Patent Publication Number: US-11660232-B2

Title: Patient interface system, camera system, method for coupling a patient interface with a patient interface holder, patient interface, and patient interface holder

Description:
FIELD 
     The invention relates to a patient interface system for positioning a patient&#39;s eye relative to a laser device for laser surgery. Furthermore, the invention relates to a camera system for such a patient interface system, to a method for coupling a patient interface to a patient interface holder of such a patient interface system as well as to a patient interface and a patient interface holder for such a patient interface system. 
     BACKGROUND 
     Such a patient interface system can for example be employed in the laser-surgical treatment of a human or animal eye. Therein, the patient interface system serves for positioning and coupling the patient&#39;s eye to a laser device, which generates the laser radiation for the treatment of the patient&#39;s eye. Corresponding laser devices for example comprise a basic apparatus with a laser source for generating pulsed laser radiation, for example nano-, femto- or pico-second laser pulses, as well as an application head, which is coupled to the patient&#39;s eye via the patient interface system for treatment. The patient interface system is usually arranged between the patient&#39;s eye and a focusing system of the laser device. A fixed coupling is required to keep the distance between the laser source and its focusing system, respectively, and the patient&#39;s eye constant in order that the laser-surgical treatment can be performed with the required high precision and the laser beam can be precisely directed to the tissue of the patient&#39;s eye to be treated, for example to the cornea. 
     A generic patient interface system includes a patient interface for coupling to the patient&#39;s eye and a patient interface holder for arrangement of the patient interface on the laser device. Therein, the patient interface includes a first positioning device for abutting the patient interface on the patient&#39;s eye. The patient interface holder in turn includes a holding device, by means of which the patient interface can be reversibly coupled to the patient interface holder. In the coupled or mounted state, thus, the patient interface is coupled to the patient&#39;s eye at the one end and to the patient interface holder at the other end, while the patient interface holder in turn is coupled to the laser device such that a correct orientation between the patient&#39;s eye and the laser source is ensured. 
     The circumstance is to be regarded as disadvantageous in the known patient interface system that monitoring the laser-surgical treatment is difficult since the optical path or the beam path for the laser beam has to be kept free. 
     SUMMARY 
     It is the object of the present invention to provide a patient interface system, which allows better monitoring of a laser-surgical treatment procedure. A further object of the invention is in providing a method for coupling a patient interface to a patient interface holder of such a patient interface system, which allows better monitoring of a laser-surgical treatment procedure. Finally, further objects of the invention are in providing a corresponding patient interface and a corresponding patient interface holder for such a patient interface system. 
     According to the invention, the objects are solved by a patient interface system with the features of claim  1 , by a camera system according to claim  11  for such a patient interface system, by a method according to claim  13  for coupling a patient interface to a patient interface holder of a patient interface system as well as by a patient interface according to claim  14  and by a patient interface holder according to claim  15 . Advantageous configurations with convenient developments of the invention are specified in the respective dependent claims, wherein advantageous configurations of each inventive aspect are to be regarded as advantageous configurations of the respectively other inventive aspects. 
     A first aspect of the invention relates to a patient interface system for positioning a patient&#39;s eye relative to a laser device for laser surgery, including a patient interface for coupling to the patient&#39;s eye and a patient interface holder for arrangement of the patient interface on the laser device, wherein the patient interface comprises a first positioning device for abutment of the patient interface on the patient&#39;s eye and the patient interface holder includes a holding device, by means of which the patient interface can be reversibly coupled to the patient interface holder. According to the invention, a better monitoring of a laser-surgical treatment procedure is allowed in that the patient interface holder includes a connection device for coupling a camera system and that the patient interface holder and the patient interface comprise channels corresponding to each other, which together bound an optical path between the connection device and the first positioning device in the coupled state of patient interface holder and patient interface. Therein, the channel of the patient interface is arranged at least partially extending on an outer circumference of a suction cup part of the patient interface. In other words, it is provided that a camera system can be arranged on the connection device of the patient interface holder and can capture the region of the first positioning device, which serves for abutment of the patient&#39;s eye, by the optical channel, which is formed commonly by a channel or partial channel of the patient interface holder and an associated channel or partial channel of the patient interface in the mounted state. Hereby, the capture of the surgical field without disturbance of the laser radiation is allowed at the same time with the mechanical coupling of patient interface holder and patient interface, which allows better monitoring of a laser-surgical treatment procedure. Preferably, the channel of the patient interface is formed partially or completely closed on the outer circumference. In addition, the optical channel commonly formed in the coupled state for the camera system at least predominantly extends separately to a passage channel of the patient interface system for a laser beam of a laser device or outside of such a passage channel of the patient interface system for a laser beam of a laser device, since impairment of an optical path of the laser and thereby potential disturbances during a surgical intervention are hereby particularly reliably prevented. In some configurations, it can be provided that the channel opens into the passage channel at its end facing away from the camera system. For example, the passage channel for the laser beam can be formed by the suction cup part or be arranged within the suction cup part of the patient interface, while the optical channel for the camera system is formed or arranged separated hereof. For example, it can be provided that the optical channel is arranged or formed on an outer side of the passage channel for the laser beam or on an outer side of the suction cup part. It can be provided that the (partial) channel of the patient interface holder has a length, which corresponds to 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% or 90% of the length of the (partial) channel of the patient interface, wherein the lengths of both (partial) channels always complement each other to 100%. Preferably, it can be provided that the (partial) channel of the patient interface holder and the (partial) channel of the patient interface at least substantially have the same length, i.e. that one of the (partial) channels has a length between 40% and 60% of the length of the other (partial) channel. 
