DE202004015645U1 - Surgical device in particular suitable for removal of bone tissue, comprising two hydraulic cylinders with differently effective cross sections - Google Patents

Abstract

The device is assembled of an operating handle (12) and a tool (14) attached to the front of the handle (12). The tool (14) comprises a stationary (18) and a movable shaft (36) sliding along the stationary shaft (18), gripping and removing bone tissue (54) with the combined gripping and cutting area (20, 38) at the front. A linear drive comprising preferably two hydraulic cylinders (98, 100) with differently effective cross sections facilitates the use of the tool (14) by applying different degrees of force as required by the particular task.

Description

The The present invention relates to a surgical instrument comprising a handling part and a tool part, the tool part at least comprises a movably mounted tool which over a Power transmission and / or Actuating mechanism which can be operated from the handling part, can be operated, and that the Power transmission and / or actuation mechanism comprises a drive unit operable with a fluid.

surgical Instruments of the type described in the introduction are known, for example in the form of bone punches for removing bones, cartilage or such tissue. A disadvantage of the known bone punches it that through the drive unit, which can be operated with a fluid, is the movably mounted one Tool only to a limited extent or even at all not sensitive actuated is. reason for that is that the Drive unit either with a fluid flow of certain pressure can be applied or not. However, this has the disadvantage Consequence that in In case of an actuation of the operating mechanism the instrument usually suddenly from a rest or starting position in a working position is transferred or the other way around. This can have the consequence that, for example, with a Bone punch not a desired one Tissue area, but an adjacent one is removed.

It is therefore an object of the present invention, a surgical To improve the instrument of the type described in the introduction so that it operates as sensitively as possible can be.

This The task is described in the case of a surgical instrument Kind according to the invention solved, that with the drive unit in a first drive position the movably mounted Tool can be loaded with a first actuating force and in at least a second drive position with at least a second actuating force is acted upon.

The Training according to the invention Known surgical instruments has the advantage that an operator the instrument in use more sensitive can operate. Especially when the first operating force from the second actuating force differs, for example, the tool in the first drive position be subjected to a force that is insufficient, for example at a bone punch to cut tissue, but at most to bring the tool to the tissue. This allows the surgeon to the instrument in the desired Position and only then the instrument in the second To transfer drive position in which the tool occupies a working position in which it can cut tissue, for example.

Advantageous it is when with the drive unit in a third actuation position the movably mounted tool with a third actuating force is acted upon. This allows the surgeon to still use the instrument sensitive operate because it has three different operating forces, for example the movably mounted tool through the power transmission and / or actuation mechanism exercise can.

Preferably corresponds to the third actuating force the sum of the first and second actuating forces. This allows the drive unit, for example, with two fluid piston units to train, each of which can assume two drive positions. So In particular, the structure of the drive unit is significantly simplified.

advantageously, there is a relationship the first and second actuating forces in the range from 4: 1 to 9: 1 first drive position a force of about 10 to 20 percent of the maximum force available from the drive unit on the transfer moving tool becomes. This force is sufficient for a bone punch, for example not enough to separate tissue to be removed.

The Structure of the instrument is further simplified if the drive unit comprises a linear drive. This could parallel to the longitudinal direction be arranged, but it is preferably relative to the longitudinal direction arranged inclined. This way he can be within one handle of the handling part are arranged. So the instrument can be special be compact and handy, for example with a Handling part in the form of a pistol grip.

Around To be able to completely do without an electrical power supply it cheap if the linear drive comprises at least one fluid cylinder. fluid cylinder are particularly low-maintenance and generally have a long service life.

In order to design the linear drive completely on the basis of fluid cylinders, it is advantageous if the linear drive comprises two coupled, separately controllable fluid cylinders. This allows one fluid cylinder to be acted upon by a fluid for generating a driving force independently of the other fluid cylinder. In the same way, however, both fluid cylinders can be acted upon with a fluid at the same time, so that a total of three active drive positions can be predetermined. Neither of the two fluid cylinders will have a fluid to generate a driving force, the instrument takes a rest position. This position is not referred to below as the drive position.

Around specify three different actuation forces to be able it is advantageous if the two fluid cylinders are different Have cross sections. If their cross sections are identical, then can either none, half or full of the drive unit available driving force can be generated. Differ however, the cross sections so a first driving force can be smaller than 50 percent of the maximum force. The second driving force corresponds then the difference between the first and the maximum force and is therefore greater than the half the maximum force.

drive positions with in particular 10 to 20 percent of the maximum force, 80 to 90 percent the maximum force and the maximum force can be specified if a relationship the cross sections are in a range from 4: 1 to 9: 1.

advantageously, the at least one fluid cylinder is a pneumatic and / or hydraulic cylinder. A pneumatic cylinder can be operate with compressed air, for example, as is usually the case in every operating room to disposal stands. This also has the advantage that it is not completely sealed In principle, the system is still operational. Since only air comes out can escape the system, this leads no impairment of a patient. this could at most be the case if hydraulic cylinders are used with an incompatible Fluid and there is a leak in the drive system.

According to one preferred embodiment of the Invention can be provided that the at least one fluid cylinder is a double acting fluid cylinder. This allows one Piston of the at least one fluid cylinder from one side with a Apply fluid to generate a desired driving force. In the opposite direction a fluid can also be applied to the piston in order to to move the instrument back to a starting position and / or to keep it in the starting position. The starting position can be chosen for an instrument, for example, that this movably mounted tool assumes an open position, that is from the Starting position by applying an actuating force is transferred to a working position in which it performs a function for example, cuts or holds tissue.

Advantageous it is to operate the instrument as a bone punch when it is is designed to remove bone, cartilage or the like Tissue, with a shaft extending in a longitudinal direction, which at its distal end is arranged transversely to the longitudinal direction or relatively contributes to this inclined cutting plate when the movably mounted Tool is a cutting element slidably mounted on the shaft, which is at its distal end towards the insert pointing cutting edge, which can be brought up to the cutting plate is for cutting tissue.

Especially It is advantageous if the tool part with the handling part solvable is connectable. This is particularly easy if at the proximal end a first coupling element of the shaft is arranged for detachable, positive connection with the power transmission and / or actuation unit, which is a second coupling element corresponding to the coupling element and if the first coupling element is a polygon, whose outer surfaces by a longitudinal axis of the shaft radially outwards point. A polygon can be particularly easy to manufacture and also allows the handling part on the tool part in a variety of discrete rotational positions around the longitudinal axis to arrange the shaft. A number usually corresponds to the potential Rotation positions of the number of outer surfaces of the polygon.

