Abstract:
In order to improve a surgical holding device for holding a surgical instrument, with a frame, with a first linkage comprising at least two links, which articulatedly connects the frame to a first articulation point associated with the instrument, and with a second linkage comprising at least two links, which articulatedly connects the frame to a second articulation point associated with the instrument, so that a large range of action of the surgical instrument held by the holding device is adjustable as simply as possible, it is proposed that the links of the first linkage be mounted for pivotal movement about pivot axes relative to one another and relative to the frame, and that the pivot axes extend parallel to one another.

Description:
[0001]     This application is a continuation of international application number PCT/EP2004/006209, filed on Jun. 9, 2004.  
         [0002]     The present disclosure relates to the subject matter disclosed in international application number PCT/EP2004/006209 of Jun. 9, 2004 and German application number 103 40 151.2 of Aug. 26, 2003, which are incorporated herein by reference in their entirety and for all purposes. 
     
    
     BACKGROUND OF THE INVENTION  
       [0003]     The invention relates to a surgical holding device for holding a surgical instrument, with a frame, with a first linkage comprising at least two links, which articulatedly connects the frame to a first articulation point associated with the instrument, and with a second linkage comprising at least two links, which articulatedly connects the frame to a second articulation point associated with the instrument.  
         [0004]     Such a holding device is known, for example, from US 2002/0038118 A1. This comprises two actuators rigidly connected to a base and two actuators movable relative to the actuators held on the base. The actuators held on the base comprise a translational drive. Translational drives have the disadvantage that they are relatively large and heavy, so that the fixed actuator must be of particularly stable construction. Furthermore, with the known device the two articulation points are only positionable within a very narrowly limited range, i. e., a radius of action of the surgical instrument is narrowly restricted.  
         [0005]     The object of the present invention is, therefore, to so improve a surgical holding device of the kind described at the outset that a large range of action of the surgical instrument held by the holding device is adjustable as simply as possible.  
       SUMMARY OF THE INVENTION  
       [0006]     This object is accomplished, in accordance with the invention, with a surgical holding device of the kind described at the outset in that the links of the first linkage are mounted for pivotal movement about pivot axes relative to one another and relative to the frame, and in that the pivot axes extend parallel to one another. In accordance with the proposed arrangement, all links are adjustable in their position relative to the frame, i. e., also a link held on the frame is mounted pivotably relative to the frame. In this way, the first articulation point is movable within a range of action which comprises a maximum area with a maximum side length, which corresponds to a total length of the links arranged one behind the other. The parallel arrangement of the pivot axes also enables a movement of the first articulation point in a plane.  
         [0007]     It is favorable for the links of the second linkage to be mounted for pivotal movement about pivot axes relative to one another and relative to the frame and for the pivot axes to extend parallel to one another. The second articulation point is thus movable in a simple way in a plane perpendicular to the pivot axes. The range of action of the second articulation point corresponds substantially to an area with a side length which corresponds to a length of the links of the second linkage arranged one behind the other.  
         [0008]     It is advantageous for the two linkages to be configured such that the first articulation point is movable in a first plane of movement and the second articulation point in a second plane of movement. Independently of a configuration of the two articulation points, movements of the two articulation points can thus be carried out and also monitored in a particularly simple way, for example, by the holding device being employed in combination with a navigation system.  
         [0009]     It is conceivable for the first plane of movement to be unchangeable relative to the second plane of movement. It is, however, advantageous for the first plane of movement to be movable relative to the second plane of movement. This makes it possible to keep the spacing between the two articulation points constant and to adapt a change in the spacing between the two articulation points, which is necessary when there is a change in the positions of the linkages.  
         [0010]     The construction of the device becomes particularly simple when the first plane of movement is pivotable relative to the second plane of movement.  
         [0011]     Furthermore, it is advantageous for a spacing between the first plane of movement and the second plane of movement to be alterable. In this way, a range of an angle of inclination of a longitudinal axis of the instrument relative to one of the pivot axes can be additionally enlarged.  
         [0012]     It is advantageous for the frame to comprise a first and at least a second frame element and for the first linkage to be arranged on the first frame element and the second linkage on the second frame element. Thus, for example, the holding device could be attached to two different stand elements, which, in particular, provides spatial advantages in the case of many surgical operations.  