     In an advantageous configuration of the invention, it is provided that the channel of the patient interface holder is closed by a window transparent for wavelengths in the range visible to the human in an end region facing away from the connection device. Hereby, the penetration of contaminations from the surgical region or the environment is avoided such that the camera system is reliably protected from pollution. 
     In a further advantageous configuration of the invention, it is provided that the channels extend at an angle between 2° and 80°, that is for example at an angle of 20, 30, 40, 50, 60, 7° 80, 90, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°, 60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79° or 80° to a direction of an intended laser radiation of the laser device in the coupled state of the patient interface and the patient interface holder. In other words, it is provided that the camera system mounted with or in the connection device is arranged at an angle to a laser radiation impinging on the patient&#39;s eye and captures the patient&#39;s eye from obliquely above. This allows better determination of both the surgical location and the environment. 
     In a further advantageous configuration of the invention, it is provided that the patient interface holder includes an illumination device, by means of which at least a region of the patient&#39;s eye can be illuminated, preferably perpendicular to a surface of a contact body of the first positioning device. The illumination device can comprise one or more lighting means such as for example LEDs. Similarly, one or more light guides can be provided. Thereby, the illumination of the surgical location or of the patient&#39;s eye can basically be directly and/or indirectly effected. Similarly, it is possible to illuminate the environment of the patient&#39;s eye, which also contributes to better capability of monitoring a laser-surgical treatment procedure. 
     In a further advantageous configuration of the invention, it is provided that the patient interface and/or the patient interface holder include at least two assemblies coupled to each other. This facilitates the realization of complex geometries as well as the mounting of different functional elements on the patient interface and/or the patient interface holder. Moreover, different assembly types can hereby be combined with each other as needed, for example to adapt the patient interface system to differently sized patient&#39;s eyes. 
     In a further advantageous configuration of the invention, it is provided that one of the assemblies carries the illumination device. Hereby, the necessity of having to provide and handle additional illumination means is omitted. Moreover, a unitary and reliable illumination of the patient&#39;s eye or the surgical region is always ensured in this manner in the mounted state of the patient interface system. 
     In a further advantageous configuration of the invention, it is provided that at least two assemblies include respective channels, which together form the channel of the patient interface holder and/or of the patient interface. Thereby, the optical path can be particularly flexibly defined and formed by mounting the assemblies. Alternatively or additionally, it is provided that at least one assembly includes a suction duct connectable to a suction device, which forms a fluid path together with a fluid-conducting device of the patient interface in the coupled state of patient interface holder and patient interface, which fluidically couples the suction duct to a suction opening of the patient interface in the region of the first positioning device, to hold the first positioning device in abutment on the patient&#39;s eye by a relative negative pressure generated by means of the suction device. Hereby, it is possible to also realize an optical coupling via the camera system and the optical channel as well as a hydraulic coupling via the suction duct and the fluid-conducting device together with the mechanical coupling of patient interface and patient interface holder. This ensures a particularly high use comfort for a user, for example a physician, and additionally reduces the number of possible sources of error. 
     In a further advantageous configuration of the invention, it is provided that at least two assemblies together form a preferably groove-shaped guiding device, along which a second positioning device of the patient interface is forcibly guided movable for coupling to the patient interface holder. This allows a particularly simple and process-reliable coupling of the patient interface to the patient interface holder since possible inadmissible relative movements in coupling and decoupling, respectively, are made impossible by the guiding device. 
     In a further advantageous configuration of the invention, it is provided that the connection device is formed for coupling a focusing system, by means of which a focus of the camera system is adjustable to the patient&#39;s eye. In this manner, high quality of the optical capture of the patient&#39;s eye is ensured. Optionally, the focusing system can be integrated in the camera system or form a common assembly with it, which is mounted on the patient interface holder by means of the connection device. 
     In a further advantageous configuration of the invention, it is provided that the patient interface is composed of a material transparent and/or light-conducting for wavelengths in the ranged visible to the human at least in certain areas. This allows sight from the outside to the patient&#39;s eye as well as illumination through a correspondingly configured wall of the patient interface. 
     A second aspect of the invention relates to a camera system for a patient interface system according to the first inventive aspect, wherein the camera system includes connection means for coupling to the connection device of the patient interface holder of the patient interface system. Hereby, the camera system can be particularly simply coupled to the patient interface system or be inserted into the patient interface holder and for example be attached to the laser device together with the patient interface holder. This allows better monitoring of a laser-surgical treatment procedure since the patient interface system can be integrally equipped with the possibility of optically determining the surgical field. Further features and the advantages thereof can be taken from the descriptions of the first inventive aspect, wherein advantageous configurations of the first inventive aspect are to be regarded as advantageous configurations of the second inventive aspect and vice versa. 
