Abstract:
A method detects proper connection of an endoscope to an endoscope processor by measuring pressure pulses applied to the connection point. The method can include measuring for the pressure pulses at a second connection point on the endoscope processor and measuring for a beat frequency produced variations in the frequency of pressure pulses input at each connection point. The method can also include looking for echoes of the pressure pulsations from physical structures within a lumen of the endoscope connected to the connection point.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to the decontamination arts including the sterilization arts. 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. 
   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 popular method for cleaning and disinfection or sterilization of such endoscopes employs an automated endoscope reprocessor which both washes and then disinfects or sterilizes the endoscope. Typically such a unit comprises a basin with a selectively opened and closed cover member to provide access to the basin. Pumps connect to various channels through the endoscope to flow fluid therethrough and an additional pump flows fluid over the exterior surfaces of the endoscope. Typically, a detergent washing cycle is followed by rinsing and then a sterilization or disinfection cycle and rinse. 
   It is desirable to ensure through testing that all of the connection ports on the endoscope have been properly connected to the corresponding connecting points on the endoscope processor. The connections are typically made via a flexible tube between the connection point on the endoscope processor and the connection port on the endoscope. If either connection of the tube is not made properly the lumen or lumens within the endoscope associated with that connection port may not receive adequate flow for washing and disinfection or sterilization. Therefore it is desirable to test for proper connections. One method employs measuring the back pressure associated with flow through the lumen and if the back pressure is below a given value assumes that the lumen is not connected. A related method seeks to measure a quantity of flow through the lumen in a given time period, which also relies upon the back pressure provided by the lumen to assess proper connection status. However, some lumens have a sufficiently large internal diameter as to make such measurements difficult by providing insufficient restriction to flow therethrough. The present invention overcomes this limitation. 
   SUMMARY OF THE INVENTION 
   A method, according to the present invention, detecting proper connection of ports on an endoscope to an endoscope processor. The method comprises the steps of: providing a pressure pulse to a first connector on the endoscope processor, the first connector being connectable to a first port on the endoscope, the first port being in fluid communication with a first lumen in the endoscope; measuring pressure at a first point which, if the endoscope is properly connected to the endoscope processor, will be in fluid communication with the first lumen; determining a status of proper connection of the endoscope to the endoscope processor based upon measurements of the pressure at the first point. 
   In one aspect of the invention, the endoscope processor comprises a second connector which is connectable to a second port on the endoscope, the second port being in fluid communication with a second lumen in the endoscope, the first lumen and the second lumens being in fluid communication with each other, and wherein the first point is in the endoscope processor and in fluid communication with the second connector. The presence of the pressure pulse at the second connector can indicate proper connection of the first connector to the first port and the second connector to the second port. The pressure pulse can be provided by a first peristaltic pump associated with the first connector. A second peristaltic pump can be associated with the second connector producing pressure pulsations at a different frequency from the first peristaltic pump, thereby forming a beat frequency due to the difference between the frequency of the first peristaltic pump and the second peristaltic pump, and wherein presence of the beat frequency indicates proper connection of the first connector to the first port and the second connector to the second port. 
   A connecting tube can be positioned between the first connector and the first port. The first point can then be on the endoscope processor in fluid communication with the first connector and wherein disconnected status between the connecting tube and the first port has a known pressure signature measured at the first point and wherein the method comprises the step of comparing pressure measurements at the first point with the known signature to assess whether the connecting tube is disconnected from the first port. 
   In one aspect of the invention, the first point is on the endoscope processor in fluid communication with the first connector and wherein disconnected status between the first connector and the first port has a known pressure signature measured at the first point and wherein the method comprises the step of comparing pressure measurements at the first point with the known signature to assess whether the first connector is disconnected from the first port. 
   In an aspect of the invention, when properly connected the endoscope has a known pressure signature measured at the first point and wherein the method further comprises comparing the pressure measurements at the first point with the known pressure signature of the properly connected endoscope to assess proper connection of the endoscope at the first connector. The method can further comprise the step of assessing which kind of endoscope is attached to the first connector by comparing pressure measurements at the first point with the known signature of the properly connected endoscope. 

