Abstract:
The invention relates to a device for preparing tissue discs, in particular cartilaginous discs. A device for preparing tissue discs that is of simple structure and ensures safe handling includes, in addition to a clamping device for securing a tissue block by clamping, at least one cutting device for treating the tissue block held in the clamping device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority of German patent application No. 10 2007 026 574.5 filed on Jun. 8, 2007 the content of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a device for preparing tissue discs, in particular cartilaginous discs. 
     BACKGROUND OF THE INVENTION 
     In preparing tissue discs, for instance to create a new nasal septum from a transplanted rib, it is essential that the plastic material that is to be created be prepared to a predetermined strength. In practice this preparation is performed manually by means of a scalpel. Aside from the fact that this skilled preparation by a scalpel poses a high risk of injury for the user, it is extremely difficult to ensure precise dimensions for the plastic material, in particular concerning the thickness of the tissue disc. 
     It is therefore the object of the invention to create a device for preparing tissue discs that guarantees both simplicity in structure and safe and precise operation. 
     SUMMARY OF THE INVENTION 
     This object is fulfilled according to the invention by a device for preparing tissue discs, in particular cartilaginous discs, said device including a clamping device for securing a block of tissue by clamping and having at least one cutting device for treating the tissue block held in the clamping device. 
     Because of the inventive combination of a clamping device and a cutting device in one apparatus, it is possible for the first time to prepare tissue discs of predetermined size and thickness quickly and precisely. With the inventive device, one can do away completely with the use of a scalpel as is common in the art. 
     According to a practical embodiment of the invention, it is proposed that the clamping device should comprise at least two clamping jaws, where at least one clamping jaw can be displaced with respect to the at least one other clamping jaw. 
     To avoid squeezing too strongly the tissue block that is to be secured by the clamping device on the one hand, while on the other hand still securing the tissue block, it is proposed with the invention that, when the clamping device is in closed position, there should remain, between the at least two clamping jaws of the clamping device, a clamping gap whose height is advantageously adjustable, so that the device can be used for various tissue disc sizes. 
     It is proposed, with a preferred embodiment of the invention, that the clamping device should comprise one rigid clamping jaw that is mounted on a base body, and one clamping jaw that can rotate with respect to the rigid clamping jaw. 
     According to the invention, the rigid clamping jaw is advantageously configured as a double-walled plate with a window-like opening in such a way that the clamping jaw that can rotate with respect to the rigid clamping jaw is mounted so that it can move within an intermediate space between the two side walls of the double-walled plate which are distanced from one another. This arrangement of the rotatable clamping jaw within the intermediate space of the rigid clamping jaw ensures a precise motion of the rotatable clamping jaw, free of canting. 
     The thickness of the tissue disc that is to be prepared can vary according to the invention owing to the fact that the breadth of the intermediate space formed by the side walls of the double-walled plate is adjustable. 
     For mounting the rotatable clamping jaw, it is proposed that it should be mounted on one side in the plate of the rigid clamping jaw, so that the height of the clamping gap remaining free between the rigid and the rotatable clamping jaw can be adjusted in the plate by displacing the mounting point of the rotatable clamping jaw. 
     To be able to hold the tissue block that is to be prepared securely and immovably in the clamping gap, it is proposed according to the invention that tooth-like fixing elements should be configured at least on the mutually facing surfaces of the at least two clamping jaws. 
     For configuring the cutting device, according to a practical embodiment of the invention it is proposed that the cutting device should be configured as a swivel arm that can be displaced with respect to the clamping device and that is equipped with at least one cutting edge, and that said swivel arm advantageously should be mounted so that it can rotate either on the base body or on the plate of the rigid clamping jaw. 
     According to a preferred embodiment of the invention, it is further proposed that the swivel arm, at least in the area of the at least one cutting edge, should comprise two arm parts running parallel to one another and each equipped with a cutting edge, said arm parts are mounted on the base body or on the plate of the rigid clamping jaw in such a way that the plate is positioned between the two arm parts. This inventive configuration of the cutting device makes possible the simultaneous treatment of two parallel pieces for preparing the tissue disc. 
     To be able to guarantee a constantly uniform cutting quality, it is further proposed that the at least one cutting edge should be positioned replaceably on the swivel arm. The replaceability of the cutting edge has the advantage, moreover, that only the cutting edge that is immediately below the direct abrasion needs to be replaced, rather than the entire swivel arm. 
     It is finally proposed with the invention that the distance of the two parallel arm parts and thus also of the two cutting edges to one another should be adjustable. Thanks to this variation in the cutting edge distance to one another, the thickness of the tissue disc that is to be prepared can be easily and reliably adjusted and maintained. 
