Abstract:
The invention relates to a test device for testing the inspection device of a washing machine for endoscopes, the inspection device including a connection that can be sealingly connected to an opening of an endoscope and feeding a fluid under pressure, said connector having a flow meter and/or a pressure transducer and the test device comprising at least one test chamber that can be sealingly connected to the connector by means of a test opening, wherein the test chamber is designed to be adjustable.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is based upon and claims the benefit of priority from PCT/EP2009/009223 filed on Dec. 22, 2009, which claims benefit to DE 10 2008 063 273.2 filed on Dec. 29, 2008, the entire contents of each of which are incorporated herein by reference. 
     
    
     BACKGROUND 
     Field 
       [0002]    The present invention generally relates to surgical endoscopes and washing machines for such surgical endoscopes, and particularly to a test device of the type indicated in claim  1 . 
         [0003]    Medical instruments and equipment that come into contact with the patient during operations are either purchased in sterile packs for single use or have to be cleaned and disinfected or sterilized after each use. 
         [0004]    Flexible endoscopes pose a particular problem. Because of their high cost, they cannot be treated as disposable. What is more, they are sensitive to heat, chemicals and mechanical stresses and therefore have to be handled with care. Flexible endoscopes also have cavities and channels that require special treatment. 
         [0005]    Therefore, in order to clean and disinfect flexible endoscopes, endoscope cleaning and disinfecting units, referred to below as “washing machines”, have been developed, which are also distributed by the applicant. In washing machines of this type, endoscopes are treated from inside and out with cleaning and disinfecting fluids in successive stages. In the course of this, the endoscopes with access openings are connected to connections on the washing machine, from which fluid is supplied under pressure to the endoscope. The fluid, i.e. the cleaning or disinfecting fluid, is intended to flow through the endoscope. An adequate flow must be guaranteed for a certain period in order to achieve the desired cleaning and disinfecting effect. 
         [0006]    The structurally long, thin channels in flexible endoscopes may become blocked during or after an operation, for example with coagulated blood or tissue residues. If a channel is blocked, it will not be flushed out and therefore not adequately sterilized. 
         [0007]    In washing machines of this type, this is prevented by an inspection device, which in the case where a connection is connected to an endoscope, checks the flow and compares it, for example, with a theoretical value of an identical, clean endoscope. If the inspection device records a blockage, this will be displayed and the endoscope will have to be flushed for longer or, if necessary, pre-cleaned by hand and treated again by the washing machine. 
         [0008]    The proper functioning of the inspection devices of such washing machines is of vital importance to the successful cleaning of the endoscopes. Therefore, the inspection devices have to be regularly checked. 
         [0009]    Various test devices for washing machines are known from the state of the art. 
         [0010]    DE 201 08 346 U1 shows a tube, which can be connected to the connection of a washing machine and in the test chamber of which test impurities have been placed. This allows the cleaning efficiency of the washing machine to be tested. 
         [0011]    WO 2008/019715 A1 shows a dummy endoscope, which approximates largely to the external shape of a flexible endoscope and which can accommodate test impurities in test chambers and also on the outside, with which the cleaning efficiency can be checked. 
         [0012]    Both these patents therefore show test devices, which can test only the cleaning efficiency but not the more important proper functioning of the inspection device. 
         [0013]    The dummy endoscope shown in the second-named patent is also shown in the “BeliMed Infection Control” brochure of BeliMed AG, Zug, Switzerland, which can be downloaded from www.belimed.com. In the lower part of page 3, in the right column, a “seal adapter to simulate the blocking of a channel” is offered for this dummy endoscope. If a connection to a washing machine is blocked with this seal adapter, it can then be checked whether the washing machine inspection device correctly detects a blocked channel. This seal adapter therefore represents a generic test device. The operation of this known test device is, however, very simple and does not allow it to be established whether the inspection device will really detect faults in a real endoscope. 
       SUMMARY 
       [0014]    The task of the present invention therefore consists in creating a generic test device, which simulates the behaviour of real endoscopes. 
         [0015]    According to the invention, the test chamber is developed to be adjustable. This makes it possible to adjust the test chamber to the desired parameters of a real endoscope. As when actually operating the washing machine, it is possible to simulate different endoscopes in succession and therefore obtain test results, which permit reliable conclusions to be drawn in respect of actual operation. 
