Method of determining the shape of a bendable instrument

• US 20070161857A1
• Filed: 11/21/2006
• Published: 07/12/2007
• Est. Priority Date: 11/22/2005
• Status: Abandoned Application

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Neoguide Systems, Inc. (Intuitive Surgical Holdings, LLC)
• Inventors: Durant, Kevin, Mintz, David, Ohline, Robert
• Application Number:
  US11/603,943
• Publication Number:
  US 20070161857A1
• Time in Patent Office: Days
• US Class Current: 600/117
• CPC Class Codes: A61B 1/00128 mechanical, e.g. for tubes or pipes
• CPC Class Codes: A61B 1/0052 Constructional details of control elements, e.g. handles
• CPC Class Codes: A61B 1/009 with bending or curvature detection of the insertion part
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/065 Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires
• CPC Class Codes: A61M 25/0155 with hydraulic or pneumatic means, e.g. balloons or inflatable compartments
• CPC Class Codes: A61M 25/0158 with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials

Abstract

Embodiments of the invention relate to methods of positioning a bendable instrument by moving at least two control elements first and second amounts to bend the instrument to a position; measuring the first and second amounts; and determining the position, shape or configuration of the instrument from the first and second amounts.

Claims

1. A method of determining the shape a bendable instrument, comprising:

moving at least two control elements first and second amounts without bending the instrument;

measuring the first and second amounts; and

determining the shape of the instrument from the first and second amounts.

2. The method according to claim 1 wherein the moving step is accomplished without using an actuator connected to a control element.

3. The method according to claim 1, wherein the moving step removes slack from the at least two control elements before the measuring step.

4. The method according to claim 3 wherein the removing step is performed by applying a known drive command to an actuator.

5. The method according to claim 4 wherein the drive command is insufficient to change the position of the instrument.

6. The method according to claim 3 wherein the removing step is performed using a tension measurement taken in a connector that couples an actuator to one of the at least two control elements.

7. The method according to claim 3 wherein the removing step is performed using a feedback loop that receives input from a sensor.

8. The method according to claim 7 wherein the input from a sensor is related to a tension measurement of a control element.

9. The method according to claim 7 wherein the sensor is located on or in the bendable instrument.

10. The method according to claim 7 wherein the sensor is located on or in a connector that joins the bendable instrument to an actuator.

11. The method according to claim 7 wherein the sensor is located on or in an actuator connected to a control element.

12. The method according to claim 3 wherein further comprising:

removing the slack from the at least two control elements during a first time period at a first force limit before removing the slack from the at least two control elements during a second time period at a second different force limit.

13. The method according to claim 12 wherein the first force limit is less than the second force limit.

14. The method according to claim 12 wherein the velocity of slack removal during the first time period is greater than the velocity of slack removal during the second time period.

15. The method according to claim 1 wherein the determining step comprises using a look up table that correlates the first and second amounts to the instrument shape.

16. The method according to claim 1 wherein the determining step comprises using a modeled kinematic relationship between first and second amounts and the instrument shape.

17. The method according to claim 1 wherein the determining step uses a calculated position delta of the at least two control elements.

18. The method according to claim 1 wherein the determining step uses a calculated position delta of complementary control elements within the at least two control elements.

19. The method according to claim 1 wherein the determining step uses a calculated position delta of a pair of opposing control elements within the at least two control elements.

20. The method according to claim 1 the measuring step further comprising:

moving a control element not being used to bend the instrument; and

determining a calculated position delta for the control element not being used to bend the instrument.

21. The method according to claim 20 wherein the determining step uses the calculated position delta for a control element not being used to bend the instrument.

22. The method of claim 1 further comprising:

positioning the bendable instrument within a lumen before the moving step.

23. The method according to claim 1 wherein the moving step is performed by a lumen acting on the instrument.

24. The method according to claim 22 further comprising:

using the determining step to determine the shape of the lumen.