to removably secure a medical
device such as an endoscope within the reprocessing bay 816a. The
medical device is preferably suspended above the washing, rinsing
or sterilizing fluid. The cassette 880 can be equipped with a
plurality of clamping members 882 for holding the medical device
being sterilized in position in the reprocessing bay 816a. The
cassette can be removably positioned in the reprocessing bay 816a
in a suspended orientation to the upper cassette guide 878a. As
best shown in FIGS. 12 and 15, the cassette is preferably removably
positioned between the upper cassette guide 878a and the lower
cassette guide 878b. As best shown in FIG. 15, the cassette 880 can
be configured to have an upper rotational member 886 and a lower
rotational member 888 which are independently able to freely rotate
about an axle member 890a, 890b which is fixedly secured to the
upper and lower portions of the cassette 880. The upper rotational
member 886 and the lower rotational member 888 are each provided
with a guiding groove 892, 894, respectively. The guiding grooves
892, 894 are sized and configured to complement the size and shape
of the upper cassette guide 878a and the lower cassette guide 878b,
respectively, for purpose of facilitating ease of movement of the
cassette into and out of the reprocessing bay 816a.
[0119] In addition, the guiding groove 894 is sized and configured
to complement the door guide 882 size and shape so as to guide and
facilitate movement of the lower rotational member 888 across the
inner surface of the reprocessing bay door 846 when the bay door
846 is in the open position.
[0120] Extending into the upper portion of the reprocessing bay
816a is a medical device connector 896 which is configured to
provide a fluid tight fitting for a wide variety of medical
devices, such as endoscopes. It is within the concept of the
present invention to provide connection adapters that will permit a
fluid tight fitting during pressure sterilization of the lumen of a
wide variety of medical devices. Washing, rinsing and sterilizing
fluids are provided to the medical device connector through tubing
conduits as shown in FIG. 16.
[0121] The floor member 854 of the reprocessing bay 816a is
configured to serve as a reservoir 898 for collection of fluids
which have been sprayed onto or through the medical device being
reprocessed and sterilized in the reprocessing system 810. The
reservoir can be equipped with a filtration system 900 of at least
two levels of filtration. A sump drain 902 for collection of fluids
is provided in the lower portion of the reservoir 898. The size of
the reservoir 898 and the vertical positioning of the reprocessing
bays 816 allows the reprocessing system 810 to operate and
recirculate about 2-5 liters of sterilant. The reprocessing system
810 preferably operates with about 3 liters of sterilant.
[0122] In operation, the preferred embodiment of the present
invention provides for asynchronous reprocessing of two endoscopes
with overlapping cycle time periods. Chemical components for the
sterilant are heated and measured as they are moved to and mixed in
the reaction chamber 836. The sterilant temperature is monitored
and controlled and the reaction of the chemical components in the
reaction chamber 836 is timed under the control of a central
processor 912. The sterilant's refractive index is measured to
ensure the chemical reaction is complete and to verify the presence
of the sterilant. Water is added to dilute the sterilant to the
use-dilution concentration. Two endoscopes can be reprocessed and
sterilized independently and asynchronously using reprocessing bays
816a, 816b. The endoscopes are mounted on the cassettes 880 and
connected to the medical device connector 896 through which the
lumen of the endoscope will be pressure washed and sterilized. The
reprocessing bay doors 846 are secured and the endoscopes are
internally and externally washed with soap and water and rinsed.
Just prior to the sterilization cycle, the endoscopes are rinsed
with hot water to ensure the sterilant will not be cooled upon
contact with the endoscopes. The endoscopes are then sterilized
internally and externally with sterilant prepared in the reaction
chamber 836 just prior to use. The cleaning and sterilization of
the endoscope lumen through the medical device connector 896 is
assisted by a flow of liquid (soap and water, rinse water, and
sterilant in turn) which receives a superimposed pulsating flow of
air. This pulsating flow of air causes the liquid flow to become
severely unsteady resulting in a scrubbing action on the lumen wall
of the endoscope.
