Abstract:
An adapter device, which is configured to couple an endoscope with a medical appliance, such that the medical appliance is provided to generate light to illuminate an object to be investigated by an endoscope, includes an adapter body with a through-hole through which light generated by the medical appliance can be transmitted, and a fastening device to removably secure the adapter body on the medical appliance. The side of the adapter body that is to face the medical appliance is configured to be held form-locked in a predetermined angle position when the adapter body is secured on the medical appliance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority of German patent application No. 10 2009 056 107.2 filed on Nov. 30, 2009, the content of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to an adapter device to couple an endoscope with a medical appliance, where the medical appliance is configured to generate light to illuminate an object that is to be investigated by means of an endoscope and on a medical appliance. 
     BACKGROUND OF THE INVENTION 
     In medical (human and veterinarian medical) and non-medical, technical applications of an endoscope, as a rule a light source is required to illuminate the observed body cavity. The light source is, for example, a halogen incandescent lamp or a xenon high-pressure gas-discharge lamp. The light source together with devices for power supply, control or regulation and a user interface is positioned in a housing. A proximal end of an endoscope can be coupled with the medical appliance by a flexible light conductor cable or directly. Light generated by the light source, in some cases by means of the flexible light conductor cable, is transmitted or conducted to the proximal end of the endoscope and by means of one or more light wave conductors from the proximal end to the distal end of the endoscope. 
     The couplings on the ends of a light wave conductor on the one hand and a coupling provided for direct coupling with a medical appliance on the proximal end of an endoscope are clearly of different configurations. Therefore a medical appliance must have two different couplings, depending on whether it is to be coupled with a light conductor cable or directly with a proximal end of an endoscope. For example, a medical appliance can alternatively be equipped either with a coupling for a light conductor cable or with a coupling for direct coupling with a proximal end of an endoscope. Because the coupling on the medical appliance must be precisely adjusted, an exchange of the coupling on a medical appliance with light source is possible only with their producer. 
     If a medical appliance is equipped with a coupling for direct coupling with a proximal end of an endoscope, if necessary a light conductor cable can be coupled with the medical appliance if necessary by means of an auxiliary adapter. This auxiliary adapter, however, clearly reduces the light yield and makes handling difficult. 
     An air connection is often required to connect an endoscope; it can take the form in particular of a videoscope, bronchoscope or the like. Thus an adapter must also be provided, which will have an air connection available to ensure the preparation of air or another fluid. 
     SUMMARY OF THE INVENTION 
     An object of the present invention consists in making possible an improved coupling of a medical appliance with integrated light source with an endoscope, for example a video scope or bronchoscope, alternatively either directly or via a light conductor cable. 
     This object is achieved through the statements in the independent claims. 
     Refinements are indicated in the dependent claims. 
     Embodiments of the present invention are based on the idea of configuring adapter devices for coupling an endoscope with a medical appliance and a coupling device on a medical appliance in such a way that an adapter device fastened on the medical appliance is held form-locked in a position at a predetermined angle in relation to the coupling device. For this purpose the adapter device comprises a recess and the coupling device has a convex device and/or the coupling device on the medical appliance has a recess and the adapter device has a convex device, so that the recess and the convex device are configured in such a way that the convex device can engage in the recess with little free play. The convex device can be, for example, a spike or pin, while the recess can be a borehole. 
     An advantage of the form-locked connection for the adapter device in a predetermined angle position relatively to the coupling device on the medical appliance consists in the fact that the adapter device can be replaced without adjustment being necessary. Replacement of the adapter device can thus be undertaken by a technical layperson without disadvantageous consequences for the optical coupling between the endoscope and the medical appliance. As a result, considerable costs can be spared for sending the medical device to the producer for replacement and adjustment of the adapter device by the producer, and for shipping the medical appliance back to the owner. Besides these costs, there is a saving in terms of the corresponding downtime of the medical appliance. While the appliance is unavailable to the owner for at least a few days in the event of a conventional replacement with subsequent adjustment by the producer, with the present invention an exchange of the adapter device is possible within a few seconds or minutes and with correspondingly minimal costs. The medical appliance is immediately available again without restriction. 
