DE29511899U1 - Holding device for surgical purposes - Google Patents

Description

A 52 708 u AESCULAP AG

u - 234 Am Aesculap-Platz

11 June 1995 78532 Tuttlingen

Holding device for surgical purposes

The invention relates to a holding device for surgical purposes with a connecting part and with a holder for surgical tools, with at least one arm arranged between the holder and the connecting part, which is connected to the holder, the connecting part or optionally to an adjacent arm via a joint, and with a pneumatically actuated device for optionally fixing and releasing the joints.

Such devices are described, for example, in EP 0 415 417 A2, EP 0 486 999 A2 or WO 93/14 704.

These arm-like holding devices are used to fix surgical tools of various kinds in a desired position, for example retractor valves, cameras, endoscopes, etc. Due to the multi-joint design of such arm-like holding devices, it is possible for the surgeon to position the tools held at the free end of such a device exactly as required and then to fix the relative position of the parts of the holding device once it has been set.

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In known devices of this type, the fixation is carried out pneumatically, i.e. the joints are locked by pneumatic actuating elements. To release the joints, the supply of the pneumatic medium in these known holding devices is interrupted and the corresponding pneumatic actuating elements are vented. This has the disadvantage that if the pneumatic supply system fails, all the joints will inevitably come loose, and this can potentially lead to injuries to a patient.

It is the object of the invention to design a holding device of the generic type in such a way that, on the one hand, a reliable retention of the once set position is ensured even when large forces are exerted on the holding device and, on the other hand, that even in the event of a failure of the supply of the pneumatic medium, it is ensured that the holding device retains its once set position.

This object is achieved according to the invention in a holding device of the type described at the outset in that the device fixes the joints under the action of a mechanical spring exerting a braking force on the joint and that the device can be pneumatically transferred against the force of this spring into a state that releases the joint.

It is therefore ensured that the joint is fixed or locked by mechanical spring means. To release the joints, a pneumatically operated working element must be provided that is sensitive to the spring force.

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counteracts. If the supply of pneumatic medium fails, the locking of the joints remains intact, it is just no longer possible to loosen the joints and adjust the holding device. However, the risk of injury is definitely ruled out.

It is advantageous if, according to a preferred embodiment of the invention, the device in its joint-releasing state does not completely release the joint, but only reduces the braking forces exerted by the spring. If an adjustment of the holding device is desired, the joints are only partially released, to such an extent that a sensitive adjustment is possible against a certain frictional force of the joint. On the other hand, however, this incomplete release of the joints means that the device does not collapse, but can only be moved to another position by exerting certain adjusting forces. These remaining braking forces on each joint can be adjusted in such a way that the holding device still holds itself under the influence of these remaining forces, but adjustment is possible. Since the lever forces acting on the joint are different over the length of the holding device, these remaining braking forces can be adjusted accordingly.

According to a first preferred embodiment, the joints are ball joints.

A particularly advantageous design is obtained if the joint comprises a ball and two clamping jaws which clamp the ball between them and are held against each other by the spring.

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pressed together and pneumatically separated from each other.

In another embodiment, the joints are single-axis swivel joints. Their axes of rotation can be arranged, for example, in the longitudinal direction of the sections of the holding arm and transversely to it, so that this also results in universal adjustability of the device as a whole.

It is particularly advantageous if the parts of the joint that can be pivoted against each other have slats that are pressed against each other by the spring and separated pneumatically.

In a preferred embodiment, it is provided that connections for a supply line of a pneumatic medium and for a vent line are arranged in the connecting part, that these connections are connected to all devices for fastening and releasing the joints and that these connections have valves which close the connections as soon as they are separated from the supply line and the vent line.

This ensures that during steam sterilization of such a device, the steam cannot penetrate into the lines of the pneumatic medium in the device, nor into the vent line. Furthermore, these valves have the advantage that the pneumatic medium enclosed in the holding device remains available when the device is disconnected from the supply of the pneumatic medium,

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it is therefore possible, even after separation, to use the enclosed volume of the pneumatic medium to release the ball joints and thus, for example, to fold up the holding device. During steam sterilization, in which the temperature of the holding device is greatly increased, the enclosed volume of the pneumatic medium expands and can therefore transfer higher opening forces to the individual joints. During steam sterilization it is therefore possible for the joints to be completely released, whereby the steam is thereby able to reach all braking surfaces of the joint, i.e. the ball and the clamping rings attached to it in the case of ball joints, and the slats in the case of single-axis swivel joints.

