Patent Document

FIELD OF INVENTION 
       [0001]    The present invention relates generally to equipment for washing medical instruments and, more particularly, to a medical washer for washing medical equipment containing internal channels (lumens). The present invention is particularly applicable to cleaning endoscopes and will be described with particular reference thereto. Although it will be appreciated that the invention has further, broader applications to other types of medical devices containing internal channels (lumens). 
       BACKGROUND OF THE INVENTION 
       [0002]    An endoscope is a long, slender, tubular optical instrument used as a viewing system for examining internal body parts, such as lungs, stomach, bladder and bowels. An endoscope may be a rigid or flexible tube, fitted with lenses, a fiber-optical light source and a variety of different medical instruments, such as probes, forceps, suction devices or other tools for examination or retrieval of tissue. In this respect, endoscopes include a plurality of elongated channels (lumens) that extend through the device. Once used within a patient, an endoscope must be cleaned and sterilized prior to subsequent use. 
         [0003]    It is known to wash endoscopes in large medical washers that expose the exterior of the endoscope, as well as the internal channels, to cleaning solutions. U.S. Pat. No. 5,279,799 to MOSER discloses an apparatus for cleaning and testing endoscopes by injecting pressurized air and washing liquids into the channels (lumens) of the endoscope and monitoring the same. The MOSER patent discloses a washing chamber that is provided with retractable racks that hold the endoscopes during cleaning and testing. The racks include a connector for detachably connecting tubes and supplying the air and washing liquid to the endoscopes. A piston-driven manifold connects a plurality of inlet lines to the tubes connected to the endoscope. 
         [0004]    A latter patent, namely, U.S. Pat. No. 8,673,212 to MCDONNELL et al., discloses an apparatus used to test for blockages and leaks in an endoscope. The apparatus insures that channels within the endoscope are unblocked and not leaking prior to cleaning, disinfecting and sterilization. The apparatus provides a means to pressurize and direct fluid to the passageways (lumens). The apparatus operates by exposing each channel to a pressurized gas. The flow value of the channel is compared to a value stored within an internal memory of a control unit. The stored value of air pressure and air flow is determined based upon the operating parameters of a known endoscope. Air flow is established through the duct, and a constant pressure value is maintained. A flow value is read and determined by the control unit and compared to the stored value. If the air flow value of the device is similar to the stored value, the duct is considered to he opened or clear. If the value is lower than the predetermined stored value, the duct is considered to be blocked. If blocked, the medical device is removed for maintenance to remove the blockage. If the air flow value is higher than the predetermined stored value, the latter indicates that there is not a proper air-tight connection between the medical device and the testing apparatus, 
         [0005]    The present invention utilizes the testing device disclosed in the prior patent to monitor and control a cleaning process during the actual cleaning and washing of the medical device. Further, the present invention provides connection means between the testing device and the actual medical instrument, which is more reliable and simplifies the connection of the “air supply lines to the medical device.” 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with a first aspect of the present invention, there is provided a washer/disinfector for washing and disinfecting instruments. The washer is comprised of a housing defining a chamber. Spray arms are disposed in the chamber. The spray arms are for spraying a fluid in the chamber. A rack is dimensioned to be received within the chamber for holding medical instruments to be washed and disinfected. The rack is movable between a first position within the chamber and a second position extending from the chamber. An apparatus for testing and/or cleaning one or more channels or lumens in a medical instrument is provided. An elongated flexible connector, having one or more passageways extending therethrough, has a first end connectable to the apparatus and a second end connectable to a medical instrument in the rack. The connector is movable with the rack as the rack moves between the first position and the second position. 
         [0007]    In accordance with another aspect of the present invention, there is provided a method for operating a computer-controlled washer/disinfector for cleaning a medical endoscope. The method comprises the steps of:
       storing in memory identification and operating characteristics for a plurality of clean endoscopes, the operating characteristics including flow characteristics for each lumen within an endoscope and a blockage threshold flow coefficient for each lumen within an endoscope;   connecting each lumen of an endoscope to be cleaned to a fluid distribution system for selectively conveying pressurized air or pressurized fluids through lumens in an endoscope;   identifying the type of endoscope to be cleaned in the washer/disinfector; determining the blockage threshold flow coefficient for each lumen for the endoscope to be cleaned;   pressurizing each lumen in the endoscope individually and determining an actual flow coefficient through the lumen;   determining whether the endoscope is suitable for cleaning by comparing the actual flow coefficients for a lumen in the endoscope to the blockage threshold flow coefficient for the lumen; and   determining whether a connection to a lumen in the endoscope is properly connected based upon the flow coefficient through the lumen.       
