Patent Publication Number: US-2023148842-A1

Title: Endoscope with working channel and a control body

Description:
The present invention relates to an endoscope with a working channel in an insertion tube, and a control body, on the distal side of which the insertion tube is connected. 
     In such an endoscope, the insertion tube is inserted into a patient for the purpose of an examination or a surgical intervention. Through the working channel, instruments can be guided through the insertion tube to a location at which the examination or surgical intervention is to take place. 
     After completing the examination or the surgical intervention, the insertion tube is pulled out. Thereafter, the endoscope is cleaned and sterilised so as to be ready for another use. Through cleaning and sterilisation, contamination as a result of previous use should be removed. 
     One objective is the invention is to create an endoscope with a working channel and a control body that is even more reliably cleaned of contaminants for another use. 
     This object is achieved by means of an endoscope with the features of claim  1 . Advantageous further developments form the subject matter of the dependent claims. 
     The invention relates to an endoscope with a working channel in an insertion tube, a control body, on the distal side of which the insertion tube is connected, and an attachment body fastenable to the control body in a detachable manner, wherein the detachably fastenable attachment body comprises a working channel assembly and a suction device assembly. 
     In the case of such an endoscope, by detaching the detachably fastenable attachment body from the control body, the working channel assembly and the suction device assembly can be removed from the endoscope. The working channel assembly and the suction device assembly are particularly difficult to clean after use, so that in spite of cleaning and sterilisation, biofilms can form and persist on the surfaces. Thus, precisely those elements, on the surfaces of which there is an increased danger of the formation of biofilms due to use in the patient, are removed from the endoscope. The endoscope can therefore better prevent the transmission of germs arising from resistant biofilms. 
     The working channel assembly can comprise the working channel, which extends to the distal end of the endoscope. The suction device assembly can comprise a suction line and a suction control valve provided on the suction line. 
     In this way, the working channel, the suction line and the suction control valve provided on the suction line are removable from the endoscope. 
     The detachably fastenable attachment body can comprise an instrument inlet section which forms an entrance section of the working channel that can be accessed from outside. The instrument inlet section is also removable from the endoscope. 
     The endoscope can comprise the attachment body detachably fastenable on the control body and an endoscope basic body with the control body onto which the detachably fastenable attachment body can be applied, wherein the endoscope basic body does not comprise the working channel assembly and the suction device assembly. 
     As the endoscope basic body does not comprise the working channel assembly and the suction device assembly, when reusing the cleaned endoscope basic body, which is now fitted with a new, unused attachment body with a new working channel assembly and a new suction device assembly, the risk of contamination through impurities or biofilms resulting from a previous use of the endoscope is massively reduced. 
     The detachably fastenable attachment body can be designed as a single-use body that can be disposed of after use. The detachably fastenable endoscope basic body can be designed as a multiple-use body that can be cleaned after use and reused. 
     The clear separation ensures safe use of the endoscope. As a multiple-use body, the endoscope basic body contains the electronic components of the endoscope. Moreover, the attachment body, configured as a single-use body, can be cost-effectively produced as it only has a detachable housing section, the working channel assembly and the suction device assembly and does not comprise the more costly electronic components. 
     The control body can comprise an incomplete housing, that can be completed with a completion component that is integrated into the detachably fastenable attachment body. The structure and separation of the incomplete housing and the completion component are simple and uncomplicated. The assembly and separation of the incomplete housing and the completion components can be carried out quickly and reliably. 
     The control body can comprise a housing basic element as an incomplete housing, that through completion with a housing addition section as a completion component forms the control body, wherein the housing addition section is arranged on the detachably fastenable attachment body and comprises the suction control valve. It is the housing, as the component group with which the user works, which provides definite information about whether the attachment body is already mounted on the endoscope or not. The user immediately recognises whether the control body is complete or not. Inadvertent use of an endoscope not yet fitted with the attachment body is immediately recognised and can be prevented. 
     The suction line can comprise a proximal suction line section, that can be connected to a suction source, and a distal suction line section that extends to the distal end of the endoscope. The suction control valve can be arranged between the proximal suction line section and the distal suction line section. Therefore, the proximal suction line section, that is connectable to the suction source, is also removable from the endoscope together with the suction control valve and the distal suction line section. 