         [0013]     For optimum adjustability of the arrangement, the first frame element can be mounted so as to be movable relative to the second frame element.  
         [0014]     The frame elements can be mounted directly on one another or arranged at locations separate from one another.  
         [0015]     A particularly simple construction of the device is obtained when the first frame element is pivotable about an axis of rotation relative to the second frame element. Such a pivotal mounting can be implemented in a simple way.  
         [0016]     Although it is conceivable to provide the axis of rotation at right angles or at an inclination to the two planes of movement, it is particularly advantageous for the axis of rotation to extend parallel to the two planes of movement. A pivotal movement of the two planes of movement relative to each other can thus be implemented in a simple way.  
         [0017]     It is favorable for the first frame element to be displaceable in a direction transverse to the first plane of movement relative to the second frame element. It is thus possible to change a spacing between the two frame elements, and a spacing between the two planes of movement is thereby also alterable. In turn, it is thus possible to bring about a necessary change in the spacing between the articulation points, which is required if the two articulation points are to be arranged at a fixed spacing from each other.  
         [0018]     In accordance with a preferred embodiment of the invention it can be provided that the first linkage comprises five links pivotable relative to one another in the first plane of movement. With five such mounted links, the first articulation point can be positioned in the desired manner in the first plane of movement.  
         [0019]     It is favorable for the five links of the first linkage to be connected to one another so as to form a closed first ring structure. This can be formed, for example, by each link comprising a first and a second end and by a first end of a link being connected to a second end of another link.  
         [0020]     For a particularly compact design of the device, it is advantageous for the first frame element to comprise one of the first five links of the first linkage. This means that two links are pivotably mounted on the first frame element.  
         [0021]     It is advantageous for the first articulation point to be associated with at least one of the links of the first linkage. It can, for example, be arranged directly on the link or be spaced from it by means of a further element. In any case it is favorable for a relative position of the first articulation point to remain constant relative to the at least one link of the first linkage.  
         [0022]     To achieve optimum positioning of the second articulation point in the second plane of movement, it is favorable for the second linkage to comprise five links pivotable relative to one another in the second plane of movement. It is thus also possible to construct particularly compact and elongated linkages. A length of the links can be varied in accordance with requirements.  
         [0023]     To obtain a particularly good guidance for the second articulation point, it is favorable for the five links of the second linkage to be connected to one another so as to form a closed ring structure. If, for example, the second articulation point is defined by a connection between two links, then the second articulation point is held and guided on both sides thereof.  
         [0024]     The device can be made of particularly compact design when the second frame element comprises one of the five links of the second linkage. Such an arrangement could, for example, be configured such that two of the five links are pivotably mounted on the second frame element.  
         [0025]     A defined positioning of the second articulation point is possible when the second articulation point is associated with at least one of the links of the second linkage. This could be a rigid association or an association which is alterable in its spacing.  
         [0026]     The device makes do without any additional joints when the pivot axes of the links of the first linkage extend at right angles to the first plane of movement.  
         [0027]     It is advantageous for the pivot axes of the links of the second linkage to extend at right angles to the second plane of movement. In this way, a movement of the second articulation point in the second plane of movement can be guided and its position held.  
         [0028]     In principle, it is conceivable to move the links of the two linkages into a desired position by hand. It is, however, advantageous for at least one link drive to be provided for moving at least one link, mounted on the frame, of one of the two linkages. This enables a positioning of the first articulation point independently of manual intervention by an operator. In this way, for example, a position of a surgical instrument in a sterile area can be altered without an operator having to intervene in the sterile area.  
         [0029]     To enable fully automatic adjustment of positions of the two articulation points in space, it is favorable for each of the two linkages to have two link drives associated with it. If all links of the linkage are connected to one another, this results, for example, in the case of five links, in a forced guidance of two non-driven links if the driven links are arranged on a fixed link.  