         [0016]    Inside, flexible endoscopes also comprise, in addition to through channels, which are flushed with fluid and checked, complex internal cavities, which are usually interconnected and in which sensitive equipment, e.g. electronics, optics and the like are arranged. These cavities lie between the channel walls and the outer walls of the endoscope and must be reliably sealed both in relation to the channels and to the outside. Therefore, washing machines comprise leak-detection devices, which apply excess or negative air pressure to the inside of the endoscope and measure the pressure gradient following shut-off, in order to determine the tightness. This washing machine leak testing device is also intended to be checked by the test device, as is also the case for example, in WO 2008/019715 A1. From preference, therefore, the invention, according to claim  2 , provides in the test device a volume-adjustable leak test chamber, with which the washing machine leak testing device can be checked. The volume-adjustable design of the leak test chamber enables precise simulation of various real endoscopes. 
         [0017]    From preference, according to claim  3 , the leak test chamber is designed from connectable sub-chambers, so that the necessary volumes can be simulated using simple switching valves. 
         [0018]    In order to simulate the channels of an endoscope, the test chamber is, from preference, designed as an adjustable test channel according to claim  4 . This can, for example, be adjusted in respect of its length or patency in order to simulate real endoscopes. 
         [0019]    From preference the test channel according to claim  5  is designed in the form of sub-channels that can be connected via switching valves. In this way, the complex channel systems of different endoscopes can be simulated as accurately as required, enabling the inspection device to be tested under very real conditions. 
         [0020]    From preference, according to claim  6 , the test channel is provided with at least one adjustable flow resistance. This allows the flow resistances of real endoscope channels to be precisely simulated, so that in complex channel systems, the hydraulic conditions can be exactly reproduced. 
         [0021]    From preference, according to claim  7 , a manometer is connected to the test chamber. The manometer can be used, for example, when checking the leak detection device, to check the manometer in the inspection device. However, the manometer may also be used for various other safety-relevant tests, for example, to check the pump pressure of the pump on the washing machine side as well as to check safety pressure sensors in the washing machine, which are intended to switch off in the event of dangerous excess pressures. 
         [0022]    Preferably, according to claim  8 , the test chamber can be connected via a flow meter. In this way, the flow meter is directly controlled in the connected connection of the washing machine inspection device. 
         [0023]    The various connections of the washing machine for fluid and air must be connected to the corresponding openings in the endoscope. As the endoscope openings may be very different, according to type or manufacturer, inspection adapters are used, which comprise, for example, simple hoses with corresponding coupling pieces at their ends, and which in each case, fit at one end to a washing machine connection and at the other end to an opening in the endoscope. The test device according to the invention is intended to simulate different endoscopes and should therefore also be suited to an inspection adapter relevant to a particular endoscope. The test device must therefore simulate the corresponding connection openings when simulating an endoscope. From preference, this problem is solved according to claim  9  with a test adapter, which on the one hand fits the test openings of the test device and on the other, makes the openings of the simulated endoscope available. 
         [0024]    From preference, the features of claim  10  are provided. In this way, from a table located in the control device, with said table containing the design data relevant to the endoscope being simulated, the test device can be set in such a way that this endoscope is precisely simulated. By switching over switching valves between the channels, channel branches may, for example, be simulated. By adjusting the flow resistance, the individual channels can be adapted to real channels. The volume of the inside of the endoscope can also be adjusted to check the leak detection device. 
         [0025]    The test device should, as far as possible, simulate a real endoscope and should therefore also be positioned in place of an endoscope in the washing machine, for the test. However, the washing machine is closed, so that the test device can no longer be fitted with connection lines from the outside. From preference, therefore, according to claim  11 , the test device has its own energy supply. 
         [0026]    Data is obtained in the test device, e.g. for example, that relating to the manometer, according to claim  7  or to the flow meter according to claim  8 . In the case of the test device positioned inside the closed washing machine, this data is not readily accessible. From preference therefore, according to claim  12 , it is provided that the test device be designed to store or, if necessary, to transmit the data. The data obtained can therefore be stored in the test device until it is removed from the washing machine, or it is directly transmitted to the outside during operation, e.g. via suitable radio links. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    Examples of the invention are shown in diagram form in the drawings. 