     The incomplete housing of the control body can have a groove running perpendicularly to the direction of extension of the control body, into which a section of the completion component of the attachment body can be fitted. The completion component can be applied to the incomplete housing in an easy, simple and unequivocally identifiable, as well as quick and uncomplicated manner, in order to complete the endoscope. 
     The incomplete housing of the control body and/or the attachment body can comprise snap-in fastening means for applying the attachment body to the incomplete housing of the control body. In this way, the completion component can be securely arranged on the incomplete housing of the control body. Inadvertent, unintentional detachment of the completion component from the incomplete housing of the control body is prevented by the snap-in fastening means. 
     The working channel assembly and the suction device assembly of the fastenable attachment body can be detachably fastened in the control body. When the working channel assembly and the suction device assembly are detachably fastened in the control body, they cannot be accessed from outside. The wall of the control body conceals the working channel assembly and the suction device assembly. The wall concealing the working channel assembly and the suction device assembly can form part of the fastenable attachment body. Alternatively, the wall concealing the working channel assembly and the suction device assembly can be separate from the fastenable attachment body. 
     The aforementioned aspects of the present invention can be suitably combined. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a schematic perspective view of the endoscope according to the invention with a control body in a first embodiment. 
         FIG.  2    shows a schematic perspective view of the endoscope of the first embodiment according to the invention, wherein an attachment body is not mounted on an incomplete housing of the control body. 
         FIG.  3    shows a schematic perspective view of a central section of the attachment body of the first embodiment. 
         FIG.  4    shows a schematic perspective view of the endoscope of the first embodiment according to the invention, wherein the attachment body is mounted on the incomplete housing of the control body. 
         FIG.  5    shows a schematic cross-sectional view of the control body of the first embodiment. 
         FIG.  6    shows a schematic cross-sectional view of the control body of the endoscope of the first embodiment. 
         FIG.  7    shows a schematic cross-sectional view of the distal end of an endoscope of a second embodiment. 
         FIG.  8    shows a schematic cross-sectional view of the distal end of an endoscope of a third embodiment. 
     
    
    
     EMBODIMENTS 
     The present invention is described in more detail below by way of exemplary embodiments with reference to drawings. The illustrations in the drawings are not necessarily true to scale, but may be distorted for the sake of improved clarity. 
     First Embodiment 
     Below, a first embodiment of the present invention is described with reference to  FIGS.  1  to  4   . 
     An endoscope  1  according to the invention has a control body  10 , an insertion tube  20  and a supply cable  30 . 
     The insertion tube  20  is connected to the control body  10  at the distal side of the control body  10 . Arranged on the distal side of the insertion tube  20  is a distal end section  40 . With the distal end section  40  first, the insertion tube  20  is inserted into a patient for the purpose of an examination or surgical intervention. In the insertion tube  20 , a working channel described below extends up to the distal end section  40 . 
     The supply cable  30  is connected to the control body  10  on the proximal side of the control body  10 . The supply cable  30  comprises an electrical line for supplying the control body  10  with electricity. The supply cable  30  also comprises a signal cable that transmits data obtained by the endoscope to a (not shown) evaluation unit. The supply cable  30  has a plug which is inserted into the evaluation unit on the proximal side of the supply cable  30 . 
     As a housing basic element, the control body  10  has an incomplete housing  150  that only forms a complete housing after the application of a completion component  105 . The completion component  105  acts as a housing addition section to complete the housing of the control body  10 . The complete housing of the control body  10  is ergonomically formed and designed so that in the middle area—seen in the direction of extension—it has a grip area  12  that can be grasped by the hand. The user grasps the grip area  12  in order to use the endoscope. The grip area  12  extends over the incomplete housing  150  and the completion component  105 , as is shown in  FIG.  1   . 
     The control body  10  has a front side, on which are arranged a suction control valve  110 , a water-air valve  152 , control buttons  153  and  154  and an instrument inlet section  120 , which forms an entrance section of the working channel that is accessible from outside, see  FIG.  1   . 
     More specifically, the suction control valve  110  and the instrument inlet section  120  are arranged on the completion component  105 . The water-air valve  152  and the control buttons  153  and  154  are arranged on the incomplete housing  150 . The water-air valve  152  serves to switch on/switch off the air and/or water supply from a not shown supply source and controls, for example, the rinsing with water at the distal end. The air and/or water supply and the water-air valve  152  can be used as in conventional endoscopes. The control buttons  153  and  154  are freely assignable and can, for example, be control buttons with processor functions, such as a button for taking a screenshot of a scenario observed by a camera at the distal end, a button for zooming an image displayed on a monitor of the scenario observed by the camera, or similar. 
