The invention relates to an end effector for a surgical instrument as well as a surgical instrument having an end effector.
Surgical interventions on human bodies are today carried out to an increasing extent with minimally invasive methods with the support of surgery robots. Depending on the type of intervention, the surgery robots can be equipped with various surgical instruments, such as, for example, endoscopes, cutting, gripping or sewing instruments. During an operation, the instruments are introduced into the body of the patient by means of one or more robots via a sheath. During the operation, the surgical instrument is then controlled by a surgeon via an input device of the robot system, such as, for example, via a joystick or by means of gesture control.
Today, a wide range of instruments are used for surgical use, such as, for example, endoscopes, laparoscopic instruments, cutting, gripping, holding, connecting or sewing instruments as well as other surgical tools. The actual end effector, such as, for example, a scalpel, scissors, a needle, a scraper, a file, a gripper, etc., is located at the distal end of the surgical instruments or tools. The surgical instruments known from prior art are typically actuated by means of a cable drive.
It is therefore the object of the present invention to create a surgical instrument which is constructed clearly more simply than known surgical instruments with a cable drive. Additionally, an object of the present invention is to create an end effector having an integrated drive unit.
This object is solved according to the invention by the features specified in the independent claims. Further embodiments of the invention arise from the sub-claims.
According to the invention, an end effector for a surgical instrument is proposed which comprises a drive unit having an electric motor which drives a shaft in a rotational manner. The drive unit furthermore comprises a rotation-translation transmission which translates a rotational movement of the shaft into a translational movement and acts on a working element, such as, for example, a gripper, such that it is driven by the transmission in a translational manner, preferably in a purely translational manner. Such an end effector is therefore constructed to be substantially simpler than an end effector having a cable drive. According to the invention, the end effector furthermore comprises a repelling component which drives the working element in a closing direction.
The translational movement of the driven working element preferably runs transversely to a rotational axis, around which the shaft of the drive unit rotates.
A working element can, for example, be the jaws of a gripper, a scalpel, a scissor blade, a needle, a clamp or any other element of a known medical tool. Differently shaped working elements can also be present in an end effector; for example, the end effector can be formed as so-called anvil scissors, in which one working element is formed as a cutting element and the other as an anvil which complements the cutting element.
Furthermore, sensors can be attached/integrated to and/or into the working elements. Sensors which typically detect pressure, force, torque, temperature, acceleration/speed, distance. Imaging sensors are, however, also conceivable, as they are already available today in small versions in so-called image processors. These then not only serve for informative support of the surgeon, but also serve the surgical instrument and/or robot systems for the open-loop-control or closed-loop-control thereof. In particular, the joining of several sensors (keyword sensor fusion) also allows the operator or the surgical robot system to make decisions which support him in his work and/or also serve above all, however, for critical assessment/analysis of the functional safety. The task of such sensors would, however, also be to detect errors in the system or operating errors, electrical, software and/or mechanical failures and/or foreign influences such as collisions and/or to evaluate them according to a safety plan, to weight them and to initiate corresponding actions.
A further field of application of these sensors would also be to enable a tracking and recognition system for the gripper and/or the instrument. In particular, the positional and temporal sensory detection in Cartesian dimensions enables not only the detection of collisions/prevention of collisions, but additionally computer-supported and/or model-based collision consideration. The possibility to calculate this proactively therefore also enables a very early warning and therefore, as a consequence, a collision prevention strategy. This would mean that the surgical operator not only receives an assistance function “to hand”, but also the possibility of an automatic non-stop device. Therefore, in the preliminary stage, collisions can already be prevented which would no longer have been able to be prevented otherwise by the operator. Assistance, as well as automatic emergency and aid functions, can therefore be affixed/implemented not only locally, so in the end effector itself, but also in the instrument and/or in the robot system.
The end effector according to the invention preferably comprises means for releasable fastening of the end effector to the shaft of a surgical instrument. The end effector can therefore be exchanged or maintained simply. To fasten the end effector to a surgical instrument, for example, a screw or plug connection can be provided which can have, if necessary, catching means. The end effector can, however, also be mounted to be fixed to the surgical instrument.