         [0030]     It is conceivable to use linear drives as link drives. It is, however, advantageous for the at least one link drive to be a rotational drive for pivoting the at least one link mounted on the frame relative to the frame. A particularly compact construction is thereby achievable for the device since the drive does not have to be integrated in the link. As a result, the links can be of particularly slim and light design. Moreover, rotary joint-type rotational drives have less play than linear drives.  
         [0031]     It is conceivable to arrange the link drive on a link. However, the at least one link drive is preferably arranged on the frame. It is thus possible to arrange the link drive outside an operating site, which significantly facilitates access to the operating site.  
         [0032]     In order to implement a robot-like holding device, it is advantageous for the link drives to be activatable independently of one another. In this way, the two articulation points can be brought independently of each other into any desired position that is adjustable with the device.  
         [0033]     It is conceivable to provide the two articulation points directly on the two linkages, for example, each on one respective link or each at one respective articulation point joining two links. It is, however, advantageous for each of the two linkages to carry a holding element and for each holding element to have one of the two articulation points associated with it. Thus, for example, a separation can be made in a simple way between a sterile area and a non-sterile area, which separate the holding element into two holding element sections, namely a sterile one and a non-sterile one. In addition, large distances between the linkage and the instrument can be set with the holding element.  
         [0034]     In order to vary a spacing between the instrument and the linkage, the at least one holding element can be detachably connectable to one of the links. In order to arrange the device, for example, partly in a non-sterile area, but to keep the instrument in a sterile area, each holding element can comprise a sterile interface. This makes it possible to arrange the holding element partly in the sterile area where it holds the instrument, and partly in the non-sterile area where the linkage and also any link drives can be arranged.  
         [0035]     The linkage is particularly compact when at least one of the two linkages comprises two intersecting links.  
         [0036]     The design of the device is particularly simple when the device comprises only rotary joints for moving the links and the articulation points relative to one another. Rotary joints are particularly easy to construct, are almost play-free and, for example, in combination also enable movement about more than only one degree of freedom.  
         [0037]     To allow almost optional adjustment of a position of the instrument, it is favorable for the first and/or second articulation point to comprise a joint with multiple degrees of freedom.  
         [0038]     It is advantageous for the joint with multiple degrees of freedom to be a ball-and-socket joint. A mounting of the instrument on the holding device by means of a ball-and-socket joint enables an almost optional orientation of a longitudinal axis of the instrument in space. In this way, the joint can also be of particularly compact design.  
         [0039]     It is favorable for the joint with multiple degrees of freedom to be in the form of a universal joint. Such a joint can be formed solely by rotary joints.  
         [0040]     If the two planes of movement are not displaceable relative to each other, it is favorable for the instrument to be held at at least one of the two articulation points so as to be displaceable. Spacings between the two articulation points can thus be optionally adjusted.  
         [0041]     In principle, the instrument could be held directly on the holding device. It is, however, advantageous for a guide to be provided for the instrument and for the two articulation points to be arranged on the guide. In this way, the guide can be positioned in space, and the instrument removed from it in a simple way. Furthermore, instruments can be exchanged particularly easily, namely by being removed from the guide and replaced by other instruments.  
         [0042]     The following description of preferred embodiments of the invention serves in conjunction with the drawings to explain the invention in greater detail. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0043]      FIG. 1  shows a perspective front view from above of a holding device according to the invention;  
         [0044]      FIG. 2  shows a perspective view of the holding device from behind;  
         [0045]      FIG. 3  shows a view from above of the holding device;  
         [0046]      FIG. 4  shows a side view of the holding device from  FIG. 3 ;  
         [0047]      FIG. 5  shows a plan view of a holding device with link positions changed with respect to one another;  
         [0048]      FIG. 6  shows a side view of the holding device from  FIG. 5 ; and  
         [0049]      FIG. 7  shows a second embodiment of a holding device according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0050]     A motor-driven platform for supporting equipment, which can be coupled as a module to various surgical holding systems, is generally designated by reference numeral  10  in FIGS.  1  to  6 . It comprises a two-part frame  12  with an upper frame half  14  and a lower frame half  16  mounted for pivotal movement about a frame pivot axis  18  relative to the upper frame half  14 . There is associated with each of the two frame halves  14  and  16  a five-member crank mechanism  20  and  22 , respectively. In the present embodiment, the crank mechanisms are of identical design. Furthermore, each of the two crank mechanisms  20  and  22  carries an articulation point  24  and  26 , respectively, at which a surgical instrument  28 , for example, in the form of a milling tool or an optical endoscope, is held.  