[0123] Operation of the reprocessing system 810 is monitored by
sensors, including those described above, which provide information
to the central processor 912. The central processor 912 receives
cycle program instructions from a user through the user interface
952. The user interface can be equipped with any form of command
signal keys or buttons as is well known in the art. Visual displays
of user commands which are entered as well as central processor 912
responses, error messages, status notifications and the like can be
presented for the user at the user interface 952. A printer
capability can be included to permit the central processor 912 to
provide written records of any aspect of reprocessing system
operation to the user. Printed records of specific endoscope
sterilization can also be printed at the completion of a
reprocessing and sterilization cycle. All aspects of the operation
of the reprocessing system 810 can be controlled by the central
processor 912, to include measuring and mixing of chemical
components for the sterilant, metering of water to the reaction
chamber 836 for sterilant dilution purposes, washing, rinsing and
sterilizing cycles, self-sterilizing, blockage detection and user
notification, door ajar sensing and responsive operation
termination, and other similar system monitoring and operational
controls.
[0124] In Operation
[0125] In operation, the valves 80, 82 alternate between a first
position and a second position as described above causing a first
fluid flow path 110 and a second fluid flow path 112. In describing
the fluid flow paths 110, 112, downstream is in the flow direction
away from the distal end 52 of the umbilical section 28 and towards
the distal end 54 of the insertion section 24.
[0126] Referring to FIGS. 3, 4, 7, and 8, in the preferred
connection to an endoscope, when the device 10 is in the first
position 106 causing a first fluid flow path 110, the first valve
80 is open to the fluid supply 84 allowing fluid to flow downstream
through the CO.sub.2 supply port 40, downstream through the
umbilical CO.sub.2 channel 22a, downstream through the CO.sub.2
cylinder 36, downstream through the control CO.sub.2 channel 22b,
into the air channel 20, splitting into two flows, the first flow
is upstream (first upstream flow) into the control air channel 20b,
and the second flow is downstream into the insertion air channel
20c, downstream into the air/water channel 56, through the
air/water nozzle 46 and exits the endoscope 12 to a drain 114 at
about atmospheric pressure. The first upstream flow continues into
the control air channel 20b and flows upstream into the air/water
cylinder 32. From the air/water cylinder 32, the fluid splits and
flows three ways; a) upstream through the umbilical water channel
16a and out the air/water supply port 42 through the second valve
82 to the drain line 88, b) upstream through the umbilical air
channel 20a and out the air/water supply port 42 and air supply
port 44 through the second valve 82 and to the drain line 88, and
c) downstream through the insertion water channel 16c, downstream
through the air/water channel 56, through the air/water nozzle 46
and exits the endoscope 12 to a drain 114 at about atmospheric
pressure. The downstream flow through the insertion water channel
16c may flow upstream depending on the relative pressure loss
between the various channels.
[0127] In a preferred connection to an endoscope, when the device
is in the second position 108 causing a second fluid flow path 112,
the second valve 82 is open to the fluid supply 84 allowing fluid
to flow downstream through the air/water supply port 42 and air
supply port 44 and downstream into both the umbilical water channel
16a and the umbilical air channel 20a meeting at the air/water
cylinder 32. The fluid splits and flows downstream through control
air channel 20b and downstream through the insertion water channel
16c, the flow continues through the insertion water channel 16c and
downstream through the air/water channel 56 and through the
air/water nozzle 46 and exits the endoscope 12 to a drain 114 at
about atmospheric pressure. The flow continues downstream through
the control air channel 20b and splits and flows upstream into the
CO.sub.2 control channel 22b and downstream through the insertion
air channel 20c. The flow continues downstream through the
insertion air channel 20c through the air/water channel 56 and
exits the endoscope 12 to a drain 114 at about atmospheric
pressure. The flow continues upstream through the control CO.sub.2
channel 22b, upstream through the CO.sub.2 cylinder 36, upstream
through the umbilical CO.sub.2 channel 22a, upstream through the
CO.sub.2 supply port 40, and through the first valve 80. The fluid
flows through the first valve 80 and to the drain line 88.
[0128] The second valve 82 may also remain completely closed when
the first valve 80 is open to the fluid supply 84. If the second
valve 82 remains closed, fluid will not flow as easily or at all
from the air/water cylinder 32 through umbilical air channel 20a
and umbilical water channel 16a.
