Physically realistic computer simulation of medical procedures

• US 20040066369A1
• Filed: 10/01/2003
• Published: 04/08/2004
• Est. Priority Date: 07/14/1994
• Status: Active Grant

• Current Assignee: Immersion Corporation Delaware
• Original Assignee: Immersion Corporation Delaware
• Inventors: Rosenberg, Louis B.
• Granted Patent: US 7,215,326 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/76 Manipulators having means for providing feel, e.g. force or tactile feedback
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: G05B 19/409 characterised by using manual data input [MDI] or by using control panel, e.g. controlling functions with the panel; characterised by control panel details or by setting parameters G05B19/408, G05B19/4093 take precedence
• CPC Class Codes: G05B 2219/35338 Display virtual tool, locus, part to check possibility of execution next block
• CPC Class Codes: G05B 2219/35441 Production design metaphore, tool, operation like input system
• CPC Class Codes: G05B 2219/40119 Virtual internal model, derive from forces on object, motion of end effector
• CPC Class Codes: G05B 2219/40137 Force sensation feedback from simulated tool
• CPC Class Codes: G05B 2219/45118 Endoscopic, laparoscopic manipulator
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

An apparatus for interfacing the movement of a shaft with a computer includes a support, a gimbal mechanism having two degrees of freedom, and three electromechanical transducers. When a shaft is engaged with the gimbal mechanism, it can move with three degrees of freedom in a spherical coordinate space, where each degree of freedom is sensed by one of the three transducers. A fourth transducer can be used to sense rotation of the shaft around an axis. The method includes the steps of defining an origin in 3-dimensional space, physically constraining a shaft in the 3-dimensional space such that a portion of the shaft always intersects the origin and such that a portion of the shaft extending beyond the origin defines a radius in a spherical coordinate system, transducing a first electrical signal related to a first angular coordinate of the radius with a first transducer, transducing a second electrical signal related to a second angular coordinate with a second transducer, transducing a third electrical signal related to the length of the radius with a third transducer, and coupling the transducers to a computer.

Claims

1. An apparatus for interfacing the motion of an elongated mechanical object with an electrical system comprising:

a support;

a gimbal mechanism having a base portion rotatably coupled to said support to provide a first degree of freedom, and an object receiving portion rotatably coupled to said base portion to provide a second degree of freedom;

a first degree of freedom electromechanical transducer coupled between said support and said base portion;

a second degree of freedom electromechanical transducer coupled between said base portion and said object receiving portion; and

a third degree of freedom electromechanical transducer coupled between said object receiving portion and an intermediate portion of an elongated object at least partially disposed within said object receiving portion;

whereby said transducers provide an electromechanical interface between said elongated object and an electrical system.

2. An apparatus as recited in claim 1 wherein said base portion rotates around a first axis and said object receiving portion rotates around a second axis that is substantially perpendicular to said first axis, and wherein said elongated object defines a radius in A spherical coordinate system having an origin at an intersection of said first axis and said second axis.

3. An apparatus as recited in claim 1 further comprising a fourth degree of freedom electromechanical transducer coupled between said object receiving portion and an intermediate portion of said elongated mechanical object.

4. An apparatus as recited in claim 3 wherein said third degree of freedom transducer is a translation transducer, and wherein said fourth degree of freedom transducer is a rotation transducer.

5. An apparatus as recited in claim 4 wherein said electrical system comprises a digital processing system.

6. An apparatus as recited in claim 5 wherein said transducers are input transducers which sense positions of said object along their respective degrees of freedom and which produce electrical signals corresponding to such positions for said digital processing system.

7. An apparatus as recited in claim 5 wherein said transducers are output transducers which impart a movement to said object along their respective degree of freedom in response to electrical signals produced by said electrical system.

8. An apparatus as recited in claim 5 wherein said transducers are bi-directional transducers which sense positions of said object along their respective degrees of freedom and which produce electrical signals corresponding to such positions for said digital processing system and which further impart a movement to said object along their respective degree of freedom in response to electrical signals produced by said electrical system.

