Robotic surgery system and surgical instrument

Abstract

A robotic surgery system includes a robot and an instrument assembly. The instrument assembly includes a drive unit with at least one rotary drive having an electric motor and a drive shaft that has a coupling part for coupling to a drive shaft of the instrument; an instrument including an instrument shaft and a drive shaft that has a coupling part for coupling to a drive shaft of the drive unit; and an instrument interface including a sheath that encompasses the drive unit. In order to detachably couple an instrument module to an instrument part of a surgical instrument, an electromagnet in a magnet assembly of the instrument module is activated or deactivated, a permanent magnet of said magnet assembly is moved into a locking position and/or an angular position of a coupled counter element assembly of the instrument part is detected by an angle sensor of the instrument module.

Claims

1. An instrument module for a robotic surgery system, comprising: a coupling element assembly including at least one coupling element for detachably coupling with a counter element assembly having at least one counter element for actuating an end effector of a surgical instrument; the coupling element assembly configured to magnetically couple with the counter element assembly in at least two different rotational orientations about its own longitudinal rotation axis when coupled thereto; wherein the longitudinal axes of the coupling element assembly and the counter element assembly are parallel; and an angle sensor detecting an angular position of the counter element assembly relative to the coupling element assembly about its rotational axis when the counter element assembly is coupled thereto.

2. The instrument module of claim 1, wherein the angle sensor is a non-contact sensor.

3. The instrument module of claim 1, wherein the coupling element moves translationally and/or rotationally in order to actuate the end effector.

4. The instrument module of claim 1, wherein the coupling element comprises a magnetic assembly for magnetically coupling the counter element assembly with the coupling element assembly.

5. The instrument module of claim 4, wherein the magnetic assembly comprises at least one selectively energizable electromagnet.

6. The instrument module of claim 4, wherein the magnetic assembly comprises at least one permanent magnet.

7. The instrument module of claim 6, wherein the permanent magnet can be adjusted at the coupling element between a locked position and an unlocked position.

8. The instrument module of claim 7, wherein the permanent magnet can be adjusted by electromotive, hydraulic, pneumatic, and/or manual means between the locked and an unlocked positions.

9. The instrument module of claim 4, wherein the coupling element comprises a magnetically conductive section for coupling with the counter element assembly when the counter element assembly is coupled thereto.

10. The instrument module of claim 9, wherein the magnetically conductive section is operable to selectively magnetically impinge the counter element assembly when the counter element assembly is coupled thereto.

11. The instrument module of claim 1, further comprising: a drive operable to actuate the coupling element assembly or an instrument shaft with an end effector that can be inserted into a patient, the end effector being actuated by the coupling element assembly.

12. A surgical instrument, comprising: an instrument module, the instrument module comprising: a coupling element assembly with at least one coupling element, and an angle sensor detecting an angular position of a counter element assembly relative to the coupling element assembly; and an instrument part, comprising: a counter element assembly detachably coupled with the coupling element assembly and including at least one counter element for actuating an end effector of a surgical instrument, the counter element comprising at least one of: a) a section that can be magnetically impinged for magnetically coupling the counter element with the coupling element, or b) a torque-proof transmitter detectable by the angle sensor of the instrument module; the coupling element assembly and the counter element assembly magnetically couplable with each other in at least two different rotational orientations about their longitudinal rotation axes, wherein the longitudinal axes of the coupling element assembly and the counter element assembly are parallel.

13. The surgical instrument of claim 12, wherein the coupling assembly and the counter element assembly can be connected in a form-fitting fashion.

14. The surgical instrument of claim 12, further comprising: a sterile barrier arranged between the coupling element assembly and the counter element assembly.

15. The surgical instrument of claim 14, wherein the sterile barrier comprises a coupling part for coupling the counter element assembly to the coupling element assembly.

16. The surgical instrument of claim 15, wherein the coupling part is magnetically conductive for magnetically coupling the counter element assembly with the coupling element assembly.

17. The surgical instrument of claim 12, further comprising: a guide supporting the coupling assembly and the counter element assembly such that there is freedom of movement between the coupling assembly and the counter element assembly.

18. A method for coupling an instrument module with at least one instrument part of a surgical instrument, the instrument module comprising a coupling element assembly with at least one coupling element and an angle sensor, the instrument part comprising a counter element assembly magnetically detachably couplable with the coupling element assembly in at least two rotational orientations about their longitudinal rotation axes, and including at least one counter element for actuating an end effector of a surgical instrument, wherein the longitudinal axes of the coupling element assembly and the counter element assembly are parallel, the method comprising at least one of: activating and deactivating an electromagnet of a magnetic assembly of the instrument module; adjusting a permanent magnet of the magnetic assembly of the instrument module into a locked position; or detecting an angular position of the coupled counter element assembly of the instrument part with the angle sensor of the instrument module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional advantages and features are discernible from the dependent claims and the exemplary embodiments. For this purpose it is shown, partially schematically:

(2) FIG. 1 a part of an instrument assembly of a robotic surgery system according to an embodiment of the invention in a perspective cross-section,

(3) FIG. 2 a transmission at the side of the instrument according to another embodiment of the present invention;

(4) FIG. 3 a transmission of FIG. 2 in another perspective cross-section;

(5) FIG. 4 a cross-section of a conical coupling of an instrument assembly according to one embodiment of the present invention;

(6) FIGS. 5A-5D additional embodiments of such a conical coupling;

(7) FIG. 6 another shaft coupling of an instrument assembly according to an embodiment of the present invention;

(8) FIG. 7 a cross-section of this shaft coupling of FIG. 6;

(9) FIG. 8 a magnetic coupling of an instrument assembly according to one embodiment of the present invention;

(10) FIG. 9 the magnetic coupling of FIG. 8 in a cross-section;

(11) FIGS. 10A, 10B a transmission according to one embodiment of the present invention in two perspective views;

