Abstract:
A handle for a medical instrument includes an actuation element, which is arranged on the handle and which is displaceable into at least a first and a second functional position. The actuation element can be moved in a plane transverse to its displacement direction, in each of the first and second functional positions, for carrying out a function. A pivotable actuation lever is arranged in the handle, the actuation lever being coupled in movement to the actuation element for displacing the actuation element into the at least two functional positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Section 371 of International Application No. PCT/EP2012/071462, filed Oct. 30, 2012, which was published in the German language on May 10, 2013, under International Publication No. WO 2013/064487 A1 and the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a handle for a medical instrument. 
     A handle of a medical instrument is usually to be understood as the part of the instrument by which the instrument is manually held and led by a grip part arranged there and on which one or more actuation elements are arranged for carrying out the functions which can be executed with the instrument. 
     Apart from handles, with whose actuation elements respectively only one function of a medical instrument can be carried out, a medical instrument having a handle is known from German published patent application DE 10 2009 051 515 A1 (counterpart: US patent application publication 2011/0106143 A1), with which several functions can be carried out with one actuation element. This instrument comprises a shank which is arranged on the proximal side of the handle and which is rotatable about its longitudinal axis. A tool which is rotatable relative to the shank is arranged at the distal end of the shank. The handle comprises an actuation element in the form of a rotation wheel, with which on the one hand the shank can be rotated and on the other hand the tool can be rotated relative to the shank. For this, the rotation wheel is axially displaceable in the handle into two functional positions, wherein in a first functional position it is coupled in movement to the shank which can then be rotated by a rotation of the rotation wheel, and in a second functional position it is coupled in movement to the tool which in this functional position can be rotated relative to the shank by rotating the rotation wheel. 
     The handle of the instrument known from DE 10 2009 051 515 A1 represents a significant improvement compared to handles with whose actuation elements only one function can be carried out in each case, wherein this handle however still does not represent the best possible solution from an ergonomic point of view. 
     BRIEF SUMMARY OF THE INVENTION 
     It is the object of the invention, to create a handle for a medical instrument, which comprises at least one actuation element for carrying out several functions, wherein this handle should have a further improved operating ability compared to the known handle of this type. 
     This object is achieved by a handle for a medical instrument, having an actuation element arranged on the handle and being displaceable into at least first and second functional positions and being movable in a plane transverse to its displacement direction, in the first as well as the second functional position for carrying out a function, wherein a pivotable actuation lever is arranged on the handle, the actuation lever being coupled in movement to the actuation element for displacing the actuation element into the at least two functional positions. Advantageous further developments of this handle are to be deduced from the subsequent description as well as the drawings and claims. Herein, according to the invention, the features specified in the dependent claims and description, respectively, but also in a technically meaningful combination, further form the solution according to the invention. 
     The handle according to the invention for a medical instrument comprises an actuation element, which is arranged on the handle and which can be displaced at least into first and second functional positions and is movable in a plane transversely to its displacement direction in the first as well as the second functional position, for executing a function. Here, the functions which can be carried out by the actuation element in the first and second functional positions differ from one another. The type of these functions executable in the at least two functional positions by the actuation element is typically directed to the type of the medical instrument with which the handle according to the invention is applied and is basically infinite. 
     For example, with the functions executable with the actuation element in the instrument known from DE 10 2009 051 515 A1, it can be the case of the rotation of a shank arranged distally of the handle in a first functional position, and of the rotation of a tool arranged at the distal end of the shank in the second functional position. Moreover, the application of the handle according to the invention is also conceivable with such a medical instrument, with which a shank arranged distally of the handle is rotatable in a first functional position and a distal end section of this shank in a second functional position can be angled with respect to the remaining shank. Preferably, the actuation element, apart from the two functional positions, can also be displaced into such a position, in which no function can be carried out by it. Moreover, a design of the handle with which the actuation element is displaceable into more than two functional positions is conceivable. 