   
     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. 
       FIG. 1  is a front elevational view of a decontamination apparatus in accordance with the present invention; 
       FIG. 2  is a diagrammatic illustration of the decontamination apparatus shown in  FIG. 1 , with only a single decontamination basin shown for clarity; and, 
       FIG. 3  is a cut-away view of an endoscope suitable for processing in the decontamination apparatus of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  shows a decontamination apparatus for decontaminating endoscopes and other medical devices which include channels or lumens formed therethrough;  FIG. 2  shows the apparatus in block diagram form. 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  14   a ,  14   b  receive the contaminated devices. Each basin  14   a ,  14   b  is selectively sealed by a lid  16   a ,  16   b , respectively, preferably in a microbe-blocking relationship to prevent the entrance of environmental microbes into the basins  14   a ,  14   b  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  20  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. 
     FIG. 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  FIG. 2 . However, the station  12  has not been shown in  FIG. 2  for clarity. Further, the decontamination apparatus can be provided with a single decontamination station or multiple stations. 
   The decontamination basin  14   a  receives an endoscope  200  (see  FIG. 3 ) or other medical device therein for decontamination. Any internal channels of the endoscope  200  are connected with flush lines  30 , preferably via a flexible interconnect tube  108  between an outlet  31  of the flush line a connection on the endoscope  200 . Only a couple of representative examples are shown in  FIG. 2 , but typically each connection to the endoscope will be made through a separate tube  108 . 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. Specifically, the pumps  32  either can draw liquid from the basin  14   a  through a filtered drain  34  and a first valve S 1 , or can draw decontaminated air from an air supply system  36  through a valve S 2 . 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  14   a  is in fluid communication with a water source  50  such as a utility or tap water connection including hot and cold inlets and a mixing valve  52  flowing into a break tank  56 . A microbe removal filter  54 , such as a 0.2 μm or smaller absolute pore size filter, decontaminates the incoming water which is delivered into the break tank  56  through the air gap to prevent backflow. A pressure type level sensor  59  monitors liquid levels within the basin  14   a . An optional water heater  53  can be provided if an appropriate source of hot water is not available. 
   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  14   a  through an enlarged helical tube  64  into which elongated portions of the endoscope  200  can be inserted. 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 a spray nozzle assembly  60  which sprays the liquid into the basin  14   a  and onto the endoscope  200 . Coarse and fine screens  71  and  73 , respectively, filter out particles in the recirculating fluid. The drain pump  72  pumps liquid from the basin drain  62  to a utility drain  74 . A level sensor  76  monitors the flow of liquid from the pump  72  to the utility drain  74 . The pumps  70  and  72  can be simultaneously operated such that liquid is sprayed into the basin  14   a  while it is being drained to encourage the flow of residue out of the basin and off of the device. Of course, a single pump and a valve assembly could replace the dual pumps  70 ,  72 . 
   An inline heater  80 , with temperature sensors  82 , downstream of the recirculation pump  70  heats the liquid to optimum temperatures for cleaning and disinfection. A pressure switch or sensor  84  measures pressure downstream of the circulation pump  70 . 
   Detergent solution  86  is metered into the flow upstream of the circulation pump  70  via a metering pump  88 . A float switch  90  indicates the level of detergent available. Typically, only a small amount of disinfectant  92  is required. To more accurately meter this, a dispensing pump  94  fills a pre-chamber  96  under control of a hi/low level switch  98  and of course the control system  20 . A metering pump  100  meters a precise quantity of disinfectant as needed. 
   Endoscopes and other reusable medical devices often include a flexible outer housing or sheath  102  surrounding the individual tubular members and the like that form the interior channels and other parts of the device. This housing  102  thus forms a closed interior space  104 , between it and the interior parts of the endoscope, 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 contaminants into the interior space  104 . The interior space can also be compromised by an internal leak, such as through a cut in an endoscope lumen. 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  104  through a conduit  112  and a valve S 5  and a test connection  106 , preferably one of the flexible tubes  108  connects to port  254  which leads to the interior space  104  (see  FIG. 3 ). These structures will be more fully described in the full description of  FIG. 3  to follow. Preferably, a filter  113  removes particles from the pressurizing air. An overpressure switch  114  prevents accidental over pressurization of the sheath. Upon full pressurization, the valve S 5  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 S 6  selectively vents the conduit  112  and the sheath through an optional filter  118  when the testing procedure is complete. An air buffer  120  smoothes out pulsation of pressure from the air pump  110 . 