     Arranged on a lateral side of the incomplete housing  150  is a control wheel  151  that serves for controlling a deflection movement of the distal section, for example. The control wheel  151  can also have other functions. 
     The incomplete housing  150  is designed in such a way that it is open on the front side. On the front side of the incomplete housing  150 , the incomplete housing  150  is closed by way of the completion component  105 . Therefore, on its front side the incomplete housing  150  has a circumferential section, the shape of which is complementary to the circumferential section of the completion component  105 . In other words, the shape of the circumferential section of the completion component  105  is matched to the shape of the circumferential section of the incomplete housing  150 . For this reason, in the embodiment, the circumferential section of the incomplete housing  150  has a first (distal) groove  160  and a second (proximal) groove  162 . Between the first groove  160  and the second groove  162  a raised section  161  projects to the front side. 
     At the edges of each of the first groove  160  and of the second groove  163 , a perpendicular edge of the raised section  161  projects to the front side. The perpendicular edges of the raised section  161  extend perpendicularly to the direction of extension of the incomplete housing  150  and thus perpendicularly to the direction of extension of the control body  10 . 
     In the area that is exposed through the absence of the completion component  105 , the incomplete housing  150  also has an opening  170  for a working channel element  122 , as is described below. The opening  170  forms an entrance to a channel that extends to the distal end section  40  and through which the working channel element  122  can be pushed. 
     The incomplete housing  150  comprises snap-in fastening means  400  on the edge of the opening that is formed by the first groove  160 , the raised section  161  and the second groove  162 . 
     The completion component  105  is part of an attachment body  100 , which is applied to the incomplete housing  150 . Without this attachment body  100 , the endoscope is still a not yet complete endoscope basic body which must be completed with the attachment body  100  in order to be used. 
     The attachment body  100  comprises the completion component  105 , a working channel assembly and a suction device assembly. The working channel assembly and the suction device assembly of the fastenable attachment body  100  are detachably fastened in the control body  10 . 
     The completion component  105  forms the additional housing section for completing the incomplete housing  150 . The shape of the circumferential section of the completion component  105  is matched to the shape of the circumferential section of the incomplete housing  150 . Thus, in the embodiment, the circumferential section of the completion component  105  has a first (distal) projection  130  and a second (distal) projection  132 . Between the first projection  130  and the second projection  132 , a recess  131  is formed. The raised section  161  of the incomplete housing  150  fits into the recess  131 . 
     Extending respectively at the edges of the first projection  130  and of the second projection  132  is a perpendicular edge of the recess  131 . The perpendicular edges of the recess  131  extend perpendicularly to the direction of extension of the completion component  105 . 
     The completion component  105  has counterparts to the snap-in fastening means  400  on the opening edge which is formed by the first projection  130 , the recess  131  and the second projection  132 . Because of the snap-in fastening means  400  on the incomplete housing  150 , the completion component  105  can engage on the incomplete housing  150 . 
     The type of snap-in fastening means  400  can be freely selected. As snap-in fastening means  400 , a snap-in connection can, for example, be selected in the form of barbed hooks which engage in corresponding openings as counterparts on the completion component  105 . Any snap-in fastening means  400  can be used. 
     Arranged on the front side of the completion component  105  is the instrument inlet section  120 . The instrument inlet section  120  is part of the working channel assembly. 
     The working channel assembly comprises a working channel element  122 . When the working channel element  122  is completely introduced into the insertion tube  20 , the working channel element  122  extends up to the distal end of the endoscope  1 . 
     The working channel element  122  is tubular and forms a channel surrounded by a casing that serves as a working channel, through which instruments can be guided to the distal end of the working channel element  122 . The proximal end of the working channel element  122  is formed by the instrument inlet section  120 . On its inner circumference the instrument inlet section  120  has a rubber seal. 
     The outer diameter of the working channel element  122  is chosen in such a way that the working channel element  122  fits into the opening  170  so that the working channel element  122  can be reliably pushed to the distal end of the endoscope  1 . 
     Arranged on the front side of the completion component  105  is the suction control valve  110 . The suction control valve no is part of the suction device assembly. 