         [0051]     The upper frame half  14  comprises a main body  30  of rectangular parallelepiped construction having on one of its narrow long sides a longitudinal groove  32  arranged in parallel with a top side  34  of the main body  30 . Protruding at right angles from an underside  36  of the main body  30  are two bearing bolts  38 , each of which is provided with a bore  40 .  
         [0052]     The lower frame half  16  comprises a main body  42 , likewise of rectangular parallelepiped construction, from the top side  44  of which there protrudes at right angles a bearing bolt  46 , likewise having a bore  48 . The bearing bolt  46  is inserted between the two bearing bolts  38  and is held between these two so as to be immovable in the direction of the frame pivot axis  18 . For this purpose, a cylindrical bearing shaft  50  is inserted in the bores  40  and  48  and rotationally fixedly connected to the bearing bolts  38 . A longitudinal groove  52  arranged parallel to the underside  54  of the main body  42  is open in a direction away from a narrow long side surface of the main body  30 .  
         [0053]     In a position of the frame half  14  relative to the frame half  16 , in which the top side  34  extends parallel to the underside  54 , both longitudinal grooves  32  and  52  are aligned parallel to each other and facing in the same direction.  
         [0054]     The crank mechanism  20  comprises a first link which is formed by a groove side wall  56  of the longitudinal groove  32 . In the longitudinal groove  32 , at one end thereof, a flat rectangular link  62  is arranged between the groove side wall  56  and a groove side wall  58  for pivotal movement about an axis of rotation  60  extending at right angles to the top side  34 . By means of a rotational drive  64  the link  62  is pivotable around the axis of rotation  60 , the rotational drive  64  also being arranged rotationally symmetrically in relation to the axis of rotation  60  on the underside  36 .  
         [0055]     In the longitudinal groove  32  at its other end there is arranged between the groove side walls  56  and  58  a second rotational drive  66 , which drives an elongated rectangular link  70  mounted for pivotal movement about an axis of rotation  68  extending at right angles to the top side  34 . A free end of the link  62  is articulatedly connected for pivotal movement about an axis of rotation  74  to a further elongated rectangular link  72 , which is somewhat shorter than the link  62 . A free end of the link  72  engages around a joint ball  76 . A free end of the link  70  is articulatedly connected for pivotal movement about an axis of rotation  78  to a fifth link  80 , which has an end engaging around the joint ball  76 . The five-member crank mechanism  20  thus comprises a total of five links, namely the groove side wall  56  and the links  62 ,  72 ,  80  and  70 .  
         [0056]     The second five-member crank mechanism  22  comprises as stationary link a first groove side wall  82 , facing in the direction towards the upper frame half  14 , of the longitudinal groove  52 , which also has a lower groove side wall  84 . At one end of the longitudinal groove  52  there is arranged between the groove side walls  82  and  84  symmetrically with an axis of rotation  88  a rotational drive  86  which serves to drive an elongated link  90  of rectangular parallelepiped construction, which is mounted at the groove side wall  82  for pivotal movement about the axis of rotation  88 . Between the two groove side walls  82  and  84  at another end of the longitudinal groove  52 , there is mounted a further elongated link  92  of rectangular parallelepiped construction for pivotal movement about an axis of rotation  94 . The link  92  is driven by a fourth rotational drive  96  which is arranged symmetrically with the axis of rotation  94 . A free end of the link  90  is mounted on a somewhat shorter, elongated link  98  of rectangular parallelepiped construction for pivotal movement about an axis of rotation  100 . A free end of the link  98  engages around a joint ball  102  of the articulation point  26 . A free end of the link  92  is connected for pivotal movement about an axis of rotation  104  to a link  106 , which has a free end engaging around the joint ball  102 . In the area of the articulation point  26 , the two links  90  and  106  therefore define a further axis of rotation  108 , in the same way as the two links  72  and  78  define a common axis of rotation  110  in the area of the articulation point  24 .  