 
         [0014]    In accordance with another aspect of the present invention, there is provided a method of testing channels or lumens within an endoscope, comprising the steps of:
       connecting each individual lumen within an endoscope to a source of pressure;   measuring the pressure and air flow through each individual lumen separately;   determining a flow coefficient for each individual lumen based on the measured air pressure and the measured air flow;   exposing each possible pair of lumens in the endoscope to the source of pressure;   determining a flow coefficient for each possible pair of lumens in the endoscope based on a measured air flow at a measured pressure for the pair of lumens; and.   comparing the flow coefficient for a pair of lumens to a sum of the flow coefficients of the individual lumens forming the pair of lumens, wherein a flow coefficient for the pair of lumens that is less than the sum of the air flow coefficients of the individual lumens forming the pair is indicative of the pair of lumens merging into a single lumen within the endoscope.       
 
         [0021]    An advantage of the present invention is a method of testing medical devices to determine whether two ducts within a device would merge into a single duct within the device. 
         [0022]    Another advantage of the present invention is a system as described above, wherein establishing a minimum flow through a known duct allows operation of a cleaning cycle. 
         [0023]    Another advantage of the present invention is a system as described above that allows for more efficient purging of fluids from a duct or passageway in a medical device through knowledge of the configuration of the duct as predetermined through an initial test and as confirmed during operation of the purging phase. 
         [0024]    Another advantage of the present invention is a system as described above that tests each individual duct or passageway through a device alone and in combination of other ducts or passageways to determine the configuration of the passageways through the medical device. 
         [0025]    A still further advantage of the present invention is a system as described above that, when pairs of ducts or passageways in a medical device merge into a single, larger duct, draining of such combination ducts (i.e., purging) is conducted simultaneously during a cleaning cycle. 
         [0026]    Another advantage of the present invention is a washer/disinfector having fewer moving parts for connecting a fluid circulation system to the internal channels of a medical instrument to be cleaned. 
         [0027]    Another advantage of the present invention is a washer/disinfector, as described above, wherein a rack for holding a medical instrument to be cleaned is always connected to a fluid circulation system. 
         [0028]    A still further advantage of the present invention is a washer/disinfector, as described above, having a resilient flexible connector that is connectable at a first end to an apparatus for testing and cleaning medical instruments and is connectable at a second end to a medical instrument, which flexible connector is movable with a movable rack that is movable into and out of the washer/disinfector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  is a front perspective view of a washing chamber of a washer/disinfector, showing a tray (a lower tray) removed from the washing chamber with an endoscope therein; 
           [0030]      FIG. 2  is a side sectional view of the washing chamber and tray shown in  FIG. 1 , showing the tray (lower tray) removed from the washing chamber; 
           [0031]      FIG. 3  is a side sectional view of the washing chamber shown in showing the tray inserted into the washing chamber; 
           [0032]      FIG. 4  is an enlarged perspective view of a mounting plate on the tray, showing one end of a flexible conduit attached to one side of the connecting plate and a plurality of connecting hoses attached to a second side of the connecting plate; 
           [0033]      FIG. 5  is a perspective view of a side wall of the washing chamber, showing another end of the flexible cable connected to connectors extending through the side wall; 
           [0034]      FIG. 6  is a cross-sectional view of the flexible connector showing a plurality of passageways extending therethrough and showing flexible rods embedded along the edges of the flexible connector; and 
           [0035]      FIG. 7  is a schematic view showing a washer/disinfector and a testing apparatus for testing inner channels (lumen) within an endoscope to be cleaned within the washing chamber of the washer/disinfector. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0036]    Referring now to the drawings wherein the showings are for the purpose of illustrating one embodiment of the invention only, and not for the purpose of limiting same,  FIG. 1  shows a schematic view of a washer illustrating one embodiment of the present invention. In the embodiment shown, washer  10  is a washer designed for washing and decontaminating medical instruments and/or devices. 
         [0037]    Washer  10  is generally comprised of a housing  12  that defines a washing chamber  30 . Housing  12  is defined by an upper wall  14 , side walls  16  and a bottom wall  18 . Bottom watt  18  is formed to include a sloped sump  22  that is disposed at the bottom of housing  12 . Sump  22  is provided to receive washing or rinsing fluids. A heating element  24  (schematically illustrated in  FIG. 7 ) is disposed in sump  22  to selectively heat fluids therein. A door  28  in a front side wall defines an access opening to washing chamber  30 . 