According to a preferred embodiment of the invention, the rotation-translation transmission comprises a rotatable element having a planar curve which engages with at least one working element, which is driven in a translational manner, and guides this. The rotating element is preferably provided on an end of the shaft driven by an electric motor and can, for example, be designed in a disc shape.
The curve provided on the rotating element can, for example, be formed as a spiral-shaped thread path or as a spiral-shaped groove.
The curve preferably spans a flat surface, the surface normal of which is directed in the direction of the rotational axis of the shaft driven by an electric motor.
According to a specific embodiment of the invention, the rotation-transformation transmission can also comprise several curves which each engage with at least one working element and drive this differently. Therefore, for example, several drive elements can be driven with different translation. Alternatively or additionally, several working elements could also be driven at staggered times, so independently of one another.
One embodiment of the end effector according to the invention comprises at least one first working element which engages with a first curve of the rotation-translation transmission, and at least one second working element which engages with a second curve. The at least one first working element can therefore be driven using a first movement profile, and the at least one second working element using a, if necessary, different second movement profile. Such an embodiment of an end effector can, for example, comprise two first working elements which are guided by a first curve, and a second working element which is guided by a second curve.
According to a specific embodiment of the invention, the end effector comprises two working elements which are arranged opposite each other with respect to the rotational axis of the shaft and can be moved towards each other or away from each other by a rotational movement of the shaft. Both working elements thereby preferably engage with the same curve.
The rotating element of the rotation-translation transmission is preferably designed as a separate component which can be brought into engagement with the shaft of the drive unit. A sprocket can be provided on the end of the shaft which can engage with a corresponding recess on the rotating element.
Preferably, the rotating element of the rotation-translation transmission is pre-tensioned such that the working elements, for example in the event of failure of the drive unit, can close automatically. For example, a repelling component, for example a (spiral) spring, which is supported on the housing inner wall of the end effector, can act on the rotating element. The spring is tensioned by a rotational movement of the rotatable element in the opening direction of the end effector and therefore counteracts the drive unit. The spring can also be integrated into the end effector by pre-tensioning such that, even in the closed state of the end effector, a force of the spring is exerted in the closing direction. By relaxing the spring, the spring drives the rotating element in the closing direction of the end effector. The spring force is advantageously selected in such a way that frictional losses as well as opposing moments of the motor can be overcome.
Preferably, the actual tool of the end effector is designed as a separate component which can be fastened releasably to the drive unit of the end effector. In this case, the tool of the end effector preferably comprises a fastening device, such as, for example, a screw, plug or catch connection. The drive unit and the end effector could, however, also be formed in one piece.
According to a preferred embodiment, the whole end effector together with its drive unit is able to be mounted on the shaft of a surgical instrument. For this purpose, a suitable connection, for example a screw, plug or catch connection, or any other known quick connection mechanism, such as, for example, a bayonet catch, can in turn be provided.
The end effector according to the invention can also comprise a second drive unit with which the end effector can be rotated around the rotational axis of the shaft. The operating possibilities of the surgical instrument can thereby be further improved.
A particularly simple embodiment of an end effector results if the first drive unit to actuate the tool or working element of the end effector is constructed identically to the second drive unit to rotate the end effector.
The drive units according to the invention preferably each comprise an electric motor. The drive unit can furthermore comprise a transmission with which the rotational movement of the shaft driven by the electric motor is transferred to a second shaft.
The invention also relates to a surgical instrument for use on a surgery robot for minimally invasive surgery. The surgical instrument has a shaft which extends in the longitudinal direction of the surgical instrument, wherein an end effector is provided at the distal end of the shaft, as was described above.
The surgical instrument according to the invention can additionally have a manipulator to position the end effector, said manipulator having several rotatable elements. The manipulator can, for example, comprise at least one first rotatable element which is arranged to be rotatable around a first rotational axis, as well as at least one second rotatable element which is arranged to be rotatable around a second rotational axis. Additionally, the manipulator comprises a first drive unit to drive the first rotatable element and a second drive unit to drive the second rotatable element. The drive units are integrated into the manipulator. Furthermore, the first and second rotational axes are arranged at an angle to each other. Due to the angled arrangement of the rotational axes, it is possible to drive the rotatable elements directly, each with the aid of an electric motor, without having to divert the rotational movement of the electric motor via a cable mechanism to the pivot axes.