     In addition, it becomes possible to avoid the disadvantages of the aforementioned auxiliary adapter for coupling a light conductor cable on a coupling device, which is primarily intended and configured for direct coupling with a proximal end of the endoscope. With an exchange of the adapter device on a medical appliance that can be executed easily and quickly, an alternative and alternating possibility is the coupling of the proximal end of the endoscope on the medical appliance. The coupling in particular can be optimal since it avoids transmission losses or a reduction of the light gain through an additional adapter. 
     An adapter device to couple an endoscope with a medical appliance that is configured to generate light to illuminate an object to be observed by means of the endoscope includes an adapter body with a through-hole through which the light generated by the medical appliance can be transmitted, and a fastening device for removable attachment of the adapter body on the medical appliance, whereby the side of the adapter body facing the medical appliance is configured to be held in form-locked connection in position at a predetermined angle when the adapter body is attached on the medical appliance. 
     With such an adapter device, on the side of the adapter body that is to face the medical appliance, it is possible to provide a borehole or other recess that is configured so that a convex device engages in the recess on the medical appliance. A convex device on the medical appliance can be, for example, a dome, pin, nub or stud. Instead of a single recess on the adapter device and a single convex device on the medical appliance, several recesses can be configured on the adapter device and several convex devices on the medical appliance to engage with one another in pairs and to establish, in a form-locked linkage, a predetermined angle position of the adapter body to the medical appliance. 
     With an adapter device as described here, the fastening device can include a fastening screw-on sheath with an outer thread that can rotate with respect to the adapter body but can slide axially only within an interval that is restricted at least in the proximal direction. Said interval, in particular, is restricted in both directions and constitutes the axial play of the fastening screw-on sheath with respect to the adapter body. Alternatively the fastening screw-on sheath can be secured on the adapter body without axial play. The outer thread is, in particular, a thread with multiple turns, for example a triple-turn thread. Specifically, a triple-turn thread, on the one hand, depending on the selected length of the thread, can be mounted with only one or a few rotations (even with less than one rotation) and therefore rapidly, while offering, on the other hand, a sufficient security against accidental release of the screw-in connection. Instead of an outer thread or in addition to it, the fastening screw-on sheath can comprise an inner thread and/or a bayonet coupling for releasable mechanical coupling with the medical appliance. The adapter device, in addition, can comprise a screw-nut that is or can be screwed onto the portion of the adapter body that is to face the medical appliance, in order to hold the fastening screw-on sheath on the adapter body or to restrict in the proximal direction the aforementioned interval of axial mobility. 
     A fastening screw-on sheath can comprise a fastening device that is especially cost-effective to produce and at the same time is robust and reliable. A fastening screw-on sheath can be configured in such a way that it can also be operated intuitively by technically non-practiced medial personnel and thus quickly and reliably without time-intensive training. 
     A three-part structure of the adapter device, consisting of adapter body, fastening screw-on sheath and a screw-nut that secures the fastening screw-on thread on the adapter body, can offer a particularly useful combination of low production costs, mechanical robustness, and precision. The adapter body, the fastening screw-on sheath and the screw-nut, in particular, can each be manufactured of stainless steel or another metallic or non-metallic material in simple manner by turning, milling and boring. 
     An adapter device as described here, in addition, can comprise a marker on the side of the adapter body facing the endoscope to indicate a foreseen angle position of the adapter body with respect to the medical appliance. Such a marking can simplify insertion and securing of the adapter body on a medical appliance. 
     An adapter device as described here can be configured to provide a coupling on a proximal end of an endoscope. 