         [0038]    A fluid circulation system  40  (schematically illustrated in  FIG. 7 ) is provided to circulate fluids through washer  10  and washing chamber  30 . Fluid circulation system  40  includes a circulation conduit  42  that fluidly connects sump  22  to first, second and third branch conduits  42 A,  42 B,  42 C that have an upper, intermediate and lower spray arm assemblies  52 A,  52 B,  52 C attached thereto, respectively. First branch conduit  42 A extends through upper wall  14  of housing  12  and has an end disposed in an upper portion of washing chamber  30  with upper spray arm assembly  52 A attached thereto. Second branch conduit  42 B extends through a side wall  16  into a middle portion of washing chamber  30  with intermediate spray arm  52 B attached to the end thereof. Third branch conduit  42 C extends through bottom wall  18  of housing  12  and has an end disposed in a lower portion of washing chamber  30  with lower spray arm assembly  52 C attached thereto. Spray arm assemblies  52 A,  52 B,  52 C are essentially identical and as such only upper spray arm assembly wilt be described in detail. Each spray arm assembly  52 A,  52 B,  52 C is comprised of a central hub  54  with arms  56  extending therefrom, as shown in  FIG. 1 . Central hub  54  defines an internal cavity (not shown) that is in fluid communication with an associated branch conduit  42 A,  42 B,  42 C. Central hub  54  is rotatable mounted to an end of a branch conduit  42 A,  42 B,  42 C. An elongated spray arm  56  defines an internal passage (not shown). Spray arm  56  is mounted to hub  54  with the internal passage therein in fluid communication with the internal cavity of central hub  54 . A series of spray holes or orifices (not shown) are disposed in a wall of arms  56  at discrete locations. 
         [0039]    A pump  62  is provided within circulation conduit  42  for pumping fluids from sump  22  to spray arm assemblies  52 A,  52 B,  52 C. A motor  64  drives pump  62 . 
         [0040]    As best seen in  FIG. 7 , a hot water line  72 , a cold water line  82  and a purified water line  92  are connected to washer  10 . Hot water line  72  is connected at one end to a source of hot water and at the other end to the top wall  14  of housing  12 . A valve  74  disposed in hot water line  72  controls the flow of hot water therethrough. Similarly, cold water line  82  is connected at one end to a cold water source and at the other end to a top wall  14  of housing  12 . A control valve  84  in cold water line  82  controls the flow of cold water from the cold water source to the washing chamber  30 . A branch line  82 A from cold water line  82  is connected to circulation conduit  42  between sump  22  and pump  62 . A valve  86  within branch line  82 A controls the flow of water therethrough. A directional check valve  88  is disposed within branch line  82 A to prevent the flow from circulation conduit  42  to the branch line  82 A. Purified water line  92  connects washer  10  to a source of purified water. A valve  94  within purified water line  92  controls flow therethrough. A first branch line  92 A connects purified water line  92  to circulation conduit  42  and in turn to spray arm assembly  52 A. A filter  112  is disposed within purified water line  92 . A pair of branch lines  92 C,  92 D extends from the filter  112  to a drain filter line  114  connecting purified water line  92  to a drain line  116 . Valves  118 A,  118 B within branch lines are provided to control the flow therethrough. 
         [0041]    A drain line  122  extends from circulation conduit  42 . A valve  124  is disposed in drain line  122  to control the flow of fluids from circulation conduit  42  to drain  116 . 
         [0042]    A plurality of storage tanks is provided for holding chemicals for use within washer  10 . In the embodiment shown, three storage tanks, designated  142 ,  152 ,  162  are shown. Tanks  142 ,  152 ,  162  include feed lines  144 ,  154 ,  164 , respectively, that connect storage tanks  142 ,  152 ,  162  to washing chamber  30 . Pumps  146 ,  156 ,  166  are provided within feed lines  144 ,  154 ,  164  from storage tanks  142 ,  152 ,  162  to pump fluids (chemicals) from storage tanks  142 ,  152 ,  162  to washing chamber  30  for mixing with water therein. Pumps  146 ,  156 ,  166  are preferably metering pumps, wherein controlled amounts of chemicals can be introduced into washing chamber  30 . In the embodiment shown, tank  142  contains an enzymatic cleaner, tank  152  contains a first part of a disinfectant and tank  162  contains a second part of a disinfectant. In the embodiment shown, flow meters  148 ,  158 ,  168  are provided in inlet lines  144 ,  154 ,  164 , respectively, to monitor flow into washing chamber  30 . 
