Surgical manipulator for a telerobotic system

• US 5,814,038 A
• Filed: 03/27/1997
• Issued: 09/29/1998
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Jensen, Joel F., Hill, John W.
• Primary Examiner(s): Buiz, Michael Powell
• Assistant Examiner(s): Shai, Daphna
• Application Number:
  US08/824,977
• Time in Patent Office: 551 Days
• Field of Search: 606/1, 606/130, 606/205, 606/206, 606/207, 604/905, 401/18, 401/21, 401/23, 401/24, 401/25, 401/41, 401/32, 401/38, 279/93, 279/94, 414/744.2, 414/744.3, 403/349, 403/348, 403/316
• US Class Current: 606/1
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 2017/00477 Coupling A61B2017/0046 takes precedence
• CPC Class Codes: A61B 2017/3445 used as instrument channel for multiple instruments catheters A61B2017/22072
• CPC Class Codes: A61B 2034/301 for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2090/0813 Accessories designed for easy sterilising, i.e. re-usable
• CPC Class Codes: A61B 2090/506 using a parallelogram linkage, e.g. panthograph
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/35 for telesurgery
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 90/50 Supports for surgical instruments, e.g. articulated arms
• CPC Class Codes: B25J 15/04 with provision for the remote detachment or exchange of the head or parts thereof
• CPC Class Codes: B25J 18/04 rotatable
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: F16B 2200/69 Redundant disconnection blocking means
• CPC Class Codes: F16B 2200/71 Blocking disengagement of catches or keys

Abstract

The invention is directed to manipulator assembly (2) for holding and manipulating a surgical instrument (14) in a telerobotic system. The assembly comprises a base (6) by fixable by means of passive or power driven positioning devices to a surface, such as an operating table, and an instrument holder (4) movably mounted on the base. The instrument holder comprises a chassis (6) and an instrument support (70) movably mounted on the body and having an interface engageable with the surgical instrument to releasably mount the instrument to the instrument holder. A drive assembly (7) is operatively coupled to the instrument holder for providing the instrument with at least two degrees of freedom. The instrument holder is separable from the base and the drive assembly so that the holder can be sterilized. The assembly further includes a force sensing element (52) mounted distal to the holder and the drive assembly for detecting forces exerted on the surgical instrument and providing feedback to the surgeon. The assembly is attached to a remote center positioner (300) for constraining the instrument to rotate about a point coincident with the entry incision and an inclinometer (350) for preventing gravitational forces acting on the system'"'"'s mechanisms from being felt by the surgeon.

Claims

1. An apparatus for manipulating a surgical instrument in a sterile surgical field comprising:

a hand controller located remote from the surgical field;

a support base fixable to a surface;

a sterilizable instrument holder movably mounted on said support base and adapted to releasably hold the surgical instrument, the instrument holder comprising;

a body; and

an instrument support movably mounted on said body and having an interface engageable with the surgical instrument to releasably mount the instrument to said instrument holder;

a drive assembly operatively coupled to said instrument holder for providing said instrument with at least two degrees of freedom, said drive assembly comprising;

a first controllable motor operatively connected to move said instrument support; and

a second controllable motor operatively connected to move said instrument holder body relative to said support base;

a servomechanism coupling the hand controller to the drive assembly such that movements of the surgical instrument directly correspond to the same movements of the hand controller; and

a coupling mechanism for removably attaching said instrument holder to said support base and said drive assembly, wherein said instrument holder is separable from said support base and said drive assembly for sterilization of said instrument holder between surgical procedures.

2. The apparatus of claim 1 wherein said instrument support is rotatably mounted to said body and wherein said first controllable motor causes rotation of said instrument support, thereby rotating said instrument with respect to said body.

3. The apparatus of claim 1 wherein said support base comprises first and second spaced support shafts and said instrument holder comprises first and second mounts slidably mounted to the first and second support shafts, respectively.

4. The apparatus of claim 3 wherein said instrument holder body further includes an arm removably coupled to said second controllable motor for axial movement of said first and second mounts along said first and second support shafts thereby moving said instrument in an axial direction.

5. The apparatus of claim 4 wherein said support base comprises a frame having distal and proximal elongate support members, said first and second shafts each having first and second ends rotatably supported within said distal and proximal support members, respectively.

6. The apparatus of claim 5 wherein said coupling means comprises a disconnecting means for separating said spaced support shafts from said support base to allow said instrument holder to be removed from said support base and said drive assembly.

7. The apparatus of claim 6 wherein said disconnecting means comprises an annular groove in each of the spaced support shafts and an internal grove in each of said mounts in communication with said annular groove, said disconnecting means further including a spring clip positioned within said annular and internal grooves so to prevent axial movement of said shafts relative to said mounts, said spring clip having an opening for allowing release of said shafts from said mounts when a threshold axial forces is applied to said shafts.