(12) FIG. 11 an enlarged cross-section of the transmission of FIGS. 10A, 10B,

(13) FIGS. 12A, 12B an instrument according to one embodiment of the present invention with a distal transmission in a perspective overall view (FIG. 12A) and/or an enlarged detail (FIG. 12B);

(14) FIG. 13 an instrument interface according to one embodiment of the present invention;

(15) FIG. 14 the instrument interface of FIG. 13 with a connected blind plug;

(16) FIG. 15 the instrument interface of FIG. 14 with the blind plug removed;

(17) FIG. 16 the instrument interface of FIG. 15 with the cap ring connected;

(18) FIG. 17 the instrument interface of FIG. 16 with the instrument coupled;

(19) FIG. 18 an instrument assembly with an inserted auxiliary instrument according to an embodiment of the present invention;

(20) FIG. 19 a part of an instrument of an instrument assembly according to another embodiment of the present invention;

(21) FIG. 20 a part of an instrument of an instrument assembly according to another embodiment of the present invention;

(22) FIGS. 21A, 21B: an encompassing of a robot with a cover according to one embodiment of the present invention;

(23) FIG. 22 a part of a surgical instrument according to one embodiment of the present invention in a longitudinal cross-section;

(24) FIG. 23 a part of a surgical instrument according to another embodiment of the present invention in an illustration according to FIG. 1

(25) FIG. 24 a part of a surgical instrument according to another embodiment of the present invention shown in FIG. 1, 2 in a respective illustration;

(26) FIG. 25 a part of a surgical instrument according to another embodiment of the present invention; and

(27) FIG. 26 a part of a surgical instrument according to another embodiment of the present invention shown to FIG. 4 in a respective illustration.

DETAILED DESCRIPTION

(28) FIG. 1 shows a part of an instrument assembly of a robotic surgery system according to one embodiment of the invention in a perspective cross-section.

(29) The instrument assembly comprises an instrument 1, a drive unit 2 connected thereto, and an instrument interface with a sterile cover 5 arranged between the drive unit and the instrument.

(30) In this exemplary embodiment the rotary axes of the drive unit coincide with a shaft axis of the instrument. This concept is in particular suitable for instruments actuated with tensile/thrust rods.

(31) The sterile surgical instrument 1 is shown in FIG. 1 at the left side, the drive unit 2 in FIG. 1 at the right side. The instrument 1 is mechanically attached in a detachable fashion to a housing 6 of the drive unit 2 via a connection flange 4 at a proximal end of the instrument shaft 3. The drive unit 2 is encompassed by a sterile cover 5 in order to prevent any contamination of the surgery area.

(32) In this exemplary embodiment, three independent rotary drives are respectively located in the housing 6 of the drive unit 2, each comprising a drive shaft 10, 13, and/or 15 and a corresponding electromotor 7, 8, and/or 9. The drive shafts 10, 13, 15 are embodied as hollow shafts and arranged coaxially in reference to each other. The drive shaft 10 is supported entirely at a bearing site 11 in the housing 6. The inner drive shaft 13 is supported with a bearing 12 in the drive shaft 10, the drive shaft 15 with a bearing 14 in the drive shaft 13. This concept advantageously allows, primarily in the radial direction, a very compact design of the detachable instrument interface. Thus, in a multi-robot application the risk of collisions between individual robots can be considerably reduced due to the shorter allowable minimum distance between the instruments.

(33) The symbolic illustrations of the electric motors 7, 8, 9 include additional components required for a regular operation, such as transmissions and/or sensors, for example. Preferred embodiments are concentrically arranged motor units, which can be implemented either as direct drives or as motors with reduction gears arranged downstream, for example planetary gears or harmonic-drive gears.

(34) In a modification, not shown, the rotary drives may be radially offset electric motors, which respectively drive the drive shafts with a spur gear or friction wheel drive, or have orthogonally offset electric motors, which drive the drive shafts respectively with a worm drive, helical drive, or crown wheel gears.

(35) The nested drive shafts 10, 13, and 15 are continued at the instrument side in the form of drive shafts 16, 17, and/or 18, which are also embodied as hollow shafts and which are arranged coaxially in reference to each other. The support of the drive shafts 16, 17, and 18 at the instrument side is embodied as fixed/floating bearings 28, 29, 30, arranged at the proximal end of the instrument shaft 3. The shaft 16 is radially and axially supported at the bearing site 28 in the instrument shaft 3. The interior drive shaft 17 is supported with the bearing 29 in the drive shaft 16, the drive shaft 18 with the bearing 30 in the shaft 17. The sliding sheaths 23, 24, and 25 act as loose bearings, which simultaneously are components of a transmission 22 at the instrument side for the conversion of the rotational drive motion into a translational motion of the tensile and/or thrust means 26, 39 and/or 40 (cf. FIGS. 10A, 10B). They finally transmit the drive motion to the instruments and/or end effector degrees of freedom at the distal end of the instrument shaft 3.

(36) FIG. 1 shows as an example only one tensile and/or thrust means 26, although for each degree of freedom of the instrument a separate transmission link being provided. Examples for such tensile and/or thrust means are pulleys, Bowden-pulleys, or tensile/thrust rods.

(37) In order to connect the drive shafts 10, 13, and 15 of the drive unit to the drive shafts 16, 17, and 18 at the instrument side a coupling mechanism is provided, which simultaneously represents a sterile barrier between the instrument and the non-sterile drive unit. The coupling shown as an example in FIG. 1 is a conical coupling, which transmits the drive moments via friction-fitting or form-fitting means.

(38) By this design principle the drive shafts 15 and 18, located inside in the coaxial arrangement, can be embodied as hollow shafts as well. This way sufficient space remains in the center of the instrument shaft 3 in order to guide additional drive means, for example a Bowden pulley, a rotary shaft with an elastic section in the area of the multiple link to drive an end effector, and/or an auxiliary instrument, in particular an electric line, a hose, or the like. Another potential application of this design principle is the insertion of special surgical instruments through the center of the instrument shaft.