     The invention also relates to a cutting device for a device for preparing tissue discs, in particular cartilaginous discs, having a clamping device for securing a tissue block by clamping. To ensure both simple structure and a safe and exact handling of the cutting device, the inventive cutting device is distinguished in that it is configured as a swivel arm that can be displaced with respect to the clamping device and is equipped with at least one cutting edge. 
     Additional characteristics and advantages of the invention can be seen by referring to the appended illustrations, in which an embodiment of an inventive device for preparing tissue discs, in particular cartilaginous discs, is depicted in merely exemplary terms, with restricting the invention to this embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective side view of an inventive device for preparing tissue discs, depicting a first working position. 
         FIG. 2  shows a view according to  FIG. 1  but depicting a second working position. 
         FIG. 3  shows a view as in  FIG. 1  rotated by  180  degrees. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The device illustrated in  FIGS. 1 through 3  for preparing tissue discs, in particular cartilaginous discs, consists essentially of a base body  1  serving as support surface and of a clamping device  2  and a cutting device  3 , which are mounted on the base body  1 . 
     This type of device serves for preparing tissue discs, for example for creating a new nasal septum from a transplanted rib piece. It is also possible of course to process other tissue, possibly including synthetic tissue, with this device. 
     In the illustrated embodiment the clamping device  1  consists of a rigid clamping jaw  4  and a clamping jaw  5  that can rotate with respect to the rigid clamping jaw  4 . As can be seen from the illustrations, the rigid clamping jaw  4  is configured as a double-walled plate  6  in such a way that the two side walls are distanced from one another so as to form an intermediate space  7 . For inserting a tissue block that is to be prepared, a window-like opening  8  is configured in the plate  6 . 
     The clamping device  2  is completed by the rotatable clamping jaw  5 , which, as can be seen from the illustrations, is mounted movably in the intermediate space  7  formed by the double-walled plate  6  of the rigid clamping jaw  4 , so that the actual rotatable mounting of the rotatable clamping jaw  5  occurs by means of a positioning pin  9  that is positioned on one end of the clamping jaw  5  and that can be inserted into a positioning recess  10  configured in the plate  6  of the rigid clamping jaw  4 . 
     As can be seen in particular from  FIG. 2 , the clamping device  2  is configured in such a way that, also when the clamping device  2  is in the closed position, that is, when the rotatable clamping jaw  5  has been rotated downward, partly closing the window-like opening  8 , an open clamping gap  11  for clamping insertion of the tissue disc that is to be prepared remains between the rotatable clamping jaw  5  and the upper edge of the rigid clamping jaw  4 . 
     In the illustrated embodiment the positioning pin  9  of the rotatable clamping device  5  is configured as non-round in such a way that the rotatable clamping jaw  5  can be inserted into the positioning recess  10  only in a position aligned basically perpendicular to the base body  1  and in the positioning recess  10  individual mounting points  12  are configured in which the rotatable clamping jaw  5  can be rotated downward in the direction of the window-like opening  8  of the plate  6  to close the clamping device  2 . To be able to vary the height of the clamping gap  11  for inserting larger or smaller tissue blocks, several mounting points  12  are configured, positioned above or below one another for rotatable mounting of the rotatable clamping jaw  5 . 
     In addition the clamping device  2 , at least on the mutually facing surfaces of the rigid clamping jaw  4  and of the rotatable clamping jaw  5 , comprises tooth-like fixing elements  13 , which ensure a secure and immovable bracing of the tissue blocks positioned for processing in the clamping device  2 . 
     The cutting device  3  in the illustrated embodiment consists of a swivel arm  14  that is configured so that it can rotate with respect to the clamping device  2  and that comprises at least one cutting edge  15  for cutting the tissue block held in the clamping device  2 , where the swivel arm  14  in the illustrated embodiment is mounted rotatably on a mounting pin  16  shaped on the plate  6 . Alternatively it is also possible, of course, to mount the swivel arm  14  on the base body  1 . 
     To be able to ensure a constantly uniform cutting quality, the at least one cutting edge  15  is preferably positioned replaceably on the swivel arm  14 . 
     In the illustrated embodiment the swivel arm  14  comprises two arm parts  17  that run parallel to one another and are each equipped with a cutting edge  15  and mounted on the plate  6  in such a way that the plate  6  is positioned between the two arm parts  17  of the swivel arm  14 . This configuration of the cutting device  3  makes possible the simultaneous execution of two parallel cuts for preparing a tissue disc from the tissue block held in the clamping device  2 . 