     The basic idea of the invention is to improve the operability of the handle by a pivotable actuation lever being arranged on the handle, the actuation lever being coupled in movement to the actuation element for displacing the actuation element into the at least two functional positions. The actuation lever is usefully designed as a two-sided lever, wherein a first lever arm of the actuation lever engages on the actuation element and a second lever arm, which is usefully longer than the first lever arm, serves for the manual force transmission onto the actuation lever. The movement coupling of the actuation lever to the actuation element is preferably such that the actuation element is displaced into a first functional position on pivoting the actuation lever in a first direction and is displaced into a second functional position on pivoting the actuation lever in a direction which is opposite to this. Compared to a direct, manual displacement of the actuation element into its two functional positions, the use of the actuation lever for this purpose has the advantage that the actuation element can be displaced with a significantly reduced force effort, so that the displacement of the actuation element into its functional positions is significantly easier. 
     Usefully, with the handle according to the invention, a displacement axis of the actuation element lies in a pivot plane of the actuation lever. That is, the pivot lever is arranged on the handle in a manner such that a pivot movement of the actuation lever and the displacement movement of the actuation element are effected in a common plane. This design has the advantage that a force component which acts directly in the displacement direction of the actuation element is exerted onto the actuation element, by the actuation lever when it is pivoted. 
     The coupling of movement of the actuation lever to the actuation element, with the handle according to the invention, is preferably effected by a positive fit between the actuation element and the actuation lever, the positive fit not being able to be released even with the common movement of the actuation lever and actuation element. In this context, according to an advantageous further development of the invention, one envisages the actuation element comprising a toothing, into which a corresponding toothing formed on the actuation lever engages. The toothed pairing of the actuation element and actuation lever is particularly advantageously designed similarly to a rack and pinion pairing, due to the linear movement guidance of the actuation element and the pivotally movable arrangement of the actuation lever about a pivot axis or rotation axis. Thus, a rack-shaped toothing can be formed on an outer side of the actuation element and a toothing which corresponds to a toothing of a section of a cog can be provided on an outer side of the actuation lever and preferably at the end of the second lever arm. 
     According to a further advantageous design, the actuation element of the handle according to the invention can comprise at least two recesses, into which a spring-biased locking element, fixedly arranged on the handle, engages in the at least two functional positions of the actuation element. This design serves for securing the actuation element with respect to an unintended linear movement, in its functional positions. Preferably, the actuation element comprises a further recess, which is arranged on the actuation element in a manner such that the locking element engages into it in a position, in which the actuation element executes no function. The locking element is preferably arranged on the handle in a manner such that a locking body of the locking element which rests on a spring element is pressed by the spring element in a direction normally to the displacement direction of the actuation element. The recesses formed on the actuation element hereby on the outer side of the actuation element usefully also extend normally to the displacement direction of the actuation element, wherein they are advantageously dimensioned such that the locking element engages into them with a positive fit. The recesses can simultaneously also be part of the previously described toothing for the engagement of the actuation lever. 
     Preferably, the actuation lever is arranged at a side of the handle, at which a fixedly arranged grip part of the handle extends essentially normally to a main axis of the handle. Here, a main axis of the handle is to be understood as an axis of the handle which extends in the direction of the longitudinal extension of a medical instrument, whose part forms the handle. That is, with respect to the medical instrument, in which the handle according to the invention is arranged, the fixedly arranged grip part is arranged in the manner of a pistol grip, wherein the actuation lever is preferably arranged in front of the grip part similarly to the trigger of a pistol. This design permits a simple accessibility of the actuation lever with a single-handed operation of the handle. 
     Advantageously, the actuation element of the handle is a rotation wheel which is axially displaceably arranged in the handle. That is, the rotation wheel is displaceable into its at least two functional positions in the direction of a central axis or rotation axis of the rotation wheel, wherein the function assigned to the respective functional position can be carried out by rotating the rotation wheel, in the two functional positions. 