Four or six defined rotational positions can be specified, if the polygon is a square, a hexagon or an octagon is. Furthermore, the configuration as a polygon is suitable for ensuring that only for the Handling part approved tool parts with the handling part can be connected. The coupling element thus also forms a kind of coding element for Coding a certain type of tool part.

Is cheap it if the shaft is sleeve-shaped at its proximal end and if that Cutting element the sleeve-like Penetrated end of the shaft. The structure of the shaft is so special simple. In addition, the sleeve-like end forms a guide of the shaft longitudinal for the Cutting element.

In order to be able to connect the cutting element to the force transmission and / or actuation mechanism in a simple manner, it is advantageous if it carries at its proximal end a third coupling element which can be detachably connected to a drive element of the force transmission and / or actuation mechanism and if it engages with the Connect the third coupling element in the longitudinal direction of the shaft stops. For example, the drive element can engage between the stops acting in the longitudinal direction of the shaft or, if the third coupling element is in the form of a Is formed protrusion, encompass the lateral stops on the coupling element or even encompass the coupling element. A secure connection and transmission of the driving force from the force transmission and / or actuation mechanism to the cutting element can thereby be achieved.

Is cheap it, when the instrument is at rest, in which with the power transmission and / or actuation mechanism no actuation force in one direction of actuation exerted on the tool with which power transmission and / or actuation mechanism in one of the direction of actuation opposite holding direction a holding force on the tool is exercisable. Without actuation of the power transmission and / or actuating mechanism this ensures that Instrument always takes the rest position. It is therefore located always in a defined starting position in front of a surgical one Commitment. Also, it cannot be caused by the holding force exerted unintentional handling, i.e. holding the instrument in such a way that this movably mounted tool oriented parallel to the direction of gravity is to be moved due to the action of gravity.

Advantageous it is when the power transmission and / or actuation mechanism an actuator comprises to operate the drive unit when the actuator is in an unactuated initial position, in which the instrument assumes the rest position, can be brought into an activation position is in which the drive unit assumes the first drive position and can be brought into at least a second activation position, in which the drive unit assumes the second drive position. This allows an operator to place the instrument in the desired position To operate wisely, namely outgoing from the unactuated Starting position the actuator to transfer into a first activation position to the movably mounted tool for example, to apply a small driving force. But it can also be the actuator so operate that this a movably mounted tool is subjected to a maximum force. The actuator can, but must not necessarily be made in one piece. It would be conceivable that actuator in particular to share, for example to separate two fluid cylinders to be controlled, for example by two independent control valves, which an operator, similar like a trumpet player, independent can operate from each other.

Around to show the operator in which position the instrument is it is convenient if the actuator is resiliently biased in the starting position. To this Sage knows one Surgeon whenever he picks up the instrument so that it is not actuated.

On Particularly simple construction of the instrument is achieved if that Swivel actuator is stored. In particular, storage about a pivot axis parallel or transverse to the longitudinal direction of the instrument.

According to one another preferred embodiment The invention can provide that in the first activation position a first restoring force on the actuator acts in the second activation position acts a second restoring force and that the second Restoring force larger than the first restoring force is. This way one gets one Operator provides tactile feedback on an actuation position or activation position of the actuator. For example the driving force in the first drive position is less than that Driving force in the second drive position, so the surgeon this through the actuator communicated indirectly. Without having to look at a scale, can a surgeon feel which drive position and thus which drive force on the movable stored tool exercised becomes.

Around to be able to clearly differentiate between the two activation positions it cheap if the second restoring force at least twice the size the first restoring force is.

Especially restoring forces can easily be generated, if a resetting unit for generating the first and second resetting force comprising a first elastic return member and a second elastic reset element is provided. A desired restoring force can thus be assigned to each drive position are selected by selecting a specific elastic return member.

conveniently, the first and / or the second reset element is a spring element. For example, in the form of a coil spring, a reliable reset element can be used to be provided.

Advantageous it may also be the case if the reset unit directly or indirectly to a control element for controlling the drive unit or on the actuator is acting. So the structure of the instrument continues simplified, which allows a particularly compact structure.

According to a preferred embodiment of the invention, a control element can be provided for controlling the drive unit and that the actuating element acts directly or indirectly on the control element. Such an embodiment is particularly advantageous when an actuating circuit and a working circuit are not operated with the same form of energy. For example, a Circuit electrically, another operated by a pressurized equipment, such as a fluid. This requires a conversion of control signals, for example electrical or mechanical, into specific fluid flows or electrical signals for the drive unit.

Especially The structure of the instrument becomes simple if the control element is at least includes a control valve. The control valve can, for example, be electrical, electronic or mechanically operated his. this makes possible to provide a mechanical, electrical or electronic actuator.

Around to be able to implement three different drive positions it cheap if the at least one control valve is at least three different Has switching positions. For example, a rest position of the instrument and a first and a second drive position can be realized in which a first and a second actuating force can be exercised on the movably mounted tool.

Advantageous it is when the control valve has a valve tappet, if at least on the valve body one connection connectable to a fluid source and two for each double-acting fluid cylinder connections are provided if at least in a first position of the valve lifter one of the fluid cylinders can be charged with fluid in a holding direction is when at least one of the fluid cylinders on both sides in a second position of the valve lifter with different fluid flows can be acted upon and if at least in a third position of the valve lifter one of the fluid cylinders against the holding direction with a fluid is acted upon. At least through the two-sided exposure one of the fluid cylinders in the second position of the valve lifter can a particularly smooth transition from the first to the second and then also to the third position of the valve lifter. In particular, it is possible with such a control valve one or more double-acting To apply a holding force to the cylinder in a second Position one of the fluid cylinders with a fluid flow against the Holding direction to apply a first, small actuating force generate, and finally in the third valve position several or all fluid cylinders with to apply a fluid to a maximum driving force produce.

Around preferably three different driving forces To be able to generate with the drive unit, it is favorable if in the second position of the valve lifter, a fluid flow on the at least two connections of a fluid cylinder is distributed unevenly. This will at least a fluid cylinder defined with a certain force difference moves in a predetermined direction and so either a holding force or generates a driving force.