     In case of immediate coupling with an endoscope, the medical appliance can include a fluid connection nipple to pump air or another fluid through the endoscope to its distal end or to suction it out from there. For optimal compatibility with a medical appliance of this configuration, an adapter device, which is configured to produce a coupling on a proximal end of an endoscope, can include a fluid connection borehole in the form of an additional through-hole to receive a fluid connection nipple of the medical appliance and a fluid connection nipple for the coupling of an endoscope. A fluid connection between the medical appliance and the endoscope can be formed via the fluid connection borehole. 
     With an adapter device as described here, the through-hole can be configured to insert a proximal end of a coupling of a light conductor cable. If the adapter device for a medical appliance is configured with a fluid connection nipple, it can include a blind hole on the side that is to face the medical appliance to insert the fluid connection nipple. Said blind hole can be configured not to be immediately contiguous with the fluid connection nipple but instead to make possible a streaming of fluid through the fluid connection nipple and between the outer surface of the fluid connection nipple and the inner surface of the blind hole. 
     An adapter set includes an adapter device in which the through-hole as described above is configured to insert a proximal end of a coupling of a light conductor cable and an adapter device as described above is configured to insert a coupling on a proximal end of an endoscope. The adapter devices of the adapter set, alternatively, can be secured on a medical appliance. Because of the form-locked securing of a predetermined angle position of the adapter body with respect to the medical appliance, the adapter devices can be exchanged with one another simply without requiring an adjustment and thus quickly. While one of the two adapter devices makes possible an optimal direct coupling between a medical appliance and an endoscope, the other allows an optimal coupling of the medical appliance and the endoscope via a light conductor cable or only the coupling of the medical appliance with a light conductor cable. The coupling here is optimal, in particular with respect to low light losses or a high transmission and/or with respect to convenience of operation. 
     A medical appliance includes a housing, a light source positioned in the housing to generate light to illuminate a site that is to be investigated with an endoscope, and a coupling device to couple a proximal end of an endoscope via an adapter device onto the medical appliance either directly or via a light conductor cable, and to transmit light from the light source to the endoscope, such that the coupling device is configured to secure an adapter body of an adapter device in form-locked connection in a predetermined angle position when the adapter body is secured to the light source. The medical appliance is configured to be connected with one of the adapter devices described above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are described in further detail hereinafter with reference to the appended drawings 
         FIG. 1  is a schematic axonometric depiction of components of a first adapter device. 
         FIG. 2  is another schematic axonometric depiction of the components of the first adapter device. 
         FIG. 3  is a schematic axonometric depiction of the first adapter device. 
         FIG. 4  presents schematic sectioned depictions of the first adapter device. 
         FIG. 5  is a schematic sectioned depiction of a medical appliance and of the first adapter device. 
         FIG. 6  is another schematic sectioned depiction of the medical appliance and of the first adapter device. 
         FIG. 7  is a schematic axonometric depiction of components of a second adapter device. 
         FIG. 8  is another schematic axonometric depiction of the components of the second adapter device. 
         FIG. 9  presents schematic axonometric depictions of the second adapter device. 
         FIG. 10  is a schematic sectioned depiction of the second adapter device. 
         FIG. 11  is a schematic sectioned depiction of the medical appliance from  FIGS. 5 and 6  and of the second adapter device. 
         FIG. 12  is a schematic sectioned depiction of the medical appliance from  FIGS. 5 ,  6  and  11  and of the second adapter device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 through 3  show schematic axonometric depictions of the components of a first adapter device or of the assembled first adapter device.  FIG. 4  shows schematic sectioned depictions of the first adapter device. At the left in  FIG. 4 , the three main components of the first adapter device are shown separately, similarly as in  FIGS. 1 and 2 , and at the right the first adapter device is shown assembled or installed. The illustrated section planes each contain the longitudinal axis of the adapter device. 