9. An apparatus for interfacing the motion of an elongated cylindrical mechanical object with an electrical system comprising:

a support;

a gimbal mechanism including;

a) a U shaped base portion having a base and a pair of substantially parallel legs extending therefrom, wherein said base of said U shaped base portion is rotatably coupled to said support; and

b) an elongated object receiving portion provided with an aperture extending therethrough which defines an object axis for an elongated cylindrical object, where said receiving portion is at least partially disposed between said legs of said U shaped base portion and is pivotally coupled thereto, said receiving portion further including a translation interface and a rotation interface, both disposed proximate to said object axis such that they engage said elongated cylindrical object when it is engaged with said aperture;

wherein said base portion rotates around a first axis and said object receiving portion rotates around a second axis substantially perpendicular to said first axis, and wherein said object axis defines a radius in a spherical coordinate system having an origin at an intersection of said first axis and said second axis;

a first input transducer coupled between said support and said U shaped base portion to produce a first input electrical signal representative of a sensed position of said U shaped base portion relative to said support;

a second input transducer coupled between said U shaped base portion and said object receiving portion to produce a second input electrical signal representative of a sensed position of said object receiving portion relative to said U shaped base portion;

a third input transducer coupled to said translation interface to produce a third input electrical signal representative of a sensed translation of said elongated cylindrical object relative to said object receiving portion; and

a fourth input transducer coupled to said rotation interface and said object to produce a fourth input electrical signal representative of a sensed rotation of said elongated cylindrical object relative to said object receiving portion.

10. An apparatus as recited in claim 9 further comprising a digital processing system coupled to said transducers.

11. An apparatus as recited in claim 10 further comprising:

a first output transducer coupled between said support and said U shaped base portion to produce a movement of said U shaped base portion relative to said support in response to a first output electrical signal;

a second output transducer coupled between said U shaped base portion and said object receiving portion to produce a movement of said object receiving portion relative to said U shaped base portion in response to a second output electrical signal;

a third output transducer coupled to said translation interface to produce a mechanical movement of said elongated cylindrical object relative to said object receiving portion in response to a third output electrical signal; and

a fourth output transducer coupled to said rotation interface to produce a mechanical movement of said elongated cylindrical object relative to said object receiving portion in response to a fourth output electrical signal.

12. An apparatus as recited in claim 9 wherein said U shaped base portion is coupled to said support by said first input transducer.

13. An apparatus as recited in claim 9 wherein said receiving portion includes a bearing section, a translation sensor section including said translation interface, and a rotation sensor section including said rotation interface.

14. An apparatus as recited in claim 13 wherein said bearing section includes a mass of material provided with a cylindrical bore receptive to said cylindrical object and forming a portion of said aperture.

15. An apparatus as recited in claim 13 wherein said translation sensor section includes a pair of opposing wall portions, each of which is provided with a cylindrical bore receptive to said cylindrical object and forming a part of said aperture.

16. An apparatus as recited in claim 13 wherein said translation interface includes a translation wheel having a translation wheel axis that is substantially perpendicular to said object axis, said translation wheel contacting a surface of said cylindrical object when said cylindrical object is engaged with said aperture of said receiving portion such that a translation of said cylindrical object along said object axis causes a rotation of said translation wheel.

17. An apparatus as recited in claim 16 wherein said translation wheel is coupled to a rotational position sensor which provides, at least in part, said third input electrical signal.

18. An apparatus as recited in claim 13 wherein said rotation sensor section includes a pair of opposing wall portions, each of which is provided with a cylindrical bore receptive to said cylindrical object and forming a part of said aperture.

19. An apparatus as recited in claim 13 wherein said rotation interface includes a rotation wheel having a rotation wheel axis which is substantially parallel to said object axis, said rotation wheel being coupled to said cylindrical object to rotate therewith.

20. An apparatus as recited in claim 19 wherein said rotation wheel is coupled to a rotational position sensor which provides, at least in part, said fourth input electrical signal.

21. An apparatus as recited in claim 19 wherein said rotation wheel contacts a surface of said cylindrical object when said cylindrical object is engaged with said aperture of said receiving portion.

22. An apparatus as recited in claim 19 wherein said cylindrical object is provided with an elongated slot substantially parallel to said object axis, and further comprising a sleeve having a bore which forms a portion of said aperture and which has a key which engages said slot of said cylindrical object such that said cylindrical object may translate within said sleeve and such that said sleeve rotates with said cylindrical, object, said wheel being coupled to said sleeve for rotation therewith.

23. An apparatus as recited in claim 22 wherein said wheel forms a portion of a rotational position sensor which provides, at least in part, said fourth input electrical signal.

24. An apparatus as recited in claim 22 wherein said wheel comprises a sheave, and further including a rotational position sensor having a shaft, said rotational position sensor providing, at least in part, said fourth input electrical signal, and a continuous loop which engages both said sheave and said shaft such that said shaft of said rotational position sensor rotates with said cylindrical object.