   The air buffer  120  can also be used to determine whether the test connection  106  is properly mated with the port  254 . The test connection  106  incorporates a normally closed valve  109  which opens only upon proper connection to the flexible tube  108 . If the connection is not made the aforementioned leak determination test will not by itself identify this failed connection. The air buffer  120  would pressurize and no leakage would occur due to the closed valve at the test connection  106 . Similarly the port  254  incorporates a normally closed valve which opens only upon proper connection to the tube  108 . When both these connections are not properly made the leak test of the interior space  104  may give false results. Unconnected status can be examined by determining whether a volume other than the air buffer  120  is being pressurized. 
   First the air buffer  120  and interior space  104  are pressurized to a predetermined level, such as 250 mbar. Then valve S 5  is closed, thus isolating the air buffer  120  from the test connection  106 . Pressure is vented through valve S 6 , which if the test connection  106  is properly attached should be venting the interior space  104 , but if not properly attached this merely vents a portion of the conduit  112 . Valve S 6  is closed and valve S 5  opened to put the test connection  106  back into fluid communication with the air buffer  120 . After the pressure settles, it is measured. It should have dropped to a measurable degree through the action of air in the air buffer  120  filling the interior space  104 . If however, it drops by a small amount that indicates that air is not flowing into the interior space  104  but is trapped by the valve in the test connection  106 . Proper pressures can be easily determined based upon the volume of the air buffer  120  and interior space  104 . To accommodate most commercial endoscopes the air buffer  120  should have a volume of between about 20 ml (which is about 10% of small endoscope) to about 1000 ml (which is about 300% of large endoscope). Ideally the volume should be between about 50% and 200% of the volume of the endoscope and most ideally it would approximate the volume of the endoscope interior space  104 . Given the variability in endoscope volumes, the volume of the air buffer can be adjustable, such as by providing multiple air buffers  120  and control valves for each one. Given the starting pressure of 250 mbar, a proper connection should typically result in a final pressure below 190 mbar. Proper pressure for a particular endoscope can be calculated based upon the volumes of the air buffer  120  and endoscope interior space  104 . The interconnection piping should be kept to a minimal volume to enhance the accuracy. 
   An alternative method to check the proper connection at the test connection  106  is to close valve S 5  while pressurizing the air buffer  120 , let the pressure settle, and then open valve S 5 . Accurate pressurization of the air buffer  120  would require a pressure sensor (not shown) at the air buffer  120  so located as to not be blocked by closure of valve S 5 . Pressure is then checked. If the pressure has not dropped sufficiently it indicates that air is not flowing into the interior space  104 , but is instead being blocked at the test connection  106  by the valve  109 . 
   Preferably, each station  10  and  12  each contain a drip basin  130  and spill sensor  132  to alert the operator to potential leaks. 
   An alcohol supply  134  controlled by a valve S 3  can supply alcohol to the channel pumps  32  after rinsing steps to assist in removing water from the endoscope channels. 
   Flow rates in the supply lines  30  can be monitored via the channel pumps  32  and the pressure sensors  42 . The channels pumps  32  are peristaltic pumps which supply a constant flow. If one of the pressure sensors  42  detects too high a pressure the associated pump  32  cycles off. The flow rate of the pump  32  and its percentage on time provide a reasonable indication of the flow rate in an associated line  30 . These flow rates are monitored during the process to check for blockages in any of the endoscope channels. Alternatively, the decay in the pressure from the time the pump  32  cycles off can also be used to estimate the flow rate, with faster decay rates being associated with higher flow rates. 