In order to achieve this automatic separation, a check valve that closes in the inflow direction can be arranged in the connection of the supply line. This is opened as soon as the connection is connected to the supply line and as soon as the pressure of the pneumatic medium supplied via the supply line exceeds the pressure of the pneumatic medium remaining in the holding device.

It is also advantageous if a spring-loaded closing valve is arranged in the connection of the vent line, which is opened by an actuating element against the action of the spring, whereby the actuating element is actuated by the positioning of the vent line at the connection. Simply by connecting the vent line to the connection, the corresponding closing valve is thus automatically actuated via the actuating element.

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opened mechanically. If the vent line is removed from the connection, the spring automatically closes this valve.

In a preferred embodiment, it is provided that a storage chamber for the pneumatic medium is arranged in the connection part, which is connected on the one hand to the connection for the supply line and on the other hand to the devices for releasing the joints. In this storage chamber a certain volume of the pneumatic medium is stored, so that when the holding device is separated from the supply line, the volume of the pneumatic medium stored in the holding device is in any case sufficient to release the joints by activating the corresponding devices again. The described effect of completely releasing the joints during steam sterilization can also be improved by this volume enclosed in the connection part.

It can also be provided that a pressure limiter is installed in the pneumatic medium line between the storage chamber and the devices for releasing the joints. This ensures that the opening forces for the individual joints correspond exactly to the desired values, regardless of the respective pressure of the pneumatic medium that is supplied via the supply line.

An actuatable closing valve can be inserted between the storage chamber and the devices for releasing the joints, the actuating element of which is arranged on the holder. The user can therefore, by operating the actuating element,

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organ and by opening this closing valve, the individual joints can be released, whereby this control can be carried out from the holder on which the surgical tools are also attached.

It is advantageous if the closing valve opens and closes the supply of pneumatic medium to all devices for releasing the joints at the same time.

In a further preferred embodiment, a mechanically actuated release element is assigned to a joint, with which the device for releasing the joints can be transferred into the state that releases the joint against the effect of its spring. This makes it possible to release the joint that is fixed in the resting state, even if there is no supply of a pneumatic medium in the holding device, for example when it is first put into operation or after a longer break in operation. It is advantageous if the release element is an eccentric lever that separates the parts that exert braking forces on the joint from one another.

The following description of preferred embodiments of the invention serves to explain in more detail in conjunction with the drawing. They show:

Figure 1: a longitudinal sectional view of a holding device with ball joints with a connecting part and two arms;

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Figure 2: an enlarged longitudinal sectional view of an arm and the holder mounted thereon;

Figure 3: an enlarged longitudinal sectional view of a portion of the connector;

Figure 4: an enlarged longitudinal sectional view of parts of the connector;

Figure 5: a view similar to Figure 4 without supply line;

Figure 6: a schematic side view of an arm in the ball joint area with an eccentric lever for mechanical release of the ball joint;

Figure 7: a longitudinal sectional view through a modified embodiment of a holding device in the area of a joint designed as a lamella joint with a direction of rotation parallel to the longitudinal direction of the arms in the tensioned state;

Figure 8: a view similar to Figure 7 with the joint in the released state and

Figure 9: a longitudinal sectional view of a modified embodiment of a holding device with a lamella swivel joint with a rotation axis transverse to the longitudinal direction of the arms in the fixed state of the swivel joint.

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The holding device shown in Figures 1 to 6 of the drawing comprises a substantially tubular connecting part 1, a first tubular arm 2, a second, also tubular arm 3 and a holder 4 which is also tubular.

The connecting part 1 carries a clamping device 5 with which the entire holding device can be fixed to another structure, for example to a holding rail 6 of an operating table 7.

The arm 2 is mounted on the connecting part 1 via a ball joint 8, the two arms 2 and 3 are connected to each other via a double ball joint 9 and the holder 4 is finally mounted on the arm 3 also via a ball joint 10.

All ball joints can be locked or released, so that when the ball joints are released, the holding device on each ball joint can be adjusted as required. Once this position has been reached, it can be fixed by securing these ball joints. This makes it possible to adjust the holder to a desired position.