(39) In order to ensure the sterility of the elements guided through the center of the instrument even in the area of the drive unit 2, the sterile barrier with an inner passage in the form of a sterile guiding tube 27 also extends through the entire drive unit 2, as described in the following.

(40) FIG. 2 shows a transmission 100 at the instrument side according to another embodiment of the present invention, in which the axes of the drive shaft and the shaft are orthogonal. This arrangement is in particular suitable for instruments which are actuated with pulleys. However, it can also be used for instruments with tensile/thrust rods, in which the transmission at the instrument side can be realized for the transmission of the rotation of a drive shaft into a translation of a tension and/or thrust means, for example as a push-crank mechanism.

(41) A housing 104 is located at the proximal end of the instrument 101, connected fixed to the instrument shaft 103. The instrument 101 is connected at the proximal end via a sterile barrier 105 to the drive unit 102 (with its housing not being shown). The drive shafts 106, 107, and 108 are coaxially arranged in the drive unit 102 in order to achieve dimensions as compact as possible. They are continued at the instrument side respectively as a pulley 109, 110, and/or 111. The connection of the shaft sections respectively occurs via the sterile intermediate coupling sections 116, 117, and 118, which are rotational in reference to each other.

(42) An intermediate coupling element 118 of the exterior drive shaft 106 is connected to the sterile barrier 105 and rotationally supported therein. In the exemplary embodiment the drive shafts of the drive unit and the instrument are coupled in a form-fitting fashion to a sprocket coupling, which is described in greater detail with reference to FIG. 6.

(43) The pulleys 112, 113, and 114 actuating the degrees of freedom of the instrument are wound about the pulleys and/or drive shafts 109, 110, and/or 111 at the instrument side, so that the force flux is closed between the drive shafts 106, 107, and 108 and the degrees of freedom of the instrument. Optionally, a tubular passage 115 may be provided, which for example can be used for guiding an auxiliary instrument, in particular a media line, to the distal end of the instrument shaft 103.

(44) Detachable Coupling with Sterile Barriers for at Least One Rotary Drive Train

(45) In order to connect the instrument to the drive unit, a simple, detachable coupling mechanism is provided, which simultaneously represents the sterile barrier between the instrument and the unsterile drive unit.

(46) FIG. 4 shows in a cross-section the conical coupling of the exemplary embodiment of FIG. 1 with a sterile barrier. The coupling assembly transmits the drive moments from the drive shafts 10, 13, and 15 by way of friction-fitting or form-fitting means to the drive shafts 16, 17, and 18 at the instrument side. At the proximal ends of the hollow shafts 16, 17, and 18 at the instrument side, coupling parts are arranged in the form of exterior cones 34, 35, and 36, which are connected fixed to the respective hollow shaft. At the distal ends of the drive shafts 10, 13, and 15 the coupling parts 31, 32, 33 are arranged with inner cones. The connection of the ends of the shaft occurs via conical intermediate elements 19, 20, and/or 21, which act as sterile barriers. These elements are connected to each other and also to the sterile barrier 5 in a sealed fashion. These connections only serve for the simple handling during the installation of the sterile barrier; however, they allow otherwise all motions required for moving the intermediate elements, in particular a rotation of the drive shafts. Simultaneously these intermediate elements 19, 20, and/or 21 represent a gap seal and/or labyrinth seal between the coupling parts.

(47) The coupling parts 31, 32, 33 arranged at the drive shafts 10, 13, and 15 are each connected to a shaft in a torque-proof, however axially displaceable fashion, for example by a geared or a polygonal shaft profile. This way, the axial pre-tension required for transmitting force can be applied by springs, for example, acting upon the coupling parts at the driving side. Simultaneously, a potential axial offset is compensated of the shaft sections between the drive side and the instrument side.

(48) Instead of the combination of the inner cones at the driving side and the outer cones at the instrument side, for each pairing an inner and an outer drive shaft of the drive unit and the instrument is possible and additional arrangements as well, which are sketched in FIGS. 5A-5D according to the following configurations:

(49) TABLE-US-00001 Coupling part FIG. FIG. FIG. FIG. 31/32/33, 34/35/36 5A 5B 5C 5D Inner hollow drive shaft Inner Outer Inner Outer of the drive unit cone cone cone cone Inner hollow drive shaft Inner Outer Inner Outer of the instrument cone cone cone cone Outer hollow drive shaft Outer Inner Inner Outer of the drive unit cone cone cone cone Outer hollow drive shaft Outer Inner Inner Outer of the instrument cone cone cone cone

(50) FIG. 6 shows a shaft coupling with a sterile barrier, which transmits the drive moments in a form-fitting fashion via the spur gears, for example a Hirth-gear, from the drive shafts 10, 13, and 15 to the drive shafts 16, 18 at the instrument side, FIG. 7 shows a cross-section of this shaft coupling. Instead of the conical coupling of FIG. 4, 5, in particular the shaft coupling can be provided in an instrument assembly according to FIG. 1, 2 or 3.

(51) For this purpose, at the proximal coupling parts of the hollow shafts 16, 17, and 18 at the instrument side spur gears 203, 204, 205 are applied, which are connected fixed to the respective hollow shaft. At the distal ends of the drive shafts 10, 13, 15, the coupling parts are arranged in the form of sliding sheaths with spur gears 200, 201, 202. The connection of the shaft ends occurs via sheath-like intermediate elements 206, 207, and 208 with spur gears at both sides, which act as sterile barriers. The intermediate sheaths 206, 207, 208 are connected to each other and to the sterile barrier 5 by the fastening rings 209, 210, 211. The inner passage and/or the sterile guide tube 27 are connected this way to the innermost intermediate sheath 208 so that the entire arrangement represents a sterile barrier with gap seals. The intermediate sheaths 206, 207, 208 only serve for the simple handling during the installation of the sterile barrier, however otherwise they allow all motions required for the function. They act as gap and/or labyrinth seals.