[0129] In an alternative connection to an endoscope, as shown in
FIG. 7, when the device is in the first position 206 causing a
first fluid flow path 210, the first valve 80 is open to the fluid
supply 84 allowing fluid to flow downstream through the air/water
supply port 42 and air supply port 44 and downstream into both the
umbilical water channel 16a and the umbilical air channel 20a
meeting at the air/water cylinder 32. In this description of the
flow, flow through the CO.sub.2 channel 22 is not included because
the CO.sub.2 valve 36 may be closed or there may not be a CO.sub.2
channel. The fluid splits and flows three ways; a) downstream
through control air channel 20b, b) downstream through the
insertion water channel 16c, and c) through the air/water cylinder
32 to the second valve 82. The flow through the control air channel
20b flows downstream through the insertion air channel 20c, through
the air/water channel 56 and exits the endoscope 12 to a drain 114
at about atmospheric pressure. The flow through the insertion water
channel 16c flows downstream through the air/water channel 56 and
through the air/water nozzle 46 and exits the endoscope 12 to a
drain 114 at about atmospheric pressure. The flow through the
air/water cylinder 32 flows through the second valve 82 and to
drain line 88.
[0130] In the alternative connection to an endoscope, as shown in
FIG. 8, when the device is in the second position 208 causing a
second fluid flow path 212, the second valve 82 is open to the
fluid supply 84 allowing fluid to flow downstream through the
air/water cylinder 32. In this description of the flow, flow
through the CO.sub.2 channel 22 is not included because the
CO.sub.2 valve 36 may be closed or there may not be a CO.sub.2
channel. The fluid splits and flows four ways; a) downstream
through control air channel 20b, b) downstream through the
insertion water channel 16c, and c) upstream into the umbilical
water channel 16a, and d) upstream into the umbilical air channel
20a. The flow through the control air channel 20b flows downstream
through the insertion air channel 20c, through the air/water
channel 56 and exits the endoscope 12 to a drain 114 at about
atmospheric pressure. The flow through the insertion water channel
16c flows downstream through the air/water channel 56 and through
the air/water nozzle 46 and exits the endoscope 12 to a drain 114
at about atmospheric pressure. The flow upstream into the umbilical
water channel 16a flows out the air/water supply port 42 through
the first valve 80 and to drain line 88. The flow upstream into the
umbilical air channel 20a flows out the air/water supply port 42
and the air supply port 44 through the first valve 80 and to drain
line 88.
[0131] The suction channel 18 may also be cleaned or sterilized by
using the above device 10. The suction channel 18 may be cleaned
simultaneously by providing third and fourth valves 90,92 or
separately by connecting to the first and second valves 80,82. The
device 10 may have a third and a fourth position 140, 142, with the
third and fourth position respectively the same as the first and
second positions except that the third valve 90 replaces the first
valve 80 and the fourth valve 92 replaces the second valve 82. The
third valve 90 may be connected to the suction supply port 38 and
the fourth valve 92 to the biopsy port 50 or alternatively to the
suction control valve 34.
[0132] With the device in the third position 140 causing a third
fluid flow path 136, fluid flows downstream through the suction
supply port 38, downstream through the umbilical suction channel
18a, downstream through the suction cylinder 34, downstream through
the control suction channel 18b, splitting into a upstream flow
through the biopsy port 50 and through the fourth valve 92 to the
drain line 88, and a downstream flow through the insertion suction
channel 18c and exiting the suction opening 48 of the endoscope 12
to a drain 114 at about atmospheric pressure.
[0133] With the device in the fourth position 142 causing a fourth
fluid flow path 138, fluid flows downstream through the biopsy port
50, splitting into a downstream flow through the insertion suction
channel 18c and exiting through the suction opening 48, and
splitting into an upstream flow through the control suction channel
18b, upstream through the suction cylinder 34, upstream through the
umbilical suction channel 18a, upstream through the suction supply
port 38 through the third valve 90 and to the drain line 88.
[0134] Cleaning and Sterilizing Methods
[0135] The apparatus and method in accordance with the present
invention provides both a method of sterilization of tubular
structures, in particular long, narrow, tubular structures, and a
method of cleaning the lumens of a medical device.
[0136] The sterilization method broadly includes the sterilization
of the interior of a tubular structure comprising: a) providing a
tubular structure 94, 96, b) providing a sterilizing fluid 116 c)
causing the sterilizing fluid 116 to flow at a positive pressure
through the tubular structure 94, 96 in a first fluid flow path
110, and d) causing the sterilizing fluid 116 to reverse flow at a
positive pressure through the tubular structure 94, 96 in a second
fluid flow path 112, so that at least part of the second fluid flow
path 112 is opposite as the first fluid flow path 110.
[0137] The sterilization method may also include providing the
sterilizing fluid 116 at a temperature preferably from about 20
degrees C. to about 50 degrees C. and most preferably about 40
degrees C. to about 50 degrees C. The sterilizing fluid is
preferably provided from about 1 minute to about 20 minutes and
most preferably for about 10 minutes.