Advantageous it is when the valve lifter with a A plurality of annular grooves is provided and in a valve body different switching positions defined different annular spaces, their cross-sectional relationships dependent on of a fluid pressure are matched to one another such that in the second switching position only a fraction of a maximum actuation force through which at least one fluid cylinder can be generated. Basically, it would be conceivable operate only a single fluid cylinder with a control valve, being a double-acting in different switching positions of the control valve Fluid cylinders with different pressure differences on both Sides of its piston is applied to make it different driving forces to create. The design of the valve lifter in the manner described is easy to manufacture. In addition, desired driving force ratios can be easily achieved pretend.

conveniently, At least two control valves are provided, each with at least one two switch positions. This way you can also do it overall Define four switch positions, one of which is a rest position. Two Control valves have the advantage that either none, one of both or both can be pressed at the same time. As a result, an operator knows also immediately what drive position the instrument is in.

advantageously, the at least two control valves can be operated manually separately. An operator can feel or feel in which drive position the instrument is in place.

Is cheap it if at least one coding unit is provided on the tool part is for coding the type and / or the type of the tool part and if a decoding unit is provided on the handling part for Decode the type and / or type of the tool part. By a Coding of the tool part can be the handling part, for example be set so that a maximum force that can be generated by the drive unit is limited. In particular then when sensitive tool parts are used, so damage to the Tool part can be prevented. Furthermore, the coding prevents using only approved tool parts can be connected to the instrument.

According to a preferred embodiment of the invention it can be provided that the at least one coding unit has no or at least one protrusion protruding on the tool part or at least one off arranged on the tool part Acceptance comprises that the decoding unit comprises an operating mode switching element corresponding to the at least one projection or the at least one recess, that the operating mode switching element has at least a first and a second operating mode position and that the operating mode switching element assumes one of the at least two operating mode positions in accordance with the coding of the tool part. For example, a fluid flow or an energy supply to the drive unit can be limited in some other way by the operating mode switching element in order to avoid damage to the tool part.

It is therefore advantageous if the at least two operating modes maximum operating forces of the Drive unit are assigned. For example, in a first Operating mode setting a maximum driving force of the drive unit are generated, however, in a second operating mode only a reduced driving force, for example only one driving force, which corresponds to approximately 80 to 90 percent of the maximum force.

Is cheap it when the operating mode switching element is coupled to the control element and when the operating mode switching element is in at least one operating mode position at least one switching position of the control element directly or indirectly except Power. For example, the operating mode switching element can be such be built that it mechanically or in terms of control technology prevents the control element into a switching position is brought, in which a maximum force with the drive unit to operate of the movable tool can be generated.

The The following description of a preferred embodiment of the invention is used in connection with the drawing of the detailed explanation. Show it:

1 : a longitudinal sectional view through a bone punch in an unactuated position;

2 : an enlarged view of the handle part of the instrument in 1 ;

3 : a partial enlargement of an in 2 illustrated switching valve;

4 : a view similar 2 the instrument in a first working position;

5 : a view similar 3 , but in the first working position;

6 : a view similar 2 in a second working position; and

7 : a view similar 3 , but in the second working position.

In the 1 to 7 A surgical instrument according to the invention is shown in the form of a bone punch, all of which is identified by the reference symbol 10 is provided. The bone punch 10 comprises two essential assemblies, namely a handle part 12 and one with the reference symbol 14 stamping tool provided.

The punching tool 14 includes one in a longitudinal direction 16 extending elongated shaft 18 which at its distal end is about 45 ° from the longitudinal direction 16 inclined insert 20 wearing. A proximal end of the shaft forms a coupling piece 22 , which is in the form of a square, elongated cuboid with a chamfered longitudinal edges. The coupling piece 22 is with the longitudinal axis 16 defining through hole 24 Mistake. It is also somewhat spaced from the proximal end of the shaft 18 on the coupling piece 22 a groove-like depression extending in the circumferential direction 26 formed, a bottom of the recess a square 28 forms. It serves as the first coupling element for connecting the punching tool in a rotationally secure manner 14 with the handle part 12 , One on the proximal side of the square 28 subsequent side wall 30 the deepening 26 forms a stop acting in the distal direction. One on the distal side of the depression 26 subsequent side wall 32 forms a stop acting in the proximal direction.

Distal side of the depression 26 are on the coupling piece 22 four identical securing holes 34 formed in the radial direction based on the longitudinal axis 16 to the through hole 24 through the coupling piece 22 extend through. Furthermore, the cuboid coupling piece tapers 22 distal side in diameter and has an essentially round sleeve-like shape at its end.

The punching tool 14 includes a punch 36 , which at its distal end is opposite the longitudinal axis 16 at the same angle as the insert 20 inclined cutting edge 38 wearing. The punch 38 lies essentially flat over its entire length on a shaft surface 40 of the shaft 18 on. The punch penetrates on the proximal side 36 the through hole 24 of the coupling piece 22 , In this area, the distal side is essentially cuboid in cross section 36 cylindrical shape. At the cylindrical section of the punch 36 a square, plate-shaped flange closes on the proximal side 42 which has a square coupling on the distal side 44 limited and forms a stop acting in the proximal direction.

At the coupling square 44 closes, one end of the punch 36 forming a square end plate 46 which forms a stop acting in the distal direction. The flange 42 also forms a stop acting in the distal direction, which at the proximal end of the coupling piece 22 strikes when the cutting edge 38 takes its most distal position, i.e. on the cutting plate 20 is applied.

To stabilize movement of the punch 36 relative to the shaft 18 is in addition to that through the coupling piece 22 trained guide at the distal end of the shaft a guide groove 48 arranged, which is from the shaft surface 40 expanded in cross section. In the guide groove 48 is one on the punch 36 protruding lead 50 led, which is parallel to the longitudinal axis 16 starting from the distal end of the punch 36 extends in the proximal direction. The lead in leadership 50 and the guide groove 48 are designed to be essentially corresponding, for example they can have a dovetail shape.