         [0043]    Washer  10  is dimensioned to contain one or more racks for holding medical instruments. In an embodiment shown, two (2) racks, i.e., an upper rack  182 A and a lower rack  182 B, are shown. Each rack  182 A,  182 B is dimensioned to hold an endoscope to be washed, as illustrated in  FIG. 1 . Upper rack  182 A is dimensioned to be disposed between upper and intermediate spray arm assemblies  52 A,  52 B, and lower rack  182 B is dimensioned to be disposed between intermediate and lower spray arm assemblies  52 B,  52 C. In the embodiment shown, each rack  182 A,  182 B, best seen in  FIG. 1 , is generally rectangular in shape and has an outer structural frame  184  and a porous bottom panel  186  formed of wire mesh or perforated metal that allows fluid to pass therethrough. Each rack  182 A,  182 B is movable between a first position within washing chamber  30  (as illustrated in  FIG. 3 ) and a second position removed from washing chamber  30  (as best seen in  FIGS. 1 and 2 ). Spaced apart rollers  188  are provided on opposite sides of frame  184  to allow a rack  182 A,  182 B to roll freely into and out of washing chamber  30  on tracks  192  formed along opposing side walls  16  of washing chamber  30 , as is conventionally known.  FIG. 2  shows door  28  in an open position with lower rack  182 B removed from washing chamber  30 . As illustrated, in  FIG. 2 , the inner surface of door  28  is formed to define a track  29  that is aligned with track  192  within washing chamber  30 , when door  28  is in an opened position. A mounting plate  196  (best seen in  FIGS. 1 and 4 ) is provided along one side of rack  182 A,  182 B. Mounting plate  196  supports a plurality of hose or tube connectors  198 . One side of connectors  198  is adapted to be connected to one end of a flexible member  320  (that shall be described in greater detail below). The other side of connector  198  is for connection to a set of connecting hoses that are designed for connection to a specific type of endoscope (as will be described in greater detail below). In the embodiment shown, eight (8) connectors  198  are shown on mounting plate  196 . One connector  198  is designated “A” on mounting plate  196  and the other seven connectors  198  are designated “1” through “7.” 
         [0044]    Washer  10  includes test system  200  for testing flow characteristic of channels (lumens) within an endoscope and for washing and cleaning the same. In the embodiment shown, test system  200  is comprised of two (2) test apparatus  210 A,  210 B. Each test apparatus  210 A,  210 B is of a type disclosed in U.S. Pat. No. 8,673,212 to MCDONNELL et al., the disclosure of which is expressly incorporated herein by reference. As best seen in  FIG. 7 , each test apparatus  210 A,  210 B is comprised of a manifold  212  defining an internal cavity (not shown). Manifold  212  includes a fluid inlet port  214  at one end and an air inlet port  216  at another end. In the embodiment shown, two test apparatuses  210 A,  210 B are connected in series with the internal cavity of apparatus  210 A connected to internal cavity of apparatus  210 B by a connection line  218 . In this respect, in the embodiment shown, fluid inlet port  214  connected to manifold  212  of test apparatus  210 B would communicate through connection line  218  to the internal cavity of manifold  212  of test apparatus  210 A. Likewise, air inlet port  216  that communicates with the internal cavity of test apparatus  210 A would communicate with the internal cavity of test apparatus  210 B, as will be understood from a later explanation of the operation of the system. 
         [0045]    Air inlet port  216  is connected to an air line  222  that connects manifold  212  of test apparatus  210 A to a source of compressed air. The fluid inlet port and the air inlet port both communicate with the internal cavity within the manifold. A pressure regulator  224  is disposed in air line  222  to regulate the air pressure within air line  222 . A valve  226  and flow meter  228  are disposed in air line  222  to monitor the amount of flow through air line  222 . A directional check valve  232  and a second control valve  234  are disposed in air line  222  between flow meter  228  and test apparatus  210 A. 
         [0046]    Valve  234  controls flow to air inlet port  216 . A pressure sensor  242  is provided in connection line  218  to detect pressure within manifold  212  of test apparatuses  210 A,  210 B. Air line  222  includes a branch line  222 A that in turn splits into sub-branch lines  222 B,  2220  that connect to side wall  16  of washer  10 . An air regulator  244  is disposed in branch line  222 A to regulate the air pressure to sub-branch lines  222 B,  222 C. Control valves  252 ,  254  are disposed in sub-branch lines  222 B,  222 C, respectively, to control air flow therethrough. Pressure sensors  256 ,  258  are disposed in sub-branch lines  222 B,  222 C, respectively, to monitor the pressure therein. 
         [0047]    A vent line  222 D connects sub-branch line  222 B to the external atmosphere. A control valve  262  controls venting of sub-branch line  222 D. Similarly, a vent line  222 E connects sub-branch line  222 C to the external atmosphere. A control valve  264  is disposed in a vent line  222 E to control venting of sub-branch line  222 C. 
         [0048]    Fluid inlet port  214  is connected to a fluid line  272  that is in fluid communication with circulation conduit  42 . A control valve  274  is disposed in fluid line  272  to control flow to test system  200 . 