     Further advantageously, the rotation wheel is preferably arranged on a sleeve. This sleeve is displaceable in the handle in the direction of its central axis and is rotatably mounted about its central axis. Several grooves, which are peripheral around the entire periphery of the sleeve, are formed on the outer periphery of the sleeve, preferably in a manner directly adjacent one another, and these grooves form a toothing. The corresponding toothing which is preferably formed on the actuation lever engages into this toothing. The number of grooves arranged on the outer side of the sleeve preferably corresponds to the number of functional positions of the actuation element formed by the sleeve and the rotation wheel which is arranged thereon. Thus, for example, three grooves can be formed on the sleeve, wherein in a first functional position of the actuation element, a first tooth of the toothing formed on the actuation lever engages into a first groove and after the pivoting of the actuation lever, which is entailed by displacement of the sleeve into a position in which the actuation cannot carry out a function, a second tooth of the toothing formed on the actuation lever engages into a second groove, and finally with a further pivoting of the actuation lever, by which the actuation element is displaced into a second functional position, a third tooth of the toothing formed on the actuation element engages into a third groove of the sleeve. 
     The grooves which are formed on the sleeve preferably have a rounded cross-sectional contour. Preferably, the profile of the grooves hereby corresponds to the profile of a flat segment of a circle. In particular, in combination with such grooves, the toothing on the actuation lever is advantageously formed by several rounded prominences which are directly adjacent one another in the pivot direction of the lever. Here, the cross-sectional profile of the prominences usefully essentially corresponds to the cross-sectional profile of the grooves formed on the sleeve. The rounded design of the grooves formed on the sleeve and the rounded design of the prominences formed on the actuation element, and which corresponds to this, permits an unproblematic rolling of the toothing arranged on the actuation lever on the toothing arranged on the sleeve during the simultaneous displacement of the sleeve or of the actuation element. 
     Usefully, the grooves formed on the sleeve also serve for fixing the actuation element in its functional positions. For this, the preferably provided, spring-biased locking element is advantageously arranged on the handle in a manner such that it engages in each case into one of the grooves formed on the sleeve, in the individual functional positions of the rotation wheel. In the handle, the locking element is preferably arranged on the side of the sleeve which is away from the actuation lever, wherein the spring element, on which the locking body of the locking element is supported, presses the looking body in the direction of the sleeve and thus in the direction of the groove arranged thereon. 
     With a design in which a rotation wheel forms the actuation element, the actuation lever can advantageously be articulated on the handle on a bow surrounding the rotation wheel at the outer side. The bow surrounds the rotation wheel at a certain distance usefully in the direction of the central axis of the rotation wheel and thus forms a mechanical protection for the rotation wheel. A longitudinal slot can be formed on the bow, in which slot the actuation lever at a distance to the rotation wheel and at a distance to the sleeve, on which the rotation wheel is arranged, is articulated in a manner such that the second lever arm of the actuation lever, which serves for the manual operation of the actuation lever, projects at the side of the bow which is away from the sleeve, out of this bow, and the toothing formed on the first lever arm of the actuation lever is engaged with the toothing formed on the sleeve. 
     In an alternative design for the movement coupling of the actuation lever and actuation element by toothings formed on the actuation lever and on the actuation element, the actuation lever can advantageously be designed in a fork-shaped manner and in one section branch into two limbs which are spaced from one another, which engage around or encompass a region of the actuation element and there are coupled in movement to the actuation element. The movement coupling of the actuation element to both limbs of the actuation lever can be effected by a groove extending over the entire periphery of the actuation element being formed on the outer side of the actuation element, into which groove a projection or pin arranged on the two limbs engages in each case. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings: 
         FIG. 1  is a lateral view of a handle for a medical instrument according to an embodiment of the invention; 
         FIG. 2  is a lateral view of a medical instrument with the handle according to  FIG. 1 ; 
         FIG. 3  is a plan view of the medical instrument according to  FIG. 2 ; 
         FIG. 4  is a partly sectioned representation of the handle according to  FIG. 1 ; 
         FIG. 5  is a sectioned lateral view of an actuation element of the handle according to  FIG. 1 ; 
         FIG. 6  is an enlarged detail Y of  FIG. 4 ; 
         FIG. 7  is an enlarged detail Z of  FIG. 4 ; 
         FIG. 8  is a partly sectioned representation of the handle according to  FIG. 1  with the actuation element in a first functional position; and 
         FIG. 9  is a partly sectioned representation of the handle according to  FIG. 1  with the actuation element in a second functional position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The handle  2  represented in  FIG. 1  is part of an endoscopic hollow shank instrument, as is represented in  FIGS. 2 and 3 . With this hollow shank instrument, a rigid hollow shank  4  is arranged distally of the handle  2  and comprises a straight, aligned hollow shank section  4   a  and a bent, distal shank section  4   b  which connects thereto obliquely to the shank section  4   a . A tool  6  in the form of a gripping forceps is arranged at the distal end of the hollow shank  4 . The hollow shank  4  is rotatably mounted on the handle  2  about the longitudinal axis of the proximal shank section  4   a , and thus is rotatable relative to the handle  2 . The tool  6  in turn is rotatable relative to the hollow shank  4 . 