The punch 36 is starting from the cutting edge 38 with a blind hole-like, parallel to the longitudinal axis 16 extending recess provided as tissue storage 52 for with the bone punch 10 removed tissue. Fabric punched out with the cutting edge 54 through a distal opening 56 of tissue storage 52 pushed into this and with further punching out of tissue 54 advanced in the proximal direction, that is in the direction of arrow A in 1 , In the embodiment shown in the figures is for emptying the tissue storage 52 on the punch 36 an emptying opening 58 provided, which through an oblique to the longitudinal axis bore of the punch 16 is formed, which is a fluid connection between the tissue storage 52 and an environment of the punch 14 manufactures. Punched out and in the tissue storage 52 stored tissue 54 can through the drain opening 58 be given to the outside world. In an alternative, not shown embodiment of the invention can in the punch 36 an ejector in the form of a parallel to the longitudinal axis 16 Slidable rod can be provided with which starting from the proximal end of the tissue storage 52 tissue stored in this 54 distally through the opening 56 can be pushed out.

The handle part 12 the bone punch 10 is essentially in the form of a pistol grip-like housing. It includes one parallel to the longitudinal axis 16 extending, elongated cuboid upper housing part 60 , which has a distal opening 66 has and an essentially elongated, cuboid-shaped receiving space 64 for the coupling piece 22 of the shaft 18 forms. It is transverse to it and slightly inclined in the proximal direction from the upper housing part 60 a handle 62 from.

The upper part of the housing 60 includes a sliding lid 70 which is parallel to the longitudinal axis 16 by means of two guides in the form of rib-like projections on both sides in longitudinal grooves per se parallel to the longitudinal axis 16 extending sidewalls 72 of the upper part of the housing 60 is led. The sliding cover covers in its most distal position 70 the recording room 64 completely, in its most proximal position, it gives the receiving space 64 predominantly free, so that an insertion opening is formed through which the coupling piece 22 in the recording room 64 in a direction transverse to the longitudinal axis 16 in the recording room 64 can be inserted.

On the inside of the side walls 72 there are two mutually opposite coupling projections forming a second coupling element 74 from. They are essentially in the form of flat cuboids, the dimensions of which are chosen so that the two coupling projections 74 between the side walls 30 and 32 into the recess 26 can immerse and essentially on the square 28 issue. This will make the punch 14 axially on the handle 12 established.

How particularly good in the 3 and 4 the coupling projections can be seen on the distal side 74 the upper housing part 60 on its underside with a cup-shaped depression open at the bottom 68 provided to the recording room 64 through a hole 76 connected is. The deepening 68 is from the recording room 64 pointing away from the outside with a disc 78 provided, which forms a radially inwardly projecting flange. The deepening 68 is used to hold a safety button 80 which one the hole 76 penetrating cylindrical bolt 82 which includes a head 84 wearing, being in the transition area between the head 84 and the bolt 82 a radially outward ring flange 86 is trained. Adjacent to the hole 76 is supported in the recess, the bolt 82 surrounding a coil spring 88 starting with your other end at the bottom of your head 84 is applied. This will make the ring flange 86 in a basic or rest position, as in the 1 and 3 is shown against the disc 78 pressed. Against the action of the coil spring 88 can the safety button 80 towards the recording room 64 be moved like this in 4 is indicated by the arrow E. The safety button 80 is also arranged so that it is in the recording room 64 inserted coupling piece 22 in the basic position, in which the coil spring 88 the ring flange 86 against the pane 78 presses the securing hole 34 essentially fills in a form-fitting manner. The safety button 80 can with inserted coupling piece 22 however only in the direction of the recording room 64 be moved when the the cylindrical part of the through hole 24 penetrating punch 14 circumferential annular groove 90 with the safety holes 34 overlapped in the radial direction. This is how in 1 shown, then the case when the punch 14 relative to the shaft 18 takes its most proximal position, that is, when the distance between the cutting edge 38 and the cutting plate 20 is maximum. Will the safety button 80 then pressed, a front end of the pin dips 82 , as in 4 shown in the ring groove 90 a, causing movement of the punch 14 parallel to the longitudinal axis 16 is prevented.

One overall with the reference symbol 92 provided pneumatic drive device is essentially in or on the handle 62 arranged. The drive device 92 includes one on a distal side of the handle 62 , directly below the upper part of the housing 60 arranged and about a transverse to the longitudinal axis 16 pivoting operating lever 94 , one with the operating lever 94 actuatable switching valve 96 and a drive unit, which has a first pneumatic cylinder 98 and a second pneumatic cylinder 100 includes.

The two pneumatic cylinders 98 and 100 are each double-acting, the first pneumatic cylinder 98 a cylindrical piston chamber 102 comprises, in which one by means of two sealing rings 104 sealed piston 106 parallel to the axis of symmetry of the piston chamber 102 is movable. The piston chamber 102 is in the same way as the handle 62 somewhat opposite the longitudinal axis 16 inclined. From the piston 106 stands a piston rod 106 towards the recording room 64 pointing away, which in a piston bore 110 which is the piston chamber 102 with the recording room 64 combines. A piston room 112 connects directly to the piston chamber 102 with a slightly larger inner diameter. In this is a displaceably mounted piston 114 by means of two sealing rings 116 sealed and via a piston rod 118 directly with the piston 106 connected. The two pneumatic cylinders 98 and 100 thus form an overall rotationally symmetrical piston-cylinder unit. The piston rooms 102 and 112 are through a sealing washer 120 separated from the piston rod 118 is enforced. Each of the two pneumatic cylinders 98 and 100 is provided with two connections X and Y through which the pistons 106 and 114 can be pressurized with compressed air. The connections X are each on one of the receiving space 64 groundbreaking end of the respective piston chamber 102 or 112 arranged so that the pistons 106 and 114 when compressed air is applied through connections X in the direction of arrow B in 1 be moved. The ports Y are at the other end of the two piston chambers 102 and 112 arranged so that by pressurizing the piston 106 and 114 the pistons via the Y connections 106 and 114 are moved in a direction opposite the arrow B.

To the piston rod 108 closes in the direction of the recording room 64 indicating a cuboidal extension 122 which is transverse to the longitudinal axis 16 and to the longitudinal axis of the piston rod 108 drive pin protruding on both sides 124 wearing. Parallel to the drive pin 124 runs in the transition area of the upper housing part 60 to the handle 62 a bearing shaft 126 arranged to support an L-shaped angle lever 128 serves. A first lever arm 130 of the angle lever 128 points essentially towards the receiving space 64 a second lever arm 132 is essentially parallel to the recording room 64 aligned in the proximal direction.