     The first adapter device  30  comprises a side that is to face a medical appliance or a proximal side  31  (compare  FIG. 2  and  FIG. 3 , right) and a side that is to face a light conductor cable or an endoscope or a distal side  32  (compare  FIG. 1  and  FIG. 3 , right). The first adapter device  30  includes an adapter body  35 , a fastening screw-on sheath  36 , and a screw-nut  37 . A catch-lock device  38  is integrated into the adapter body  35 . The adapter body  35 , fastening screw-on sheath  36 , and a screw-nut  37  are each partly rotationally symmetrical to an axis that extends from the proximal side  31  to the distal side  32 . The rotational symmetry of the adapter body  35 , fastening screw-on sheath  36 , and screw-nut  37 , however, is interrupted by several elements in each case, for example by boreholes and threads. 
     The adapter body  35  comprises a through-hole  51  with a ring-shaped recess  52 . As can be seen in particular from  FIG. 4 , the through-hole  51  is positioned essentially parallel to the longitudinal axis of the first adapter device  30 . The through-hole  51  comprises two essentially cylindrical segments, between which the ring-shaped recess  52  is positioned. 
     In addition the adapter body  35  comprises a first blind hole  53 , which extends from the proximal side outward into the adapter body  35 . The contour of the first blind hole  53  is shown in broken lines in  FIG. 4  because it is situated outside the illustrated section plane. The first blind hole  53  comprises an essentially cylindrical segment. At the entrance of the first blind hole  53  on the proximal side  31  of the adapter body  35 , the first blind hole  53  comprises a spherical or conical segment. 
     The adapter body  35  comprises, in addition, a second blind hole  54 , which is positioned essentially parallel to the longitudinal axis of the first adapter device  30 . The second blind hole  54  is essentially cylindrical, with a spherical or conical segment at the entrance of the proximal side  31  of the adapter body  35 . 
     The adapter body  35  of the first adapter device  30  also comprises a ring-shaped recess  56  close to the distal end of the adapter body  35  and an outer thread  57  close to the proximal end of the adapter body  35 . 
     The fastening screw-on sheath  36  of the first adapter device  30  comprises close to its proximal end an outer thread  63  and a proximal front surface  64 . The outer thread is in particular a multiple-turn thread, for example a triple-turn thread, to make screw attachment possible with one turn or fewer turns or less than one turn. Close to the distal end the fastening screw-on sheath  36  comprises on its outer surface a ring-shaped ribbed gripping surface  65 . In addition, the fastening screw-on sheath  36  comprises a ring-shaped recess  66  between two cylindrical segments of its inner surface. 
     The screw-nut  37  comprises an inner thread  71  that can be screwed in complementary manner or with the outer thread  57  onto the adapter body  35 . On its outer periphery the screw-nut  37  comprises one or more grooves  72  positioned essentially parallel to the longitudinal axis of the first adapter device  30 . A rotary moment can be transmitted onto the screw-nut  37  via the grooves  72  with an appropriate tool to screw the screw-nut onto the outer thread  57  of the adapter body  35  and to tense it with said body in order to prevent accidental loosening of the screw-nut  37 . Accidental loosening of the screw-nut  37  from the adapter body, in addition, can be prevented through one or more soldering points, by welding, cementing, use of a splint or other actions. In addition the screw-nut  37  comprises a front surface  74 . 
     The catch-lock device  38  includes a transverse borehole  81 , close to the distal side  32  of the adapter body  35 , extending from an outer mantle surface of the adapter body  35  to the through-hole  51 . In addition, the catch-lock device  38  includes a sphere  82 , a coil spring  83  and a dowel. The depiction in  FIG. 4  shows a variant in which a piston is positioned between the sphere  82  and the coil spring  83 . The transverse borehole  81 , on its end bordering on the through-hole  51 , has a reduced cross-section, so that the sphere  82  and transverse borehole  81  can enter or extend only partway into the through-hole  51 . 
     The coil spring  83  is partly compressed between the sphere  82  and the dowel  84  in the transverse borehole  81 , so that the sphere  82  is pre-tensed in the direction into the through-hole  51 , but can be forced completely out of the cross-section of the through-hole  51  by a sufficient force. 