         [0057]     Each of the links  62 ,  70 ,  90  and  92  can also be optionally driven directly by a drive worm which is not illustrated.  
         [0058]     The instrument  28  is held at the two articulation points  24  and  26  in a rotationally fixed manner at the joint balls  76  and  102 . Rotation of a shaft  112  of the instrument  28  about a longitudinal axis  118  is possible as the joint balls  76  and  102  are mounted in a freely rotatable manner on the links  72 ,  80  and  98 ,  106 , respectively.  
         [0059]     Each crank mechanism  20  and  22 , respectively, comprises two intersecting links, namely links  62  and  70  in crank mechanism  20  and links  90  and  92  in crank mechanism  22 .  
         [0060]     The crank mechanism  22  is of five-member construction and comprises the groove side wall  82  and links  90 ,  98 ,  106  and  92 .  
         [0061]     The axes of rotation  60 ,  74 ,  110 ,  78  and  68  of the crank mechanism  20  are all orientated parallel to one another and perpendicularly to the top side  34  of the upper frame half  14 . The axes of rotation  88 ,  100 ,  108 ,  104  and  94  are likewise aligned parallel to one another and at right angles to the underside  54  of the lower frame half  16 . Consequently, the articulation point  24  can be moved in a first plane  114  and the second articulation point  26  in a second plane  116  by means of the two crank mechanisms  20  and  22 , respectively.  
         [0062]     The link  62  is freely pivotable by means of the rotational drive  64 . In the same way, the link  70  is pivotable by means of the rotational drive  66 . As free ends of the links  72  and  80  are connected to one another for pivotal movement about the axis of rotation  110 , a forced guidance results for the articulation point  24 . The more parallel the links  62  and  70  become aligned to each other, the further does the articulation point  24  move away from the frame  12 . If, as shown in FIGS.  1  to  6 , the two crank mechanisms  20  and  22  are of identical design, and if they are initially identically adjusted in their relative positions, then the longitudinal axis  118  of the shaft  112  initially runs parallel to the axis of rotation  110 . This position is shown in  FIGS. 3 and 4 .  
         [0063]     If the crank mechanism  22  remains unchanged, but the links  62  and  70  are pivoted relative to each other, so that the axes of rotation  74  and  78  move closer together, then the articulation point  24  is moved away from the frame  12 . As a result, the longitudinal axis  118  of the shaft  112  tilts relative to the axis of rotation  110 . As the distance between the joint balls  76  and  102  is fixedly predetermined and, therefore, constant because the shaft  112  is rotationally fixedly connected to the joint balls  76  and  102 , the frame half  14  tilts relative to the frame half  16  by pivoting about the frame pivot axis  18 .  
         [0064]      FIG. 7  shows a slightly modified platform for supporting equipment, which is generally designated by reference numeral  10 ′. Two crank mechanisms  20 ′ and  22 ′ are held in the above-described manner on a frame  12 ′. From the link  80 ′ there protrudes at an incline a two-part spacer, generally designated by reference numeral  120 ′, and in a similar way a spacer  122 ′ from link  106 ′. The spacers  120 ′ and  122 ′ are in the form of elongated bars which are joined to each other at approximately the center by a two-part plug connection comprising a plug  124 ′ and a socket  126 ′. A sterile foil  128 ′, which separates a sterile area  130 ′ from a non-sterile area  132 ′, is clampable between the plugs  124 ′ and the sockets  126 ′. Free ends of the spacers  120 ′ and  122 ′ carry the articulation points  24 ′ and  26 ′ which are defined by bearing rings  134 ′ held at a free end of the spacers  120 ′ and  122 ′ and joint balls  76 ′ and  102 ′ surrounded by bearing rings  134 ′. The shaft  112 ′ of the instrument  28 ′ is rotationally fixedly connected to the joint balls  76 ′ and  102 ′.  
         [0065]     The instrument  28 ′ can be held in a desired setting and position in a sterile area  130 ′ by means of the platform  10 ′ for supporting equipment. In this case, the crank mechanisms  20 ′ and  22 ′ are located in a non-sterile area, which may also be outside an operating site.