Free ends of the two lever arms 130 and 132 are each in the direction of the bearing shaft 126 parallel to a plane of symmetry of the bone punch 10 slotted so that the free ends are each U-shaped. The angle lever 128 is arranged such that the slotted free end of the first lever arm 130 , which is in the form of two disc-shaped drivers 134 is formed, the square coupling 44 between the flange 42 and the end plate 46 encompasses on both sides, but not laterally over the flange 42 and the end plate 46 protrudes. The first lever arm 130 is also like this to the drivers 134 tapered that only this abuts the flange 42 and the end plate 46 can come. The slotted end of the second lever arm 132 is with a slot-like slot 136 provided and surrounds the extension 122 , with the drive pin 124 into the slots 136 immersed and guided in it.

The second lever arm 132 is about twice as long as the first lever arm 130 , The angle lever thus forms 128 on the one hand a force deflection unit of a driving force, which in the direction of arrow B in 1 from the pneumatic cylinder 98 and 100 can be generated in a parallel to the longitudinal axis 16 running drive direction, which is indicated by the arrow C in 1 is symbolized. At the same time, the angle lever forms 128 also a transmission unit with which the driving force generated by the piston-cylinder unit due to the length ratio of the lever arms 130 and 132 is doubled.

To control the pneumatic cylinders 98 and 100 serves the switching valve 96 which is in the area of one of the recording room 64 pointing the way 63 of the handle 62 in a parallel to the second pneumatic cylinder 100 trending, elongated cylindrical cavity 137 is arranged and one of the actuator 94 actuable, parallel to the piston 106 and 114 sliding plunger 138 includes. The switching valve 96 is formed rotationally symmetrical overall, the plunger 138 one the switching valve 96 penetrating, elongated cylindrical plunger body 139 having. One towards the operating lever 94 pointing end of the plunger 138 forms a plunger tip with reduced diameter in one step 162 which one the cavity 137 on an inner face 164 penetrating hole 166 interspersed and right at one end 63 indicative operating area 95 of the operating lever 94 is applied. The hole 166 is smaller in diameter than an outer diameter of the tappet body 139 , so that the end face forming an inner ring surface 164 a stop for the tappet body 139 forms.

One from the actuator 94 pointing end of the tappet body 139 is with one towards the end 63 open blind hole 140 provided so that this end of the plunger body 137 is designed like a sleeve. At one towards the end 63 pointing blind hole bottom 141 of the blind hole 140 a coil spring is supported 142 from.

The cavity 137 Filling out over its entire length is a sleeve-like valve insert 168 used, which from the plunger body 139 is penetrated along its axis of symmetry. The valve insert 168 is adjacent to its end 63 pointing end with a short male thread section 170 provided, which corresponds to a short internal thread section 172 adjacent to the end 63 pointing end of the cavity 137 is trained. The valve insert 168 is by means of the external thread section 170 in the cavity 137 screwed in and thus axially fixed.

An inside diameter of the valve core 168 corresponds approximately to a maximum outer diameter of the tappet body 139 , Furthermore, the valve insert 168 in the inner diameter approximately on the length of the external thread section 170 Expanded in one step in the inner diameter, so that a valve chamber 148 is formed, the diameter of which is somewhat larger than a maximum outer diameter of the tappet body 139 , The valve room 148 is towards the end 63 through a lid 174 closed, the inside of one towards the operating lever 94 pointing floor 151 forms.

The floor 150 is central of an inlet opening 150 perforated in the form of a hole. Thanks to the single-stage expansion inside the valve insert 168 is one towards the floor 151 pointing ring wall running parallel to this 147 educated. This forms a stop for a disc 144 whose outside diameter is the same as the inside diameter of the valve chamber 148 agrees and which has a circular opening which is slightly smaller in diameter than a maximum outer diameter of the tappet body 139 , The coil spring already mentioned 142 supports with its other end, the inlet opening 150 of the valve space surrounding the floor 151 from. Its maximum outer diameter is chosen so that it breaks through the disc 144 enforced without play. The coil spring 142 presses the plunger 138 towards the operating lever 94 out so that the switching valve 96 in the unactuated state with its plunger tip 162 on the operating surface 95 of the operating lever 94 is applied. Another coil spring 146 is supported on the one hand on the disc 144 , on the other hand on the ground 151 and surrounds the coil spring 142 , The coil spring 146 has a spring constant that that of the coil spring 142 by a multiple.

The pestle 138 can from an unactuated position, as in the 1 to 3 is shown against the action of the coil spring 142 towards the disc 144 be moved until the sleeve-like end of the plunger body 139 on the disc 144 strikes. The switching valve 96 then takes up a first switching position, as in the 4 and 5 is shown. Will the operating lever 94 pivoted further, then takes the sleeve-like end of the plunger body 139 the disc 144 now also against the action of the coil spring 146 With. This second switch position is in the 6 and 7 shown. So can when operating the operating lever 94 by an operator due to the coil springs 142 and 146 generated restoring forces on the plunger 138 to a switching position of the switching valve 96 getting closed. Because the spring constant of the coil spring 146 is many times larger than that of the coil spring 142 , an operator receives tactile feedback that the switch has been made from the first switch position to the second switch position.

The valve insert 168 is starting from his at the front 164 adjacent end with a total of eleven identical ring grooves 176 to 186 provided, being in all even-numbered ring grooves 176 . 178 . 180 . 182 . 184 . 186 each have a sealing lip for the tappet body 139 forming sealing ring 188 is used.

The plunger body 139 is provided with a ring groove system, which is based on 3 beschrie will. In the in 3 shown basic position of the switching valve 96 seals in the ring groove 176 inserted sealing ring 188 the plunger body 139 towards the hole 166 from. At the level of the ring groove 177 is an outer diameter of the tappet body 139 reduced in one step and forms an annular groove 190 , Opposite that in the ring groove 178 used sealing ring 188 is the outside diameter of the tappet body 139 tapered again in one step and forms an annular groove 191 , The outside diameter of the tappet body then increases 139 again in one step and forms one of the ring grooves 189 opposite ring groove 192 , The one in the ring groove 180 inserted sealing ring 188 is sealing again on the maximum outer diameter of the tappet body 139 on. Adjacent to it is an annular groove 193 on the tappet body 139 on, which is tapered in one step in the outer diameter, but has a larger outer diameter than the identical ring grooves 190 and 192 , The one in the ring groove 182 inserted sealing ring 188 there is another ring groove opposite 194 whose outer diameter is approximately that of the ring groove 190 and 192 equivalent. This is followed by an annular groove 195 trained the the ring groove 193 corresponds and the ring groove 184 is formed opposite. The one in the ring groove 184 inserted sealing ring 188 in turn seals the tappet body 139 completely.