     In particular at the right in  FIG. 4  it can be recognized that, with the first adapter device  30  in installed or assembled position, an axial movement of the fastening screw-on sheath  36  in the distal direction is restricted by the contiguity of the ring-shaped recess  66  of the fastening screw-on sheath  36  to the ring-shaped recess  56  on the adapter body  35 . It an also be seen that an axial movement of the fastening screw-on sheath  36  in the proximal direction is restricted by a contiguity of the proximal front surface  64  of the fastening screw-on sheath  36  on the one hand and of the distal front surface  74  of the screw-nut  37  on the other hand, which partially overlap with one another. 
     At the right in  FIG. 4 , in addition, it can be seen that the adapter body  35 , fastening screw-on sheath  36  and screw-nut  37  of the first adapter device  30  are of such dimensions that the fastening screw-on sheath  36  is secured with little or no free play in the axial direction between the ring-shaped recess  56  on the adapter body  35  on the one hand and the distal front surface  74  of the screw-nut  37 , which is entirely screwed onto the adapter body  35 , on the other hand. The fastening screw-on sheath  36 , however, can rotate freely around the longitudinal axis of the first adapter device  30 . 
       FIGS. 5 and 6  show schematic sectioned depictions of a medical appliance  10  with a light source  11  and a lens  12  in a housing  14 . A coupling device  20  with a recess  21  is positioned in an opening of the housing  14 . Said recess  21  is essentially rotation-symmetric and adapted to the outer shape of the first adapter device  30 . A through-hole  22  in the coupling device  20  extends from the recess  21  in the direction toward the lens  12  and light source  11 . Positioned on the wall of the recess  21  is an inner thread  23 , which can be screwed complementarily to the outer thread  63  of the fastening screw-on sheath  36  of the first adapter device  30  or with it. 
     A fluid connection nipple  24  and a pin or mandrel  26  extend into the recess  21 . The contour of the mandrel  26  is illustrated with an interrupted line because the mandrel  26  lies outside the section plane shown in  FIG. 5 . Contrary to the depiction in  FIGS. 5 and 6 , one end of the fluid connection nipple  24 , which is turned away from the recess  21 , can end or continue in a tube, which takes another direction, for example at a right angle to the fluid connection nipple  24 . 
     Not shown in  FIGS. 5 and 6  are additional devices of the medical appliance  10 , for example devices for power supply, control or adjustment of the light source  11 , a user interface, a pump or blower, either of which is connected with the fluid connection nipple  24 . 
     It can be recognized in  FIG. 6  that the first adapter device  30  can be inserted partially into the recess  21  of the coupling device  20 . In the process, the outer thread  63  on the fastening screw-on sheath  36  and the inner thread  23  on the coupling device  20  engage with one another or are screwed together with one another. In addition, the mandrel  26  engages in the first blind hole  53  in the adapter body  35 . Because of a precise fit or the smallest possible free play between the mandrel  26  on the coupling device  20  on the one hand and the first blind hole  53  on the other hand, the first adapter device  30  is held in a predetermined angle position with respect to the coupling device  20 . 
     It can also be seen in  FIG. 6  that the fluid connection nipple  24  of the coupling device  20  engages in the second blind hole  54 . Between the outer wall of the fluid connection nipple  24  on the one hand and the inner wall of the second blind hole  54  on the other hand, there remains a gap through which a fluid coming through the fluid connection nipple  24  can flow. The result is a reduction in the build-up of excess or low pressure in the fluid connection nipple  24  and the connected components when the first adapter device  30  is in operation. This also prevents any backed-up pressure in the medical appliance and the pump installed in it. 
     With the corresponding precise fit or low free play between the fluid connection nipple  24  and the second blind hole  54 , the fluid connection nipple  24  and the second blind hole  54  can assume the function of the form-locked securing of the first adapter device  30  in a predetermined angle position with respect to the coupling device  20 . In this case the mandrel  26  and first blind hole  53  are dispensed with. This is subject to the condition that the fluid connection nipple and the connection for the light conductor are asymmetrical to one another. 