(52) The sliding sheaths 200, 201, 202 arranged on the drive shafts 10, 13, and 15 are each connected to the shafts in a torque-proof yet axially displaceable fashion, for example by a geared or polygonal shaft profile. This way the axial pre-stressing necessary for transmitting force can be applied for example by springs which act upon the sliding sheaths 200, 201, 202. Simultaneously a potential axial offset is compensated between the shaft sections at the drive side and the instrument side.

(53) Another variant of the shaft coupling with sterile barriers is the magnetic coupling shown in FIG. 8. The shaft coupling may be provided instead of the conical and/or shaft coupling of FIGS. 4 to 7, in particular in an instrument assembly according to FIG. 1, 2 or 3.

(54) Coupling parts in the form of magnetic rings 200, 201, and/or 202 are fixed at the distal ends of the drive shafts 10, 13, and 15. Similar thereto, coupling parts are fixed in the form of magnetic rings 203, 204, and/or 205 at the hollow shafts 16, 17, and 18 respectively at the instrument side. All magnetic rings 200 to 205 are sectionally magnetized and aligned towards each other with a preferably small axial distance and/or air gap in order to allow transmitting the highest possible drive moments. The strength of the moment that can be transmitted depends, in addition to the air gap, also on the magnetic field strength and the number of magnetic sectors.

(55) FIG. 9 shows in a cross-section a magnetic coupling with sterile barriers. The magnetic rings are aligned towards each other with minimal axial distance in order to allow transmitting the highest possible drive moments. An advantageous feature of this coupling principle is the simple design of the sterile cover 5. Due to the narrow axial air gap of the magnetic coupling a simple film can be used and no specially formed part is necessary.

(56) Implementing the Rotation-Translation Movement Type at the Instrument Side

(57) In one embodiment of the present invention only rotary drives are used. The drive trains in robotic guided surgical instruments however use, due to the tight design space inside the instrument shaft, primarily pulleys or tension/thrust rods for transmitting the drive motions to the distal end of the instrument. Thus, according to the above-described detachable instrument interface, a transmission 22 is provided at the instrument side in order to convert the rotary drive motion into a translational motion of the pulleys or tension/thrust rods.

(58) FIG. 10 shows in two perspective illustrations a converting transmission 22 according to one embodiment of the present invention, in which a separate sliding sheath is provided for each drive shaft. In the case shown here, the three sliding sheaths 23, 24, and 25 convert the rotation of the drive shafts 16, 17, and 18 into a translation of the tension and/or thrust means 26, 39, and 40. The sliding sheaths 23, 24 and 25 act simultaneously as a distal loose bearing for the hollow shafts 16, 17, and/or 18. The sliding sheaths themselves only have a translational degree of freedom, which allows the displacement along the axis of the shaft. The restriction of the degree of freedom of the sliding sheaths 23, 24 and 25 is achieved by groove-guides 41, 42, and 43, which are nested in each other. The sliding sheaths 23, 24, and 25 are inserted into each other such that a sheath positioned outside accepts the bearing of the sheath located inside. This way, a very compact design is achieved.

(59) Accordingly, the exterior sliding sheath 23 is supported in the instrument shaft 3. A transitional fitting between the sheath 23 and the shaft 3 serves as a radial bearing. A rotation of the sheath 23 is blocked by a feather key 41 fixed at the sheath 23, gliding in a groove inserted in the instrument shaft 3. The sliding sheath 24 is supported in the exterior sliding sheath 23. A transitional fitting between the sheath 24 and the sheath 25 serves as a radial bearing. A rotation of the sheath 24 is blocked by the groove guide 42. The inner sliding sheath 25 is supported in the sliding sheath 24. A transitional fitting between the sheath 25 and the sheath 24 serves as a radial bearing. A rotation of the sheath 25 is blocked by the groove guide 43.

(60) The coupling of the drive shafts to the sliding sheaths is done with a guiding groove, with its functionality being explained as an example with reference to the hollow shaft 18 located at the inside, and FIG. 11, which shows an enlarged cross-section. A helical groove 37 is inserted at the distal end of the hollow shaft 18. A pin 38, which is fixed at the sliding sheath 25, engages the helical groove 37 in a form-fitting fashion. Thus, a rotation of the hollow shaft 18 leads to a displacement of the sheath 25 along the axis of the shaft and thus also to an adjustment motion of the tensile and/or the thrust means 26. At the distal end of the sliding sheaths 23, 24, and 25 the tensile and/or thrust means 26, 39, and 40 are connected, which transfer the drive motion to the degrees of freedom of the instrument and/or an end-effector at the distal end of the instrument shaft 3.

(61) One advantage of this solution is that the drive motions, in particular the adjustment angle and the angular speed, can be adjusted within every instrument to the respective requirements, as the incline of the guide bar determines the transmission ratio and the operating range. Thus, the drive unit can be used for the highest possible number of different instruments and the efficiency and user friendliness can be increased.

(62) Instead of the proximal arrangement shown in FIGS. 10, 11, the transmission can alternatively also be arranged at the distal end of the instrument, thus as close as possible at the instrument kinematics and the end effector. FIGS. 12A and 12B show an instrument 400 according to an embodiment of the present invention with a distal transmission in a perspective, comprehensive view (top in FIG. 12A) and/or an enlarged detail (bottom in FIG. 12B).