This holder 4 has at its free end a receptacle 11 for any surgical tools, for example for spatulas, for retractor valves, for endoscopes, for optical cameras, etc.

In principle, all ball joints are constructed in a similar way. The structure of such a ball joint is therefore explained in more detail below using the example of the ball joint between the holder 4 and the arm 3. In this regard, reference is made in particular to the illustration in Figure 2.

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The tubular holder 4 has a tubular extension 12 at its end opposite the receptacle 11, the outer diameter of which is smaller than that of the holder 4. At the end of this extension 12, a ball 13 is attached with a through hole through which the extension 12 passes. The ball can be screwed or welded onto the extension 12, for example.

The ball 13 is covered by a hood 14, which has an opening 15 on the front, the diameter of which is slightly smaller than the diameter of the ball 13, so that the edge of the opening 15 rests against the ball 13. This hood 14 is arranged on the arm 3 so as to extend it, for example screwed onto it. A pot-shaped clamping element 16 is mounted so as to be longitudinally displaceable within the hood 14, which rests against the ball 13 with its free edge 17, the diameter of which is slightly smaller than the diameter of the ball 13. This edge 17 and the edge of the opening 15 thus form two clamping jaws which clamp the ball 13 between them when they are pushed against each other.

The pot-shaped clamping element 16 has on its base an extension 18 which projects into the interior of the arm 3, passes through a transverse wall 19 of the arm 3 and carries at its free end a piston 20 which is longitudinally displaceable in the arm 3 and sealed relative to it.

Between the base 21 of the cup-shaped clamping element 16 on the one hand and between the transverse wall 19 on the other hand, a very strong helical spring 22 is arranged surrounding the extension 18, which clamps the cup-shaped clamping element

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16 is pressed strongly against the front side of the hood 14 and thus the ball 13 is clamped between the two clamping jaws, which are formed by the edge of the opening 15 and by the edge 17. The force of the coil spring 22 is chosen to be so great that the ball 13 is secured against any movement by this clamping force. This can be supported by the hood 14 and the edge

17 in the clamping area are covered with corresponding high-friction surfaces, for example these surfaces can be roughened.

The piston 20 closes off a chamber 23 in the arm 3, which is not clearly visible in the drawing and into which a supply line 24 opens. A pneumatic medium can be introduced into the chamber 23 through this supply line 24, and this then leads to a displacement of the piston 20 against the direction of force of the coil spring 22. This displacement of the piston 20 also lifts the cup-shaped clamping element 16 off the ball 13 under compression of the coil spring 22, so that the clamping forces with which the ball is clamped between the two clamping jaws are reduced. This enables the ball to move between the two clamping jaws. The displacement movement of the piston 20 is chosen to be so small that the clamping forces that are still exerted on the ball 13 when the piston is displaced do not disappear completely, but are only reduced. For example, these clamping forces can be selected so that the ball joint formed by the ball and the clamping jaws can absorb the weight of the holding device, i.e. it does not adjust under its own weight, but can be adjusted when larger moments are applied.

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All ball joints described above are essentially constructed in the same way, so each ball joint is assigned two clamping jaws, which are moved by spring force into the position in which the swivel joint is fixed. Each ball joint can be released pneumatically to enable the adjustment of the holding device.

In order to supply the individual devices with the pneumatic medium, two connections are arranged on the connection part 1, namely a connection 25 for a supply line for a pneumatic medium, for example compressed air, and a connection 26 for a vent line. For this purpose, the connection part 1 has a cylindrical end piece 27, which is screwed into a tubular section 28 (Figures 4 and 5). The connection 25 passes through this end piece 27 in the form of a central bore 29, which ends in a connection piece 30. A constriction 31 is provided in the bore 29, one side of which forms a conical valve seat 32 for a check valve body 33, which is freely movable in the end of the bore 29 on the connection part side. It is held captive in the bore 29 by a plate 34 inserted between the pipe section 28 and the end piece 27, which has an opening 35 in the extension of the bore 29, the diameter of which is smaller than the diameter of the bore 29 and the check valve body 33.