     The handle  2  comprises an actuation element  10  for the rotation of the hollow shank  4  and the tool  6 , and this element extends between a grip part  8 , which is fixedly arranged on the handle  2  and which extends essentially normally to a main axis A ( FIG. 4 ) of the handle  2 , and the distal end of the handle  2 , on which the hollow shank  4  is led out of the handle  2 . As can be particularly deduced from  FIG. 5 , the actuation element  10  is formed by a sleeve  12  and a rotation wheel  14  which is arranged thereon. Sections  12   a  and  12   b  of the sleeve  12  project beyond the face ends of the rotation wheel  14 , in the direction of a central axis of the actuation element  10 , whose position in the installed condition of the actuation element  10  in the handle  2  corresponds to the position of the main axis A of the handle. A toothing  16  is formed distally and a toothing  18  is formed proximally, on the face ends of the sleeve  12 . 
     In the handle  2 , the actuation element  10  is rotatably mounted about its central axis, i.e. about the main axis A of the handle, and in a limited region is displaceable in the direction of this central axis (see  FIGS. 8 and 9 ). As can be deduced from  FIG. 6 , the axial displacement path of the actuation element  10  in the distal direction is limited by a hub  20 , which is coupled in movement to the hollow shank  4 . A hub  22  which is coupled in movement to an actuation rod of the tool  6 , which rod is not shown in the drawings, limits the displacement path of the actuation element  10  in the proximal direction. The hub  20  and the hub  22  are each provided with a toothing. Thus, the hub  20  at its proximal end comprises a toothing  24 , and the hub  22  at its distal end comprises a toothing which is not evident from the drawings. 
     The actuation element  10  in  FIGS. 6 and 8  is represented axially displaced into a proximal end position. Here, it is the case of a first functional position of the actuation element  10 , in which the actuation element  10  is connected to the tool  6  in a rotationally fixed manner by engagement of the toothing  18  formed on the proximal side of the sleeve  12  into the toothing formed on the hub  22 , so that the tool  6  can be rotated by rotating the rotation wheel  14  relative to the hollow shank  4 . If the actuation element  10  is axially displaced in the distal direction, the toothing  16  formed distally on the sleeve  12 , in a second functional position of the actuation element  10  engages into the toothing  24  of the hub  20 . The actuation element  10  is connected to the hollow shank  4  in a rotationally fixed manner by this, so that the hollow shank  4  can be rotated by rotating the rotation wheel  14  relative to the handle  2 . 
     The handle  10  comprises an actuation lever  26  for the axial displacement of the actuation element  10 . This actuation lever  26  is pivotably mounted next to the hand grip  8 , on a bow  28  encompassing the rotation wheel  14  of the actuation element  10 . The actuation lever  26  is designed as a two-sided lever and comprises a first lever arm  30  and a second lever arm  32 , wherein the first lever arm  30  serves for the subsequently explained movement coupling the actuation lever  26  to the actuation element  10 , and the second lever arm  32  forms the operating part of the actuation lever  26 . 