(63) The transmission is located at the distal end of the instrument 400 and thus near the instrument kinematics 402 and the end effector 403. The actuation of the distal joint 402, which in the example shown is embodied as a parallel kinematics, occurs with tensile and/or thrust means in the form of coupling rods 408 and 409, which are rotationally connected to the segment carrying the end effector. The respectively other ends of the coupling rods 408 and 409 are rotationally connected to the sliding sheath 406 and 407, which are displaced along the axis of the shaft for adjusting the angle of the joint. The sliding sheaths 406 and 407 are connected to the hollow shafts 404 and/or 405, with the conversion of the rotary drive motion into the translational feed motion of the sheath occurring via the guide bar mechanics described in reference to FIGS. 10A, 10B, and 11. Sufficient space remains in the center of the inner hollow shaft 405 in order to pass drive means through it, for example a Bowden pulley or a rotary shaft with a flexible section in the area of the multiple joint for driving the end effector 403 and/or an auxiliary instrument, in particular electric supply lines, hoses, or the like.

(64) Contrary to the pulleys used in common instruments of minimally invasive robotic surgery, in this embodiment the drive performance is transmitted from the drive unit to the tip of the instrument via hollow shafts, coaxial in reference to the shaft of the instrument. This can yield a considerably higher resilience and stiffness of the drive train in reference to pulleys or thin solid shafts, so that advantageously higher driving forces can be transmitted. Accordingly this embodiment is especially recommended for instruments in which higher processing forces develop, e.g., devices for placing staple sutures.

(65) Sterile Barrier Between the Drive Unit and the Instrument

(66) Some components of the drive unit cannot tolerate the environmental conditions during a sterilization process. Accordingly, the instrument interface comprises a sterile cover which shields the drive unit during operation. In addition to the cover, which securely encompasses the housing of the drive unit and commonly is embodied as a film hose, the instrument interface between the drive unit and the instrument should allow the transmission of mechanic power and electric signals and simultaneously prevent any contamination of the surgery area by an unsterile drive unit.

(67) FIG. 13 shows an overview of the instrument interface 500 with various partial components, which may be provided for example for the instrument assembly of FIG. 1.

(68) The instrument interface 500 comprises a sterile film cover 501, which encompasses the housing of the drive unit 2, an inherently stable flange and/or instrument carrier 5, which for the purpose of coupling the drive trains, comprises for example the conical intermediate elements 19, 20, 21 described in reference to FIG. 4, as well as an inner passage in the form of the guiding tube 27. A connection ring 503 connects the guide tube 27 to the film cover 501. In order to ensure the sterility of the guide tube 27 during the insertion process into the drive unit 2 the guiding tube 27 is initially closed at its proximal end with a blind plug 502, which also covers a section of the jacket. The instrument interface 500 is designed as a comprehensive assembly, in which all parts are combined to form a unit. This way the handling is greatly simplified. In case of the magnetic coupling explained in reference to FIG. 8, a film is sufficient as a sterile barrier and/or instrument interface between the shaft sections.

(69) The other FIGS. 14 to 17 illustrate the sterile packaging of the drive unit and the connection of a surgical instrument thereto. The instrument carrier 5 is placed onto the drive unit as the first step (cf. FIG. 14). Simultaneously the sterile guide tube 27 is inserted into the hollow shaft as well as the intermediate parts 19, 20, 21 of the shaft couplings into the drive unit 2, and the film cover is slid over the drive unit 2. Then the blind plug 502, which after passing through the sterile guide tube 27 has become unsterile due to the hollow shaft of the drive unit 2, is pulled off the guiding tube 27 and discarded by an unsterile member of the surgery team (cf. FIG. 15). Due to the fact that the blind plug 502 also covers a portion of the jacket of the guiding tube 27, the section of the guiding tube 27 projecting out of the drive unit 2 remains sterile. Finally, the sterile cover is sealed by a placement of the cap ring 503 onto the guiding tube 27 (cf. FIG. 16). FIG. 17 finally shows the docking of a surgical instrument 1 to the sterilely packaged drive unit 2.

(70) Guiding Additional Drive Trains and/or Auxiliary Instruments Through the Instrument Shaft Towards the Distal End of the Instrument

(71) In addition to a simple mechanic design of the detachable instrument interface, the coaxial arrangement of all drive shafts offers the advantage that the center of the drive unit and the instrument are clear for additional driving means, for example pulleys, Bowden pulleys, and/or rotary shafts being guided through it to actuate the end effector. For example, a Bowden pulley can be used in duplicate; the cover serves for transmitting a first actuating force, the core of the transmission. Additionally, electric lines for monopolar or bipolar instruments, suction and rinsing hoses may be guided in the center of the instrument shaft. Similarly, other auxiliary instruments may also be guided by the robot, for example fiber optics for laser applications or flexible instruments for the argon-plasma coagulation, for cryosurgery, or water jet surgery, frequently used for tumor resection.

(72) FIG. 18 shows an instrument assembly with a stiff or flexible auxiliary instrument being inserted and/or guided through.

(73) For this purpose, after the placement of the sterile cover 501, the auxiliary instrument 504 is advanced from the rear through the guiding tube 27 through the drive unit 2 to the distal end of the instrument 1 and fixed in this position. Subsequently, the auxiliary instrument 504 can be used like a common robot-guided instrument and be moved by the degree of freedom provided by the instrument 1 in the surgery area. In addition to the suitability for stiff and flexible auxiliary instruments this solution offers the advantage that no additional design space is required in the area of the detachable instrument interface in order to insert the auxiliary instrument 504 into the instrument shaft.

(74) FIG. 19 shows a part of an instrument of an instrument assembly according to another embodiment of the present invention which is in particular suitable for flexible auxiliary instruments. Here, the auxiliary instrument 507 is not introduced through the drive unit 2, but through a curved tubular section 506, which is arranged at the instrument shaft 505 directly in front of the drive unit 2 and/or the instrument interface. In this solution a sterile cover 501 can be designed in a simpler fashion, because the auxiliary instrument 507 is not guided from the rear through the drive unit.