     To be able to produce tissue discs of varying thicknesses by means of the cutting device  3 , there exist two possibilities for altering the distance between the two arm parts  17  of the swivel arm  14  of the cutting device  3 , namely, first the alteration of the width of the intermediate space  7  configured between the side walls of the double-walled plate  6 , by widening or narrowing the side wall distance of the plate  6 , and second alteration of the distance between the two arm parts  17  of the swivel arm  14  of the cutting device  3  without changing the widths of the intermediate space  7  formed between the side walls of the double-walled plate  6 . 
     Alternatively to the illustrated configuration of the cutting device  3  with a rotatably mounted swivel arm  14 , it is also possible of course to configure the cutting device  3  in such a way that the cutting device  3  comprises at least one cutting arm that can slide axially with respect to the clamping device  2  and that is equipped with at least one cutting edge  15 . The axial mobility of the cutting arm with respect to the clamping device  2  makes it possible to exert a sawing cutting motion of the cutting device  3 . 
     The assembly and operation of the above-described device for preparing tissue discs occur as follows. 
     Before the use of the device, the rotatable clamping jaw  5  and the swivel arm  14  of the cutting device  3  are first connected with the device. For this purpose the rotatable clamping jaw  5  is inserted into the positioning recess configured in the double-walled plate  6 , in a position aligned essentially perpendicular to the base body  1  with the positioning pin  9  in front, until the positioning pin  9  reaches mounting point  12 , which corresponds to the height of the clamping gap  11  that is necessary for the particular purpose. 
     Then the rotatable clamping jaw  5  can be rotated 90 degrees downward until the particular minimal height of the clamping gap  11  is reached. 
     Next the swivel arm  14  of the cutting device is placed on the mounting pin  16  configured on the plate  6 , for which purpose a mounting recess that corresponds with the contour of the mounting pin  16  is configured on the front end of the swivel arm  14 . To prevent accidental separation of the swivel arm  14  from the mounting pin  16 , the mounting pin  16  is of non-round configuration so that the swivel arm  14  can be mounted on the mounting pin  16  only in one position, namely essentially perpendicular to the base body  1 , and can be separated from it again. In all other positions the mounting on the mounting pin  16  allows only the rotation of the swivel arm  14  around the mounting pin  16 . 
     To preserve the greatest possible range of rotation for the swivel arm  14  and the rotatable clamping jaw  5 , the positioning points of the components  5  and  14  are positioned opposite one another on the plate  6 . 
     Alternatively it is also possible, of course, to position the positioning points of components  5  and  14  on one side of the plate  6  and to configure the swivel arm  14 , for instance, as divided in two parts spanning the entire clamping device  2 . 
     For comfort in handling the device, on the ends opposite the positioning ends, both of the rotatable clamping jaw  5  and of the swivel arm  14  of the cutting device  3 , hand grips  18  are formed permitting components  5  and  14  to be rotated easily. In addition, the illustrated device comprises a handle  18  formed on the plate  6  of the rigid clamping jaw  4  in order, first, to be able to offer sufficient clamping force by gripping the handgrips  18  of both clamping jaws  4  and  5  and, second, to be able to transport the ground body  1  with the rigid clamping jaw  4  easily and safely. 
     After installing the rotatable clamping jaw  5  and the swivel arm  14 , the device is ready for use. 
     To install a tissue block for treatment in the clamping device  2 , first the rotatable clamping jaw  5  and the swivel arm  14  of the cutting device  3  are rotated upward in the direction of the perpendicular position until they contact one another. Then a transplanted piece of cartilage or a different tissue piece, for instance, is inserted into the window-like opening  8  of the plate  6  and is clamped in by moving the rotatable clamping jaw  5  securely and immovably downward, so that the tooth-like fixing elements  13  ensure an additional support. 
     The actual free preparation of the tissue disc occurs in the next working step by moving downward the swivel arm  14 . The two cutting edges  15  positioned on the parallel arm parts  17  simultaneously execute two parallel cuts with the downward motion of the swivel arm  14  and thus produce the required tissue disc in just one working step. 
     The width of the tissue disc that is to be prepared can be achieved either by altering the width of the intermediate space  7  formed between the side walls of the double-walled plate  6  or by altering the distance between the two arm parts  17  of the swivel arm  14  of the cutting device  3 . These distances can be altered, for instance, either by a thread, where the alteration of these distances can be provided with a scale and can be adjusted by means of the handgrip  18  or one or more additional handgrips, adjusting screws, rotary knobs, or the like. 
     Here it is possible, first, merely to adjust the distance of the two cutting edges  15  to one another or, second, in addition to adjust the intermediate space  7  between the side walls of the double-walled plate  6 , that is, the distance of the two side walls of the double-walled plate  6  to one another. 
     In addition to its simplicity of structure, a device constructed in this manner for preparing tissue discs is distinguished by its safe and precise handling.