     Three projections, which are arranged in a row directly next to one another and which are formed by rounded prominences  34 ,  36  and  38  (see  FIG. 6 ), are formed on the end of the first lever arm  30  of the actuation lever  26 , the end being away from the second lever arm  32 . Together, the prominences  34 ,  36  and  38  form a toothing. The sleeve  12  of the actuation element  10  in the section  12   a  distally of the rotation wheel  14  is surrounded by a ring  40 , which is rigidly connected to the sleeve  12 . Three grooves  42 ,  44  and  46 , which are arranged in a row directly next to one another and which each extend over the entire outer periphery of the ring  40 , are formed on the outer periphery of the ring  40 . The grooves  42 ,  44  and  46  in each case have a rounded cross-sectional contour which corresponds to the cross-sectional contour of the prominences  34 ,  36  and  38 , which are formed on the first lever arm  30  of the actuation lever  26 . The grooves  42 ,  44  and  46  form a toothing, which is engaged by the toothing formed by the prominences  34 ,  36  and  38  on the part of the actuation lever  26 . This is evident from  FIGS. 4, 6, 8, and 9 . 
     In  FIGS. 4, 6 and 8 , the actuation lever  26  is pivoted in the distal direction into an end position, in which the prominence  38  distally arranged on the lever arm  30  engages into the groove  46  arranged distally on the ring  40 . Here, the actuation element  10  is displaced as far as possible in the proximal direction, wherein the toothing  18  formed on the sleeve  12  engages into the toothing formed on the hub  22 . The actuation element  10  is connected to the hub  22  in a rotationally fixed manner by this, and is entailed by this in a rotationally fixed manner to the tool  6 . 
     If the actuation lever  26  is now pivoted in the proximal direction or in the direction of the grip part  8 , the prominence  38  disengages and, in the course of the displacement of the actuation element  10  in the distal direction, the prominence  36  engages into the middle groove  44  formed on the ring  40 . In this position, the actuation element  10  is neither coupled to the hub  22  nor to the hub  20 . 
     If one pivots the actuation lever further in the direction of the grip part  8 , the prominence  36  disengages and, in the course of the displacement of the actuation element  10  in the distal direction, the prominence  34  engages into the groove  42  formed proximally on the ring  40 . The toothing  16 , which is formed on the sleeve  12  of the actuation element  10 , now engages into the toothing  24  formed on the hub  20 , so that the actuation element  10  is connected to the hub  20  and thus to the hollow shank  4  of the medical instrument in a rotationally fixed manner ( FIG. 9 ). 
     As described, the actuation element  10 , due to the three prominences  34 ,  36  and  38  formed on the lever arm  30  of the actuation lever  26  and the three grooves  42 ,  44  and  46  which are formed on the ring  40  of the sleeve  12 , can be displaced by the actuation lever  26  into three functional positions, specifically a first proximal functional position, in which the actuation element  10  is coupled to the tool  6  in a rotationally fixed manner, into a second functional position in which the actuation element is neither coupled to the tool nor to the hollow shank  4 , and into a third distal functional position, in which the actuation element  10  is coupled to the hollow shank  4  in a rotationally fixed manner. 
     The handle  2  comprises a locking element  48  ( FIG. 7 ), in order to be able to fix the actuation element  10  in each of the three functional positions. The locking element  48  is arranged on a bow  50 , which surrounds the rotation wheel  14  of the actuation element  10  and which is arranged on the handle  2  lying directly opposite the bow  28 . The locking element  48  consists essentially of a screw  52  with a hollow shank, in which a locking body  54  is supported on a helical spring  56  designed as a compression spring. 
     The locking element  48  is screwed in a threaded bore  58 , which is formed on the bow  50 , is open to the actuation element  10  and extends normally to the main axis A of the handle  2 , radially in the direction of the section  12   a  of the sleeve  12 . In each of the three functional positions of the actuation element  10 , the locking body  54  of the locking element  48  diametrically opposite the actuation lever  26  engages into one of the grooves  42 ,  44  or  46  formed on the ring  40  of the sleeve  12 . 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the invention as defined by the appended claims.