[0138] The sterilizing method may also provide that the sterilizing
fluid 116 provided in the flow and reverse flow method of the
present invention has a flow volume from preferably about 100
ml/min to about 1400 ml/min. The flow volume is preferably about
100 ml/min to about 250 ml/min for lumens with a diameter of about
1 mm to about 2 mm and about 600 ml/min to about 1400 ml/min for
lumens with a diameter of about 3 mm to about 6 mm. The sterilizing
fluid 116 provided in the flow and reverse flow method of the
present invention has a flow velocity from preferably about 50
cm/sec to about 500 cm/sec and most preferably about 50 cm/sec to
about 250 cm/sec. The sterilizing fluid 116 provided in the flow
and reverse flow has a pressure preferably below about 20 psi and
most preferably about 10 psi to about 20 psi.
[0139] The sterilization method may also include wherein the
tubular structure 94, 96 has a diameter of less than about 6
mm.
[0140] The sterilization method may also include starting the first
fluid flow path 110 and the second fluid flow path 112 in one end
of a medical device.
[0141] The sterilization method may also include starting one fluid
flow path 210,212 in the control head or other central attachment
point of a medical device.
[0142] The sterilization method may also include providing the
device 10 of the present invention.
[0143] The sterilization method may also include controlling the
flow and said reverse flow by a central processor.
[0144] The present invention also includes a method of cleaning a
medical device with lumens 14. The cleaning method broadly includes
a method of cleaning the lumens 14 of a medical device including a)
providing a medical device with a first lumen 120 and a second
lumen 122, each lumen 120, 122 having a proximal end 124, 128 and a
distal end 126, 130 and the distal end 126, 130 of at least one of
the lumens 120,122 is open to a drain 114 at about atmospheric
pressure; b) providing a cleaning fluid 86; c) causing the cleaning
fluid 86 to flow through the lumens 120,122 in a first fluid flow
path 110 starting at the proximal end 124 of the first lumen 120;
and d) causing the cleaning fluid 86 to reverse flow through the
lumens 120, 122 in a second fluid flow path 112 starting at the
proximal end 128 of the second lumen 122, wherein at least part of
the second fluid flow path 112 is opposite the first fluid flow
path 110.
[0145] The cleaning method may also include providing a medical
device with the proximal end 124, 128 of each lumen 120, 122
located in one end of the medical device.
[0146] The cleaning method may also include starting one fluid flow
path 210, 212 in the control head or other central attachment point
of a medical device.
[0147] The cleaning method may also include providing the device 10
of the present invention.
[0148] The cleaning method may also include draining the first
fluid flow path 110 through the proximal end 128 of the second
lumen 122 and draining the second fluid flow path 112 through the
proximal end 124 of the first lumen 120.
[0149] The cleaning method may also provide that the cleaning fluid
86 provided in the flow and reverse flow has a flow volume from
preferably about 100 ml/min to about 1400 ml/min. The flow volume
is preferably about 100 ml/min to about 250 ml/min for lumens with
a diameter of about 1 mm to about 2 mm and about 600 ml/min to
about 1400 mil/min for lumens with a diameter of about 3 mm to
about 6 mm. The cleaning fluid 86 provided in the flow and reverse
flow has a flow velocity from preferably about 50 cm/sec to about
500 cm/sec and most preferably from about 50 cm/sec to about 250
cm/sec. The cleaning fluid 86 provided in the flowing and reverse
flowing has a pressure preferably below about 20 psi and most
preferably from about 10 psi to about 20 psi.
[0150] The cleaning method may also include providing the device 10
of the present invention.
[0151] The cleaning method may also provide controlling the flow
and the reverse flow by a central processor.
[0152] The present device and method also improves sterilization of
endoscopes. As shown in the following examples, complete
sterilization of the lumens of endoscopes can be difficult, in
particular, the CO.sub.2 lumen of the endoscope. The CO.sub.2 lumen
typically has bends, connections, restrictions, and irregularities
making it difficult to provide complete cleaning or sterilization
of the CO.sub.2 lumen.
[0153] The following tests show that the device and method of the
present invention provides an unexpected improvement in the
sterilization of the endoscope.
[0154] For the following experiments, the endoscope was coiled
loosely and attached to a rack, which held it vertically. The
control head was mounted so that the eyepiece was up and the
control knobs were vertical. The suction, air/water, and CO.sub.2
channels were inoculated with a total of 1-8.times.10.sup.6 spores
and dried for an hour. The endoscope was treated with a performic
acid based sterilant in a device that pumped sterilant through the
channels and sprayed the exterior of the endoscope with sterilant.