(75) FIG. 20 shows a part of an instrument of an instrument assembly according to another embodiment of the present invention in which the axis of the drive and the axis of the shaft are orthogonal. Here, both stiff as well as flexible auxiliary instruments can be inserted and/or passed through. The auxiliary instrument 508 is fed from the rear through a guiding tube 115 and through the housing 104 to the distal end of the instrument shaft 103 and fixed. Subsequently, the auxiliary instrument 508 can be used like a common robot-guided instrument and moved with the degrees of freedom provided by the instrument 100 in the surgery area. Here, too, no design space is required at the proximal end of the instrument shaft in order to insert the auxiliary instrument 508.

(76) The drive unit provides the mechanic drive capacity for all active degrees of freedom of the surgical instrument. It is located at the proximal end of the instrument and is designed as an independent module which is suitable to drive different instruments. In order to avoid any contamination of the surgery area the drive unit is hermetically sealed with a sterile protective cover.

(77) The detachable instrument interface is located between the drive unit and the surgical instrument. Its primary purpose is the mechanical connection of the surgical instrument to the drive unit. On the one hand it provides a force flux between the drive and instrument functional units, and ensures a precise and repeatable relative positioning and fixation of these units. In order to transmit the required mechanical power to the instrument, the detachable instrument interface additionally comprises detachable couplings, which generate the force flux between the individual drives in the drive unit and the drive trains in the instrument. In order to ensure the sterility of the surgical instrument under all circumstances, the detachable instrument interface acts simultaneously as a sterile barrier between the unsterile drive unit and a sterile instrument.

(78) Advantageously the coupling of a surgical instrument of an instrument assembly according to one embodiment of the present invention is simple and requires no detailed special professional knowledge in robotic systems. The detachable instrument interface according to one embodiment advantageously allows the repeatable and reliable coupling of the instrument including all force transmission elements without any visual inspection. The interface can preferably transmit one or more drive motions from a drive unit to a surgical instrument, while the sterility at the instrument side can be ensured. The drive unit and/or the detachable instrument interface advantageously require little structural space in order to minimize the risk of collision in case of a system with several robots, for example. In order to improve the performance of a robotic guided instrument with regards to control technology the transmission of mechanic drive energy to the surgical instrument shall be embodied with as little play and slippage as possible.

(79) FIGS. 21A, 21B show an enclosure of a robot with a cover according to one embodiment of the present invention. The robot, with its robotic hand being partially indicated in FIGS. 21A, 21B comprises a hollow shaft. A tubular interior passage 27 of a cover 501 is guided through it, which includes an outlet opening 507. The end of the inner passage 27 guided through is covered at its beginning with a blind plug 502, for example in a clamped fashion, which has a closed face and a tubular jacket, in order to protect the interior and a facial circumferential section of the inner passage 27 from soiling when being guided through.

(80) The blind plug 502 is guided through the hollow shaft and the outlet opening 507 (FIG. 21A) and subsequently removed. At the circumferential section of the inner passage 27, which was released thereby, and the edge of the outlet opening 507 a sterile cap ring 503A, 503B is fastened, once more for example in a clamping fashion (FIG. 21B). This way, in a simple fashion a sterile encompassing of the robot can be provided with the hollow shaft and/or simultaneously the drive unit of an instrument assembly.

(81) In the exemplary embodiment the inner passage 27 is supported with its end (bottom in FIGS. 21A, 21B) opposite the blind plug 502 and/or the cap ring 503 at the cover 501 in a rotary fashion, for example as described above with reference to the intermediate elements of the instrument interface. The cap ring is embodied in two parts, with one part 503A of the cap ring, fastened at the circumferential section of the inner passage, being supported rotationally at a part 503B of the cap ring fastened at the outlet opening of the cover. This way, the inner passage 27 in its entirety is supported rotationally at the cover 501 and can be entrained, in particular with an auxiliary instrument moved by the hollow shaft. In a variant (not shown) the inner passage may also be embodied integrally and/or in one piece with the cover and/or connected thereto via a one-piece cap ring, with it being possible to compensate any potential rotation of the hollow shaft, for example by loose [sections] of the inner passage and/or the cover.

(82) FIG. 22 shows a part of a minimally invasive surgical instrument according to one embodiment of the present invention in a longitudinal cross-section with an instrument module 1 and a detachable instrument part 2 connected thereto.

(83) The instrument part comprises an instrument shaft 22 with an end effector (not shown), which can be inserted into a patient, with the instrument module comprising a drive for actuating the end effector, as well as an electro-mechanical interface for fastening at a robot (not shown).

(84) The instrument module 1 comprises a coupling element assembly with several coupling elements in the form of translationally moved tappets 10, which are guided in a sliding bearing 12 of the instrument module in a torque-proof but displaceable fashion, and with only one being shown in FIG. 22 for better visibility. The instrument part comprises a respective counter element assembly with counter elements in the form of translationally moved (counter) tappets 20, which are guided in a sliding bearing of the instrument shaft 22 in a torque-proof but displaceable fashion in order to respectively actuate a degree of freedom of the end effector. The translational movement of the tappets and counter-tappets in order to actuate an intra-corporeal degree of freedom of the minimally invasive instrument by the extracorporeal drive is indicated in FIG. 22 by the double arrow of the motion.

(85) The tappets 10 of the coupling element assembly can be magnetically coupled with the counter-tappets 20 of the counter element assembly. For this purpose, the tappets 10 each include a magnetic assembly for a magnetic coupling of the opposite counter tappet 20, which has a section 21 which can be magnetically impinged, comprising a ferromagnetic or permanently magnetic material. The tappets 10 of the coupling element assembly include a magnetically conductive section 11 made from a ferromagnetic material, which has an exterior ring and a central yoke.

(86) An electric coil is arranged about this yoke and cast with a non-magnetic casting material 13, in order to integrally form an electromagnet 31 of the magnetic assembly with the tappet 10, which can optionally be electrified and/or is electrified by a control means provided for this purpose, which is implemented in a drive control of the instrument (not shown).