         [0049]    Referring now to test system  200 , in the embodiment shown, washer  10  includes two (2) racks  182 A,  182 B, each rack for washing an endoscope. Accordingly, test system  200  includes two test apparatuses  210 A,  210 B, one apparatus to be associated with each endoscope to be cleaned. Test apparatuses  210 A,  210 B are essentially the same, and operate the same, and therefore only one test apparatus  210 B shall be described in detail, it being understood that such description applies equally to test apparatus  210 A. As best seen in  FIG. 7 , a plurality of outlet ports extends from manifold  212  of test apparatus  210 B. In the embodiment shown, seven outlet ports, designated  280 - 1 ,  280 - 2 ,  280 - 3 ,  280 - 4 ,  280 - 5 ,  280 - 6 , and  280 - 7 , extend from manifold  212 . Each outlet port  280 - 1 ,  280 - 2 ,  280 - 3 ,  280 - 4 ,  280 - 5 ,  280 - 6 ,  280 - 7  is connected to an outlet line  292  that connects to a connector  312  mounted to side wall  16  of washer  10 . Connectors  312  are conventional hose or tube connectors that allow a fluid connection to be made through side wall  16 . A control valve  294  is disposed in each outlet line  292  from outlet ports  280 - 1 ,  280 - 2 ,  280 - 3 ,  280 - 4 ,  280 - 5 ,  280 - 6 ,  280 - 7  from the manifold  212  to control flow therethrough. 
         [0050]    In accordance with one aspect of the present invention, an elongated flexible member  320  having a plurality of side by side passageways  322  formed therethrough are attached to connector  312  within washing chamber  30 . Elongated flexible member  320  is basically a polymer extrusion wherein eight distinct passageways  322  are formed to extend parallel to each other in a common plane. In a preferred embodiment, flexible member  320  is formed of silicon. The ends of the flexible members  320  are splayed to separate each passageway  322  so as to allow connection of one end of flexible member  320  to connector  312  on side wall  16 , as best seen in  FIG. 5 . In this respect, each outlet port  280 - 1 ,  280 - 2 ,  280 - 3 ,  280 - 4 ,  280 - 5 ,  280 - 6 ,  280 - 7  from manifold  212  is connected to a passageway  322  through flexible member  320  via an associated connection line  292 . The other end of elongated flexible member  320  is connected to connector  198  on mounting plate  196  on a rack within washing chamber  30 . Elongated flexible member  320  is basically a ribbon-like structure that is disposed within washing chamber  30  to replicate over itself as a rack  182 A,  182 B is moved within washer  10 . 
         [0051]    In accordance with another aspect of the present invention, flexible member  320  is formed to include elongated flexible rods  324  (best seen in  FIG. 6 ) extending along the lateral sides thereof. Elongated rods  324  are preferably formed of a spring-like, metal material having an original, normal, straight-line configuration. In this respect, when elongated flexible member  320  is replicated over itself, elongated rods  324  extending therethrough bias elongated member  320  to a generally flat, planar configuration. In the embodiment shown, elongated flexible member  320  has eight passageways  322  extending therethrough. As best seen in  FIG. 5 , a first bracket  332 , attached to side wall  16  of washer  10  near connectors  312 , captures and maintains the position of the first end of flexible member  320  relative to wall  16  of washer  10 . A second bracket  334  attached to mounting plate  196  (best seen in  FIG. 4 ) captures and maintains the position of the second end of flexible member  320  relative to rack  182 B. 
         [0052]    Flexible member  320  is connected to connectors  312  on side wall  16  and to connectors  198  on mounting plate  196  such that the connector  198  designated “A” on mounting plate  196  is fluidly connected to branch line  222 C of air line  222 , and connectors  198  designated “1, 2, 3, 4, 5, 6, and 7” on mounting plate  196  are fluidly connected respectively to outlet ports  280 - 1 ,  280 - 2 ,  280 - 3 ,  280 - 4 ,  280 - 5 ,  280 - 6 ,  280 - 7  on manifold  212 . 
         [0053]    As will be appreciated, the second end of elongated flexible member  320  moves with rack  182 B as it moves from a position within the washing chamber  30  ( FIG. 3 ) to a position outside washing chamber  30  ( FIG. 2 ) and vice versa. 
         [0054]    A guide/stop  336  is disposed along the inner surface of side wall  16  to guide and position a flexible member  320  when a rack  182 A,  182 B is positioned within washing chamber  30 . As illustrated in  FIG. 3 , that shows lower rack  182 B within washing chamber  30 , guide/stop  336  causes flexible member  320  to assume a generally U-shaped configuration, when rack  182 B is within washing chamber  30 . In this configuration, flexible member  320  has a first, generally straight section  320   a  above a second, generally straight section  320   b.  In this respect, elongated rods  324  embedded in flexible member  320  help align first and second sections  320   a,    320   b  into generally straight configurations. A curved section  320   c  connects first section  320   a  to section  320   b.  Guide/stop  336  is preferably positioned relative to connectors  312  to slope first section  320   a  downward toward curved section  320   c.  Similarly, a holder  338  on tray  1829  slightly slopes section  320   b  toward connectors  198 . In this respect, flexible member  320  preferably slopes continuously downward from connector  312  to connector  198  to facilitate draining of passageways  322  in flexible member  320 . 