In addition to the central bore 29, a further through-bore 36 is provided in the end piece 27, which accommodates a spring-loaded closing valve 38 in an extension 37. Its valve body 39 is pressed by a coil spring 40 against a valve seat 41, which is

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Shoulder is formed between the through hole 36 and the extension 37. The closing valve 38 is thus normally closed.

A tappet 42 protruding from the end piece 27 through the through hole 36 is held on the valve body 39 (Figure 5), which can be pushed into the end piece 27 against the action of the coil spring 40, so that the valve body 39 is lifted off the valve seat 41 and the closing valve 38 is opened (Figure 4). This displacement of the tappet 42 is carried out by a supply line 43, shown only in dashed lines in Figure 4, pushed onto the end piece 27, in which lines are arranged which can be tightly connected to the connections 25 and 26, which are not shown in the drawing.

When the supply line 43 is pushed onto the end piece 27, the closing valve 38 is automatically opened, which is conversely automatically closed as soon as the supply line 43 is removed.

The through hole 36 is connected via a connecting hose 44 to the vent holes of the chambers 23 of all ball joints, so that pneumatic medium flowing out of the chambers 23 is fed via this common hose 44 and the connection 26 to a vent line in the supply line 43. This ensures that the pneumatic medium does not escape into the environment in an uncontrolled manner during venting.

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The bore 29 connected to the connection 25 opens into a storage chamber 45, which is formed by the tubular section 28. This tubular section 28 is screwed into a tube 47 with a larger outer diameter by means of a union ring 46, which forms the second part of the connection part 1. This tube 47 is closed off by a transverse wall 48, which simultaneously closes the storage chamber 45 at the front and which also has an annular projection 49 into which the tubular section 28 is immersed.

The transverse wall 48 carries on its side facing away from the storage chamber 45 a pressure limiter 50 with a cylindrical base 51 formed in one piece with the transverse wall 48, a cylindrical housing 52 which covers and surrounds the base and is fixed to the transverse wall 48 at a distance, a closure body 53 which is longitudinally displaceable in the housing and a helical spring 54 which surrounds the base 51 and is arranged inside the housing 52 and presses the closure body 53 against the upper end wall of the housing 52.

A through hole 55 is arranged in the base 51, which is connected to the storage chamber 45 and which ends at the opposite end in a nozzle-shaped opening 56. In this area, the base 51, which is provided with a nipple-shaped projection 57, penetrates in a sealed manner into a hole 58 in the closure body 53, in which a central valve body 59 is arranged directly opposite the nozzle-shaped opening 56.

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The housing 52 has lateral through-openings 60, through which the housing 52 in the annular space accommodating the coil spring 54 is connected to the interior of the tube 47. In the part arranged above the closure body 53, the housing 52 is closed and opens into a pressure line 61, which leads through the entire holding device to the holder 4.

The arrangement described acts as a pressure limiter. If the pressure in the housing 52 exceeds a certain value, the closure body 53 is pushed downwards against the action of the coil spring 54, and as a result the valve body 59 rests against the opening 56 and closes it. However, if this pressure is below a desired maximum value, the closure body 53 remains in the raised open position. This reliably prevents certain maximum pressure values from being exceeded in the pressure line 61.

The pressure line 61, like all lines for the pneumatic medium and all vent lines, is led centrally through the ball joints; for this purpose, the balls 13 and the extensions 12 supporting them are provided with a through-channel 62.

The pressure line 61 is led from the described pressure limiter 50 into the holder 4 and flows there into a closing valve 63, which is normally closed and can be moved into the open position via an actuating element 64 protruding laterally from the holder 4. This closing valve 63 is connected via further lines 65 to all supply chambers 24 of the chambers

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23 of the ball joints 8, 9, 10, which are thus all simultaneously acted upon by the pneumatic medium when the closing valve 63 is opened, so that the holding forces are simultaneously reduced for all ball joints. This allows the holding device to be adjusted in the desired and described manner as long as the actuating element 64 of the closing valve 63 is pressed.

If the actuating element 64 is released again, the closing valve 63 is closed, and this leads to the pistons 20 in the individual ball joints being moved again in the direction of the balls 13 under the effect of the coil spring 22, thus the clamping effect is fully restored. The chambers 23 are thereby vented, and the expelled volume of the pneumatic medium is fed to the vent connection 26 via the hose 44.