In an advantageous embodiment of the invention, the drive units of the manipulator and the drive unit of the end effector are constructed identically.
The invention is explained in more detail below by way of example by means of the enclosed drawings. Here are shown:
With regard to the explanation of
The surgical instrument 1 depicted in
The surgical instrument 1 can, for example, be a gripping, holding, cutting, sawing, grinding, connecting or joining instrument or any other surgical instrument. The end effector 7 of the surgical instrument 1 can, for example, be formed as a scalpel, scissors, tongs, a trocar, etc. The use of optical or image-processing tools, such as, for example, lamps, laparoscopes or cameras, is also possible.
The tool 38 of the end effector 7 is fastened releasably to the drive unit 6. To fasten the tool 38, a fastening device 5 is provided on the proximal end of the tool 38. The fastening device 5 can, for example, comprise a screw, plug or catch connection. With the aid of the fastening device 5, it is possible to exchange the tool 38 quickly and simply for another or to replace it if needed. It is therefore no longer required to exchange the entire surgical instrument 1.
Alternatively, the tool 38 could naturally also be formed as a unit together with the drive unit 6. In this case, a corresponding fastening device could be provided on the proximal end of the drive unit 6.
A sprocket 21 is located on the free end of the output shaft 18, said sprocket being plugged into a corresponding recess of a rotation-translation transmission 29. Alternatively, any other known device for torque transfer could, of course, be provided in which the torque exerted by the shaft 18 driven by the electric motor is transferred directly to the tool 38, such as, for example, a shaft hub connection.
The rotation-translation transmission depicted in
A plug connection is provided here to fasten the tool 38 to the distal end of the drive unit 6. The tool 38 comprises, for this purpose, a fastening section 5 which can be plugged onto the distal end of the drive unit 6. The fastening section 5 preferably comprises catch means (not shown) to latch with the drive unit 6.
The drive unit 6 depicted in
The end effector depicted in
At this point, it should be noted that the invention is not limited to the use of a spring, but alternatively other components can be used as a repelling component 41, which cause an automatic closing of the working elements 8.
The element 40a comprises, in this embodiment, a drive unit 6a, as is depicted by way of example in
The first rotatable element 40b is rotatable around a first rotational axis 32 which runs in the longitudinal direction L of the shaft 3. A distally connected second rotatable element 40c is rotatable around a second rotational axis 33 relative to the element 40b, said second rotational axis being inclined compared to the first rotational axis 32 at a predetermined angle. A third rotatable element 40d which is distally adjacent to the element 40c is rotatable around a third rotational axis 34 compared to the element 40c, said third rotational axis being inclined compared to the rotational axis 35 at a second angle. The two angles are preferably of the same size, but can also be of different sizes.
The individually rotatable elements 40b-40d are each driven in a rotational manner by an associated drive unit 6a-6c. The first drive unit 6a to drive the first rotating element 40b is thereby integrated into element 40a.
The drive unit 6b to drive the second rotatable element 40c in a rotational manner is arranged in the first rotatable element 40b. The third drive unit 6c to drive the third rotatable element 40d in a rotational manner is accommodated in the third rotatable element 40d. A drive unit is not provided in the second rotatable element 40c in this variant.
By actuating the first drive unit 6a, the first rotatable element 40b rotates around the first rotational axis 32. If the second drive unit 6b is driven, the second rotatable element 40c rotates around the second rotational axis 33. By actuating the third drive unit 6c, the third rotatable element 40d finally rotates around the third rotational axis 34.
By driving the second and third rotatable element 40c and 40d in a rotational manner around their rotational axes 33, 34, the end effector 7 connected to the distal end of the manipulator 4 can be unwound at a determined angle relative to the longitudinal axis L of the surgical instrument. This angle thereby corresponds to double the sum of the two angles, around which the rotational axes 33 and 34 are inclined relative to the longitudinal axis L or rotational axis 35. If the two angles, for example, each amount to 22.5 degrees, the end effector 7 can be deflected by up to 90 degrees. Depending on the design of the rotational axes 33, 34, larger or smaller angles can of course also be achieved.
As can furthermore be recognised in
Number | Date | Country | Kind |
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10 2013 110 216.6 | Sep 2013 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/069282 | 9/10/2014 | WO | 00 |