It finds particular application in conjunction with the decontamination of medical devices, especially medical devices such as endoscopes and other devices having channels or lumens that must be decontaminated after use.

Sterilization is typically defined as the absence of all life forms including bacterial endospores which are the living organisms most resistant to known sterilants. Disinfection, by distinction, only connotes the absence of pathogenic life forms. Herein, the general term, decontamination, will be used to describe both disinfection and sterilization.

Endoscopes and similar medical devices having channels or lumens formed therethrough are being used on an ever increasing basis in the performance of medical procedures. The popularity of these devices has led to calls for improvements in the decontamination of these devices between use, both in terms of the speed of the decontamination and the effectiveness of the decontamination. One drawback associated with many known endoscope decontamination devices is their reliance on reusable glutaraldehyde or the like as a liquid decontaminant solution. While glutaraldehyde is generally effective for disinfection, sterilization with glutaraldehyde can take 10 to 12 hours which is too long in today's healthcare facilities. Another drawback to glutaraldehyde systems is that they sterilize without cleaning, i. e., they leave sterile biological waste matter on the medical instruments.

Another drawback associated with many known decontamination devices is their lack of a decontaminated rinse liquid. Many known decontamination devices are concerned only with cleaning and disinfecting the devices and consequently rely on unfiltered"tap"water for rinsing. Even those that filter or otherwise decontaminate the rinse liquid often do not decontaminate the rinse liquid flow paths between the source of rinse liquid and the decontamination basin under the incorrect assumption that these apparently closed rinse liquid flow paths cannot become contaminated. Thus, with these devices, it is possible for microorganisms to be reintroduced onto the medical device from the rinse liquid. One known endoscope sterilizer does provide a sterile rinse and rinse liquid flow path (STERIS SYSTEM 1 STERIS Corporation, Mentor, Ohio). However, it would be desirable to include additional features in conjunction with the sterile rinse and sterile rinse flow paths of this unit.

Prior medical instrument decontamination devices do not include a simple and effective means for accurately delivering a select charge of both detergent concentrate and decontaminant concentrate as needed to form a cleaning solution and a decontamination solution, respectively. Instead, many prior devices rely upon a large tank to hold a reusable decontaminant such as glutaraldehyde and rely upon tank of detergent that must be refilled. The need to refill these tanks periodically decreases efficiency and also puts an operator in contact with decontaminant and detergent liquid and vapors.

Further, glutaraldehyde is an environmentally hazardous material that needs to be chemically deactivated.

Disposal or reprocessing of diluted or contaminated glutaraldehyde is inconvenient and costly.

Furthermore, with these systems, it is possible

for the detergent tank or the decontaminant tank to run dry without the knowledge of the machine operator. Also, it is not always possible to verify that the detergent or decontaminant has actually been properly and accurately dispensed into the decontamination basin. It would be desirable to provide a decontamination apparatus that simply and accurately dispenses a select dose of detergent concentrate and decontaminant concentrate as needed, without requiring tanks to be refilled and without exposing an operator to detergents and decontaminants. It would also be desirable to provide such a system which reduces the possibility that an incorrect amount of detergent or decontaminant will be dispensed.

The present application is therefore directed to a method and apparatus which overcomes these problems and others while providing better overall decontamination results and efficiency.

Summary of the Invention In accordance with one aspect of the present invention, an apparatus for cleaning and microbially decontaminating a medical device having at least one internal channel formed therein includes a decontamination area for receiving a non-sterile device and at least one pump having an inlet in fluid communication with the decontamination area and an outlet for connection with the at least one internal channel of the device such that liquid from the decontamination area is circulated through the at least one internal channel by the at least one pump. At least one spray nozzle is positioned in the decontamination area and is fluidically connected to the at least one pump to spray liquid onto exterior surfaces of the device in the decontamination area. A source of sterile rinse liquid includes a

microbe removal filter and rinse liquid pathways in selective fluid communication with the pump so that liquid microbial decontaminant is selectively communicated from the decontamination area into the microbe removal filter and through the rinse liquid pathways to microbially decontaminate the filter and the pathways. The apparatus further includes a mixing chamber for sequentially dispensing (i) a detergent concentrate and, thereafter (ii) a microbial decontamination concentrate into liquid passing through the mixing chamber. The mixing chamber is adapted to receive a multi-compartment ampule including a first interior compartment holding a charge of detergent concentrate and at least a second interior compartment holding a charge of microbial decontamination concentrate. A means is provided for sequentially opening the first interior compartment of the ampule to release the charge of detergent concentrate and, thereafter, the at least one second interior compartment of the ampule to release the charge of decontaminant concentrate. An electronic control means is operatively connected to and controls the ampule opening means to open the first interior compartment during a cleaning cycle of the apparatus and to open the second interior compartment during a microbial decontamination cycle of the apparatus.