           [0028]      FIG. 1  shows a diagram of a simple, flexible endoscope with washing machine inspection device connected and 
           [0029]      FIG. 2  shows the diagram of a test device according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIG. 1  shows in highly diagrammatical form a flexible endoscope  1 , where only the inner and outer walls are shown as a simple line. The endoscope  1  comprises a main body  2  from which an insertion hose  3  branches off, and which is intended to be inserted into the body, for example, into the intestine of a patient. A feed tube  4  also branches off from the main body  2 . Inside the endoscope  1 , a channel system is located with an insertion channel  5 , which leads outwards from the distal tip of the insertion hose  3 . The insertion channel  5  also passes through the main body  2 . An access opening  6  is open to the outside and leads into the insertion channel. Biopsy forceps or other suitably long and flexible working instruments can be advanced through the access opening  6  into the insertion channel  5 . 
         [0031]    The insertion channel  5  ends at a valve opening  7 , in which a control valve is normally positioned, which however is removed during cleaning. At the valve opening  7 , a supply channel  8  branches off from the insertion channel  5  and continues to the end of the supply hose  4 . Rinsing fluid, for example, is fed through the supply channel  8  and can be controlled by the valve which is normally positioned in the valve opening  7 . 
         [0032]    Around the channels  5  and  8 , i.e. between them and the outer wall of the endoscope, an internal space  9  is developed, which must be well sealed both from the fluid carrying channels and towards the outside, because it receives sensitive instruments, not shown in  FIG. 1 , such as electronic or optical instruments. The internal space  9  is accessible from the outside through an opening  10 . This opening is usually used to admit compressed air to the internal space  9  while the endoscope is in the washing machine, so that no water can penetrate as a result of leaks. 
         [0033]      FIG. 1  shows the endoscope  1  illustrated in its connected state, as when it is being sterilised in a washing machine. The valve opening  7  is connected to a coupling piece  11  of a inspection adapter  14 , said coupling piece  11  being adjusted to the valve opening. The inspection adapter comprises the coupling piece  14 , a hose  12  and a coupling piece  13  at the other end of the hose. 
         [0034]    A further inspection adapter  15  is connected to the access opening  6  by means of a suitable coupling piece. A third inspection adapter  16  is correspondingly connected to the opening  10  of the interior space  9 . The coupling pieces of the inspection adapters on the endoscope side are suitably developed for the openings of the respective endoscope. The other coupling pieces fit the washing machine. If a different endoscope is connected, the set of inspection adapters must be changed as necessary. 
         [0035]    The washing machine, which is not shown in greater detail, comprises a flushing pump  17 , which pumps fluid, e.g. water or disinfectant in the direction of the arrow, into a distribution line  18 , of which a first connection  19  is connected via a corresponding coupling to the inspection adapter  14 . A parallel second connection  20  is connected to the inspection adapter  15 . In other words, fluid can be pumped in parallel into the valve opening  7  and the access opening  6  of the endoscope  1 . Located in the two connections  19  and  20  in each case is a flow meter,  21 ,  22 . As indicated in the drawing by a branch, further connections with flow meters can branch off from the distribution line  18  and these further connections can be connected to other openings of more complex endoscopes. 
         [0036]    The flow meters  21  and  22  are connected to an electronic device, not shown, in the washing machine, which knows the precise data relating to the connected endoscope  1 , in particular its channel structure and flow resistances. The evaluation of the flow values measured by the flow meters  21 ,  22  therefore makes it possible to make statements about the patency of the channels  5  and  8  and also the patency of channel  5  in the area between the openings  6  and  7 . Particularly a partially or completely blocked channel can be detected. 
         [0037]    During the sterilisation process not only a channel inspection device  23  is connected, to which the first connection  19  and the second connection  20  belong, but also a leak inspection device  24 , which is connected to the inspection adapter  16  and the interior space  9 . This leak inspection device  24  supplies to the interior space  9  a fluid in gaseous form, normally air, and for this purpose, it has a gas pump  25 , which pumps gas in the direction of the arrow through a switching valve  26  up to the coupling with the inspection adapter  16 . A manometer  28  is connected between switching valve  26  and connection  27 . 