     In an advantageous configuration of the invention, it is provided that the camera system includes at least one component from the group of diaphragm, lens, spring element, spring bearing, camera housing, adjusting means, mounting block and focusing screw. Thereby, the camera system can be optimally adapted to its respective purpose of employment and the configuration of the patient interface system. 
     A third aspect of the invention relates to a method for coupling a patient interface of a patient interface system according to the first inventive aspect to a patient interface holder of a patient interface system according to the first inventive aspect, in which the patient interface is moved relative to the patient interface holder until the patient interface and the patient interface holder are coupled and the channels of patient interface holder and patient interface corresponding to each other together bound an optical path between the connection device for the camera system and the first positioning device of the patient interface, wherein the channel of the patient interface is arranged at least partially extending on an outer circumference of a suction cup part of the patient interface. This allows better monitoring a of laser-surgical treatment procedure since a user, for example a physician, also establishes an optical coupling together with the mechanical coupling of patient interface holder and patient interface without additional manual movements, which allows capturing the patient&#39;s eye or the surgical field via the camera system without disturbance of the laser radiation. Further features and the advantages thereof can be taken from the descriptions of the first and the second inventive aspect, wherein advantageous configurations of the first and the second inventive aspect are to be regarded as advantageous configurations of the third inventive aspect and vice versa. 
     A fourth aspect of the invention relates to a patient interface for a patient interface system according to the first inventive aspect, wherein the patient interface includes a channel, which bounds an optical path between the connection device of the patient interface holder and the first positioning device of the patient interface together with a corresponding channel of the patient interface holder in the coupled state of patient interface holder and patient interface, wherein the channel of the patient interface is arranged at least partially extending on an outer circumference of a suction cup part of the patient interface. This allows better monitoring of a laser-surgical treatment procedure, since a user, for example a physician, can also establish an optical coupling together with the mechanical coupling of patient interface holder and patient interface without additional manual movements, which allows capturing the patient&#39;s eye or the surgical field via the camera system without disturbance of the laser radiation. Further features and the advantages thereof can be taken from the descriptions of the first, the second and the third inventive aspect, wherein advantageous configurations of the first, the second and the third inventive aspect are to be regarded as advantageous configurations of the fourth inventive aspect and vice versa. 
     A fifth aspect of the invention relates to a patient interface holder for a patient interface system according to the first inventive aspect, wherein the patient interface holder includes a connection device for coupling a camera system and comprises a channel, which bounds an optical path between the connection device and the first positioning device of the patient interface together with a corresponding channel of the patient interface in the coupled state of patient interface holder and patient interface, wherein the channel of the patient interface is arranged at least partially extending on an outer circumference of a suction cup part of the patient interface. This allows better monitoring of a laser-surgical treatment procedure, since a user, for example a physician, can also establish an optical coupling together with the mechanical coupling of patient interface holder and patient interface without additional manual movements, which allows capturing the patient&#39;s eye or the surgical field via the camera system without disturbance of the laser radiation. Further features and the advantages thereof can be taken from the descriptions of the first, the second, the third and the fourth inventive aspect, wherein advantageous configurations of the first, the second, the third and the fourth inventive aspect are to be regarded as advantageous configurations of the fifth inventive aspect and vice versa. 
     A further aspect of the invention relates to a method for preparing and/or performing a laser-surgical treatment procedure on a patient&#39;s eye, in which a patient interface system according to the first inventive aspect is provided, and the patient interface is moved relative to the patient interface holder until the patient interface and the patient interface holder are coupled and the channels of patient interface holder and patient interface corresponding to each other together bound an optical path between the connection device for the camera system and the first positioning device of the patient interface, wherein the channel of the patient interface is arranged at least partially extending on an outer circumference of a suction cup part of the patient interface. This allows better monitoring of the laser-surgical treatment procedure, since a user, for example a physician, also establishes an optical coupling together with the mechanical coupling of patient interface holder and patient interface without additional manual movements, which allows capturing the patient&#39;s eye or the surgical field via the camera system without disturbance of the laser radiation. 
     Further features of the invention are apparent from the claims, the figures and the description of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not comprise all of the features of an originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or deviate from the feature combinations set out in the relations of the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic perspective view of a patient interface system according to the invention according to a first embodiment. 
         FIG.  2    is a schematic bottom view of the patient interface system. 
         FIG.  3    is a schematic cross-sectional view of the patient interface system. 
         FIG.  4    is a schematic exploded representation of an embodiment of an inventive patient interface of the patient interface system. 
         FIG.  5    is a schematic side view of the patient interface. 
         FIG.  6    is a schematic sectional view of the patient interface. 
         FIG.  7    is an enlarged view of the detail area VII shown in  FIG.  6   . 
         FIG.  8    is a schematic perspective view of a suction cup part of the patient interface from above. 
         FIG.  9    is an enlarged view of the detail IX shown in  FIG.  8   . 
