Abstract:
An ocular device for a surgical instrument, the surgical instrument having an optical window frame and an optical assembly arranged in an interior space of the surgical instrument, the ocular device including: an ocular window separated from the optical assembly by a space; a holder configured to be connected to the ocular window frame; and at least one elastic element, wherein in a connected state, the at least one elastic element transmits a clamping force from the holder to bias the ocular window towards the space.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is a continuation of PCT/EP2016/050866 filed on Jan. 18, 2016, which is based upon and claims the benefit to DE 10 2015 202 002.9 filed on Feb. 5, 2015, the entire contents of each of which are incorporated herein by reference. 
     
    
     BACKGROUND 
     Field 
       [0002]    The present application relates to an ocular device for a surgical instrument, and in particular, to an endoscope, with an optical assembly which can be seated or is seated in an ocular window frame in an interior space of the surgical instrument, wherein the optical assembly is separated from an exterior space by an ocular window, and the ocular window is seated in a holder which is connectible or connected to the ocular window frame, wherein in a connected state, the holder exerts a holding force on the ocular window in a clamping direction. Moreover, the present application relates to a surgical instrument, and in particular, to an endoscope with an ocular device. 
       Prior Art 
       [0003]    Endoscopes for minimally invasive surgery on the human or animal body are generally known. With the assistance of a lens system at the distal tip of the endoscope shaft, it is possible to view a surgical field or investigated field in the body&#39;s interior. For this purpose, a plurality of optical assemblies are arranged within the endoscope shaft by means of which light is guided from a body cavity out to a proximal end of the endoscope at which the endoscope is held and operated by a surgeon. 
         [0004]    At the proximal end of the endoscope, for example on a handle, there is frequently an eyepiece with an ocular, that is, an optical assembly, from which the light entering the distal tip of the endoscope exits. Such an ocular can be used to directly observe the surgical field with the naked eye. Frequently, a camera head is connected to the ocular so that the surgical field can be observed on a monitor, or the captured image data can be supplied to a connected image processing system. Such an endoscope is known for example from EP 0 501 088 A1. 
         [0005]    The optical assemblies in an interior space of the endoscope, for example in its shaft, are separated from each other from an exterior space that surrounds the endoscope by an ocular window. 
       SUMMARY 
       [0006]    It is an object to present an ocular device and a surgical instrument with an ocular device, wherein the hazard of soiling the optical assembly is reduced and hygiene is improved. 
         [0007]    Such object can be solved by an ocular device for a surgical instrument, such as an endoscope, with an optical assembly which can be seated or is seated in an ocular window frame in an interior space of the surgical instrument, wherein the optical assembly is separated from an exterior space by an ocular window, and the ocular window is seated in a holder which is connectible or connected to the ocular window frame, wherein in a connected state, the holder exerts a clamping force on the ocular window in a clamping direction, wherein the ocular device comprises at least one elastic element transmitting the clamping force. 
         [0008]    In conventional ocular devices of surgical instruments such as ocular devices of endoscopes, frequently a gap remains between the holder and the ocular window frame which serves to compensate for the tolerance when inserting the ocular window. In this region of the surgical instrument, the danger exists, however, of dirt particles collecting which can only be removed with a great deal of effort. 
         [0009]    Moreover, the possibility exists of dirt or dust particles penetrating into the interior space of the surgical instrument between the holder and the ocular window and reducing the optical quality of the optical assembly. To clean the optical assembly, it is necessary to remove the ocular window which is associated with significant effort. With the ocular device provided herein, an elastic element is provided which transmits the clamping force. The tolerance compensation which is always necessary accordingly occurs by a more or less strongly preferred elastic deformation of this element. Accordingly, gaps which otherwise may arise from the tolerance compensation are largely avoided. 
         [0010]    Moreover, the ocular window is prevented from experiencing great stress while tightening the holder. In this context, the elastic element functions as a damper. 
         [0011]    According to one embodiment, the ocular device can be developed in that the elastic element, viewed in the direction of clamping, is at least sectionally arranged between the holder and the ocular window. 
         [0012]    This can create a seal between the ocular window and the holder so that dirt or dust particles practically can no longer enter the ocular device. 