   A more accurate measurement of flow rate in an individual channel may be desirable to detect more subtle blockages. A metering tube  136  having a plurality of level indicating sensors  138  fluidly connects to the inputs of the channel pumps  32 . One preferred sensor arrangement provides a reference connection at a low point in the metering tube and a plurality of sensors  138  arranged vertically thereabove. By passing a current from the reference point through the fluid to the sensors  138  it can be determined which sensors  138  are immersed and therefore determine the level within the metering tube  136 . Other level sensing techniques can be applied here. By shutting valve S 1  and opening a vent valve S 7  the channel pumps  32  draw exclusively from the metering tube. The amount of fluid being drawn can be very accurately determined based upon the sensors  138 . By running each channel pump in isolation the flow therethrough can be accurately determined based upon the time and the volume of fluid emptied from the metering tube. A flow rate which is too slow indicates a blocked channel and a flow rate which is too fast indicates that the channel is probably disconnected and therefore providing no resistance to the flow. 
   In addition to the input and output devices described above, all of the electrical and electromechanical devices shown are operatively connected to and controlled by the control system  20 . Specifically, and without limitation, the switches and sensors  42 ,  59 ,  76 ,  84 ,  90 ,  98 ,  114 ,  116 ,  132  and  136  provide input I to the microcontroller  28  which controls the decontamination and other machine operations in accordance therewith. For example, the microcontroller  28  includes outputs O that are operatively connected to the pumps  32 ,  38 ,  70 ,  72 ,  88 ,  94 ,  100 ,  110 , the valves S 1 -S 7 , and the heater  80  to control these devices for effective decontamination and other operations. 
   Turning also to  FIG. 3 , an endoscope  200  has a head part  202 , in which openings  204  and  206  are formed, and in which, during normal use of the endoscope  200 , an air/water valve and a suction valve are arranged. A flexible insertion tube  208  is attached to the head part  202 , in which tube a combined air/water channel  210  and a combined suction/biopsy channel  212  are accommodated. 
   A separate air channel  213  and water channel  214 , which at the location of a joining point  216  merge into the air/water channel  210 , are arranged in the head part  202 . Furthermore, a separate suction channel  217  and biopsy channel  218 , which at the location of the joining point  220  merge into the suction/biopsy channel  212 , are accommodated in the head part  202 . 
   In the head part  202 , the air channel  213  and the water channel  214  open into the opening  204  for the air/water valve. The suction channel  217  opens into the opening  206  for the suction valve. Furthermore, a flexible feed hose  222  connects to the head part  202  and accommodates channels  213 ′,  214 ′ and  217 ′ which via the openings  204  and  206 , are connected to the air channel  213 , the water channel  214  and the suction channel  217 , respectively. In practice, the feed hose  222  is also referred to as the light-conductor casing. 
   The mutually connecting channels  213  and  213 ′,  214  and  214 ′,  217  and  217 ′ will be referred to below overall as the air channel  213 , the water channel  214  and the suction channel  217 . 
   A connection  226  for the air channel  213 , connections  228  and  228   a  for the water channel  214  and a connection  230  for the suction channel  217  are arranged on the end section  224  (also referred to as the light conductor connector) of the flexible hose  222 . When the connection  226  is in use, connection  228   a  is closed off. A connection  232  for the biopsy channel  218  is arranged on the head part  202 . 
   A channel separator  240  is shown inserted into the openings  204  and  206 . It comprises a body  242 , and plug members  244  and  246  which occlude respectively openings  204  and  206 . A coaxial insert  248  on the plug member  244  extends inwardly of the opening  204  and terminates in an annular flange  250  which occludes a portion of the opening  204  to separate channel  213  from channel  214 . By connecting the lines  30  to the openings  226 ,  228 ,  228   a ,  230  and  232 , liquid for cleaning and disinfection can be flowed through the endoscope channels  213 ,  214 ,  217  and  218  and out of a distal tip  252  of the endoscope  200  via channels  210  and  212 . The channel separator  240  ensures the such liquid flows all the way through the endoscope  200  without leaking out of openings  204  and  206  and isolates channels  213  and  214  from each other so that each has its own independent flow path. One of skill in the art will appreciate that various endoscopes having differing arrangements of channels and openings will likely require modifications in the channel separator  240  to accommodate such differences while occluding ports in the head  202  and keeping channels separated from each other so that each channel can be flushed independently of the other channels. Otherwise a blockage in one channel might merely redirect flow to a connected unblocked channel. 