(87) Additionally, each magnetic assembly includes a permanent magnet 30, which is opposite the electromagnet 31, with its magnetic field being at least essentially compensated by the electrified electromagnet 31 in a facial coupling area of the tappet and the counter-tappet.

(88) Via the optionally electrifiable electromagnet 31 a current-free closed coupling is provided between the coupling element and the counter element; as long as the electromagnet 31 is current-free, the permanent magnet 30 couples the section 21 of the counter tappet 20, which can be impinged magnetically, in a secure fashion to the magnetically conductive section 11 of the tappet 10. By electrifying the electromagnet 31 it compensates the magnetic field of the permanent magnet 30 in its facial coupling area to such an extent that the instrument part 2 can be removed from the drive module 1, preferably under its own weight and/or minor manual force.

(89) Similarly, the electrified electromagnet 31 and the permanent magnet 30 may also act in the same direction and/or their magnetic fields may amplify each other in a facial coupling area of the tappet and the counter tappet.

(90) Optionally a sterile barrier 40 is arranged between the coupling element assembly and the counter element assembly, which is embodied like a film and is flexible in the coupling area in order to follow under elastic deformation any translational movement of the tappet 10 and the counter tappet 20 in order to actuate the end effector.

(91) In one variant, not shown, the permanent magnet 30 may be omitted in order to inversely provide a currentless open coupling between the coupling element and the counter element by an optional electrifying of the electromagnet 31; as long as the electromagnet 31 is electrified, it couples the section 21 of the counter tappet 20, which can be impinged magnetically, in a secure fashion to the magnetically conductive section 11 of the tappet 10. When the electromagnet 31 is currentless the instrument part 2 can be removed from the drive module 1.

(92) FIG. 23 shows a part of a minimally invasive surgical instrument according to another embodiment of the present invention in an illustration according to FIG. 22. Equivalent elements are marked with identical reference characters so that reference is made to the other descriptions, and in the following only the differences from the embodiment shown in FIG. 22 are discussed.

(93) In the embodiment of FIG. 23 the magnetic assembly is not provided with an electromagnet but only with the permanent magnet 30. In particular in order to decouple the coupling element from the counter element 10, 20 without rendering them distant from each other, in this embodiment the permanent magnet 30 can be displaced in the coupling element and/or the tappet 10 between the locked position shown in FIG. 23 and an unlocked position distanced therefrom indicated in dot-dash lines in FIG. 23, which is indicated in FIG. 23 by a dot-dash double arrow showing the motion. The permanent magnet 30 is guided in a displaceable fashion in a longitudinal bore of the tappet 10 and can be adjusted for example by an electromotive, hydraulic, pneumatic, and/or manual displacement of the thrust rod on which it is arranged, and locked in the locked and the unlocked position.

(94) The facial, magnetically conductive section 11 of the tappet 10 is only magnetically impinged by the permanent magnet 30, at least essentially, when it is in the locked position. In the unlocked position (indicated in dot-dash lines in FIG. 23) the permanent magnet 30 is however separated from the magnetically conductive section 11 of the tappet 10 and arranged in a magnetically non-conductive section of the tappet 10 made from plastic with a permeability value .sub.r which amounts to maximally 2.

(95) By adjusting the permanent magnet 30 in the bore of the tappet 10 into the locked position, its magnetically conductive section 11 can be optionally impinged magnetically by the magnetic assembly to couple the counter tappet.

(96) In the embodiment of FIG. 23 the optionally sterile barrier 40 comprises a stiff coupling part 41 made from a magnetically conductive material, in order to improve the mechanic force transmission and the magnetic coupling. In one variant, not shown, the optional sterile barrier may also be embodied like a film, as in FIG. 22, and/or the optional barrier may include a coupling part as the embodiment of FIG. 22.

(97) In the embodiment of FIG. 23, a part comprising a non-magnetic material is marked 13. It may be designed as in the embodiment of FIG. 22 as a casting compound and thus it carries the same reference character. Similarly, the part 13 may be a molded part, which is fastened at the magnetically conductive section 11 and acts as a stop for the displaceable permanent magnet 30.

(98) FIG. 24 shows a part of a minimally invasive surgical instrument according to another embodiment of the present invention in an illustration according to FIGS. 22, 23. Equivalent elements are again marked with identical reference characters so that reference is made to the other description, and in the following only the differences from the embodiment of FIGS. 22, 23 are discussed. In particular, the magnetic assembly and the magnetically conductive sections are not shown in FIG. 24 for a better overview, they may in particular be embodied as shown in FIG. 22 or 23 and/or explained with reference thereto.

(99) In the embodiment of FIG. 24, in addition to the magnetic coupling the tappet 10 and the counter tappet 20 can be connected and/or are connected in a form-fitting fashion. For this purpose, the tappet 10 engages a sheath and/or socket section of the counter tappet 20 like a pin when the coupling element and the counter element are coupled to each other. This way the coupling element and the counter element are fixed in a form-fitting fashion perpendicular in reference to their vertical longitudinal extension, in FIG. 24, i.e. horizontal in the drawing level and/or perpendicular in reference thereto, with the magnetic coupling fixates them in a force-fitting fashion in the direction of their longitudinal extension.

(100) The tappet 10 and the counter tappet 20 are thereby centered in reference to each other in a form-fitting fashion. In order to compensate a lateral and/or angular offset the counter tappet 20 is supported in the embodiment of FIG. 24 with play in the sliding bearing of the instrument shaft 22.

(101) In the embodiment of FIG. 24 the magnetically conductive section 21 of the counter tappet 20 is arranged inside the sheath and/or socket section of the counter tappet 20 in order to this way preferably avoid any unintended magnetic interference.