         [0013]    The elastic element can be a spring element, wherein the spring element can be a disc spring, a spring ring, and/or a wave washer. The elastic element can also be rubber elastic materials, such as in the form of an O-ring. 
         [0014]    According to one embodiment, the ocular window frame can comprise a stop for the holder which limits a movement of the holder in the clamping direction. 
         [0015]    Such configuration makes it possible to seat the ocular window by the elastic element free of play during installation and then tighten the holder until it contacts the stop. Therefore, a gap between the ocular window frame that surrounds the stop and the holder can be avoided. This improves the hygiene properties of the ocular device, or respectively the surgical instrument, in which the ocular device is installed. 
         [0016]    The stop can limit a movement of the holder in the clamping direction so that when the holder is in a fastened state when the holder contacts the stop, a clamping gap exists between the holder and the ocular window viewed in the direction of clamping, wherein the elastic element is arranged at least sectionally in the clamping gap. 
         [0017]    Since a clamping gap can be provided structurally between the holder and the ocular window, the ocular window can be prevented from experiencing excessive stress even when the holder is tightened all the way. Therefore, overloading the ocular window, which may be associated with damaging the ocular window, can be avoided. 
         [0018]    The holder can comprise an edge that is connectible or connected to the ocular window frame and a collar adjacent thereto, wherein the collar surrounds an opening in which the ocular window is at least partially seated, and wherein the collar comprises a first clamping region on its bottom side facing the ocular window, and wherein the ocular window has a cutout running along its outer perimeter, wherein the ocular window has a second clamping region in the region of the cutout at a top side facing the collar, wherein the elastic element is arranged between the first and second clamping region. 
         [0019]    The spring element can comprise a disc spring contacting one side of the holder, such as the bottom side of the collar of the holder, wherein, the disc spring can extend from an outer side of the holder toward a center of the holder starting from a contact region toward its free end. 
         [0020]    Therefore, given the provided alignment, or respectively arrangement of the disc spring, the penetration of dirt or dust particles into a region between the ocular window and the holder, and from there continuing toward the optical assembly, can be largely avoided. 
         [0021]    The collar can be at least sectionally configured as a spring element. If a part of the holder, such as its collar, is configured as a spring element, a component, i.e., the elastic element itself, can advantageously be discarded. This is in fact formed by the collar of the holder itself. This measure simplifies the production of the ocular device and moreover offers cost advantages. 
         [0022]    In addition, the holder can be a union nut, and the union nut can have an inner thread which, in an installed state, meshes with an outer thread on the ocular window frame. 
         [0023]    The holder and/or the ocular window frame can be formed of a metal or plastic. The elastic element can also be made of a metal, such as spring steel, or can alternatively be formed of plastic. Also suitable are, for example, rubber or similarly suitable elastic materials. The clamping gap can be between the first and second clamping region. The elastic element can be available, or respectively arranged in the clamping gap. The elastic element can be an O-ring, etc. The ocular window can be designed as an optical flat, i.e., has two plane-parallel surfaces. The ocular window can be circular, as can the ocular window frame. A side edge of the ocular window and the ocular window frame can be constructed to be complementary in terms of form and function. For this purpose, the ocular window can have a cutout in its outer edge in which the holder engages. This side edge of the ocular window can be configured to be ring-shaped. The ocular window frame and the ocular window can be glued to each other. For example, the ocular window can be glued at its outer edge along its perimeter, such as completely along its perimeter, to the ocular window frame. The surgical instrument can be a laparoscope. The aforementioned elements can be applicable to all embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Further features will become apparent from the description of embodiments together with the claims and the included drawings. Embodiments can fulfill individual characteristics or a combination of several characteristics. 
           [0025]    The embodiments will be described below without restricting the general idea of the invention, based on exemplary embodiments in reference to the drawings, wherein we expressly refer to the drawings with regard to the disclosure of all details that are not explained in greater detail in the text. 
           [0026]      FIG. 1  illustrates a schematic and simplified side view of a surgical instrument, 
           [0027]      FIG. 2  illustrates a detailed view of an ocular device, in a schematic and simplified longitudinal section, and 
           [0028]      FIG. 3  illustrates a schematic and simplified detailed view of the longitudinal section through the ocular device of  FIG. 2 . 
       