The endoscope was rinsed briefly and assayed for surviving
organisms. If even one survivor was found, the endoscope was judged
nonsterile. As shown in the table below, a large number of
variables were tested in our efforts to sterilize endoscopes
consistently. The best results seemed to be obtained when the
pressure (flow rate) in the lumens was increased to 20 psi, close
to the maximum allowed. We noted that survivors were rarely found
in the suction channel, the largest, least complex channel.
Survivors were frequently found in the CO.sub.2 channel, which has
a small lumen and an intricate, constricted valve construction.
Flowing sterilant in both directions unexpectantly consistently
eliminated all of the survivors in the endoscopes including in the
CO.sub.2 channel. As shown in the table, this procedure gave
consistent sterilization even with a reduced pressure of 12 psi in
the lumens.
1TABLE I Sterilizing endoscopes with performic acid based
sterilant, 10 minutes at 40-45.degree. C. Number Con- scopes nec-
sterile/ tion total point Variable tested Control 4 psi pressure in
lumens 0/3 head 10 psi pressure in lumens 1/2 20 psi pressure in
lumens 3/4 Light 4 psi pressure in lumens 0/3 guide 10 psi pressure
in lumens 0/5 20 psi pressure in lumens 5/8 Control Scope
orientation - lay 2/4 head flat or light guide Control Scope
orientation - control 0/2 head knobs horizontal Scope orientation -
control 0/2 head upside down Light Increase sterilant volume 1/3
guide three-fold Prewarm scope to 45.degree. C. 1/2 Control Use
restrictors to channel 2/7 head more flow to CO.sub.2 channel Light
Connect to air/water only, 2/8 guide flow to CO.sub.2 channel from
control head Control Interrupt sterilant flow 1/5 head with
periodic air pulses or light guide Light Reverse flow in the
CO.sub.2 10/10 guide channel
[0155]
2TABLE II DETAILED DATA TABLE: Improved Application of Liquids to
Lumens by Reverse Flow Sterilization of endoscopes on an automatic
endoscope reprocessor, 40-45.degree. C., 15% performic acid based
sterilant in RO water, 10-minute exposure. Number of
survivors.sup.k A/W A/W CO.sub.2 Suct port Conn.sup.f Chann press
Other Suct.sup.a CO.sub.2.sup.b ACI.sup.j Ext port valve Port LG CH
Connectors 0 0 0 0 0 0 0 0 attached 1 0 0 0 0 0 0 0 before
inoculation, foamy, airpulse during sterilization (performic acid
based sterilant without phosphoric) CH Foamy, no 0 0 1 0 0 0 0 0
airpulse LG Leaking plugs 32 TNTC TNTC 0 0 7 0 0 (modified ACI) 2
66 8 0 0 0 0 0 at CH, foamy, 0 0 0 0 0 0 0 0 performic acid based
sterilant plus phosphoric acid CH 10 psi 12 L 0 0 0 0 0 0 0 0
sterilant, lay 0 0 0 0 0 0 0 0 scopes flat CH 4 psi Low foam by 0 0
1 0 0 0 0 0 low pump 0 3 2 0 0 0 0 0 speed 0 2 0 0 0 0 0 0 (400
rpm) LG 4 psi Low foam 0 0 7 0 0 0 0 0 0 1 0 0 0 0 0 0 0 12 4 0 0 0
0 0 CH 10 psi Standard 0 0 0 0 0 0 0 0 position, 0 1 1 0 0 0 0 0
raise channel pressure by restricting flow to spray arms (from this
point forward) Knobs up on 1 111 0 0 0 0 0 control head 0 1 0 0 0 0
0 0 Upside down 0 38 17 0 0 0 0 0 2 7 0 0 0 0 0 0 LG 10 psi 0 13 9
0 0 0 0 0 0 2 0 0 0 0 0 0 LG 18-20 psi 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 4 0 0 0 0 0
0 1 0 0 0 0 0 0 0 23 4 0 0 0 0 0 LG 18-20 psi 12 L sterilant 0 0 0
0 0 5 0 0 0 0 0 0 0 0 0 ND 1 0 0 0 0 0 0 0 LG 18-20 Dry at
45.degree. C. 2 TCTN TNTC 0 0 0 0 0 0 0 0 0 0 0 0 0 CH 18-20 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0 0 CH 18-20
Add restrictor 0 2 17 0 0 0 0 0 to A/W 0 0 0 0 0 0 0 0 connector on
