CALIBRATION SYSTEM FOR A FORCE-SENSING CATHETER

• US 20120089358A1
• Filed: 10/07/2010
• Published: 04/12/2012
• Est. Priority Date: 10/07/2010
• Status: Active Grant

• Current Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Original Assignee: Biosense Webster Israel Ltd. (Johnson & Johnson)
• Inventors: Ludwin, Doron, Bonyak, Yevgeny, Levy, Dror Shlomo
• Granted Patent: US 8,731,859 B2
• Time in Patent Office: Days
• US Class Current: 702/104
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2018/00988 Means for storing information, e.g. calibration constants, or for preventing excessive use, e.g. usage, service life counter
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 2560/0238 Means for recording calibration data
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 25/0082 Catheter tip comprising a tool

Abstract

An apparatus, consisting of a rolling element, which is resting on a surface, and a force-sensing device, which is coupled to the surface. The force-sensing device is configured to make a first measurement indicative of a force exerted in a direction perpendicular to the surface. The force is exerted by a force-sensing probe pressing against the rolling element so as to hold the rolling element stationary. The apparatus further includes a calibration processor, which is configured to collect the first measurement from the sensing device, to collect a second measurement indicative of the force from the force-sensing probe, and to calibrate the force-sensing probe based on the first and second measurements.

Claims

1. An apparatus, comprising:

a rolling element, which is resting on a surface;

a force-sensing device, which is coupled to the surface and is configured to make a first measurement indicative of a force exerted in a direction perpendicular to the surface by a force-sensing probe pressing against the rolling element so as to hold the rolling element stationary; and

a calibration processor, which is configured to collect the first measurement from the sensing device, to collect a second measurement indicative of the force from the force-sensing probe, and to calibrate the force-sensing probe based on the first and second measurements.

2. The apparatus according to claim 1, wherein the surface is planar.

3. The apparatus according to claim 1, wherein the rolling element comprises a silicone rubber ball.

4. The apparatus according to claim 1, wherein the force-sensing device comprises a load cell.

5. The apparatus according to claim 1, wherein the processor is configured to make the first measurement by collecting, from the force-sensing device, first signals indicating the force.

6. The apparatus according to claim 1, wherein the probe comprises a flexible insertion tube, a distal tip, and a joint connecting a distal end of the flexible insertion tube to the distal tip.

7. The apparatus according to claim 6, wherein pressing the force-sensing probe against the rolling element causes a distortion of the distal tip.

8. The apparatus according to claim 7, wherein the processor is configured to make the second measurement by reading from the probe one or more signals indicative of the distortion.

9. The apparatus according to claim 7, wherein the distortion comprises an axial displacement of the distal tip parallel to an axis of symmetry of the distal end.

10. The apparatus according to claim 7, wherein the distortion comprises an angular deflection of the distal tip from an axis of symmetry of the distal end.

11. The apparatus according to claim 1, wherein calibrating the probe comprises computing one or more calibration coefficients for assessing the force as a function of the first and the second measurements.

12. The apparatus according to claim 11, wherein the processor is configured to store the calibration coefficients to a memory coupled to the probe.

13. The apparatus according to claim 12, wherein the memory comprises an Electronically Erasable Programmable Read Only Memory (E²PROM).

14. A method, comprising:

positioning a rolling element on a surface coupled to a force-sensing device;

pressing a force-sensing probe against the rolling element so as to hold the rolling element stationary on the surface while exerting, through the rolling element, a force on the force-sensing device in a direction perpendicular to the surface;

while pressing the force-sensing probe, making first and second measurements of the force using the force-sensing device and the probe, respectively; and

calibrating the force-sensing probe based on the first and second measurements.

15. The method according to claim 14, wherein the surface is planar.

16. The method according to claim 14, wherein the rolling element comprises a silicone rubber ball.

17. The method according to claim 14, wherein the force-sensing device comprises a load cell.

18. The method according to claim 14, wherein making the first measurement comprises collecting, from the force-sensing device, first signals indicating the exerted force.

19. The method according to claim 14, wherein the probe comprises a flexible insertion tube, a distal tip, and a joint connecting a distal end of the flexible insertion tube to the distal tip.

20. The method according to claim 19, wherein pressing the force-sensing probe against the rolling element causes a distortion of the distal tip.

21. The method according to claim 20, wherein making the second measurement comprises reading from the probe one or more signals indicative of the distortion.

22. The method according to claim 20, wherein the distortion comprises an axial displacement of the distal tip parallel to an axis of symmetry of the distal end.

23. The method according to claim 20, wherein the distortion comprises an angular deflection of the distal tip from an axis of symmetry of the distal end.

24. The method according to claim 14, wherein calibrating the probe comprises computing one or more calibration coefficients for assessing the force as a function of the first and the second measurements.

25. The method according to claim 24, and comprising storing the calibration coefficients to a memory coupled to the probe.

26. The method according to claim 25, wherein the memory comprises an Electronically Erasable Programmable Read Only Memory (E²PROM).