         [0038]    The leak inspection device  24  pressurises the internal space  9  of the endoscope and then locks the switching valve  26 . The air pressure is then monitored by the manometer  28 . The extent of any leak can be calculated from the pressure drop curve. 
         [0039]    The test device  30  shown in  FIG. 2  is used to check the washing machine inspection device comprising the parts  23  and  24  shown in  FIG. 1 . 
         [0040]    The test device  30  in the embodiment shown comprises three compartments edged with broken lines, which may, for example, be positioned in a common housing and in each case have their own test devices. The housing is preferably water-tight so that the test device  30  can be fitted inside a washing machine. 
         [0041]    A leak testing device  31  comprises a test opening  32  shown in highly schematic form, which is to be connected to connection  27  of the leak inspection device  24 . This connection is made via the inspection adapter  16 , which does not, however, normally fit the test opening  32 . Therefore an additional test adapter  33 , which on the one hand fits the test device  30  shown in  FIG. 2  and on the other, simulates the opening  10  of the endoscope  1 , is provided between the test opening  32  and the inspection adapter  16 . 
         [0042]    The leak testing device  31  is intended to simulate the interior space  9  of the endoscope  1 , but not only this but also interior spaces of other endoscopes. For this purpose the leak testing device  31  has a leak testing chamber comprising two chambers  34  and  35  of different size. The larger chamber  35  can be connected to the smaller chamber  34  by a switching valve  36 . The chamber  34  is connected to the test opening  32 . Also connected to the latter is a manometer  37 , which is connected to a line  40 , which leads to the outside through a switching valve  38  and an adjustable flow resistance  39 . Both chambers  34  and  35  and, if necessary, other additional chambers of the leak testing device  31  can simulate random internal space sizes of endoscopes. By adjusting the flow resistance  39 , random test leaks can be simulated and switched on and off using the switching valve  38 . The manometer  28  provided directly on the washing machine side can be tested using the manometer  37 . 
         [0043]    A channel testing device  41  has two test openings  42  and  43 , which, like test opening  32 , can be appropriately connected by way of test adapters  44 ,  45  to the inspection adapters  14  and  15 . With the latter they can be connected to the connections  19  and  20  of the channel inspection device  23 . The test openings  42  and  43  must correspond to the access opening  6  or the valve opening  7 , so that, for example, the endoscope  1  shown in  FIG. 1  can be simulated. 
         [0044]    The channel testing device  41  comprises a series of channels, with which larger channel systems of very complex endoscopes can also be simulated. Only some of the channels are required to simulate the endoscope  1  in  FIG. 1 . 
         [0045]    In order to simulate endoscope  1  in  FIG. 1 , the test opening  43 , which is connected to the inspection adapter  14 , shall correspond to the valve opening  7 . From there, a channel  46 , which simulates the supply channel  8  of endoscope  1 , runs to its free end with a drain that guarantees unimpeded drainage. 
         [0046]    A cross-channel  47  runs to the test opening  42 , which corresponds to the access opening  6  of the endoscope  1 . The channel  47  thus corresponds to that part of the insertion channel  5 , which lies inside the main body  2  of the endoscope  1 , between openings  6  and  7 . 
         [0047]    From test opening  42 , a channel  48  branches off, which likewise leads to a free discharge and which simulates that part of the insertion channel  5  of endoscope  1 , which runs from the access opening  6  to the distal end of the insertion hose  3  of endoscope  1 . No further parts of the channel system of the channel testing device  41  are needed to simulate the endoscope  1  illustrated in  FIG. 1 . For this purpose a switching valve  49  is closed. 
         [0048]    In order to simulate the precise dimensions of the supply channel  8  of endoscope  1 , its flow resistance is simulated by an adjustable flow resistance  50  in the channel  46 . Channel  46  can be completely shut off using a switching valve  51  if, for example, it is not required when simulating another endoscope. 
         [0049]    Appropriately, channel  48  is also adjustable and is fitted with a switching valve  52  and an adjustable flow resistance  53 . The cross-channel  47  between the test openings  43  and  42  is likewise fitted with switching valve  54  and adjustable flow resistance  55  for the sake of completeness. 
