CATHETER WITH PRESSURE SENSING

• US 20090093806A1
• Filed: 10/08/2007
• Published: 04/09/2009
• Est. Priority Date: 10/08/2007
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Govari, Assaf, Altmann, Andres Claudio, Ephrath, Yaron, Schwartz, Yitzhack
• Granted Patent: US 8,357,152 B2
• Time in Patent Office: Days
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 2090/067 for measuring angles
• CPC Class Codes: A61B 2090/3958 emitting a signal
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• 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 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems

Abstract

A medical probe includes a flexible insertion tube, having a distal end for insertion into a body cavity of a patient, and a distal tip, which is disposed at the distal end of the insertion tube and is configured to be brought into contact with tissue in the body cavity. A resilient member couples the distal tip to the distal end of the insertion tube and is configured to deform in response to pressure exerted on the distal tip when the distal tip engages the tissue. A position sensor within the probe senses a position of the distal tip relative to the distal end of the insertion tube, which changes in response to deformation of the resilient member.

Claims

1. A medical probe, comprising:

a flexible insertion tube, having a distal end for insertion into a body cavity of a patient;

a distal tip, which is disposed at the distal end of the insertion tube and is configured to be brought into contact with tissue in the body cavity;

a resilient member, which couples the distal tip to the distal end of the insertion tube and is configured to deform in response to pressure exerted on the distal tip when the distal tip engages the tissue; and

a position sensor within the probe for sensing a position of the distal tip relative to the distal end of the insertion tube, which changes in response to deformation of the resilient member.

2. The probe according to claim 1, wherein the position sensor is configured to generate a signal indicative of an axial displacement and an orientation of the distal tip relative to the distal end of the insertion tube.

3. The probe according to claim 1, wherein the position sensor is configured to generate a signal indicative of the position of the distal tip responsively to a magnetic field that is generated in a vicinity of the distal tip.

4. The probe according to claim 3, wherein the position sensor is disposed in the distal end of the insertion tube, and wherein the probe comprises a magnetic field generator within the distal tip for generating the magnetic field.

5. The probe according to claim 3, wherein the position sensor is disposed in the distal tip, and wherein the probe comprises a magnetic field generator within the distal end of the insertion tube for generating the magnetic field.

6. The probe according to claim 5, wherein the position sensor and the magnetic field generator comprise coils.

7. The probe according to claim 1, wherein the resilient member comprises a spring.

8. The probe according to claim 1, wherein the position sensor is configured to generate a signal, responsively to the deformation, which is indicative of the pressure exerted on the distal tip.

9. The probe according to claim 1, wherein the distal tip comprises an electrode, which is configured to make electrical contact with the tissue.

10. The probe according to claim 9, wherein the electrode is coupled to apply electrical energy to the tissue so as to ablate a region of the tissue.

11. Apparatus for performing a medical procedure inside a body of a patient, the apparatus comprising:

a first magnetic field generator, for disposition outside the body of the patient, for generating a first magnetic field within the body;

a probe, which comprises;

an insertion tube having a distal end for insertion into a body cavity of a patient;

a second magnetic field generator within the distal end of the insertion tube for generating a second magnetic field;

a distal tip, which is flexibly coupled to the distal end of the insertion tube; and

a sensor, which is disposed within the distal tip and is configured to generate first and second signals responsively to the first and second magnetic fields, respectively; and

a processor, which is coupled to receive and process the first signal so as to determine coordinates of the distal tip within the body and to receive and process the second signal so as to detect changes in a position of the distal tip relative to the distal end of the insertion tube.

12. The apparatus according to claim 11, wherein the changes in the position of the distal tip detected by the processor comprise axial displacement of the distal tip and deflection of the distal tip relative to the distal end of the insertion tube.

13. The apparatus according to claim 11, wherein the distal tip is rigid, and wherein the probe comprises a resilient member, which couples the distal tip to the distal end of the insertion tube.