(102) In the embodiments explained, the coupling element and the counter element are formed like tappets and coupled to each other abutting and/or at their faces, with the magnetic assembly of the coupling element and the counter element pulling them towards each other in the direction of their longitudinal extension in order to transfer tensile forces, while pressures are transmitted in a form-fitting fashion.

(103) Additionally or alternatively, coupling elements and counter elements 10, 20 can be rotationally mobile in the embodiments in order to respectively actuate a degree of freedom of the end effector. The magnetic assembly pulls the coupling element and the counter element in the direction of their longitudinal direction towards each other in order to allow a transmission of torque in one embodiment. This can occur in a friction-fitting fashion due to the axial tension by the magnetic assembly. Equivalently, it may also occur in a form-fitting fashion. For this purpose, in a variant not shown the tappet 10 or the counter tappet 20 may include one or more eccentric projections, in particular gears, which engage respective recesses, in particular inverse gears in the counter tappets 20 and/or the tappet 10, when the coupling element and the counter element are magnetically coupled to each other. In one variant, not shown either, the tappet 10 or the counter tappet 20 includes Hirth-gears.

(104) In such a case, the coupling part 41 may in particular be connected via a rotary seal in a rotational fashion to the remaining barrier 40. Similarly the coupling part 41 can be connected via a translational seal to the remaining barrier 40 in a displaceable fashion, as respectively indicated in FIG. 24.

(105) FIGS. 25, 26 respectively show a part of a minimally invasive surgical instrument according to another embodiment of the present invention in a longitudinal cross-section with an instrument module 1 and a detachable instrument part 2 connected thereto. Equivalent elements are once more marked with identical reference characters so that reference is made to the above-stated description, and in the following only the differences from the embodiment of FIGS. 22-24 are discussed.

(106) In the embodiment of FIG. 26 a coupling element in the form of a rotationally supported drive shaft 10 of an electric motor of the drive (not shown) and a counter element in the form of a rotationally supported drive shaft 20, supported parallel and offset in reference thereto, of an effector of the instrument (not shown) can be coupled to each other in a form-fitting fashion by mutually engaging spur gears 14, 24. In the embodiment of FIG. 25 a sterile barrier 40 is arranged between the coupling assembly and the counter element assembly with a rotationally supported coupling part 42 having two spur gears, which engage the spur gears 14 and/or 24 and this way also couple the coupling element and the counter element 10, 20 in a form-fitting fashion.

(107) A rotary bearing and/or a housing of the instrument module 1 and/or the instrument part 2 are indicated with 12 and/or 22 respectively.

(108) In a variant, not shown, the coupling element and the counter element 10, 20 may additionally or alternatively be magnetically coupled to each other in a torque-proof fashion, as explained above with reference to FIGS. 22-24.

(109) The spur gears between the spur wheels 14, 24 and perhaps 42 are ambivalent and/or can be coupled in various orientations, offset in reference to each other by the tooth pitch.

(110) In order to nevertheless be able to actuate the end effector by a drive without any prior recalibration, the instrument module 1 includes in the embodiments of FIGS. 25, 26 a touchless angle sensor in the form of a magnetic encoder for detecting the angular position of the coupled drive shaft 20 in reference to the housing and/or the rotary bearing 12 of the instrument module 1. The drive shaft 20 comprises accordingly a torque-proof transmitter in the form of a permanent bar magnet 51, which is embodied to be detected by the angle sensor 50. The north-south axis of the bar magnet 51 is aligned perpendicular in reference to the axis of rotation of the drive shaft 20.

(111) During or after the coupling of the instrument part 2 to the instrument module 1 in one or more alignments, the angular position of the transmitter 51 is detected in the coupled drive shaft 20, which in FIGS. 25, 26 once more is only shown as an example, in reference to a point fixed at the housing of the instrument module by the angle sensor 50 of the instrument module. This way, after the detection of the orientation of the counter elements, a position of the end effector is also known, so that the end effector can be correctly actuated by a drive without recalibration.

(112) While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.

LIST OF REFERENCE CHARACTERS

(113) In the FIGS. 1 to 21:

(114) 1, 100, 101, 400 Instrument 2, 102 Drive unit 4 Connection flange 3, 103, 505 Instrument shaft 5, 105, 501 (Sterile) cover 6, 104 Housing 7, 8, 9 Electric motor 11, 12, 14, 28, 29, 30 Bearing site 19, 20, 21, 206, 207, 208 Intermediate element 22 Transmission 23, 24, 25, 37, 38, 200, 201, 202, Sliding sheath (guide bar) 406, 407 26, 39, 40 Tensile/thrust means 31-36, 200-205, 300-305 Spur gearing (coupling part) 27, 115 (Sterile) guide tube 37 Helical groove 38 Pin 41, 42, 43 Groove guide 10, 13, 15, 16, 17, 18, Drive shaft 106, 107, 108, 109, 110, 111, 404, 405, 406 402 Instrument kinetics 403 End effector 408, 409 Coupling rod 100 Transmission at the instrument side 112, 113, 114 Pulleys 115 Guide tube 116, 117, 118 Intermediate coupling segment 209, 210, 211 Fastening ring 500 Instrument interface 501 (Sterile) film cover 502 Blind plug 503 Cap ring 504, 507, 508 Auxiliary instrument 506 Tubular section 507 Outlet opening
In the FIGS. 22 to 26: 1 Instrument module 10 Tappet; shaft (coupling element) 11 Magnetically conducting section 12 Housing of the instrument module, sliding/rotary bearing 13 Casting compound, form part/component 14 Spur wheel 2 Instrument part 20 Tappet, shaft (counter element) 21 Section that can be magnetically impinged 22 Instrument shaft, sliding/rotary bearing 24 Spur wheel 30 Permanent magnet 31 Electromagnet 40 Sterile barrier 41, 42 Coupling part 50 Angle sensor 51 Permanent bar magnet (transmitter)