In accordance with another aspect of the invention, a method of cleaning and sterilizing the exterior surfaces and interior channels of a medical device includes placing the device in a receiving area, circulating a cleaning solution over the exterior surfaces and through the internal channels of the device, and draining cleaning solution from the device receiving area. A rinse liquid is circulated over the exterior surfaces and through the internal channels of the device

in the receiving area and is drained from the device receiving area. Internal channels of the device are flushed with air to remove residual liquid from the channels in the device. The method further includes circulating liquid sterilant over the exterior surfaces and through the internal channels of the device in the device receiving area, circulating the liquid sterilant into a rinse water microbe removal filter and through rinse liquid pathways between the microbe removal filter and the device receiving area to sterilize the filter and pathways, and draining the liquid sterilant from the device receiving area. A rinse water is passed through the microbe removal filter to sterilize the rinse water and the sterile rinse water is communicated through only the previously sterilized rinse liquid pathways to the device receiving area. The sterile rinse water is circulated over the exterior surfaces and through the internal channels of the device in the receiving area, and drained from the device receiving area. The cleaning solution is formed by mixing detergent concentrate with water by opening a first compartment of a multi- compartment container that contains detergent concentrate to dispense the detergent concentrate in the water. The liquid sterilant is formed by mixing sterilant concentrate with water by opening at least a second compartment of the multi-compartment container that contains sterilant concentrate to dispense the sterilant concentrate into the water.

One advantage of the present invention is that it provides an improved decontamination apparatus and method.

Another advantage of the present invention is that it provides for accurately and conveniently dispensing detergent and decontaminant concentrate ingredients into a liquid to form a cleaning solution or

a decontamination solution.

Still another advantage of the present invention resides in the use of a single-use decontaminant.

A further advantage of the present invention is that it provides a decontaminated rinse liquid and decontaminated rinse liquid flow paths for communicating the decontaminated rinse liquid onto and through the channels of the decontaminated medical device.

A further advantage of the present invention resides in its provision of a leak test system for testing the integrity of a sheath or housing forming a part of an endoscope or other device being decontaminated.

A further advantage of the present invention is that it allows each interior flow channel of a medical device to be individually flushed with liquid or decontaminated air and that each interior channel of the medical device can be monitored for blockage.

Yet another advantage of the present invention is the provision of a"break tank"water supply system for isolating the apparatus from a utility or"tap"water supply system.

Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon their reading and understanding of the following specification of the preferred embodiments.

Brief Description of the Drawings The invention may take form in various components and arrangements of components and in various steps and arrangements of steps. The drawings are for purposes of illustrating preferred embodiments only, and are not to be construed as limiting the invention.

FIGURE 1 is a front elevational view of a

decontamination apparatus in accordance with the present invention; FIGURE 2 is a diagrammatic illustration of the decontamination apparatus shown in FIGURE 1, with only a single decontamination basin shown for clarity; and, FIGURE 3 is an exploded view of a detergent and decontaminant concentrate delivery system in accordance with the present invention.

Detailed Description of the Preferred Embodiment FIGURE 1 shows a decontamination apparatus for decontaminating endoscopes and other medical devices which include channels or lumens formed therethrough.

The decontamination apparatus generally includes a first station 10 and a second station 12 which are at least substantially similar in all respects to provide for the decontamination of two different medical devices simultaneously or in series. First and second decontamination basins 14a, 14b receive the contaminated devices. Each basin 14a, 14b is selectively sealed by a lid 16a, 16b, respectively, preferably in a microbe- blocking relationship to prevent the entrance of environmental microbes into the basins 14a, 14b during decontamination operations. The lids can include a microbe removal or HEPA air filter formed therein for venting.

A control system 20 includes one or more microcontrollers, such as a programmable logic controller (PLC), for controlling decontamination and user interface operations. Although one control system is shown herein as controlling both decontamination stations 10, 12, those skilled in the art will recognize that each station 10, 12 can include a dedicated control system. A visual display 22 displays decontamination parameters and machine conditions for an operator and at least one printer 24

prints a hard copy output of the decontamination parameters for a record to be filed or attached to the decontaminated device or its storage packaging. The visual display 22 is preferably combined with a touch screen input device. Alternatively, a keypad or the like is provided for input of decontamination process parameters and for machine control. Other visual gauges 26 such as pressure meters and the like provide digital or analog output of decontamination or medical device leak testing data.

FIGURE 2 diagrammatically illustrates one station 10 of the decontamination apparatus. Those skilled in the art will recognize that the decontamination station 12 is preferably similar in all respects to the station 10 illustrated in FIGURE 2.