         [0050]    By adjusting the adjustable flow resistances  50 ,  53  and  55 , the channel system of endoscope  1  can be precisely simulated. Channels can be completely shut-off by operating the switching valves. This is particularly necessary, if other endoscopes are simulated. Partial blockages may also be simulated by adjusting the adjustable flow resistances or complete blockages by closing the switching valves. The channel inspection device  23  of the washing machine must be monitored for corresponding reactions. 
         [0051]    As already mentioned, channel testing device  41  can simulate not only endoscope  1  in  FIG. 1  but also other endoscopes. If an additional test opening  56  is used with a channel  57 , which leads to the outside, a correspondingly developed endoscope can be simulated. If a further channel  58  leading to the outside is provided in the endoscope parallel to channel  57 , which leads to the outside, channel  58  can be connected or shut down using a switching valve  59 . The flow resistances in channels  57  and  58  can be adjusted by adjustable flow resistances  60  and  61 . If the switching valve  59  is operated, channel  58  is connected or shut down. The channel inspection device  23  should be able to detect this. 
         [0052]    If an endoscope is to be simulated, which corresponds to that in  FIG. 1 , but has an additional opening, the test opening  56  is used and the channels  57  and  58  are shut down by a switching valve  62 . The switching valve  49  is opened in order to establish the connection with the test openings  43  and  42 , if necessary, by restricting the flow with an adjustable flow resistance  64 . 
         [0053]    The description of the channel testing device  41  in  FIG. 2  is only intended as an example, to explain the possibilities of such a channel system. Actual test devices may comprise even more channels and valves, in order to be able to simulate very complex endoscopes. 
         [0054]    In addition to the two compartments  31  and  41  discussed, the test device  30  also has a third compartment  65 , which acts as a flow testing device. In the embodiment, it contains two flow meters  66  and  67 , which are connected to test openings  68  and  69 . At the other ends, the flow meters  66  and  67  are connected to the outside by the lines  70  and  71  shown. 
         [0055]    The flow test device  65  can be connected, for example, using the test openings  68  and  69  and, if necessary, adapters to the connections  19  and  20  of the channel inspection device  23 , so that fluid flows successively through the flow meters  22  and  66  or  21  and  67 , thus making it possible to check directly the flow meters  22  and  21  on the washing machine side. 
         [0056]    With appropriate wiring provided by additional adapters or by internal channel connections and valves, the flow meters  66  and  67  of the flow testing device  65  can also, for example, be switched between the test openings  42  and  43  of the channel testing device  41  and the adapters that branch off from it, so that when the channel testing device  41  is used, the flow measurement is simultaneously tested. The flow testing device  65  can, for example, only have one flow meter or even more than the two illustrated. Furthermore, additional manometers can also be provided in the flow testing device  65 . 
         [0057]    As shown in  FIG. 2 , a control device  73  is fitted at a suitable place in the test device  30  and is connected by control lines, not shown, to the switching valves shown and the adjustable flow resistances of the test device  30 , in order to set the latter by way of appropriate control signals. The control device  73  can preferably obtain information from a built-in memory, where the data from different endoscopes is stored. If, for example, the endoscope shown in  FIG. 1  is called up from this memory, the control device  73  of the test device  30  shown in  FIG. 2  will close the switching valve  49  and open the switching valve  54 , as well as the switching valves  51  and  52 . The adjustable flow resistances  50 ,  53  and  55  would be set to the values of endoscope  1 . The control device  73  can, of course, also control the leak testing device  31 . 
         [0058]    Additional electronic devices can be provided, which are built into the test device  73  or developed as separate instruments. 
         [0059]    Data, for example, measurements from the manometer  37  and the flow meters  66  and  67  is collected in the test device  30 . The switching and control states of all switching valves and flow resistances can also be stored for logging. For this purpose, an internal memory can be provided, which stores all the measured values until the test process is concluded and the test device  30  can be removed from the washing machine in order to connect it by a suitable data interface to a computer from where the data can be called off. 
         [0060]    A data transmission device can also be provided, which regularly transmits the data obtained from the washing machine, for example, using suitable wireless transmission methods. 
         [0061]    As the test device  30  has to operate for a longish time inside a washing machine, a cable connection would be unsuitable. This applies not only to the data transfer but also to the power supply. For this reason a battery  74 , shown in  FIG. 2 , is provided, with which the control device  73  as well as the switching valves and adjustable flow resistances can be supplied.