     The suction device assembly comprises a suction line  320 . The suction line  320  is formed by a channel-like line which comprises a proximal suction line section  325 , connectable to a (not shown) proximal suction source (negative pressure source), and a distal suction line section  326 . The distal suction line section  326  extends to the working channel element  122  and opens out into this, see  FIG.  5   . The suction control valve  110  is arranged between the proximal suction line section  325  and the distal suction line section  326 . Through operating the suction control valve  110 , the suction line  320  is opened or closed. Through operation to open the suction control valve  110 , the negative pressure of the suction source acts at the distal end of the suction line  320 . Through operation to close the suction control valve  110 , the suction line  320  is closed so that the negative pressure of the suction source no longer acts at the distal end of the suction line  320 . 
     The proximal suction line section  325  projects at the proximal side of the completion component  105 . On its proximal side, the proximal suction line section  325  has a (not shown) connection element that is connectable to the suction source. 
     When the attachment body  100  is arranged on the incomplete housing  150 , the proximal suction line section  325  is guided on the outer edge of the incomplete housing  150  and on the supply cable  30 . More particularly, on the supply cable  30 , a ring element  35  is provided as a fastening means. The proximal suction line section  325  is pushed through the ring element  35 . Along the supply cable  30 , several ring elements  35  can be provided. In this way, the proximal suction line section  325  can extend in parallel to and closely adjoining the supply cable  30 , see  FIG.  1   . 
     The distal suction line section  326  is integrated into the working channel element  122 . More particularly, the distal suction line section  326  and the working channel element  122  form a Y shape. The working channel element  122  is divided into a proximal working channel section  123  and a distal working channel section  124 . The proximal working channel section  123  extends from the instrument inlet section  120  to the junction point between the distal suction line section  326  and the working channel element  122 . The distal working channel section  124  extends from the junction point between the distal suction line section  326  and the working channel element  122  to the distal end of the endoscope. 
     When the attachment body  100  is arranged on the incomplete housing  150 , the distal working channel element section  124  is fully inserted through the opening  170  into the insertion tube  20 , wherein the distal suction line section  326  extends to the distal end of the endoscope  1 . The working channel element  122  is thus pushed into the opening  170 . 
     As described above, the suction line  320  opens out into the working channel element  122 . Looked at in another way, the endoscope  1  has a continuous channel element from the suction source to the distal end of the working channel. On the completion component  105  a lateral access to this channel element is provided. The access has, as the entrance, the instrument inlet section  120  and opens into the channel element. 
     At the distal end section  40  of the endoscope  1 , the distal working channel element section  124  jointly forming the working channel and the suction channel, is open. 
     The details of the distal end section  40  of the endoscope  1  are shown in  FIG.  6   . It should be noted here that  FIG.  6    only shows the transition from the insertion tube  20  to the distal end section  40  schematically as an illustration of the principle. The invention is not restricted to this depiction. The distal end section  40  can have various elements which are not shown, e.g. lighting, a camera, a rinsing nozzle etc. 
     The distal end section  40  has an opening  42  on the distal side. The distal working channel section  44  of the working channel is provided in the distal end section  40 . At the opening  42 , the distal working channel section  44  has a section  43  with a reduced diameter. On the proximal side of the section  43  with a reduced diameter, the distal working channel section  44  forms a shoulder surface  46  extending outwards from the section  43  with a reduced diameter. The inner diameter of the section  43  with a reduced diameter corresponds to the inner diameter of the distal working channel section  124 . 
     The distal working channel section  44  therefore has an inner diameter that is greater than the inner diameter of the opening  42 . 
     The distal working channel element section  124  can therefore be pushed into the distal working channel section  44  up to the shoulder surface  46 . 
     The distal working channel element section  124  cannot be pushed over the shoulder surface  46 . In the furthest pushed position in the distal direction, the distal working channel element section  124  is in contact with the shoulder surface  46 . 
     In this way, the endoscope  1  according to the invention is divided into an endoscope basic body and the attachment body  100 . All mechanical and electronic parts are arranged in the endoscope basic body. Not arranged in the endoscope basic body are the elements of the working channel assembly and suction device assembly of the endoscope  1  that have to be cleaned after use of the endoscope  1 . 