         [0055]    A controller  400  is provided to monitor and control the operation of testing system  200 , as well as washer  10 . In this respect, all the pressure sensors and the flow measuring devices within washer  10  and test system  200  are connected to controller  400 . Controller  400  monitors signals from the pressure sensors as well as flow through the various sections of air inlet line  222 . Pressure sensor  242  connected to manifold  212  provides signals to controller  400  with respect to the pressure within manifolds  212 . Controller  400  likewise controls all control valves within air inlet line  222  as well as the control valves in circulation system  40 . In addition, controller  400  controls each of control valves  294  associated with outlet ports from module  212  wherein flow through each of outlet lines  292  can be individually controlled. 
         [0056]    Referring now to the operation of the system  10 , as indicated above, there are typically hundreds of known endoscopes, each having its own internal configuration with passageways. The present invention allows connection to an endoscope (designated “ES” in the drawings) with up to seven internal passageways. 
       Set-Up Procedure 
       [0057]    Prior to washing endoscopes ES within washer/disinfector  10 , a set-up procedure is performed to establish baseline operating characteristics for each endoscope ES to be cleaned within washer/disinfector  10 . In this respect, as indicated above, many different types of endoscopes ES exist, and each has a particular internal configuration with respect to the number and shape of lumens therein. Prior to actually washing endoscopes ES within washers/disinfector  10 , a clean endoscope ES is attached to a test apparatus  210 A or  2109  via connection lines  292  and flexible member  320  within washer/disinfector  10 . A “characterization test” is then performed on the endoscope ES to establish baseline operating characteristics for a clean endoscope ES of that type. More specifically, three tests are performed on each endoscope ES to provide specific information regarding the operating characteristics of the endoscope ES. First, the flow characteristics of the endoscope ES (and the lumens therein) are established. Specifically, a flow coefficient (C v ) is established for each channel or lumen in the endoscope ES by performing an air pressure/flow test thereon. 
         [0058]    Specifically, pressurized air is applied to each lumen of the endoscope ES by allowing air at a set pressure to flow through manifold  212  and connection line  292 . Flow through the lumen at an established pressure is monitored by flow meter  220 . A flow coefficient (C v ) is calculated for each lumen in the endoscope ES based upon the air flow at the given pressure. 
         [0059]    Knowing the flow coefficient for each lumen of a clean endoscope ES, the controller then calculates and stores a “blockage value” or “blockage threshold value” that is used to determine whether or not a lumen is suitable for cleaning. This “threshold value” is determined as a percentage of flow of a clean lumen. In a preferred embodiment, controller  400  is programmed to set 30% to 40% blockage as a value above which the lumen is not suitable for cleaning. In other words, if 40% blockage is set as the blockage threshold value, a lumen is suitable for cleaning if 60% or more of the original flow value of the lumen exists, These values for each of the lumens for a particular endoscope ES are stored in controller  400 . 
         [0060]    After determining a “blockage threshold value” for each of the lumens in the endoscope ES, a second test is performed wherein, each connection to the endoscope ES is disconnected, and pressurized air is applied through the test apparatus to determine air flow through each of connection lines  292 . This value is also stored in memory in controller  400  with respect to the tested endoscope ES. Thus, according to the present invention, a threshold flow value and a disconnect flow value is determined and stored in controller  400  for each lumen in each endoscope ES. 
         [0061]    Lastly, a third test is performed to determine the configuration of lumens within the endoscope namely whether two or more lumens merge into a single lumen or channel within the endoscope ES. In accordance with another aspect of the present invention, following the initial test to determine a flow coefficient (C v ) for each of the lumens within the clean endoscope ES, each possible pair of lumens within the endoscope ES is tested together under the set pressure to determine a “pair flow coefficient (C v -pair)” for the selected pair of lumens. The pair flow coefficient (C v -pair) for the pair is then compared to the sum of the individual flow coefficients of the two lumens that make up the pair. In other words, two lumens in the endoscope ES are tested together and a pair flow coefficient (C v -pair) for the pair of lumens is established. This pair flow coefficient (C v -pair) is compared to the sum of the separate flow coefficients (C v ) of the two lumens. If both values are equal, this is an indication that the two lumens are separate. If, however, a lower flow coefficient is established for the pair flow coefficient (C v -pair) of the two lumens as compared to the sum of the individual flow coefficients (C v ) of the two lumens, this is an indication that the two lumens merge into a single lumen within the endoscope ES. In this respect, as indicated above, in sonic endoscopes ES, two passageways (lumens) merge into a single passageway within the endoscope. The ability to determine when pairs of lumens merge into a single lumen is important when purging fluid from combined lumens, as shall be described in greater detail below. Flow characteristics of any merged or joined lumens are stored in memory in controller  400 . 