         FIG.  10    is a schematic top view of the patient interface. 
         FIG.  11    is a schematic perspective view of an embodiment of an inventive patient interface holder of the patient interface system. 
         FIG.  12    is schematic lateral sections of engaging bodies of the patient interface holder and perspective top views to their corresponding engaging surfaces of the patient interface. 
         FIG.  13    is a partial lateral sectional view of the patient interface in the region of engaging surfaces opposing each other, which cooperate with corresponding engaging bodies of the patient interface holder. 
         FIG.  14    is a schematic exploded representation of the patient interface holder. 
         FIG.  15    is a schematic exploded representation of a first assembly of the patient interface holder. 
         FIG.  16    is a schematic exploded representation of a second assembly of the patient interface holder. 
         FIG.  17    is a schematic and partial sectional view from above to a suction duct of the patient interface holder and a part of a fluid-conducting device of the patient interface. 
         FIG.  18    is a schematic and partially transparent perspective view of the region of the patient interface system shown in  FIG.  17   . 
         FIG.  19    is a schematic sectional view of a male connector, which engages with a corresponding female fitting of the patient interface. 
         FIG.  20    is a schematic sectional view of an embodiment of the patient interface. 
         FIG.  21    is a schematic perspective view of an embodiment of a collecting container. 
         FIG.  22    is a schematic perspective view of the collecting container, which is provided with a filter element. 
         FIG.  23    is a schematic perspective view of the patient interface in the region of a mounting opening for the collecting container. 
         FIG.  24    is a schematic perspective view of the patient interface, wherein the collecting container is arranged in the mounting opening. 
         FIG.  25    is a schematic sectional view of the collecting container in the region of a fitting, in which an end region of a negative pressure hose is arranged. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows a schematic perspective view of a patient interface system  10  according to the invention according to a first embodiment. The patient interface system  10  serves for positioning a patient&#39;s eye (not shown) relative to a laser device (not shown) for the laser surgery and includes a patient interface  12  for coupling to the patient&#39;s eye and a patient interface holder  14  for arranging the patient interface  12  on the laser device. In the following,  FIG.  1    will be explained in synopsis with  FIG.  2   , which shows a schematic bottom view of the patient interface system  10 . Presently, the patient interface  12  is integrally formed of multiple assemblies adhered to each other, while the patient interface holder  14  is presently composed of three assemblies exemplary in number and orientation, which are screwed to each other and are explained in more detail in the following. The patient interface holder  14  includes a holding device  16 , by means of which the patient interface  12 , which can basically be a one-way or disposable part, can be reversibly coupled to the patient interface holder  14  and which is formed to position the patient interface  12  relative to the patient interface holder  14  in the coupled state. Hereto, the holding device  16  includes two opposing, groove-shaped guiding devices  18 , along which a second positioning device  20  (see  FIG.  4   ) of the patient interface  12  is forcibly guided movable for coupling and decoupling. Thereby, the patient interface  12  can be plugged into the holding device  16  of the patient interface holder  14  in drawer-like manner for coupling and again be withdrawn for decoupling. 
     One further recognizes that the patient interface holder  14  includes a connection device  22  for coupling a camera system  24  as well as an illumination device  26 , by means of which at least a region of the patient&#39;s eye is illuminated perpendicular to a surface of a contact body  28  or a contact plate  28  of a first positioning device  30  of the patient interface  12 . Hereto, the illumination device  26  presently includes four lighting means (e.g. LEDs)  32 —exemplary in number and arrangement—the respective light cones of which are illustrated with circles in  FIGS.  1  and  2   . Since the patient interface  12  is composed of an optically transparent material in complete manner or at least in the region of the first positioning device  30 , which is brought in abutment on the patient&#39;s eye for a laser-surgical treatment, the radiation of the lighting means  32  penetrates the wall of the patient interface  12  substantially funnel-shaped in this region and thereby indirectly irradiates both the surgical region below the contact plate  28 , which can also referred to as contact glass, and directly the environment thereof. 
     Furthermore, the patient interface holder  14  and the patient interface  12  are connectable to a suction device (not shown), for example a vacuum pump, in a manner described in more detail in the following, to generate a relative negative pressure and to hold the patient interface  12  and its first positioning device  30 , respectively, in abutment on the patient&#39;s eye. One in particular recognizes in  FIG.  1    that all of the connection cables  34  for the camera system  24  and the illumination device  26  as well as a negative pressure hose  36  for connection of the suction device emerge from the patient interface holder  14  in the same direction and are arranged on a side of the patient interface holder  14  opposing the insertion side of the patient interface  12 . Hereby, the patient interface  12  can be particularly simply and operationally reliably coupled to and uncoupled from the patient interface holder  14 , respectively, wherein an engagement, positioning and connection to the camera system  24 , the suction device and the illumination device  26  are effected at the same time with the coupling, without additional manual movements or working steps by a user being required hereto. 