The odd-numbered ring grooves 177 . 179 . 181 . 183 and 185 are provided with air inlet openings X, Y and P, which are shown schematically in dashed lines in the figures and with the two pneumatic cylinders 98 and 100 and a compressed air source, not shown, are connected as follows. The ring groove 181 is provided with an inlet port designated P, which is connected to the compressed air source, not shown. The one on the ring groove 179 The intended inlet opening X with the two inlet openings is the pneumatic cylinder 98 and 100 connected, which are also labeled X there. Furthermore, the ring groove 183 provided with an inlet opening marked with Y, which in turn with the inlet openings labeled Y with the pneumatic cylinders 98 and 100 connected is. Furthermore, with the ring grooves 177 and 185 Connected inlet openings, both denoted by R. These form ventilation openings through which compressed air can escape from the system.

The three possible switching positions of the switching valve 96 are explained in more detail below. In the in the 1 to 3 shown unactuated position of the operating lever 94 , a so-called rest or starting position, are, as already described, with the ring grooves 177 and 179 connected inlet openings X and R of the cavity 137 in fluid connection. This will make the two pneumatic cylinders 89 and 100 vented through their inlet openings X. The same applies to the ring grooves 181 and 183 connected inlet openings P and Y by means of the ring grooves 193 . 194 and 195 defined annular spaces in fluid communication. In this way the compressed air source is via the switching valve 96 with the inlet openings Y of the pneumatic cylinder 98 and 100 connected such that the two pneumatic cylinders 98 and 100 are moved together against the direction indicated by arrow B to their end position. The instrument thus assumes a stop position that corresponds to the rest or basic position. A distance between the cutting edge 38 and the cutting plate 20 is maximum.

Will the operating lever 94 towards the handle 62 pivoted towards, so the plunger 138 towards the disc 144 moved there. The switching valve 96 then take that into the 4 and 5 shown first switching position. Due to the differently chosen outer diameter of the ring grooves 190 to 195 are the ring grooves 181 . 179 and 177 connected together so that compressed air through the inlet P of the switching valve 96 and via the inlet X on the ring groove 179 to the inlets X of the two pneumatic cylinders 98 and 100 can flow, but this over the connection by means of the ring groove 190 . 191 and 192 also with the vent R of the ring groove 177 are connected. On the other hand, the inlet P is on the annular groove 181 over the ring groove 193 . 194 and 195 with the inlet Y on the ring groove 183 and the inlet R on the ring groove 185 in fluid communication. This allows compressed air to enter the pneumatic cylinders via the inlets Y. 98 and 100 stream. Due to the specially selected outer diameter of the ring grooves 190 . 191 . 192 such as 193 . 194 and 195 the fluid flows into the inlets X and Y, with which the two pneumatic cylinders 98 and 100 are applied so distributed that a resulting driving force acting in the direction of arrow B is about 20 percent of a maximum with the two pneumatic cylinders 98 and 100 generated propulsive force corresponds. This force is sufficient, as in the area D in outlined in dashed lines 4 shown, not made to remove tissue 54 to cut, but at most the cutting edge 38 in contact with the tissue 54 bring to.

Will the operating lever 94 however, continue towards the handle 62 the plunger is moved as far as it will go 138 transferred to the second switch position, which in the 6 and 7 is shown. The one in the ring grooves 178 such as 182 and 186 inserted sealing rings 188 seal the tappet body 139 completely, so that on the one hand a fluid connection between the with the annular groove 179 connected inlet opening X with the annular groove 181 connected inlet port P is made, on the other hand, a fluid connection between the with the annular groove 183 connected inlet opening Y and with the annular groove 185 connected inlet opening R. In this Switch position both pneumatic cylinders 98 and 100 pressurized with compressed air via its inlet openings X from the compressed air source. An opposite pressurized air is not possible, since the inlet openings Y with the ring groove 185 connected vent opening R and are thereby vented. Both pneumatic cylinders 98 and 100 are thus in the direction of arrow B in 1 driven, which creates maximum driving force and on the punch 36 can be transferred.

In order to further improve tactile feedback for an operator of the bone punch, the one with the ring groove 179 connected inlet opening X also to the inlet opening 150 of the valve space 148 get connected. Are namely in the second switching position, as in the 6 and 7 is shown, both of the pneumatic cylinder 98 and 100 pressurized with compressed air of maximum pressure, this pressure also acts in the same direction as the two coil springs 142 and 146 , whereby an operator has to apply an increased actuating force to the second switching position of the actuating lever 94 maintain.

The operation of a slightly modified embodiment of the drive device 92 of the instrument is explained in more detail below.

In an unactuated position of the actuating lever 94 becomes the first pneumatic cylinder 98 Compressed with compressed air via its inlet Y such that the piston 106 against the sealing washer 120 is moved. The bone punch then assumes its open position, that is, the driver 134 holds the end plate 46 the punch 36 in its most proximal position. The distance between the cutting edge 38 and the cutting plate 20 is maximum.

Will the operating lever 94 against the coil spring 142 moved without the plunger 138 on the disc 144 strikes, only the piston 106 in the direction of arrow B in 1 by means of compressed air through the inlet X between the pistons 106 and the turntable 120 emotional. A ratio of the cross sections of the first pneumatic cylinder 98 and the second pneumatic cylinder 100 is about 1: 4, so that initially only a driving force of about 20 percent of a maximum possible driving force is generated and via the angle lever 128 on the punch 36 is transmitted. The so diminished, on the punch 36 acting force is typically not sufficient to remove tissue 54 , for example to cut bone parts. The force is sufficient, as in the area D in delineated by dashed lines 4 illustrated, just to cut the edge 38 to the tissue. In this first operating position of the operating lever, an operator of the bone punch can 10 with it the insert 20 in the desired manner to the tissue to be removed 54 put on without there already being a severing of the tissue 54 comes.