         [0062]    According to another aspect of the present invention, purge times for each of the channels (lumens) within an endoscope ES are determined based upon the flow coefficient values (C v ) determined during the flow/check at the beginning of set-up cycle. In other words, once the flow coefficient (C v ) for each of the lumens or for each joined pair of lumens is determined, a purge time sufficient to purge fluid from the lumen is calculated. If channels within the endoscope are found to be merged (as indicated above), the purge time is then the sum of all purge times of all of the merged channels. It has been found that the time necessary to purge a lumen can be determined based upon its flow coefficient. Specifically, the purge time (in seconds) =52500· C   v−1.15 +2. This relationship is determined based upon the dimension of a particular lumen, as well as the flow characteristics of the lumen at a given point in time. This calculation determines the time to clear liquid from lumen based upon the flow characteristics of the lumen. 
         [0063]    The foregoing tests and calculations are performed for each lumen or channel in each type or model of endoscope ES to be cleaned within washer/disinfector  10  to establish 1) a threshold blockage value that would indicate whether the endoscope ES is suitable for cleaning, 2) a disconnect value indicative of an improper connection, and 3) flow values indicating merged or joined lumens or channels within an endoscope ES. This data is stored in memory in controller  400  for each endoscope ES to be washed within washer/disinfector  10 . Each endoscope ES can be identified in controller  400  by a customer number or by a serial number on the endoscope ES. Thus, a directory of different types of endoscopes ES to be cleaned is stored within controller  400  for use during a washing cycle. 
         [0064]    For a given type or model of endoscope ES, a set  522  of connecting tubes  522   a  (best seen in  FIG. 1 ) are provided to connect specific ports on the endoscope ES to specific connectors  198  on mounting plate  196 . Connection tubes  522   a  are then connected to the endoscope ES and to respective connectors  198  on the mounting plate  196  of rack  182 B, rack  182 B, with the endoscope ES thereon, is slid into washing chamber  30  and the door to washing chamber  30  is closed. An operator then initiates a washing cycle. 
         [0065]    Washing/Disinfection Cycle 
         [0066]    A preferred washing/disinfection cycle, in accordance with one aspect of the present invention, includes a first endoscope check phase, a pre-wash phase, a wash phase, a first rinse phase, a chemical disinfection phase, a final air phase, and a second endoscope ES check phase. As will be appreciated, the pre-wash phase, wash phase, rinse phases and chemical disinfection phases all involve use of a liquid. Following each of these phases, the liquid within the lumens of the endoscope ES are purged from the lumens prior to a subsequent operational phase, as shall be described in greater detail below. 
         [0067]    During the endoscope check phase, pressurized air is applied to each lumen of the endoscope ES by allowing air at a set pressure to flow through manifold  212 , connection line  292  and flexible member  320 . The flow through each lumen is detected by flow meter  228  that sends signal to controller  400 . 
         [0068]    Flow through each lumen in the endoscope ES is determined and compared by controller  400 , the “threshold flow value” and “disconnected flow value” stored in memory. A flow value too low (i.e., below the “threshold flow value”) indicates a lumen is obstructed and not suitable for cleaning. A flow value too high (i.e., at or above the “disconnect flow value”) for a lumen indicates that the lumen is improperly connected or not connected, and therefore not suitable for cleaning. In this respect, a flow value between the “threshold flow value” and the “disconnect flow value” indicates a lumen is suitable for cleaning. 
         [0069]    If a lumen does not meet the “threshold flow value,” according to another aspect of the present invention, a purge is performed on the obstructed lumen. The purge involves blowing pressurized air through the lumen for a predetermined period of time. Thereafter, the flow value through the lumen is retested. If the lumen is still determined to be obstructed (i.e., the flow through the lumen does not meet the threshold value), controller  400  provides an indication to the user, by either audio or visual indication, that a lumen within the endoscope ES is blocked and the endoscope ES cannot be reprocessed. The user may be prompted or instructed that the endoscope ES requires manual cleaning prior to washing/disinfecting in washer/disinfector  10 . 