       FIG.  3    shows a schematic cross-sectional view of the patient interface system  10 . One in particular recognizes the camera system  24  coupled to the patient interface holder  14  by means of the connection device  22  and that the patient interface holder  14  and the patient interface  12  comprise channels  38  corresponding to each other, which commonly bound an optical path P between the connection device  22  and the first positioning device  30  in the coupled state of patient interface holder  14  and patient interface  12 . Within the scope of the present disclosure, identical or functionally identical elements are usually denoted by identical reference characters if a varying denotation is not provided. The channel  38  of the patient interface holder  14  is closed by a window  40  transparent for wavelengths in the range visible to the human in an end region facing away from the connection device  22 , such that foreign matter cannot enter and disturb the optical systems. The channels  38  and thereby the optical path P extend at an angle of about 45° to a direction of an intended laser radiation L of the laser device and to a surface of the contact plate  28  facing the laser device, respectively, in the coupled state of the patient interface  12  and the patient interface holder  14 . One recognizes that the channels  38  have substantially the same length and that the optical channel  38 - 38  for the camera system commonly formed in the coupled state is formed separately to a passage channel of the patient interface  12  for a laser beam L (see  FIG.  10   ) of a laser device or outside of such a passage channel for the laser beam L, since an impairment of the laser beam L and thereby potential disturbances during a surgical intervention are hereby particularly reliably prevented. Presently, the passage channel for the laser beam L is formed or bounded by the suction cup part  58  or arranged within the suction cup part  58  of the patient interface  12 , while the optical channel  38 - 38  for the camera system is formed or arranged separated herefrom. One recognizes that the optical channel  38 - 38  is arranged or formed at least partially extending on an outer circumference of the suction cup part  58  of the patient interface  12  or on an outer side of the passage channel for the laser beam L (see also  FIG.  5   ). 
       FIG.  4    shows a schematic exploded representation of an embodiment of the patient interface  12  according to the invention. One sees that the patient interface  12  is composed of multiple assemblies, which are connected to each other by plug, shrinking and adhesive connections. From top to bottom, the assemblies include an interface body  42 , which includes the second positioning device  20  as well as a holder  44 , by means of which the patient interface  12  can be held by a user with thumb (from above) and index finger (from below), to couple the patient interface  12  to the patient interface holder  14  and to decouple it from the patient interface holder  14 . The holder  44  has a concavely curved shape, which allows comfortable and safe gripping. One additionally recognizes a female fitting  45 , with which a corresponding male connector  47  of the patient interface holder  14  engages in the coupled state with the patient interface holder  14  to also achieve a fluidic coupling besides the mechanical coupling. Furthermore, the patient interface  12  includes a filter element  46 , which is arranged in a mounting opening  48  of an integrally formed collecting container  50 . Since the mounting opening  48  is configured asymmetrical in the present example, the filter element  46  can only be inserted into the mounting opening  48  in the correct orientation, whereby a mounting without confusion is ensured. For example, this is reasonable if the filter element  46  requires a unidirectional flow direction. The collecting container  50  presently has a volume of about 120 mm 3 , whereby it is large enough to securely avoid overflow or clogging during a laser-surgical intervention. The volume of about 120 mm 3  theoretically allows the performance of about five laser-surgical interventions, whereby a sufficient safety buffer is ensured. The collecting container  50  is in turn inserted into a corresponding mounting opening  52  of the interface body  42  together with the filter element  46  for mounting. 
     The collecting container  50  includes a fitting  54 , in which a first end region of a negative pressure hose  56  is arranged. The opposing end region of the negative pressure hose  56  is inserted into a further fitting  54  for mounting, wherein the further fitting  54  is formed on a suction cup part  58  of the patient interface  12  and opens into a suction opening  64 . The suction cup part  58  additionally includes the channel  38  for the camera system  24  and the first positioning device  30 , which is fitted onto the patient&#39;s eye. Within the suction cup part  58 , the contact plate  28  is fixed, for example adhered, in the region of the first positioning device  30 . 
     The female fitting  45 , the filter element  46 , the collecting container  50  and the negative pressure hose  56  together form a fluid-conducting device  60 , which together form a fluid path in the coupled state of patient interface  12  and patient interface holder  14 , which fluidically couples a suction duct  62  of the patient interface holder  14  to a suction opening  64  of the patient interface in the region of the first positioning device  30  to be able to bring the first positioning device  30  in abutment on the patient&#39;s eye and to hold it on the patient&#39;s eye, respectively, by a relative negative pressure generated by means of the suction device. 
       FIG.  5    shows a schematic side view of the patient interface  12  in the mounted state. One in particular recognizes the fluid-conducting device  60 , which fluidically connects the first positioning device  30  to the female fitting  45  in the interface body  42  via the negative pressure hose  56 , the collecting container  50  and the filter element  46 . Furthermore, one recognizes that the channel  38  of the patient interface  12  is arranged at least partially extending on an outer circumference of the suction cup part  58  of the patient interface  12 . 