However, the station 12 has not been shown in FIGURE 2 for clarity. Further, the decontamination apparatus can be provided with a single decontamination station or multiple stations.

The decontamination basin 14a receives an endoscope E or other medical device therein for decontamination. Any internal channels of the medical device E are connected with flush lines 30. Each flush line 30 is connected to an outlet of a pump 32. The pumps 32 are preferably peristaltic pumps or the like that pump fluid, such as liquid and air, through the flush lines 30 and any internal channels of the medical device E. Specifically, the pumps 32 can either draw liquid from the basin 14a through a drain 34 and a first valve S1, or can draw decontaminated air from an air supply system 36 through a valve S2. The air supply system 36 includes a pump 38 and a microbe removal air filter 40 that filters microbes from an incoming air stream. It is preferable that each flush line 30 be provided with a dedicated pump 32 to ensure adequate

fluid pressure and to facilitate the individual monitoring of the fluid pressure in each flush line 30.

A pressure switch or sensor 42 is in fluid communication with each flush line 30 for sensing excessive pressure in the flush line. Any excessive pressure sensed is indicative of a partial or complete blockage, e. g., by bodily tissue or dried bodily fluids, in a device channel to which the relevant flush line 30 is connected. The isolation of each flush line 30 relative to the others allows the particular blocked channel to be easily identified and isolated, depending upon which sensor 42 senses excessive pressure.

The basin 14a is in fluid communication with a water source 50 such as a utility or"tap"water connection. A pump is optionally provided to boost the pressure of the water from the utility water connection 50. Alternatively, a"break tank"52 and an associated pump P provide a source a water which is isolated from the utility connection 50 as is required in certain applications. A valve S3 selectively blocks the flow of utility water into the basin 14a from the source 50. A microbe removal filter 54, such as a 0.2/m or smaller absolute pore size filter, decontaminates the incoming water which is delivered into the basin through a faucet fixture 56 or the like. A valve S4 selectively allows the decontaminated water to flow through a rotating spray nozzle assembly 60 to spray decontaminated rinse water into the basin 14a and onto the medical device E. The condition of the filter 54 can be monitored by directly monitoring the flow rate of water therethrough or indirectly by monitoring the basin fill time using a float switch or the like. When the flow rate drops below a select threshold, this indicates a partially clogged filter element that requires replacement.

A basin drain 62 drains liquid from the basin

14a. The drain 62 can include an enlarged helical tube 64 into which elongated portions of the medical device E can be inserted if needed to ensure that the device can be accommodated in the basin 14a. The drain 62 is in fluid communication with a recirculation pump 70 and a drain pump 72. The recirculation pump 70 recirculates liquid from the basin drain 62 to the spray nozzle assembly 60 or otherwise back to the basin to contact the medical device E. The drain pump 72 pumps liquid from the basin drain 62 to a utility drain 74. A flow switch 76 monitors the flow of liquid from the pump 72 to the utility drain 74. The pumps 70,72 can be simultaneously operated such that liquid is sprayed into the basin 14a while it is being drained to encourage the flow of residue out of the basin and off of the device.

Likewise, the valves S3 and S4 can be opened while the pump 72 operates to spray decontaminated rinse water into the basin 14a and onto the medical device E during draining operations to provide a better draining of decontaminant or cleaning fluid residue. Of course, a single pump and a valve assembly could replace the dual pumps 70,72.

A mixing chamber assembly 80 includes an inlet 82 in fluid communication with an outlet of the recirculation pump 70. An outlet 84 of the mixing chamber assembly 80 communicates with the spray nozzle assembly 60 through a heating element 86 which selectively heats liquid passing therethrough. A pressure switch or sensor 88 monitors the fluid pressure between the mixing chamber assembly 80 and the spray nozzle assembly 60.

With reference now also to FIGURE 3, the mixing chamber assembly 80 includes an ampule receiving chamber 90 that receives an ampule A or an equivalent container.

The chamber 90 is preferably positioned for easy operator

access in the top surface of the basin 14a and a means is provided for securing an ampule A in the chamber 90. For example, if the chamber 90 is formed in the top surface of the basin 14a, an inner surface of the lid 16a can be utilized to secure an ampule in the chamber 90 when the lid 16a is closed.

The ampule A includes a first interior compartment A1 which contains a detergent concentrate in liquid or dry form. The ampule A also includes second and third interior compartments A2, A3 which contain liquid or dry decontaminant concentrate ingredients. The ampule A is made from a frangible material such as plastic and includes a vented foil, paper, or plastic lid to seal its contents while permitting outgassing.

Analogously, releasable panels or other closures can separate and provide selective access to the compartments.