     Illustrated in  FIG. 6  is a coupling  91  on the proximal end of a light conductor cable that is inserted into the through-hole  51  in the adapter body  35  and into the through-hole  22  of the coupling device. In this way the catch-lock device  38  secures the coupling  91  in the predetermined axial position. Because of the form-locked securing of the angle position of the first adapter device  30  with respect to the coupling device  20 , the coupling  91  and a light-admitting window  92  are aligned precisely on the proximal end of the coupling  91  opposite the light source  11  and the lens  12  to ensure the most complete possible coupling of the light of the light source  11  into the light conductor cable. 
       FIGS. 7 through 9  show schematic axonometric depictions of the components of a second adapter device or of the assembled second adapter device.  FIG. 10  shows a schematic sectioned depiction of the three main components of the second adapter device. It is further described below, with reference to  FIGS. 11 and 12 , that the second adapter device is intended and configured to be applied on the same medical appliance, like the first adapter device described above with reference to  FIGS. 1 through 6 . Contrary to the first adapter device described above, the second adapter device, however, is not intended to be coupled with a coupling on one end of a light conductor cable. Instead, the second adapter device is intended and configured to be coupled directly with one proximal end of an endoscope. This is the reason for the differences, described hereinafter, between the second adapter device and the first adapter device. 
     The second adapter device  40  comprises a side that is to face a medical appliance or proximal side  41  (compare  FIG. 7  and  FIG. 9 , left) and a side that is to face a light conductor cable or an endoscope or distal side  42  (compare  FIG. 7  and  FIG. 9 , right). Similarly as in the first adapter device  30  described above, the second adapter device  40  includes an adapter body  45 , a fastening screw-on sheath  46  and a screw-nut  47 , which however differ in part from the corresponding components in the first adapter device. The adapter body  45 , the fastening screw-on sheath  46  and the screw-nut  47  are each partly rotation-symmetrical to an axis that extends from the proximal side  41  to the distal side  42 . The rotation symmetry of the adapter body  45 , fastening screw-on sheath  46  and screw-nut  47  is, however, interrupted by several elements, for example by boreholes and threads. 
     Described below are only those properties of the components of the second adapter device  40  by which the second adapter device  40  is distinguished from the first adapter device  30 . Those properties of the components of the second adapter device  40  not mentioned below correspond to the properties of the first adapter device  30 . 
     The adapter body  45  comprises a through-hole  51  with a cross-section that remains constant from the proximal side  41  to the distal side  42 . The through-hole  51  is positioned essentially parallel to the longitudinal axis of the second adapter device  40 . In addition the adapter body  45  comprises a first blind hole  53 , which corresponds in terms of its position, size and shape to the blind hole in the adapter body of the first adapter device  30 . 
     Instead of a second blind hole, the adapter body  45  comprises a fluid connection borehole  58  in the form of a through-hole that is positioned essentially parallel to the longitudinal axis of the second adapter device  40 . The fluid connection borehole  58  comprises on its proximal side  41  and on the distal side  42  one area each with a step-shaped broadened cross-section. Inserted in these two areas are a first O-ring  85  and a first threaded bushing  86  or a second O-ring  87  and a second threaded bushing  88 . Apart from the elastic O-rings  85 ,  87 , which protrude somewhat into the cross-section of the fluid connection borehole  58 , the result is a channel with an essentially constant cross-section from the proximal side  41  to the distal side  42  of the adapter body  45  or of the second adapter device  40 . 
     Contrary to the fastening screw-on sheath  36  of the first adapter device  30 , the fastening screw-on sheath  46  of the second adapter device  40 , with the second adapter device  40  in installed or assembled position, extends beyond the adapter body  45  on the distal side  42 . In addition, the fastening screw-on sheath  46 , in the area in which it extends beyond the adapter body  45 , comprises a ring-shaped groove  67  on the inside close to its distal border. The function of this groove is described more fully below with reference to  FIG. 12 . 