25. A method for interfacing movements of an elongated mechanical object with an electrical system comprising the steps of:

defining an origin in a 3-dimensional space;

physically constraining an elongated object in said 3-dimensional space such that a portion of said object always intersects said origin and such that a portion of said object extending from said origin defines a radius in a spherical coordinate system;

transducing a first electrical signal related to a first angular coordinate of said radius in said spherical coordinate system with a first transducer;

transducing a second electrical signal related to a second angular coordinate of said radius in said spherical coordinate system with a second transducer;

transducing a third electrical signal related to the length of said radius with a third transducer; and

electrically coupling said transducers to an electrical system.

26. A method as recited in claim 25 further comprising the step of transducing a fourth electrical signal related to a rotation of said object around an object axis which intersects said origin with a fourth transducer.

27. A method as recited in claim 26 wherein said electrical system is a digital processing system.

28. A method as recited in claim 27 wherein said transducers are input transducers which convert movement of said object into said electrical signals.

29. A method as recited in claim 27 wherein said transducers are output transducers which convert said electrical signals into movement of said object.

30. A method as recited in claim 27 wherein said transducers are bi-directional transducers which convert movement of said object into input electrical signals to said digital computer system and which convert output electrical signals from said digital computer system into movement of said object.

31. A human/computer interface apparatus comprising:

a support;

a gimbal mechanism having a base portion rotatably coupled to said support, and a shaft receiving portion rotatably coupled to said base portion;

an elongated shaft engaged with said shaft receiving portion, said shaft having a grip area to be grasped by a hand of an operator;

a first sensor coupled between said support and said base portion, said first sensor having a first output;

a second sensor coupled between said base portion and said shaft receiving portion, said second sensor having a second output;

a third sensor coupled between said shaft receiving portion and an intermediate portion of said shaft, said third sensor having a third output; and

a computer having an input coupled to said first output, said second output, and said third output;

whereby said first output, said second output, and said third output correspond to three degrees of motion of said shaft as it is manipulated by said operator.

32. An apparatus as recited in claim 31 wherein said base portion rotates around a first axis and said shaft receiving portion rotates around a second axis that is substantially perpendicular to said first axis, and wherein said shaft defines a radius in a spherical coordinate system having an origin at an intersection of said first axis and said second axis.

33. An apparatus as recited in claim 31 further comprising a fourth sensor coupled between said shaft receiving portion and an intermediate portion of said shaft, said fourth sensor having a fourth output coupled to said computer input and corresponding to a fourth degree of motion of said shaft as it is manipulated by said operator.

34. An apparatus as recited in claim 33 wherein said third sensor is a translation sensor, and wherein said fourth sensor is a rotation sensor.

35. An apparatus as recited in claim 33 wherein said first output, said second output, said third output, and said fourth output are coupled to said input of said computer by an electronic interface.

36. An apparatus as recited in claim 34 further comprising:

a first actuator coupled between said support and said base portion, said first actuator having a first input;

a second actuator coupled between said base portion and said shaft receiving portion, said second actuator having a second input;

a third actuator coupled between said shaft receiving portion and an intermediate portion of said shaft, said third actuator having a third input; and

a fourth actuator coupled between said shaft receiving portion and an intermediate portion of said shaft, said fourth actuator having a fourth input;

wherein said first input, said second input, said third input, and said fourth input are coupled to an output of said computer, and correspond to four degrees of motion of said shaft as said shaft exerts a force on a hand of an operator.

37. An apparatus as recited in claim 36 wherein said first sensor and said first actuator are combined, said second sensor and said second actuator are combined, said third sensor and said third actuator are combined, and said fourth sensor and said fourth actuator are combined.

38. A human/computer interface apparatus comprising:

a shaft receiving portion;

an elongated, flexible shaft engaged with said shaft receiving portion, said flexible shaft having a grip area to be grasped by a hand of an operator;

a first sensor coupled to said shaft receiving portion and a first intermediate portion of said shaft to detect translational movement of said shaft relative to said shaft receiving portion, said first sensor having a first output; and

a second sensor coupled to said shaft receiving portion and a second intermediate portion of shaft to detect rotational movement of said shaft relative to said shaft receiving portion, said second sensor having a second output.

39. An apparatus as recited in claim 38 further comprising a first actuator coupled to said shaft receiving portion to impart a translational force on said shaft, and a second actuator coupled to said shaft receiving portion to impart a rotational force on said shaft.

40. An apparatus as recited in claim 38 wherein said flexible shaft is selected from the group consisting of wires and catheters.