Once the cutting position has been determined, the operating lever can be used 94 be fully pushed through. The pestle 138 is now also against the coil spring 146 moves what the operator feels by the greater actuating force to be brought in, which is required to the actuating lever 94 to pivot. The switching valve 96 then assumes a switching position in which both the first pneumatic cylinder 98 as well as the second pneumatic cylinder 100 are pressurized with compressed air via their inlets X, in such a way that both pistons 106 and 114 be moved in the direction of arrow B. So that a maximum force of the drive device 92 over the angle lever 128 on the punch 36 transfer which is suitable to tissue 54 cut in the desired way. Inlets Y of the pneumatic cylinders not pressurized with compressed air 98 and 100 are ventilated in this position.

Will the operating lever 94 relieved again, so the coil springs press 142 and 146 the pestle 138 back to its starting position, the punch 36 is then again by pressurizing the pneumatic cylinder 98 applied in a direction opposite to arrow B, whereby the punch 36 from their to the 6 and 7 shown cutting position on their in 4 and 5 shown intermediate position in their in 1 shown basic position, i.e. its most proximal position, is transferred back.

So much for the operation of the slightly modified embodiment of the drive device 92 ,

To inadvertently actuate the drive device 92 by pressing the operating lever 94 to be excluded by an operator is in the proximal area of the upper housing part 60 a safety valve 154 arranged. The safety valve 154 includes one transverse to the longitudinal axis 16 slidably mounted, against an inside of the lid 70 spring-loaded valve lifter 156 , Is the lid like in 1 shown, closed, the valve lifter takes 156 a position in which there is a fluid connection between the compressed air supply line 152 and the inlet opening 150 of the switching valve 96 manufactures. Will the lid 70 however, when opened, it slides out of the safety valve 154 protruding end of the valve lifter 156 on a ramp 158 on the inside of the lid 70 along, causing the spring-loaded valve lifter 156 further from a body of the safety valve 154 is moved out. This changes the safety valve 154 its switch position, it un now breaks a connection between the compressed air supply line 152 and the inlet opening 150 of the switching valve 96 , so that an actuation of the actuating lever 94 remains ineffective since the drive device 92 is therefore separated from the compressed air source. Only when the sliding cover 70 is completely closed again, the valve lifter 156 so far in the body of the safety valve 154 pushed in that the safety valve 154 returns to the switch position in which the compressed air supply line 152 in fluid communication with the inlet opening 150 of the switching valve 96 stands.

Got the bone punch 10 be cleaned during an operation, for example because there is tissue 54 between the cutting edge 38 and the cutting plate 20 an operator has to jam the bone punch 10 don't put it down. A person assisting the surgeon can leave a space between the cutting edge 38 and the cutting plate 20 clean without risk of injury, even if the operator pulls the operating lever 94 actuated. In an unactuated position of the actuating lever 94 overlap the ring groove 90 and the safety holes 34 ,

This is in 1 shown. The person assisting the surgeon can now use the safety button 80 against the action of the coil spring 88 press so that the bolt 82 in the ring groove 90 immersed like this in 4 is shown. A movement of the punch 36 in the distal direction is thereby prevented, even when the operator pulls the operating lever 94 would push. Is the tissue part to be removed 54 cut off, the person assisting the surgeon can press the safety button 80 Release the surgeon and the surgeon can continue the surgery. The cleaning process described can be carried out particularly easily since the safety button 80 far enough away from the operating lever 94 is arranged, in particular the distal side thereof, so that the safety button 80 is always freely accessible to the person assisting the surgeon.

Due to the special design of the coupling piece 22 , especially by providing the square 28 , it is possible to use the punching tool 14 in four different positions with the handle 12 connect to. In the 1 to 5 is the punching tool 14 with the handle part 12 connected such that a space between the cutting plate 20 and the cutting edge 38 points upwards. The two parts of the bone punch 10 However, can also be connected to each other so that the space is down or to one of the two sides of the bone punch 10 has. For changing a relative position of the punch 14 to the handle part 12 only the sliding cover 70 be moved in the proximal direction until the receiving space 63 opened and the punch 14 can be removed. The punching tool 14 can be rotated by 90 °, 180 ° or 270 ° and back into the recording room 64 be used. Moving the lid 70 closes the recording space in the distal direction 64 and also secures the coupling piece 22 and with it the punching tool 14 on the handle 12 ,

Claims (37)