light guide end CH 18-20 As above. 0 P 41.sup.h 0 0 0 0 0 Sample
A/W in 24.sup.g both E 9 directions 0 P 16.sup.i 0 0 0 0 0 from
control 6 head, sample E1 CO.sub.2 from 7 control head to light
guide as well as entire channel CH 18-20 Clamp on CO.sub.2 0 2 6 0
0 0 0 0 valve to hold 0 0 0 0 0 0 0 0 it open, 0 0 1 0 0 0 0 0
smaller restrictor on A/W connector on light guide end LG 18-20
Connect 0 0 0 0 0 0 0 0 suction & A/W 0 1 0 0 0 0 0 0 only,
tight restrictor on prong, standard inoculum LG Connect 0 2 2 0 0 0
0 0 suction, A/W, 5 0 1 0 0 0 0 0 and CO.sub.2, no restrictor,
standard inoculum, run at 400 rpm as has been done above to reduce
foam LG 9-10 Connect 0 0 1 0 0 0 0 0 suction, A/W 0 1 0 0 0 0 0 0
and CO.sub.2, no 0 0 4 0 0 0 0 0 restrictor, standard inoculum, run
at 800 rpm, foamy LG 9-10 As above 0 0 0 0 0 0 0 0 except try to 0
2 2 0 0 0 0 0 inoculate distal end only of air/water/ CO.sub.2
channel (.about.0.3 ml inoculum rather than 5) LG 9-10 As above 0 1
0 0 0 0 0 0 except lay A/W = 3.sup.j scopes as flat 0 5 6 0 0 0 0 0
as possible in A/W = 2 rear of bay LG 13-14 Connect 0 0 0 0 0 0 0 0
suction, A/W 0 0 0 Mold 0 0 0 0 and air prong, 0 17 33 0 0 0 0 0
standard A/W = 4 inoculum, 0 2 2 0 0 0 0 0 10-12 800 rpm 0 0 0 0 0
0 0 0 Connect 0 28 14 0 0 0 0 0 suction, A/W, A/W = 1 restrictor on
prong. Inoculate exterior-back of knob, insertion tube, control
head 11-12 Purge with air 0 6 1 0 0 0 0 0 for 5 sec in A/W = 1
every minute 0 4 1 0 0 0 0 0 of exposure, connect as above 12-13
Purge with 0 1 3 0 0 0 0 0 air for 15 sec every other minute of
exposure (total of 4 times), connect as above 10-13 Alternate 0 0 0
0 0 0 0 0 direction 0 0 0 0 0 0 0 0 of flow in 0 0 0 0 0 0 0 0
CO.sub.2 channel 0 0 0 0 0 0 0 0 every 0 0 0 0 0 0 0 0 minute of 0
0 0 0 0 0 0 0 exposure, 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 No 0 0 0 0 0 0 0 0 preheat, otherwise as above .sup.aSuction
channel flushed and brushed first .sup.bCO.sub.2 channel flushed
with syringe then all channels flushed with all-channel irrigator
for ACI count .sup.cThe tubing connection to the air/water and
CO.sub.2 channels was disconnected when the scope was partially
removed from the chamber. It is possible that it came loose during
the cycle. .sup.dThe exposure cycle was stopped for about 1 minute.
The light guide end fell off the rack and pulled a tubing
connection loose. .sup.eFilters clogged during survivor recovery
from neutralizer, most probably due to agar present in the
neutralizer from previous use of bottle .sup.fLG = light guide, CH
= control head .sup.gP = control head to light guide, E = entire
length of channel .sup.hA/W only - proximal (CH to LG) = 0, distal
end (CH to nozzle) = 3 .sup.IA/W proximal = 0, distal end = 0
.sup.jAfter (and including) 46.sup.th test sampled the air and
water channels from the light guide end to distal tip. This was
done after the gas channel sampling but before the ACI. Results are
reported only if there were survivors. .sup.kIf the number of
survivors is > 0, the test failed.
[0156] Although the description of the preferred embodiment has
been presented, it is contemplated that various changes, including
those mentioned above, could be made without deviating from the
spirit of the present invention. It is therefore desired that the
present embodiment be considered in all respects as illustrative,
not restrictive, and that reference be made to the appended claims
rather than to the foregoing description to indicate the scope of
the invention.
* * * * *