         [0070]    If the endoscope ES meets the conditions for washing, a pre-wash phase is initiated. During the pre-wash phase, non-heated cold water is introduced into washer  10  by controller  400  opening valve  84 . The cold water is collected in sump  22  and conveyed by pump  62  to spray assemblies  52 A,  52 B,  52 C within the washer  10  to wash the exterior of the endoscope ES. The cold water is also conveyed to manifold  212  and to lumens within the endoscope ES to pre-wash the interior of each of the lumens. Pre-wash is conducted for a predetermined period of time. Following the pre-wash, each of the lumens is purged by directing compressed air from air line  222  through manifold  212  to each of the lumens (passageways) within the endoscope During the purge phase, each lumen is exposed to pressurized air to force the pre-wash fluid within the lumens out thereof. Since a purge time has been established for each of the lumens, air pressure is maintained on each of the lumens for the select purge time for each lumen. Once the purge time for a particular lumen has elapsed, closing control valve  294  associated with the lumen shuts off further flow of compressed air to the lumen. As will be appreciated by one skilled in the art, the lumens within an endoscope ES vary in length, as well as diameter. Longer lumens with large diameter passageways contain significantly more fluid than smaller, shorter lumens with smaller inner diameters. Thus, the time to purge these different types of lumens could vary significantly. In accordance with the present invention, once the calculated purge time for a particular lumen has been reached, control valve  294  to the specific lumen is shut, thereby preventing further air from being forced through the already-purged lumen. In this respect, once a calculated purge time for a particular lumen is reached, the associated control valve  294  is closed to maintain a maximum pressure at the inlets of other channels still being purged. As will be appreciated, the purge cycle to purge the entire endoscope ES is the purge time for the particular lumen having the longest purge time. 
         [0071]    Once the purge cycle phase been completed, a wash phase is initiated. The wash phase consists of introducing heated and cold water into washer  10  through hot water line  72 . Washing chemicals are introduced into washing chamber  30  from tanks  142 ,  152 , or  162 . A washing fluid is pumped by pump  62  to spray assemblies  52 A,  52 B,  52 C and to manifold  212  from which the washing fluid is directed into each of the lumens of the endoscope ES. The wash fluid flows through each lumen (i.e., through the endoscope ES) for a predetermined period of time, such that each lumen is exposed to the washing fluid for a minimum predetermined time necessary to wash the lumen. 
         [0072]    Following the wash cycle, the lumens are purged of washing fluid by conducting another purge cycle, as described above. As indicated above, the purge cycle is based upon the flow coefficient (C v ) established during the endoscope ES check phase of the overall reprocessing cycle. 
         [0073]    As noted above, one aspect of the present invention is the ability to detect passageways (lumens) that merge within the endoscope ES. The purge time for such combined channels is the purge time determined for each individual channel. In this respect, the combined channels are also purged together rather than independently to avoid the problem of fluid being forced back up one branch of the combined channels, which might occur if one channel were purged separately. By purging the two channels together for a prolonged period of time, it insures that all of the fluids within the channels that merge are purged from the endoscope ES. 
         [0074]    Following the purge phase to remove washing fluid from the endoscope ES, a rinse phase is initiated. Non-heated cold water is circulated through washing chamber  30 , sprayed onto the exterior of the endoscope ES and forced through manifold  212  through the lumens of the endoscope ES. 
         [0075]    Following the first rinse phase, the lumens of the endoscope ES are purged of the rinse water in a manner as described above. Following this purge phase, the endoscope ES is exposed to a chemical disinfectant by introducing a chemical disinfectant and water to washing chamber  30 . The chemical disinfectant is circulated through the circulation system to spray assemblies  52 A,  52 B,  52 C onto the exterior of the endoscopes ES, and circulated through manifold  212  to the passageways (lumens) of the endoscope ES. The chemical disinfectant is circulated through the circulation system and through the lumens for a predetermined period of time, wherein each lumen has a minimum exposure time to the chemical disinfectant. 
         [0076]    Following the chemical disinfection, the lumens are again purged of fluid for a predetermined period of time, as described above. Following the chemical disinfection, a second rinse phase is initiated to rinse the exterior of the endoscope ES and the passageways within the endoscope ES with clean filtered rinse water. A third rinse phase is then conducted with clean filtered rinse water to further rinse any chemical disinfectant from the exterior and interior passageways (lumens) through the endoscope ES. 
         [0077]    Following the third rinse, a final air purge phase is initiated to purge the lumens of any rinse water within the endoscope ES. The final air purge may extend for a duration longer than the previous purge phases to insure near drying of the endoscope ES. 
         [0078]    Following the final air purge, a second endoscope ES check phase test is conducted. This second endoscope ES test phase tests the flow characteristics of each of the passageways (lumens) within the endoscope ES by monitoring the air pressure and air flow individually through each of the lumens. 
         [0079]    The present invention thus provides a method of cleaning passageways (lumens) within an endoscope that automates the cycle times and purge times of the washing of the lumens based upon initial flow characteristics determined at the beginning of a reprocessing cycle. In addition, the present invention provides a method of determining which passageways within an endoscope may merge into a single passageway within the endoscope, thereby insuring proper cleaning and purging of the endoscope during the respective phases of the overall washing cycle.

Technology Category: 1