Surgical instrument ( 10 ) comprising a handling part ( 12 ) and a tool part ( 14 ), the tool part ( 14 ) at least one movable tool ( 36 ) which, via a power transmission and / or actuation mechanism ( 92 . 128 ) which of the handling part ( 12 ) can be operated, is actuated, and that the power transmission and / or actuation mechanism ( 92 . 128 ) a drive unit that can be operated with a fluid ( 92 ), characterized in that with the drive unit ( 92 ) in a first drive position the movably mounted tool ( 36 ) can be acted upon with a first actuating force and can be acted upon with at least one second actuating force in at least one second drive position. Instrument according to claim 1, characterized in that with the drive unit ( 92 ) in a third actuation position the movably mounted tool ( 36 ) can be acted upon by a third actuating force. Instrument according to claim 2, characterized in that the third actuating force corresponds to the sum of the first and second actuating forces. Instrument according to one of the preceding claims, characterized characterized that a relationship the first and second actuating forces is in the range from 4: 1 to 9: 1. Instrument according to one of the preceding claims, characterized in that the drive unit ( 92 ) comprises a linear drive. Instrument according to claim 5, characterized in that the linear drive ( 92 ) at least one fluid cylinder ( 98 . 100 ) includes. Instrument according to one of claims 5 or 6, characterized in that the linear drive ( 92 ) two coupled, separately controllable fluid cylinders ( 98 . 100 ) includes. Instrument according to claim 7, characterized in that the two fluid cylinders ( 98 . 100 ) have different cross sections. Instrument according to claim 8, characterized in the existence relationship the cross sections are in a range from 4: 1 to 9: 1. Instrument according to one of claims 6 to 9, characterized in that the at least one fluid cylinder ( 98 . 100 ) is a pneumatic and / or a hydraulic cylinder. Instrument according to one of claims 6 to 10, characterized in that the at least one fluid cylinder ( 98 . 100 ) is a double-acting fluid cylinder. Instrument according to one of the preceding claims, characterized in that the instrument ( 10 ) is designed to remove bone, cartilage or such tissue ( 54 ), with one in a longitudinal direction ( 16 ) extending shaft ( 18 ), which at its distal end is transverse to the longitudinal direction ( 16 ) arranged or inclined cutting plate relative to this ( 20 ) that the movably mounted tool is on the shank ( 18 ) slidably mounted cutting element ( 36 ) which is at its distal end towards the cutting plate ( 20 ) pointing cutting edge ( 38 ) that attaches to the insert ( 20 ) can be used to cut tissue ( 54 ). Instrument according to claim 12, characterized in that at the proximal end ( 22 ) of the shaft ( 18 ) a first coupling element ( 28 ) is arranged for detachable, positive connection to the power transmission and / or actuation unit ( 92 . 128 ) which is a coupling element ( 28 ) corresponding second coupling element ( 74 ) and that the first coupling element ( 28 ) is a polygon, the outer surfaces of which are from a longitudinal axis ( 16 ) of the shaft ( 18 ) point radially outwards. Instrument according to claim 13, characterized in that the polygon is a square ( 28 ), a hexagon or an octagon. Instrument according to one of claims 12 to 14, characterized in that the shaft ( 18 ) at its proximal end ( 22 ) is shaped like a sleeve and that the cutting element ( 36 ) the sleeve-like end ( 22 ) of the shaft ( 18 ) enforced. Instrument according to one of claims 12 to 15, characterized in that the cutting element ( 36 ) at its proximal end, a third, with a drive element ( 128 ) of the power transmission and / or actuation mechanism ( 92 . 128 ) detachably connectable coupling element ( 44 ) and that the third coupling element ( 44 ) longitudinal ( 16 ) of the shaft ( 18 ) acting stops ( 42 . 46 ) connect. Instrument according to one of the preceding claims, characterized in that in a rest position of the instrument ( 10 ), in which with the power transmission and / or actuation mechanism ( 92 . 128 ) no operating force on the tool in one direction ( 36 ) is exercised with the power transmission and / or actuation mechanism ( 92 . 128 ) a holding force on the tool in a holding direction opposite to the actuating direction ( 36 ) can be exercised. Instrument according to claim 17, characterized in that the power transmission and / or actuation mechanism ( 92 . 128 ) an actuator ( 94 ) includes to actuate the drive unit ( 92 ) that the actuator ( 94 ) from an unactuated starting position in which the instrument ( 10 ) assumes the rest position, can be brought into a first activation position in which the drive unit ( 92 ) assumes the first drive position, and can be brought into at least one second activation position, in which the drive unit assumes the second drive position. Instrument according to claim 18, characterized in that the actuating member ( 94 ) is resiliently biased in the starting position. Instrument according to one of claims 18 or 19, characterized in that the actuating member ( 94 ) is pivotally mounted. Instrument according to one of claims 18 to 20, characterized in that in the first activation position a first restoring force on the actuating member ( 94 ) acts that a second restoring force acts in the second activation position and that the second restoring force is greater than the first restoring force. Instrument according to claim 21, characterized in that the second restoring force at least twice the size the first restoring force is. Instrument according to one of claims 21 or 22, characterized in that a restoring unit (to generate the first and second restoring force ( 142 . 146 ) comprising a first elastic reset member ( 142 ) and a second elastic reset element ( 146 ) is provided. Instrument according to claim 23, characterized in that the first and / or the second reset element is a spring element ( 142 . 146 ) is. Instrument according to one of claims 23 or 24, characterized in that the resetting unit ( 142 . 146 ) directly or indirectly on a control element ( 96 ) to control the drive unit ( 92 ) or on the actuator ( 94 ) acting trained det. Instrument according to one of claims 18 to 25, characterized in that a control member ( 96 ) to control the drive unit ( 92 ) is provided and that the actuator ( 94 ) directly or indirectly on the control element ( 96 ) works. Instrument according to claim 26, characterized in that the control member ( 96 ) comprises at least one control valve. Instrument according to claim 27, characterized in that the at least one control valve ( 96 ) has at least three different switching positions. Instrument according to claim 27 or 28, characterized in that the control valve ( 96 ) a valve lifter ( 138 ) has that on the valve body ( 137 ) at least one connection that can be connected to a fluid source and for each double-acting fluid cylinder ( 98 . 100 ) two connections are provided that in a first position of the valve tappet ( 138 ) at least one of the fluid cylinders ( 98 . 100 ) can be acted upon with fluid in a holding direction, that in a second position of the valve tappet ( 138 ) at least one of the fluid cylinders ( 98 . 100 ) can be acted upon on both sides with different fluid flows and that in a third position of the valve tappet ( 138 ) at least one of the fluid cylinders ( 98 . 100 ) can be acted upon with a fluid against the holding direction. Instrument according to claim 29, characterized in that in the second position of the valve tappet ( 138 ) a fluid flow to the two connections of at least one fluid cylinder ( 98 . 100 ) is distributed unevenly. Instrument according to one of claims 29 or 30, characterized in that the valve tappet ( 138 ) with a plurality of ring grooves ( 190 . 191 . 192 . 193 . 194 . 195 ) is provided and in a valve body ( 137 ) defines different annular spaces in different switching positions, the cross-sectional ratios of which are coordinated with one another as a function of a fluid pressure such that in the second switching position only a fraction of a maximum actuating force by the at least one fluid cylinder ( 98 . 100 ) can be generated. Instrument according to one of claims 27 to 31, characterized in that at least two control valves ( 96 ) are provided with at least two switching positions each. Instrument according to claim 32, characterized in that the at least two control valves ( 96 ) can be operated manually separately. Instrument according to one of the preceding claims, characterized in that on the tool part ( 14 ) at least one coding unit is provided for coding the type and / or the type of the tool part ( 14 ) and that on the handling part ( 12 ) a decoding unit is provided for decoding the type and / or type of the tool part ( 14 ). Instrument according to claim 34, characterized in that the at least one coding unit has no or at least one on the tool part ( 14 ) protruding projection or at least one on the tool part ( 14 ) arranged recess comprises that the decoding unit comprises an operating mode switching element corresponding to the at least one projection or the at least one recess, that the operating mode switching element has at least a first and a second operating mode position and that the operating mode switching element corresponds to the coding of the tool part ( 14 ) occupies one of the at least two operating modes. Instrument according to claim 35, characterized in that the at least two operating mode positions maximum actuation forces of the drive unit ( 92 ) assigned. Instrument according to one of claims 35 or 36, characterized in that the operating mode switching element with the control element ( 96 ) is coupled and that the operating mode switching element in at least one operating mode position has at least one switching position of the control element ( 96 ) directly or indirectly.