14. The apparatus according to claim 13, wherein the resilient member is configured to deform in response to pressure exerted on the distal tip when the distal tip engages tissue inside the body, and wherein the changes in the position of the distal tip are indicative of deformation of the resilient member.

15. The apparatus according to claim 14, wherein the processor is configured to generate, responsively to the deformation, an output that is indicative of the pressure exerted on the distal tip.

16. The apparatus according to claim 11, wherein the sensor and the second magnetic field generator comprise coils.

17. The apparatus according to claim 11, wherein the resilient member comprises a spring.

18. The apparatus according to claim 11, wherein the distal tip comprises an electrode, which is configured to make electrical contact with the tissue.

19. The apparatus according to claim 18, wherein the electrode is coupled to apply electrical energy to the tissue so as to ablate a region of the tissue.

20. The apparatus according to claim 11, wherein the processor is configured to generate a control input for automatically controlling motion of the probe within the body cavity responsively to the first and second signals.

21. A method for contacting tissue in a body cavity of a patient, the method comprising:

inserting a probe into the body cavity, the probe comprising a flexible insertion tube and a distal tip, which is coupled to a distal end of the insertion tube by a resilient member, and comprising a position sensor, which generates a signal indicative of a position of the distal tip relative to the distal end of the insertion tube, which changes in response to deformation of the resilient member;

advancing the probe within the body cavity so that the distal tip engages and applies a pressure against the tissue, thereby causing the resilient member to deform; and

processing the signal while the distal tip engages the tissue so as to provide an indication of the pressure.

22. The method according to claim 21, wherein the signal is indicative of an axial displacement and an orientation of the distal tip relative to the distal end of the insertion tube.

23. The method according to claim 21, wherein advancing the probe comprises bringing an electrode on the distal tip into electrical contact with the tissue.

24. The method according to claim 23, and comprising applying electrical energy to the electrode so as to ablate a region of the tissue that is engaged by the distal tip.

25. The method according to claim 24, wherein applying the electrical energy comprises controlling application of the energy responsively to the indication of the pressure, so that the electrical energy is applied to the electrode when the pressure is within a desired range.

26. The method according to claim 21, wherein the position sensor is configured to generate the signal responsively to a magnetic field that is created in a vicinity of the distal tip.

27. The method according to claim 26, wherein the position sensor is disposed in the distal tip, and wherein the probe comprises a magnetic field generator within the distal end of the insertion tube for creating the magnetic field.

28. The method according to claim 27, wherein the magnetic field generated by the magnetic field generator in the distal end of the insertion tube is a first magnetic field, and the signal generated by the position sensor responsively to the first magnetic field is a first signal, and wherein the method comprises:

creating a second magnetic field in a frame of reference that is fixed outside the body cavity; and

processing a second signal generated by the position sensor in response to the second magnetic field signal so as to determine coordinates of the distal tip within the body cavity.

29. The method according to claim 26, wherein the position sensor is disposed in the distal end of the insertion tube, and wherein the probe comprises a magnetic field generator within the distal tip for creating the magnetic field.

30. The method according to claim 29, wherein the signal generated by the position sensor responsively to the magnetic field is a first signal, and wherein the method comprises:

sensing the magnetic field at a predetermined location in a frame of reference that is fixed outside the body cavity so as to generate a second signal; and

processing the second signal in order to determine coordinates of the distal tip within the body cavity.

31. Apparatus for performing a medical procedure inside a body of a patient, the apparatus comprising:

a probe, which comprises;

an insertion tube having a distal end for insertion into a body cavity of a patient;

a distal tip, which is flexibly coupled to the distal end of the insertion tube;

a magnetic field generator, which is disposed within the distal tip and is configured to generate a magnetic field; and

a first sensor within the distal end of the insertion tube for generating a first signal in response to the magnetic field; and

a second sensor, for disposition outside the body of the patient, for generating a second signal in response to the magnetic field;

a processor, which is coupled to receive and process the second signal so as to determine coordinates of the distal tip within the body and to receive and process the first signal so as to detect changes in a position of the distal tip relative to the distal end of the insertion tube.