   The leakage port  254  on the end section  224  leads into the interior portion space  104  of the endoscope  200  and is used to check for the physical integrity thereof, namely to ensure that no leakage has formed between any of the channels and the interior  256  or from the exterior to the interior  256 . 
   Some endoscope channels, such as the suction/biopsy channel  212  in some endoscopes have internal diameters which are too large to adequately assess their connection status with the metering tube  136 . For these channels, pressure pulses induced by the pumps  32  can be examined to assess proper connection. 
   Connection is made at connection  230  to the suction channel  217  and at connection  232  for the suction/biopsy channel  212 . Each of these connections is made via one of the flexible tubes  108 . By examining the pressure measured at the corresponding pressure sensor  42  the connection status between the connections  232 ,  230  and their corresponding flush line outlet  31  can be examined. 
   For instance, if the pump  32  in the flush line  30  connected (via one of the tubes  108 ) to the connection  230  is turned off and the pressure sensor  42  in this same flush line  30  is read, pressure pulses from the pump  32  in the flush line  30  connected to the connection  232  should be read. The suction channel  217  and suction/biopsy channel  212  meet internally inside the endoscope  200  putting the connections  230  and  232  in fluid communication with each other. The pumps  32  are peristaltic pumps which produce a known pressure wave at about 10 Hz, which of course will vary with the speed of the pump. Other methods could be used to induce the pressure pulses or waves, but the pumps  32  are quite convenient. Preferably the readings from the pressure sensor  42  are filtered electronically to remove noise above and below the target frequency (in the present example 10 Hz). If a significant pressure signal is not measured at the target frequency that indicates that one of the connections is not made; proper connection must be made between the flexible tube  108  and connection  230 , and at the opposite end of that flexible tube and the appropriate outlet  31 , as well as between a second of the flexible tubes  108  and the connection  232  and at the opposite end of this flexible tube and the appropriate outlet  31 . 
   It is not necessary to stop one of the pumps  32  to assess proper connection. The pumps will never be in perfect synchronization and at the exact same frequency and therefore with two of the pumps running through the connections  230  and  232  a beat frequency formed by the difference in each pump&#39;s frequency should be detectable at each of the pressure sensors  42  associated therewith. Only one of the pressure sensors  42  need be measured. 
   Readings at the pressure sensors  42  can also detect improper connection at either connection  230 , connection  232 , or some other connection, by listening for the reflection of the pressure waves. Here, the pressure sensor  42  in the flush line  30  connected via a flexible tube  108  to connection  232  would be listening for reflections from the pump  32  in that flush line  30 . These reflections would come from any discontinuities in the path between the pump  32  and where the biopsy/suction channel  212  leaves the distal end of the insertion tube  208 . When properly connected, the major echo should come from the open end of the channel  212  at the distal end of the insertion tube  208 . Other reflections would come from the connection between the flexible tube  108  and the connection  232 , the connection between the flexible tube  108  and the outlet  31 , the intersection of channels  217  and  212  and perhaps other surfaces and discontinuities therein. When one end of the tube  108  is not connected a different echo signature would be presented. 
   Echo signatures from different types of endoscopes  200  can be stored in the controller  28  and compared with the measured results to determine whether it matches that of a properly connected endoscope. Signatures for a disconnection at the connection  232  or a disconnection at the outlet  31  could also be stored for comparison. Different types and configurations of the flexible tube  108  may be used for different endoscope types which should be taken into consideration. Similar signatures can be stored for the connection  230  or any other connection on the endoscope. Although it is possible to prepare and store signatures for individual endoscope models, there is sufficient similarity among related endoscopes that signatures for broad classes of endoscopes could be used. If signatures for each endoscope model are stored, they could also be used to verify that the proper endoscope model has been entered into the controller. 