8. The apparatus of claim 3 wherein the surgical instrument comprises an end effector and a movable end effector actuator, said instrument holder further including a movable actuator driver mounted on said body and having a second interface engageable with the end effector actuator of the surgical instrument.

9. The apparatus of claim 8 wherein said drive assembly further comprises a third controllable motor operatively connected to said support base for moving at least a portion of said actuator driver relative to said support base to thereby actuate the end effector of the instrument.

10. The apparatus of claim 9 wherein said first and second support shafts are rotatably mounted on said base frame and said first and third controllable motors are operatively coupled to said first and second support shafts, respectively, for rotation of said shafts.

11. A manipulator assembly adapted to be robotically driven by a controller for manipulation of a surgical instrument of the type having a shaft with distal and proximal end portions, the assembly comprising:

a support base fixable to a surface;

an instrument holder movably coupled to said base and having a mount for releasably holding the surgical instrument;

a drive assembly operatively coupled to said instrument holder for providing the instrument with at least two degrees of freedom;

a gas sealing trocar sleeve having a distal end configured for introduction through a percutaneous penetration in a patient, said trocar sleeve being mounted to said support base distal to said instrument holder and said drive assembly, said trocar sleeve having an axial passage for receiving the shaft of the instrument and for providing an access port into the patient; and

a force sensing element coupled within said axial passage of said trocar sleeve for detecting lateral forces transmitted to said trocar sleeve by the distal end portion of the instrument shaft, said force sensing element being operatively coupled to the controller for transmitting signals representing said lateral forces to the controller;

wherein said lateral forces acting on said surgical instrument are detected substantially without disturbances from forces acting on said trocar sleeve.

12. The assembly of claim 11 further comprising a bearing mounted within said sleeve for rotatably and slidably supporting said instrument shaft within said sleeve, said force sensing element being coupled to said bearing for detecting lateral forces transmitted to said bearing by the distal end portion of the instrument shaft.

13. The assembly of claim 11 wherein said force sensing element comprises at least one strain gauge.

14. The assembly of claim 11 wherein said force sensing element comprises at least one force sensing resistor.

15. The assembly of claim 11 wherein said sleeve is a cannula having a distal end configured for introduction through a percutaneous penetration in a patient, said force sensing element being positioned within said cannula adjacent said distal end.

16. The assembly of claim 11 wherein said support base comprises a frame having distal and proximal elongate support members, said distal support member having an opening for receiving the instrument shaft, said instrument holder being movably mounted between said support members and said trocar sleeve being mounted to said distal support member and aligned with said opening.

17. A surgical system comprising:

a surgical instrument comprising an elongate shaft with proximal and distal ends and a mounting means laterally extending from the shaft intermediate the proximal and distal ends;

an instrument holder for releasably holding the surgical instrument, the instrument holder comprising a body and an instrument support movably mounted on said body and having an interface engageable with the surgical instrument to releasably mount the instrument to said instrument holder; and

a device for constraining the movement of said instrument about a desired spherical center of rotation at a desired location along said instrument, the device comprising;

a base for supporting said instrument holder;

a first linkage, including at least a first rod, pivotally mounted on said base for rotation about an axis, said instrument holder holding said instrument in a position so that the desired remote center of spherical rotation along the instrument intersects said axis; and

a second linkage, including at least a second rod, connected to said instrument holder for moving said instrument holder in a parallel-plane relationship to said second linkage, said second linkage being pivotally connected to said first linkage so that said second rod remains parallel to said axis and said first rod remains parallel to the instrument;

wherein said first and second linkages constrain movement of said instrument, such that said desired location on said instrument remains fixed at said spherical center of rotation; and

an actuator driver having a second interface engageable with the surgical instrument and a coupling for connecting said actuator driver to the drive assembly, said actuator driver further comprising a transducer for translating rotational movement of the coupling into axial displacement of the second interface relative to said body to actuate the end effector of the instrument.

18. The system of claim 17 further comprising a drive assembly operatively coupled to said instrument holder for providing said instrument with at least two degrees of freedom.

19. The system of claim 18 wherein said drive assembly comprises a first controllable motor operatively connected to move said instrument support and a second controllable motor operatively connected to move said instrument holder body relative to said support base.

20. The system of claim 18 further comprising a coupling means for removably attaching said instrument holder to said support base and said drive assembly.

21. The system of claim 17 wherein said device for moving said instrument about a desired spherical center of rotation is fixable to a surface at an orientation with respect to the vertical, the system further including an inclinometer mounted to said device for measuring said orientation.

22. The system of claim 18 wherein said instrument defines a longitudinal axis and said instrument support is rotatably coupled to said body and has a coupling structured and arranged to connect said instrument support to the drive assembly for rotating said instrument about the longitudinal axis.