    
    
       [0029]    In the drawings, the same or similar types of elements and/or parts are provided with the same reference numbers so that a re-introduction is omitted. 
       DETAILED DESCRIPTION 
       [0030]      FIG. 1  shows a schematic and simplified side view of a surgical instrument  2 , such as an endoscope. At its distal end, the surgical instrument  2  comprises a tubular shaft  4  with a lens system that makes it possible to observe a surgical or investigated region that lies distally relative to a distal end of the shaft  4 . A proximal end of the shaft  4  terminates in a housing  6  that has an eyepiece  8  at a proximal end. The housing  6  is for is handling the surgical instrument  2 . On a distal side of the housing  6  is a light source  10  such as an LED light source. The light source  10  is connected by a connecting cable  12  to a suitable power supply. 
         [0031]    A schematically portrayed camera head  14  with an ocular adapter (not shown) is arranged on the eyepiece  8 . The camera head  14  detects the light exiting the ocular of the surgical instrument  2  with its own lens system, and images it on an optical surface (image) sensor such as a CCD or CMOS chip. The camera head  14  is supplied with power by means of a connection  16 . Furthermore, it is possible to send image signals by the connection  16  from the surface sensor of the camera head  14  to an external evaluation unit and transmit control signals to the camera head  14 . 
         [0032]    In a partial schematic simplified longitudinal section,  FIG. 2  shows a detailed view of an ocular device  20 , such as is provided in the region of the eyepiece  8  at the proximal end of a surgical instrument  2 , for example an endoscope. 
         [0033]    The ocular device  20  comprises an ocular window frame  22  in which an optical assembly  24  is seated. The optical assembly  24  is for example one or more lenses or lens groups, prisms, filters, etc. that form an optical system. The optical axis A of the optical system is depicted in a dash-dot line. The optical device  20  is located in an interior space of the surgical instrument  2 , such as an interior space enclosed by the housing  6  of the endoscope depicted in  FIG. 1 . The optical system seated thereby serves to image the light beam entering from an investigated region on an image sensor of the camera head  14  at the distal end of the shaft  6 . 
         [0034]    The camera head  14  is removable. In this state, an ocular window  26  comprising the ocular device separates the exterior space from the interior space of the surgical instrument  2 . 
         [0035]    The ocular window  26  is seated in a holder  28 . A union nut is depicted in  FIG. 2  as a holder  28  only as an example. The holder  28  has an inner thread which meshes with an outer thread on the ocular window frame  22 . The holder  28  is thereby detachable from or attachable to the ocular window frame  22 . In an attached state, which is shown in  FIG. 2 , the holder  28  exerts a clamping force on the ocular window  26  in the direction of clamping K. That is, the elastic element  30  biases the ocular window  26  towards the window frame  22 . 
         [0036]    Viewed in the direction of clamping K, at least one elastic element  30  transmitting the clamping force is located between the holder  28  and the ocular window  26 . The elastic element is for example a disc spring. However a spring ring, wave washer, elastomer, such as an O-ring, etc. may also be used as the elastic element. 
         [0037]    Furthermore, the ocular window frame  22  comprises a stop  32  that limits the movement of the holder  28  in the clamping direction K. The stop  32  limits the movement of the holder  28  in the clamping direction K such that when the holder  28  is in a fastened state as shown in  FIG. 2 , the holder  28  contacts the stop  32 . However, a clamping gap  34  remains between the ocular window  26  and the holder  28 . The elastic element  30  is arranged at least sectionally in the clamping gap  34 . 
         [0038]    In a schematic simplified longitudinal section,  FIG. 3  shows a detail of the ocular device  20  of  FIG. 2 . The holder  28  can be configured such that it surrounds an edge  36  that is connectible to the ocular window frame  22  and a collar  38  adjacent thereto. On its inside facing the ocular window frame  22 , the edge  36  is provided with an inner thread. In the direction of the optical axis A, the collar  38  abuts the edge  36  and surrounds an opening through which the ocular window  26  partially extends. In other words, the ocular window  26  is at least partially seated in the opening surrounded by the collar  38 . 
         [0039]    At its bottom side facing the ocular window  26 , the collar  38  has a first clamping region  40 . The ocular window  26  has a cutout  42  that runs along its outer parameter. In this region, the ocular window  26  has a second clamping region  44  on its top side facing the collar  38 . The elastic element  30  which is not shown in  FIG. 3  for reasons of clarity is located between the first clamping region  40  and the second clamping region  44 . 
         [0040]    The holder  28  is dimensioned such that it contacts the stop  32  of the ocular window frame  22 , and a clamping gap  34  remains nonetheless. This prevents excessive pressure from being exerted on the ocular window  26 . At the same time, it ensures that a gap in which dirt particles may collect does not arise on the outside between the holder  28  and the ocular window frame  22  where the stop  32  is located. 
         [0041]    Furthermore, the penetration of dirt particles or dust into the interior space of the ocular window frame  22  can be avoided. The gap between the holder  28  and ocular window  26  is tightly sealed by the elastic element  30 . In this regard, it is particularly advantageous when the elastic element  30 , which for example can be a spring element, contacts the bottom side of the collar  38  on one side. The disc spring provided as an elastic element  30  extends starting from a contact region in the direction of its free end from s an outer side of the holder  28  in the direction of its center, i.e., in the direction of the optical axis A. Accordingly as shown in  FIG. 2 , the contact point between the disc spring and the ocular window  26  lies in the region of a knee point in the cutout  42 . This prevents the penetration of dirt or dust particles. 
         [0042]    The ocular window frame  22  has a shoulder  46  that extends along the inner space enclosed by the ocular window frame  22 , such as completely along the perimeter. On an annular surface of the shoulder  46  facing the ocular window  26 , the ocular window  26  is glued to the ocular window frame  22 . 
         [0043]    According to another exemplary embodiment, the collar  38  of the holder  28  itself is configured at least sectionally as a spring element and hence functions as an elastic element  30 . 
         [0044]    While there has been shown and described what is considered to be preferred embodiments, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims. 
       REFERENCE NUMBER LIST 
       [0000]    
       
         
           
               2  Surgical instrument 
               4  Shaft 
               6  Housing 
               8  Eyepiece 
               10  Light source 
               12  Connecting cable 
               14  camera head 
               16  Connection 
               20  Ocular device 
               22  Ocular window frame 
               24  Optical assembly 
               26  Ocular window 
               28  Holder 
               30  Elastic element 
               32  Stop 
               34  Clamping gap 
               36  Edge 
               38  Collar 
               40  First clamping region 
               42  Cutout 
               44  Second clamping region 
               46  Shoulder 
             A Optical axis 
             K Clamping direction