   The cleaning and sterilization cycle in detail comprises the following steps. 
   Step 1. Open the Lid 
   Pressing a foot pedal (not shown) opens the basin lid  16   a . There is a separate foot pedal for each side. If pressure is removed from the foot pedal, the lid motion stops. 
   Step 2. Position and Connect the Endoscope 
   The insertion tube  208  of the endoscope  200  is inserted into the helical circulation tube  64 . The end section  224  and head section  202  of the endoscope  200  are situated within the basin  14   a , with the feed hose  222  coiled within the basin  14   a  with as wide a diameter as possible. 
   The flush lines  30 , preferably color-coded, are attached, one apiece, to the endoscope openings  226 ,  228 ,  228   a ,  230  and  232 . The air line  112  is also connected to the connector  254 . A guide located on the on the station  10  provides a reference for the color-coded connections. 
   Step 3. Identify the User, Endoscope, and Specialist to the System 
   Depending on the customer-selectable configuration, the control system  20  may prompt for user code, patient ID, endoscope code, and/or specialist code. This information may be entered manually (through the touch screen) or automatically such as by using an attached barcode wand (not shown). 
   Step 4. Close the Basin Lid 
   Closing the lid  16   a  preferably requires the user to press a hardware button and a touch-screen  22  button simultaneously (not shown) to provides a fail-safe mechanism for preventing the user′s hands from being caught or pinched by the closing basin lid  16   a . If either the hardware button or software button is released while the lid  16   a  is in the process of closing the motion stops. 
   Step 5. Start Program 
   The user presses a touch-screen  22  button to begin the washing/disinfection process. 
   Step 6. Pressurize the Endoscope Body and Measure the Leak Rate 
   The air pump is started and pressure within the endoscope body is monitored. When pressure reaches 250 mbar, the pump is stopped, and the pressure is allowed to stabilize for 6 seconds. If pressure has not reached 250 mbar in 45 seconds the program is stopped and the user is notified of the leak. If pressure drops to less than 100 mbar during the 6-second stabilization period, the program is stopped and the user is notified of the condition. 
   Once the pressure has stabilized, valve S 5  is closed and valve S 6  opened to vent pressure from the interior space  104  beneath the sheath  102 . Valve  56  is closed and S 5  opened. Pressure is allowed to stabilize for one to six seconds and the new pressure is checked. If it is greater than 190 mbar, it is determined that the test connection  106  is not connected properly or at all to the port  254 . The cycle is stopped and the user notified of the condition. Assuming proper connection, pressure is then monitored over the course of 60 seconds. If pressure drops more than 10 mbar within 60 seconds, the program is stopped and the user is notified of the condition. If the pressure drop is less than 10 mbar in 60 seconds, the system continues with the next step. A slight positive pressure is held within the endoscope body during the rest of the process to prevent fluids from leaking in. 
   Step 7. Check Connections 
   A second leak test checks the adequacy of connection to the various ports  226 ,  228 ,  228   a ,  230 ,  232  and the proper placement of the channel separator  240 . A quantity of water is admitted to the basin  14   a  so as to submerge the distal end of the endoscope in the helical tube  64 . Valve S 1  is closed and valve S 7  opened and the pumps  32  are run in reverse to draw a vacuum and to ultimately draw liquid into the endoscope channels  210  and  212 . The pressure sensors  42  are monitored to make sure that the pressure in any one channel does not drop by more than a predetermined amount in a given time frame. If it does, it likely indicates that one of the connections was not made correctly and air is leaking into the channel. In any event, in the presence of an unacceptable pressure drop the control system  20  will cancel the cycle an indicate a likely faulty connection, preferably with an indication of which channel failed. For larger channels, proper connection is checked using the aforementioned method of reading the pressure of the beat frequency of pumps  32 . 
   Pre-Rinse 
   The purpose of this step is to flush water through the channels to remove waste material prior to washing and disinfecting the endoscope  200 . 
   Step 8. Fill Basin 
   The basin  14   a  is filled with filtered water and the water level is detected by the pressure sensor  59  below the basin  14   a.    