       FIG.  6    shows a schematic sectional view of the patient interface  12  according to the sectional plane VI-VI shown in  FIG.  5   . In the following,  FIG.  6    is explained in synopsis with  FIG.  7   , which shows an enlarged view of the detail area VII shown in  FIG.  6   . One recognizes the contact body  28  fluid-tightly adhered to the suction cup part  58 , which has a concave bottom side, which bounds a cavity  66 , into which the fluid-conducting device  60  opens. The first positioning device  30  further includes a plurality of teeth  68 , which are annularly arranged spaced from each other in the end region of the patient interface  12  facing the patient&#39;s eye. The teeth  68  ensure an applanation of the patient&#39;s eye together with the contact body  28 , wherein they minimize the applanation forces and suction load at the same time. 
       FIG.  8    shows a schematic perspective view of the suction cup part  58  of the patient interface  12  from above, wherein the contact plate  28  is not yet mounted such that the annularly arranged teeth  68  of the first positioning device  30  as well as mounting ribs  70  for the contact plate  28  are recognizable.  FIG.  9    shows an enlarged view of the detail IX shown in  FIG.  8   , wherein the contact plate  28  is now inserted into the suction cup part  58  in the region above the teeth  68  and adhered to it. 
       FIG.  10    shows a schematic top view of the patient interface  12 . One in particular recognizes the second positioning device  20 , which comprises three engaging surfaces  72   a ,  72   b ,  72   c  in the present embodiment, which are arranged in the shape of a triangle and between which a path or passage channel extending through the patient interface  12  for the laser beam L of the laser device is provided. Furthermore, the second positioning device  20  of the patient interface  12  includes two ramps  74   a ,  74   b  exemplary in number and arrangement, wherein the ramps  74   a ,  74   b  are arranged in front of their associated engaging surfaces  72   a ,  72   b  related to a coupling path K and ascend along the coupling path K. In the present embodiment, the engaging surface  72   a  has a frustoconical geometry, while the engaging surface  72   b  is slit-shaped and the engaging surface  72   c  is flat. In the coupled state of patient interface  12  and patient interface holder  14 , the engaging surfaces  72   a - c  cooperate with corresponding spring-loaded engaging bodies  76   a - c  of the patient interface holder  14 , whereby the following restrictions of the three translational and three rotational degrees of freedom result in the following embodiment: 
     Engaging surface  72   a :  2  translational degrees of freedom blocked 
     engaging surface  72   b :  2  rotational degrees of freedom blocked 
     engaging surface  72   c :  1  rotational degree of freedom blocked 
     This means that the patient interface  12  is not rigidly coupled to the patient interface holder  14  in the coupled state, but slightly movable only in z-direction, that is perpendicular to the applanated patient&#39;s eye and translational along the direction of the laser beam L, respectively, to be able to compensate for tolerances and to allow a simpler coupling and decoupling without having to accept losses with respect to the correct positioning. Furthermore, collars  78  of the second positioning device  20  are apparent, which are shifted into the groove shaped guiding devices  18  in coupling and forcibly guided moved along the substantially linear coupling path K in the manner of a drawer. Due to the ramps  74   a ,  74   b , a continuously increasing insertion force is required for coupling until the engaging bodes  76   a ,  76   b  engage with the engaging surfaces  72   a ,  72   b . This generates a unique haptic feedback for a user about the progress of the coupling operation as well as about the effected coupling due to the engagement of the engaging bodes  76   a ,  76   b .  FIG.  11    shows a schematic perspective view of the embodiment already shown in  FIG.  1    of the inventive pati 
     ent interface holder  14  of the patient interface system  10  without coupled patient interface  12 . One in particular recognizes that the patient interface holder  14  presently includes three assemblies  80   a - c  connected to each other. Therein, the assembly  80   a  functions as an upper holding group, the assembly  80   b  functions as a lower holding group and the assembly  80   c  functions as an illumination holder. The assemblies  80   a ,  80   b  together form the groove-shaped guiding device  18 . Moreover, the assembly  80   a  includes the connection device  22 , into which the camera system  24  is inserted. 
       FIG.  12    shows schematic lateral sections of engaging bodies  76   a - c  of the patient interface holder  14 , which cooperate with their corresponding engaging surfaces  72   a - c  of the patient interface  12  in the coupled state of patient interface  12  and patient interface holder  14 . The engaging bodes  76   a - c  are presently ceramic balls of identical diameter, which are rigidly fixed to the patient interface holder  14 . These ceramic balls are mechanically very resistant on the one hand and can easily slide along the surface and the ramps  74   a ,  74   b  of the second positioning device  20  during the coupling operation on the other hand. It is understood that varying materials such as for example steel or plastic can basically also be used. The individual engaging bodies  76   a - c  can basically also be composed of different materials and/or have varying geometries. Below the individual pairings, perspective partial top views of the engaging surfaces  72   a - c  of the patient interface  12  without the engaging bodies  76   a - c  are respectively shown. 