     Arranged in the attachment body  100  are the elements of the working channel assembly and the suction device assembly of the endoscope  1 . The working channel assembly and the suction device assembly in particular are exposed to contamination when the endoscope  1  is used. Therefore, the elements of the endoscope  1  that can be particularly heavily contaminated during use are accommodated in the attachment body  100 . 
     Function 
     For initial use of the endoscope  1 , a new attachment body  100  is inserted on the endoscope basic body as shown in  FIG.  4   . For this, the proximal suction line section  325  is pushed through the ring element  35  on the supply cable  30  (see  FIG.  1   ) and connected to the suction source. 
     The working channel element  122  is pushed into the opening  170 . 
     Finally, the completion component  105  is placed on the incomplete housing  150 , in that the circumferential section with the first projection  130 , the recess  131  and the second projection  132  is mounted on the circumferential section of the incomplete housing  150  with the first groove  160 , the raised section  161  and the second groove  162  perpendicularly to the direction of extension of the incomplete housing  150 . The first projection  130  fits into the first groove  160 . The recess  131  fits the raised section  161 . The second projection  132  fits into the second groove  162 . Through the snap-in fastening means  400 , the completion component  105  is firmly engaged on the incomplete housing  150 . 
     The endoscope  1  is now ready for use. The endoscope  1  can be inserted into the patient. Instruments can be introduced through the instrument inlet section  120 . Suction can take place via the combined working channel/suction channel. 
     After use of the endoscope  1 , the attachment body  100  is removed from the endoscope basic body. The attachment body  100  can be disposed of. 
     The remaining endoscope basic body that has been released from the used attachment body  100 , can now be cleaned and sterilised and then dried and stored. 
     To use the endoscope  1  again, the cleaned and reprocessed endoscope basic body is provided with a new attachment body  100 . 
     Advantages 
     The endoscope  1  can be divided into the endoscope basic body and the attachment body  100 . The endoscope basic body with the incomplete housing  150 , the insertion tube  20  and the supply cable  30  is reusable and can be cleaned and reprocessed after use. 
     Arranged in the attachment body  100  are the elements of the working channel assembly and the suction device assembly of the endoscope  1 . After use, the attachment body  100  can be disposed of. 
     To use the endoscope  1  again, the cleaned and reprocessed endoscope basic body is provided with a new attachment body  100  which can be removed from a sterile package shortly before attachment to the endoscope basic body. 
     In this way, contamination on the endoscope  1  through impurities originating from a previous use can be better prevented when the endoscope  1  is used again. 
     Particularly the working channel and the suction channel are channels in which a biofilm can form on the inner walls of the channel during use. During reprocessing after the use of an endoscope, such a biofilm can be particularly difficult to remove. As in the present invention, specifically those sections of an endoscope on which the formation of a biofilm is likely, namely the working channel and the suction channel, are moved into the attachment body  100  that can be disposed of after use, the probability of biofilm formation on the surfaces of the reusable endoscope basic body can be massively reduced. Through this, the danger of cross-contamination, whereby germs from one patient are transmitted to another, can be drastically reduced. 
     The cleaning of the used endoscope basic body is less costly and complicated in comparison with a conventional endoscope, as the working channel assembly and the suction device assembly, as the principally contaminated elements, have been removed. 
     As the grip area  12  extends over the incomplete housing  150  and the completion component  105 , it can be reliably concluded from the shape of the incomplete housing  150  that the completion component  105  is missing and that the endoscope  1  is not yet complete. Incorrect use of the endoscope  1  can be prevented. 
     The perpendicular edges of the raised section  161  that project to the front side extend perpendicularly to the direction of extension of the incomplete housing  150 . As a result, the completion component  105  can be securely pushed onto the housing  150 . 
     In the present invention, in order to assemble the attachment body  100  on the endoscope basic body, the working channel assembly and the suction device assembly are positioned accordingly (proximal suction line section  325  to the proximal side into the ring element  35 ; working channel element  122  into the opening  170 ), and the completion component  105  is pushed onto the incomplete housing  150  and clicked on. In this way the endoscope  1  can assembled in a quick and uncomplicated manner. 
     The attachment body  100  can also be simply, easily and rapidly removed from the endoscope basic body. 