The ball joints described so far can all only be released pneumatically. In the embodiment of Figure 6, in addition to the pneumatic device described for releasing the ball joint, a mechanical device is also provided. This comprises a U-shaped pivot lever 66, which laterally grips the respective arm in the area of the ball joint and is pivotally mounted on the arm on opposite sides of the arm (Figure 6). This pivot lever 66 protrudes through the hood 14 and has eccentrics 67 on the inside, which engage in lateral openings of the cup-shaped clamping element 16. When the pivot lever 66 is pivoted, this eccentric 67 can therefore

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shaped clamping element 16 can be moved slightly against the force of the coil spring 22, i.e. in the same direction as the pneumatic device, so that the clamping forces with which the ball 13 of the ball joint is held are reduced. It is therefore possible to release the respective swivel joint regardless of the presence of a pneumatic medium. This not only enables a swivel joint to be released in cases where there is insufficient pressure from the pneumatic medium, but this swivel lever 66 can also be used to release individual ball joints if necessary without releasing the other ball joints at the same time, since the swivel levers 66 only act selectively on one ball joint at a time.

The embodiment of a holding device described so far with reference to Figures 1 to 6 provides a ball joint connection between adjacent arms. In principle, however, other joints are also possible in this area, for example single-axis swivel joints. Figures 7 to 9 show embodiments with such single-axis swivel joints. Otherwise, the holding device is constructed in the same way as in the embodiment of Figures 1 to 6, corresponding parts therefore have the same reference numerals, and explicit reference is made to the description of the embodiment of Figures 1 to 6.

To design a joint with a rotation axis running parallel to the longitudinal direction of the arms 2 and 3, one arm 2 carries a joint head 70 with a cylindrical chamber 71 open towards the other arm, into the base 72 of which a central retaining screw 73 is screwed.

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The arm 3 also carries a joint head 74, which covers the chamber 71 and which surrounds the retaining screw 73 in the form of a sleeve-shaped extension 75. This extension 75 carries a pressure plate 76 at its free end, which is sealed from the inner wall 77 of the chamber 71 by a ring seal 78 and from the retaining screw 73 by a ring seal 79. This results in a pressure chamber 80 between the pressure plate 76 and the bottom 72 of the chamber 71, which is connected via a bore 81 to the line 65, i.e. to the pressure medium line, which can be opened optionally using the actuating element 64.

A compression spring 83 surrounding the head 82 of the retaining screw 73 is supported on the latter, the other end of which rests against the pressure plate 76, so that the pressure plate is removed from the head of the retaining screw 73 by the compression spring 83.

Several ring-shaped plates, referred to below as lamellae 84, are inserted into the chamber 71 at a distance from one another. These are firmly connected to the inner wall 77 of the chamber 71 so that they are secured against rotation about the axis of the retaining screw 73. This also ensures that their position is precisely fixed in the axial direction.

The sleeve-shaped extension 75 has a plurality of ring-shaped plates on its outside, which are referred to below as slats 85 and whose mutual spacing is selected such that the slats 85 engage between the slats 84. The slats 85 are permanently and firmly connected to the sleeve-shaped extension 75.

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Due to the effect of the compression spring 83, the slats are usually pressed strongly against the slats 84 and, due to a frictional connection, prevent the two joint heads 70 and 74 from rotating against each other, i.e. from rotating around the axis of rotation formed by the retaining screw 73. However, if a pressure medium is introduced into the pressure chamber 80, as is symbolized in Figure 8 by the arrow in the hole 81, the slats 85 are lifted off the slats 84 against the effect of the compression spring 83, i.e. the frictional forces are reduced in this area, so that the joint heads 70 and 74 can rotate against each other. In this case, too, the reduction in the frictional forces preferably only goes so far that the rotation is possible against a certain residual resistance.

Figure 9 shows a similar swivel joint in which, unlike the embodiment in Figures 7 and 8, the axis of rotation runs transversely to the longitudinal direction of the arms. Otherwise, the structure is largely the same, so that the same reference numerals are used as in Figures 7 and 8. Another difference is that the chamber 71 is not formed exclusively by the joint head 70, but partly by the joint head 70 and partly by the joint head 74.