       FIG.  13    shows a partial lateral sectional view of the patient interface  12  in the region of engaging surfaces  72   b ,  72   b ′ opposing each other, which cooperate with corresponding engaging bodes  76   b ,  76   b ′ of the patient interface holder. In contrast to the engaging body  76   b , the engaging body  76   b ′ is spring-loaded and ensures a reliable coupling of patient interface  12  and patient interface holder  14  since the patient interface  12  and patient interface holder  14  are only movable relative to each other with overcoming an overall spring force of all of the spring-loaded engaging bodies  76   a ′- c ′ in the coupled state. With overcoming the overall spring force, however, at least a translational movement in z-direction, that is against the spring forces F, is possible such that the patient interface  12  and patient interface holder  14  are not rigidly, but resiliently connected and do not behave like an integral body, respectively, also in the coupled state. The engaging bodies  76   b ,  76   b ′ as well as the engaging bodies  76   a ,  76   a ′,  76   c ,  76   c ′ not explicitly illustrated form an engaging device  82  together with their corresponding engaging surfaces  72   a - c ,  72   a ′- c ′. The engaging bodies  76   a ′- c ′ too are presently formed as ceramic balls and arranged in a housing  86  together with respective springs  84 . It is understood that the engaging bodies  76   a ′- c ′ can also be formed of varying materials and/or have varying geometries. Similarly, it can be provided that all of the springs  84  have identical or different spring forces F. 
       FIG.  14    shows a schematic exploded representation of the patient interface holder  14 . One recognizes that the camera system  24  is pluggable into the connection device  22  and capable of being screwed to the first assembly  80   a  in the shown embodiment. The assembly  80   b  supports the spring-loaded engaging bodies  76   a ′- c ′ supported in their housings  86 . Furthermore, one recognizes the suction duct  62  and the male connector  47  arranged therein, which is connected to the negative pressure hose  36 . The illumination device  26  presently including four LEDs, which is integrated in the third assembly  80   c  and is electrically supplied via its connection cables  34 , is also well recognizable. 
       FIG.  15    shows a schematic exploded representation of the first assembly  80   a  of the patient interface holder  14  from obliquely below. Here, the engaging bodies  76   a - c  not spring-loaded, but rigidly supported in the first assembly  80   a  are in particular apparent, which are inserted into corresponding mounting openings in the assembly  80   a . Furthermore, four screws  88  are illustrated as fixing means, by means of which the assemblies  80   a - c  are screwed to each other. It is understood that other fixing means, a varying number of fixing means as well as a varying orientation of the fixing means can also be provided. 
       FIG.  16    shows a schematic exploded representation of the second assembly  80   b  of the patient interface holder  14 . Therein, only the housings  86  of the spring-loaded engaging bodies  76   a ′- c ′ are shown of the engaging device  82 , which are inserted into corresponding mounting openings of the second assembly  80   b . Furthermore, it is apparent that the negative pressure hose  36  is connected to the male connector  47  and inserted into the suction duct  62 . The connector  47  is in turn applied with force by a further spring-loaded engaging body  76   d ′, wherein also only the housing  86  of it is shown. The housing  86  of this engaging body  76   d ′ is fixed to the second assembly  80   b  by means of a bracket  90 . 
       FIG.  17    shows a schematic and partial sectional view from above to the suction duct  62  of the patient interface holder  14  as well as a part of the fluid-conducting device  60  of the patient interface  12  coupled to the patient interface holder  14 . Due to the engagement of the male connector  47  with the female fitting  45 , the patient interface holder  14  and the patient interface  12  are fluidically coupled such that the patient interface  12  can be held in abutment on the patient&#39;s eye by means of a relative negative pressure, which is generated by a suction device connected to the negative pressure hose  36 . Therein, the female fitting  45  comprises an inner cone, in which a corresponding outer cone of the male connector  47  is arranged in the coupled state. The outer cone and the inner cone presently have a contact angle of about 12-° according to amount, whereby a gas-tight connection is ensured on the one hand and a fast and uncomplicated coupling and decoupling with a force of at most about 2 N by an axial movement along the coupling path K are ensured on the other hand. Although the male connector  47  and the female fitting  45  can also be interchanged, the shown arrangement of the female fitting  45  at the patient interface  12  has the advantage that the risk of contaminations between unpacking and coupling the patient interface  12  is reduced since the contact surface of the female fitting  45  is less severely exposed to the environment than with a male connector  47 . By reducing the risk of contamination, later connecting problems are also avoided besides possible hygienic problems. While the male connector  47  is in direct contact with the wall of the female fitting  45 , a certain backlash is allowed in the region denoted by the arrow XVII. 
     As one sees in  FIG.  18   , which shows a schematic and partially transparent perspective view of the region of the patient interface system  10  shown in  FIG.  17   , the male connector  47  is floating supported and movable in all three spatial directions, wherein the connector  47  is pressed towards the female fitting  45  by the engaging body  76   d ′. This allows a particularly reliable and gas-tight connection with compensation for possible manufacturing tolerances. For further clarification,  FIG.  19    shows a schematic sectional view of the connector  47 , which engages with the female fitting  45  of the patient interface  12 . 