       FIGS. 11 and 12  show schematic sectioned depictions of the medical appliance  10  already described above with reference to  FIGS. 5 and 6  and of the second adapter device  40 . In  FIG. 11  the second adapter device  40  is aligned with respect to the coupling device  20  on the medical appliance  10 , but is not yet inserted into said device.  FIG. 12  shows the second adapter device  40  inserted in the coupling device  20  on the medical appliance  10  or in its recess  21 . As already explained above for the first adapter device  30  with reference to  FIGS. 5 and 6 , in the second adapter device  40  as well, the outer thread  63  on the fastening screw-on sheath  46  engages in the inner thread  23  of the coupling device  20 . It can further be seen in  FIG. 12  that the fluid connection nipple  24  of the coupling device  20  engages in the fluid connection borehole  58  coming from the proximal side  41 . 
     The mandrel of the coupling device  20  engages in the first blind hole  53  in the adapter body  45 . Because of a precise fit or the least possible free play between the mandrel  26  on the coupling device  20  on the one hand and the first blind hole  53  in the adapter body  45  on the other hand, the second adapter device  40  is secured in a predetermined angle position with respect to the coupling device  20 , similarly as is shown above for the first adapter device  30  with reference to  FIG. 6 . 
     Also shown in  FIG. 12  is a coupling  95  on the proximal end of an endoscope that is not depicted further in  FIG. 12 . The coupling  95  includes a spring washer  96  in a ring-shaped groove on the coupling  95 . In the illustrated position of the coupling  95  with respect to the second adapter device  40 , the spring washer  96  engages in the ring-shaped groove  67  on the fastening screw-on sheath  36 . Owing to the elastic property of the spring washer  96  pre-tensed outward, the coupling  95  is held elastically form-locked on the second adapter device  40 . 
     The coupling  95  comprises a fluid connection nipple  97  and a light conductor tube  98  with a light-admitting window  99 . The fluid connection nipple  97  and light conductor tube  98  of the coupling  95  extend out in the proximal direction beyond other parts of the coupling  95 . 
     The fluid connection nipple  97 , from the distal side  42 , engages in the fluid connection borehole  98  in the adapter body  45 . The lumen of the fluid connection nipple  24  of the coupling device  20  and the lumen of the fluid connection nipple  97  of the coupling  95  are in connection with one another via the lumen of the fluid connection borehole  58 . The elastic O-rings  85 ,  87  are contiguous with the outer surfaces of the fluid connection nipples  24 ,  97 . Thereby the connection between the fluid connection nipple  24  of the coupling device  20  of the medical appliance  10  on the one hand and the fluid connection nipple  97  of the coupling  95  on the proximal end of the endoscope on the other hand are insulated from penetration by fluids from the outside. 
     The light conductor tube  98  engages in the through-hole  51  in the adapter body  45  and in the through-hole  22  of the coupling device  20 . Because of the predetermined angle position of the adapter body  45  relative to the coupling device  20  imposed as a result of the mandrel  26  on the coupling device  20  and the blind hole  53  in the adapter body  45 , the light conductor tube  98  and in particular the light-admitting window  99  of the coupling  95  are aligned precisely with respect to the light source  11  and the lens  12 . As a result, an optimal optic coupling is made possible between the light source  11  and the endoscope. 
     The first adapter device  30  and the second adapter device  40 , on the proximal side  31  or  41  and to the extent that they engage in the recess  21  in the coupling device  20 , are adapted to the coupling device  20  with respect to their outer shape, the position of the first through-holes  51 , the arrangement, form and dimensions of the first blind hole  53 , the arrangement and dimensions of the second blind hole  54  or of the fluid connection borehole  58 . Thus the aforementioned properties of the adapter devices  30 ,  40  are basically identical or at least similar. The adapter devices  30 ,  40 , however, differ from one another with respect to the cross-sections of the first through-holes  51  and with respect to the configuration of the second blind hole  54  on the one hand, or of the fluid connection borehole  58  on the other hand.