As is indicated by the arrow 92, the ampule A is inserted into the chamber 90. A lance 94 or the like protrudes into the chamber 90 and opens, e. g., pierces, a wall of the first ampule compartment A1 when the ampule is inserted into the chamber 90. In this manner, any water or other liquid flowing through the chamber 90 (indicated by the arrows W) mixes with the detergent concentrate in the compartment A1 to form a liquid cleaning solution. The cleaning solution is optionally heated by the element 86 and is communicated into the decontamination basin 14a through the spray nozzle assembly 60. The liquid cleaning solution is recirculated with the pump 70 through the spray nozzle assembly 60 to clean the exterior of the device E and is recirculated with the pumps 32 to clean any internal channels of the device E. After cleaning, the pump 72 removes the detergent and water mixture. Sterile rinse water sterilized by the filter 54 flushes the detergent

and any contaminants resulting from washing operations out of the system. At this point, the pumps 32 are optionally activated along with the opening of the valve S2 and the operation of the air pump 38 to flush sterile air through all channels of the medical device E. This "air rinse"is useful for removing residual sterile water from the channels of the medical device which could undesirably dilute any sterilant subsequently passed through the channels.

In a like manner, the mixing chamber assembly 80 subsequently accesses the second and third interior compartments A2, A3 to introduce decontaminant concentrate ingredients into water, received through the filter 54, in the chamber 90 where the ingredients mix with each other and the water to form liquid decontaminant. A preferred decontamination concentrate is a peracetic acid sterilant concentrate described in U. S. Patent 5,077,008, which is expressly incorporated by reference herein.

However, any other suitable decontaminant concentrate can be utilized. The mixing chamber assembly 80 selectively accesses the compartments A2, A3 by advancing the lance 94 further into the chamber 90 (as shown in phantom) to pierce a wall of the compartments A2, A3. An actuator 96, such as one or more solenoids, fluid cylinders, or the like, selectively advances and retracts the lance 94 as indicated by the arrow 98 and optionally rotates the lance 94 as indicated by the arrow 100 to pierce or otherwise access the compartments A2, A3. The decontaminant concentrate in the compartments A2, A3 mixes with clear rinse water or other liquid in the chamber 90 to form a decontaminant solution such as liquid peracetic acid. A seal S prevents liquid flow between the outer surface of the lance and the chamber 90.

Each time decontaminant concentrate is mixed with water or other liquid in the chamber 90 to form the

liquid decontaminant, the valve S4 is preferably opened (while the valve S3 remains closed), at least for a select duration, so that liquid decontaminant flows into the microbe removal water filter 54 and the conduit 58 decontaminating the rinse liquid flow paths in their entirety from the filter 54 to the basin 14a. The liquid decontaminant decontaminates the filter 54 and the flow path 58 to ensure that a truly decontaminated rinse liquid is communicated into the basin 14a and onto the device E.

After the decontamination cycle, the pump 72 drains the decontaminant solution and a sterile rinse is again introduced through the filter 54. Once any decontaminant residue is flushed from the device E, the air pump 38 and the pumps 32 are again activated to pump sterile air, sterilized by the filter 40, through channels in the device E to blow out any trapped liquid.

Optionally, the sterile air can be used for partially or for fully drying the device.

Endoscopes and other reusable medical devices often include a flexible outer housing or sheath surrounding the individual tubular members and the like that form the interior channels and other parts of the device. This housing defines a closed interior space which is isolated from patient tissues and fluids during medical procedures. It is important that the sheath be maintained intact, without cuts or other holes that would allow contamination of the interior space beneath the sheath. Therefore, the decontamination apparatus includes means for testing the integrity of such as sheath.

An air pump, either the pump 38 or another pump 110, pressurizes the interior space defined by the sheath of the device through a conduit 112 and a valve 85.

Optionally, a HEPA or other microbe removing filter

removes microbes from the pressurizing air. An overpressure switch 114 prevents accidental overpressurization of the sheath. Upon full pressurization, the valve S5 is closed and a pressure sensor 116 looks for a drop in pressure in the conduit 112 which would indicate the escape of air through the sheath. A valve S6 selectively vents the conduit 112 and the sheath through an optional filter 118 when the testing procedure is complete.

In addition to the input and output devices described above, all of the electrical and electromechanical devices described are operatively connected to and controlled by the control system 20.

Specifically, the switches and sensors 42,76,88,114,116 provide input I to the microcontroller 28 such as a PLC.

The PLC 28 receives the input I and controls the decontamination and other machine operations in accordance therewith. For example, the PLC 28 includes outputs O that are operatively connected to the pumps 32,38,54,70,72,110, the valves S1-S6, the mixing chamber assembly actuator 94, and the heating element 86 to control these devices for effective decontamination and other operations.