     As the working channel and the suction line are combined as one channel distally of the junction point, this one channel can have a small diameter, which is suitable for the respective purpose of pushing through the desired instrument and also suction. The receiving channel  44  that is formed in the insertion tube  20  and in the distal end section  40  and at the entrance comprises the opening  170  can thus also have a small diameter. The outer diameter dimension of the insertion tube  20  and of the distal end section can thus be correspondingly small. 
     Since the distal working channel element section  124  cannot be pushed beyond the shoulder surface  46  and since in the furthest pushed position of the working channel element section  124  in the distal direction it rests on the shoulder surface  46 , the working channel element  122  does not come into contact with the patient when being used. Only the distal end section  40  surrounding the working channel element  122  comes into contact with the patient. In this way, the working channel element  122  is more protected from impurities. 
     Second Embodiment 
     With reference to  FIG.  7    a second embodiment is described. In the second embodiment, the distal area of the distal working channel element section  124  has been modified. The remaining structure is the same as in the first embodiment. 
     The distal working channel element section  124  has a distal end region  125 . On the outer surface of the distal end region  125 , the distal end region  125  is provided with a circumferential recess  126 . The circumferential recess  126  extends along the outer circumference of the distal end region  125 . 
     On the inner surface of the distal working channel  44 , the distal working channel section  44  is provided with a circumferential recess  47 . The circumferential recess  47  extends along the inner circumference of the distal working channel section  44 . 
     The circumferential recess  47  is more deeply recessed into the distal working channel section  44  than the circumferential recess  126  in the distal end region  125 . A holding element  48  is firmly inserted in the circumferential recess  47 . 
     The holding element  48  can be designed as a ring element. The holding element  48  can be a sealing ring. The holding element  48  can also be a spring element or another elastic element. 
     In the situation in which the working channel element  122  is pushed into the endoscope  1 , i.e. completely (fully) pushed into the insertion tube  20  and distal end section  40 , the circumferential recess  126  of the distal working channel element section  145  and the circumferential recess  47  of the distal working channel section  44  are opposite each other. In this assembled state, the holding element  48  of the distal end section  40  engages in the circumferential recess  126  of the distal working channel element section  124 . Through this, in the assembled state the distal working channel section  44  can snap into the distal end section  40 . In this way the distal working channel section  44  can be securely held on the distal end section  40 . In this embodiment too, the working channel element  122  does not come into contact with the patient. 
     Third Embodiment 
     With reference to  FIG.  8    a third embodiment is described. In the third embodiment, the distal region of the distal working channel element section  124  has been modified. The remaining structure is the same as in the first embodiment. 
     The distal working channel element section  124  has a distal end region  125 . On the outer surface of the distal end region  125 , the distal end region  125  is provided with a conical outer surface  127 . The conical outer surface  127  narrows in the distal direction of the distal end region  125 . The outer diameter of the distal end region  125  therefore decreases in the distal direction of the distal end region  125 . 
     At the distal end, on the inner surface of the distal working channel section  44 , the distal working channel section  44  is provided with a conical inner surface  49 . The conical inner surface  49  narrows in the distal direction of the distal working channel section  44 . In other words, on the conical inner surface  49 , the inner diameter of the distal working channel section  44  decreases in the distal direction of the distal working channel section  44 . 
     The slant of the conical inner surface  49  corresponds to the slant of the conical outer surface  127 . 
     In the situation in which the working channel element  122  is completely (fully) pushed into the endoscope  1  and into the distal end section  40 , the conical outer surface  127  of the distal working channel element section  124  rests on the conical inner surface  49  of the distal end section  40  and cannot be moved any further in the distal direction. 
     Through this, in the assembled state the distal working channel section  44  can adjoin the distal end section  40  in a contact position. In this way the distal working channel section  44  can be securely held on the distal end section  40 . In this embodiment too, the working channel element  122  does not come into contact with the patient. 
     Other Alternatives 
     In the first embodiment a control wheel  151  is described. The endoscope can comprise several control wheels for various purposes. 
     The control wheel  151  can be omitted if the invention is used, for example, in an endoscope whose distal section cannot be deflected. 
     In the first embodiment, the circumferential section of the incomplete housing  150  comprises the first (distal) groove  160  and the second (proximal) groove  162  and the raised section  161  between the grooves  160 ,  162 , which match the projections  130   132  and the recess  131  of the completion component  105  which are designed as counterparts. The invention is not restricted to this. The precise shape of the circumferential section of the incomplete housing  150  and its apposite counter-shape on the completion component  105  can be freely selected. The user should only be able to recognise that the casing without the completion component  105  is incomplete. Furthermore, it must only be guaranteed that the completion component  105  fits onto the incomplete housing  150 . 