   Step 9. Pump water through channels 
   The water is pumped via the pumps  32  through the interior of the channels  213 ,  214 ,  217 ,  218 ,  210  and  212  directly to the drain  74 . This water is not recirculated around the exterior surfaces of the endoscope  200  during this stage. 
   Step 10. Drain 
   As the water is being pumped through the channels, the drain pump  72  is activated to ensure that the basin  14   a  is also emptied. The drain pump  72  will be turned off when the drain switch  76  detects that the drain process is complete. 
   Step 11. Blow Air through Channels 
   During the drain process sterile air is blown via the air pump  38  through all endoscope channels simultaneously to minimize potential carryover. 
   Wash 
   Step 12. Fill Basin 
   The basin  14   a  is filled with warm water (35° C.). Water temperature is controlled by controlling the mix of heated and unheated water. The water level is detected by the pressure sensor  59 . 
   Step 13. Add Detergent 
   The system adds enzymatic detergent to the water circulating in the system by means of the peristaltic metering pump  88 . The volume is controlled by controlling the delivery time, pump speed, and inner diameter of the peristaltic pump tubing. 
   Step 14. Circulate Wash Solution 
   The detergent solution is actively pumped throughout the internal channels and over the surface of the endoscope  200  for a predetermined time period, typically of from one to five minutes, preferably about three minutes, by the channel pumps  32  and the external circulation pump  70 . The inline heater  80  keeps the temperature at about 35° C. 
   Step 15. Start Block Test 
   After the detergent solution has been circulating for a couple of minutes, the flow rate through the channels is measured. If the flow rate through any channel is less than a predetermined rate for that channel, the channel is identified as blocked, the program is stopped, and the user is notified of the condition. The peristaltic pumps  32  are run at their predetermined flow rates and cycle off in the presence of unacceptably high pressure readings at the associated pressure sensor  42 . If a channel is blocked the predetermined flow rate will trigger the pressure sensor  42  indicating the inability to adequately pass this flow rate. As the pumps  32  are peristaltic, their operating flow rate combined with the percentage of time they are cycled off due to pressure will provide the actual flow rate. The flow rate can also be estimated based upon the decay of the pressure from the time the pump  32  cycles off. 
   Step 16. Drain 
   The drain pump  72  is activated to remove the detergent solution from the basin  14   a  and the channels. The drain pump  72  turns off when the drain level sensor  76  indicates that drainage is complete. 
   Step 17. Blow Air 
   During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover. 
   Rinse 
   Step 18. Fill Basin 
   The basin  14   a  is filled with warm water (35° C.). Water temperature is controlled by controlling the mix of heated and unheated water. The water level is detected by the pressure sensor  59 . 
   Step 19. Rinse 
   The rinse water is circulated within the endoscope channels (via the channel pumps  32 ) and over the exterior of the endoscope  200  (via the circulation pump  70  and the sprinkler arm  60 ) for 1 minute. 
   Step 20. Continue Block Test 
   As rinse water is pumped through the channels, the flow rate through the channels is measured and if it falls below the predetermined rate for any given channel, the channel is identified as blocked, the program is stopped, and the user is notified of the condition. 
   Step 21. Drain 
   The drain pump is activated to remove the rinse water from the basin and the channels. 
   Step 22. Blow Air 
   During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover. 
   Step 23. Repeat Rinse 
   Steps 18 through 22 are repeated to ensure maximum rinsing of enzymatic detergent solution from the surfaces of the endoscope and the basin. 
   Disinfect 
   Step 24. Fill Basin 
   The basin  14   a  is filled with very warm water (53° C.). Water temperature is controlled by controlling the mix of heated and unheated water. The water level is detected by the pressure sensor  59 . During the filling process, the channel pumps  32  are off in order to ensure that the disinfectant in the basin is at the in-use concentration prior to circulating through the channels. 