The single-axis swivel joints shown in Figures 7 to 9 can be used, for example, in such a way that two such joints are arranged next to one another, so that rotation around the longitudinal axis of the arms and transversely to it is possible, so that universal adjustability of the holding device is ensured.

Claims (1)

&bull; * A 52 708 u AESCULAP AG u - 234 Am Aesculap-Platz 11 June 1995 78532 Tuttlingen PROTECTION CLAIMS 1. Holding device for surgical purposes with a connecting part and with a holder for surgical tools, with at least one arm arranged between the holder and the connecting part, which is connected to the holder, the connecting part or optionally to an adjacent arm via a joint, and with a pneumatically actuated device for selectively fixing and releasing the joints, characterized in that this device fixes the joints (8, 9, 10; 70, 74) under the action of a mechanical spring (22; 83) exerting a braking force on the joint (8, 9, 10; 70, 74) and that the device (16; 76) can be pneumatically transferred against the force of this spring (22; 83) into a state releasing the joint (8, 9, 10; 70, 74). 2. Holding device according to claim 1, characterized in that the device (16; 76) in its state releasing the joint (8, 9, 10; 70, 74) does not release the joint completely, but only reduces the braking forces exerted by the spring (22; 83). AESCULAP AG .;!. "*·* * ·..- · * *" ... ^: A 52708 u 11 June 1995 u-234 - 21 - 3. Device according to claim 1 or 2, characterized in that the joints are ball joints (8, 9, 10). 4. Device according to claim 3, characterized in that the ball joint comprises a ball (13) and two clamping jaws (15; 17) clamping the ball between them, which are pressed against one another by the spring (22) and are pneumatically separated from one another. 5. Device according to claim 1 or 2, characterized in that the joints are single-axis pivot joints (70, 74). 6. Device according to claim 5, characterized in that the parts (70, 74) of the joint that can be pivoted relative to one another carry slats (84, 85) that are pressed against one another by the spring (83) and are pneumatically removed from one another. 7. Device according to one of the preceding claims, characterized in that in the connecting part (1) connections (25, 26) for a supply line of a pneumatic medium and for a vent line are arranged, that these connections (25, 26) are connected to all devices (16; 76) for fastening and releasing the joints (8, 9, 10; 70, 74), and that these connections (25, 26) have valves (32, 33; 39, 41) which close the connections (25, 26) as soon as they are separated from the supply line and the vent line. AESCULAP AG .:.. : ·,.· ; ..·...· ^A 52708 u 11 June 1995 u-234 - 22 - 8. Device according to claim 7, characterized in that a check valve (32, 33) closing in the inflow direction is arranged in the connection (25) of the supply line. 9. Device according to claim 7 or 8, characterized in that in the connection (26) of the vent line a spring-loaded closing valve (39, 41) is arranged, which is opened by an actuating element (42) against the action of a spring (40), wherein the actuating element (42) is actuated by the positioning of the vent line at the connection (26). 10. Device according to one of claims 7 to 9, characterized in that a storage chamber (45) for the pneumatic medium is arranged in the connection part (1), which is connected on the one hand to the connection (25) for the supply line and on the other hand to the devices (16) for releasing the joints (8, 9, 10; 70, 74). 11. Device according to claim 10, characterized in that a pressure limiter (50) is inserted in the line of the pneumatic medium between the storage chamber (45) and the devices (16; 76) for releasing the joints (8, 9, 10; 70, 74). AESCULAP AG <,;.. : ·,.· : ..·..»· A 52708 U 11 June 1995 "" u-234 - 23 - 12. Device according to claim 10 or 11, characterized in that an actuatable closing valve (63) is inserted between the storage chamber (45) and the devices (16; 76) for releasing the joints (8, 9, 10; 70, 74), the actuating member (64) of which is arranged on the holder (4). 13. Device according to claim 12, characterized in that the closing valve (63) simultaneously opens or closes the supply of the pneumatic medium to all devices (16; 76) for releasing the joints (8, 9, 10; 70, 74). 14. Device according to one of the preceding claims, characterized in that a joint (8, 9, 10; 70, 74) is assigned a mechanically operable release member (66), with which the device (16; 76) for releasing the joints can be transferred into the state releasing the joint against the action of its spring (22; 83). 15. Device according to claim 14, characterized in that the release member (66) comprises an eccentric (67).