     In the situation in which the completion component  105  is applied on the incomplete housing  150 , in the first embodiment the proximal suction line section  325  on the outer side of the incomplete housing  150  extends in the proximal direction. In an alternative, in the incomplete housing  150  on the proximal side a channel with a (distal) opening is provided, which similar to the opening  170  is here designed for the proximal suction line section  325 . On the proximal side, this channel opens out on the outer side of the incomplete housing  150  close to the connection point of the supply cable  30  on the incomplete housing  150 . Through this channel, the proximal suction line section  325  can be pushed in the proximal direction, whereby it can also run along the supply cable  30  in a parallel and closely adjoining manner. This improves the optical appearance, as on the grip area  12  of the control body  10  itself, no section of the suction line  320  is exposed. 
     In the first embodiment, on the supply cable  30 , the ring element  35  is provided as a fastening means for the proximal suction line section  325 . Any other fastening means can be used as alternatives. For example, a clamp, a strap or Velcro strip can be used for this. 
     In the first embodiment the working channel element  122  is pushed into the opening  170 . The working channel element  122  is connected to the distal suction line section so that the working channel in the working channel element  122  can also be used as a suction line. In an alternative, two tube elements (channel elements) are arranged on the completion component  105  pointing in the distal direction. Namely, a distal suction line section and a working channel element can be formed as two separate tube elements which extend to the distal end of the endoscope  1 . One of these tube elements is the working channel element of the working channel assembly. The other tube element is the distal suction line section. The distal suction line section and the working channel element are pushed into the opening  170 . The opening  170  and its channel up to the distal end are of a size which allows the incorporation of the distal suction line section and the working channel element. When the suction line section and working channel element are completely introduced into the insertion tube  20 , the suction line section and the working channel element extend up to the distal end of the endoscope  1 . 
     In a further alternative, the distal suction line section and the working channel element are designed as a one-piece structure. In the one-piece design, the distal suction line section and the working channel element form a joint tube element, the inner space of which is divided by a partition element into two chambers, which each extend to the distal end of the endoscope  1 . The one-piece design results in a particularly small construction, since the channel with the opening  170  in the insertion tube  20  can be reduced in size accordingly. The joint tube element can be produced by extrusion. On the proximal section of the joint tube element, the joint tube element can be connected in such a way that the proximal section of the distal is connected on the suction control valve  100  and the proximal section of the working channel element is connected on the instrument inlet section  120 . 
     In a further alternative, the detachably fastenable attachment body  100 , which comprises the working channel assembly and the suction device assembly, is formed without the completion component  105 . This detachably fastenable attachment body can be removed through an opening on the endoscope, for example on the control body  10 . The control body  10  then has a complete housing. In this alternative too, the working channel assembly and the suction device assembly of the fastenable attachment body  100  are detachably fastened in the control body  10 . 
     The invention can be advantageously used in a flexible endoscope. More particularly, the invention can be advantageously used in a gastrointestinal endoscope. The principle of the invention can also be used in any other type of endoscope. 
     LIST OF REFERENCE NUMBERS 
       1  Endoscope 
       10  Control body 
       12  Grip area 
       20  Insertion tube 
       30  Supply cable 
       35  Fastening means 
       40  Distal end section 
       42  Opening 
       43  Section with reduced diameter 
       44  Distal working channel section 
       46  Shoulder surface 
       47  Circumferential recess 
       48  Holding element 
       49  Conical inner surface 
       100  Attachment body 
       105  Additional housing section, completion component 
       110  Suction control valve 
       120  Instrument inlet section 
       122  Working channel element 
       123  Proximal working channel element section 
       124  Proximal working channel element section 
       125  Distal end area 
       126  Circumferential recess 
       127  Conical outer surface 
       130  Projection 
       131  Recess 
       132  Projection 
       150  Incomplete housing 
       151  Control wheel 
       152  Water-air valve 
       153  Control button 
       154  Control button 
       160  Groove 
       161  Raised section 
       162  Groove 
       170  Opening for working channel element 
       320  Suction line 
       325  Proximal suction line section 
       326  Distal suction line section 
       400  Snap-in fastening means