   Step 25. Add Disinfectant 
   A measured volume of disinfectant  92 , preferably CIDEX OPA orthophalaldehyde concentrate solution, available from Advanced Sterilization Products division Ethicon, Inc., Irvine, Calif., is drawn from the disinfectant metering tube  96  and delivered into the water in the basin  14   a  via the metering pump  100 . The disinfectant volume is controlled by the positioning of the fill sensor  98  relative to the bottom of the dispensing tube. The metering tube  96  is filled until the upper level switch detects liquid. Disinfectant  92  is drawn from the metering tube  96  until the level of the disinfectant in the metering tube is just below the tip of the dispensing tube. After the necessary volume is dispensed, the metering tube  96  is refilled from the bottle of disinfectant  92 . Disinfectant is not added until the basin is filled, so that in case of a water supply problem, concentrated disinfectant is not left on the endoscope with no water to rinse it. While the disinfectant is being added, the channel pumps  32  are off in order to insure that the disinfectant in the basin is at the in-use concentration prior to circulating through the channels. 
   Step 26. Disinfect 
   The in-use disinfectant solution is actively pumped throughout the internal channels and over the surface of the endoscope, ideally for a minimum of 5 minutes, by the channel pumps and the external circulation pump. The temperature is controlled by the in-line heater  80  to about 52.5° C. 
   Step 27. Flow Check 
   During the disinfection process, flow through each endoscope channel is verified by timing the delivering a measured quantity of solution through the channel. Valve S 1  is shut, and valve S 7  opened, and in turn each channel pump  32  delivers a predetermined volume to its associated channel from the metering tube  136 . This volume and the time it takes to deliver provides a very accurate flow rate through the channel. Anomalies in the flow rate from what is expected for a channel of that diameter and length are flagged by the control system  20  and the process stopped. 
   Step 28. Continue Block Test 
   As disinfectant in-use solution is pumped through the channels, the flow rate through the channels is also measured as in Step 15. 
   Step 29. Drain 
   The drain pump  72  is activated to remove the disinfectant solution from the basin and the channels. 
   Step 30. Blow Air 
   During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover. 
   Final Rinse 
   Step 31. Fill Basin 
   The basin is filled with sterile warm water (45° C.) that has been passed through a 0.2μ filter. 
   Step 32. Rinse 
   The rinse water is circulated within the endoscope channels (via the channel pumps  32 ) and over the exterior of the endoscope (via the circulation pump  70  and the sprinkler arm  60 ) for 1 minute. 
   Step 33. Continue Block Test 
   As rinse water is pumped through the channels, the flow rate through the channels is measured as in Step 15. 
   Step 34. Drain 
   The drain pump  72  is activated to remove the rinse water from the basin and the channels. 
   Step 35. Blow Air 
   During the drain process sterile air is blown through all endoscope channels simultaneously to minimize potential carryover. 
   Step 36. Repeat Rinse 
   Steps 31 through 35 are repeated two more times (a total of 3 post-disinfection rinses) to ensure maximum reduction of disinfectant residuals from the endoscope  200  and surfaces of the reprocessor. 
   Final Leak Test 
   Step 37. Pressurize the Endoscope Body and Measure Leak Rate 
   Repeat Step 6. 
   Step 38. Indicate Program Completion 
   The successful completion of the program is indicated on the touch screen. 
   Step 39. De-pressurize the Endoscope 
   From the time of program completion to the time at which the lid is opened, pressure within the endoscope body is normalized to atmospheric pressure by opening the vent valve S 5  for 10 seconds every minute. 
   Step 40. Identify the User 
   Depending on customer-selected configuration, the system will prevent the lid from being opened until a valid user identification code is entered. 
   Step 41. Store Program Information 
   Information about the completed program, including the user ID, endoscope ID, specialist ID, and patient ID are stored along with the sensor data obtained throughout the program. 
   Step 42. Print Program Record 
   If a printer is connected to the system, and if requested by the user, a record of the disinfection program will be printed. 
   Step 43. Remove the Endoscope 
   Once a valid user identification code has been entered, the lid may be opened (using the foot pedal as in step 1, above). The endoscope is then disconnected from the flush lines  30  and removed from the basin  14   a . The lid can then be closed using both the hardware and software buttons as described in step 4, above. 
   The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.