       FIG.  20    shows a schematic sectional view of an embodiment of the patient interface  12 . One in particular recognizes the suction opening  64 , into which the fitting  54  opens. Furthermore, it becomes clear that the suction cup part  58  comprises a circumferential collar  100 , into which the interface body  42  is inserted and adhered to the suction cup part  58 . By the configuration of the collar  100 , self-centering is effected upon mounting. In that the collar  100  also comprises a vertical section besides a horizontal section, on which the interface body  42  rests, horizontal and vertical tolerances can be compensated for by the geometric configuration of the collar  100 . Therein, the collar  100  forms a reservoir for excessive adhesive and ensures that the adhesive is drawn into the gap between interface body  42  and suction cup part  58  by capillary forces. This ensures a high-quality firmly bounded connection of both assemblies of the patient interface  12 . 
       FIG.  21    shows a schematic perspective view of an embodiment of a collecting container  50  and is explained in synopsis with  FIG.  22    in the following, which shows a schematic perspective view of the collecting container  50 , which is provided with the filter element  46 . One sees in  FIG.  21    that the mounting opening  48  for the filter element  46  is asymmetrically formed and comprises a circumferential edge  102 . When the collecting container  50  with the filter element  46  is inserted into its associated mounting opening  52  of the interface body  42  and heated, this edge  102  collapses, whereby the gap between collecting container  50  and interface body  42  decreases and the filter element  46  is operationally reliably and fluid-tightly clamped between both parts. 
       FIG.  23    shows a schematic perspective view of the patient interface  12  in the region of its mounting opening  52  for the collecting container  50 . The walls of the interface body  42  bounding the mounting opening  52  comprise ribs  108  directed outwards on the one hand and inwards on the other hand, such that the collecting container  50 , which comprises complementary ribs  108 , can be shifted into the mounting opening  52  without tilt. A support surface  106  of the patient interface  12  comprises a circumferential lip  104  on its inner circumference, which contributes to laterally sealing the filter element  46  together with the edge  102  in the mounted state. Therefore, fluid can only flow from the fitting  54  through the collecting container  50 , the filter element  46  and the fitting  54 .  FIG.  24    shows a schematic perspective view of the patient interface  12 , wherein the collecting container  50  is arranged and fixed in the mounting opening  52 . 
       FIG.  25    shows a schematic sectional view of the collecting container  50  in the region of its fitting  54 . The fitting  54  comprises a mounting duct  110 , in which an end region of the negative pressure hose  56  is arranged. The mounting duct  110  in turn has an inner diameter decreasing in three steps along a mounting direction XXV starting from an introduction opening, the inner diameter of which is larger than an outer diameter of the negative pressure hose  56 . In the first section S 1 , which serves for fixing, the inner diameter of the mounting duct  110  is larger than the outer diameter of the negative pressure hose  56  as mentioned and wetted with an adhesive for mounting. In the second section S 2 , which serves for positioning, the inner diameter of the mounting duct  110  is only slightly larger than the outer diameter of the negative pressure hose  56 , whereby centering of the negative pressure hose  56  in the mounting duct  110  is achieved. In the third section S 3 , which also serves for positioning, the inner diameter of the mounting duct  110  is smaller than the outer diameter of the negative pressure hose  56 . Thereby, the negative pressure hose  56  is shifted into the mounting duct  110  until it stops in the third section S 3 , whereby a correct axial positioning is ensured. It is understood that the fitting  54  of the suction cup part  58  can be analogously formed. 
     The parameter values indicated in the documents for the definition of process and measurement conditions for the characterization of specific characteristics of the inventive subject matter are to be considered as encompassed by the scope of the invention also within the scope of deviations—for example due to DIN tolerances and the like. 
     LIST OF REFERENCE CHARACTERS 
     
         
           10  Patient interface system 
           12  patient interface 
           14  patient interface holder 
           16  holding device 
           18  guiding device 
           20  second positioning device 
           22  connection device 
           24  camera system 
           26  illumination device 
           28  contact body 
           30  first positioning device 
           32  lighting means 
           34  connection cable 
           36  negative pressure hose 
           38  channel 
           40  window 
           42  interface body 
           44  holder 
           45  fitting 
           46  filter element 
           47  connector 
           48  mounting opening 
           50  collecting container 
           52  mounting opening 
           54  fitting 
           56  negative pressure hose 
           58  suction cup part 
           60  fluid-conducting device 
           62  suction duct 
           64  suction opening 
           66  cavity 
           68  teeth 
           70  mounting ribs 
           72   a  engaging surface 
           72   b  engaging surface 
           72   c  engaging surface 
           72   a ′ engaging surface 
           72   b ′ engaging surface 
           72   c ′ engaging surface 
           74   a  ramp 
           74   b  ramp 
           76   a  engaging body 
           76   b  engaging body 
           76   c  engaging body 
           76   a ′ spring-loaded engaging body 
           76   b ′ spring-loaded engaging body 
           76   c ′ spring-loaded engaging body 
           76   d ′ spring-loaded engaging body 
           78  collar 
           80   a  assembly 
           80   b  assembly 
           80   c  assembly 
           82  engaging device 
           84  springs 
           86  housing 
           88  screws 
           90  bracket 
           100  collar 
           102  edge 
           104  lip 
           106  support surface 
           108  ribs 
           110  mounting duct 
         P optical path 
         K coupling path 
         L laser radiation 
         F spring force