Electrophysiology catheter

• US 20040231683A1
• Filed: 05/21/2003
• Published: 11/25/2004
• Est. Priority Date: 05/21/2003
• Status: Active Grant

• Current Assignee: Stereotaxis, Inc.
• Original Assignee: Stereotaxis, Inc.
• Inventors: Eng, Michael, Viswanathan, Raju R., Munger, Gareth T., Tunay, Ilker, Werp, Peter R., Pandey, Ashwini K.
• Granted Patent: US 6,980,843 B2
• Time in Patent Office: Days
• US Class Current: 128/899
• CPC Class Codes: A61B 1/00158 using magnetic field
• 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 2017/00053 Mapping
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• 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 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]

Abstract

An electrophysiology catheter includes a tube having a proximal end, a distal end, and a lumen therebetween. The tube is preferably comprised of multiple sections of different flexibility, arranged so that the flexibility of the catheter increases from the proximal end to the distal end. There is a first generally hollow electrode member at the distal end. At least one magnetically responsive element is disposed at least partially in the hollow electrode, for orienting the distal end of the catheter with an externally applied magnetic field. Multiple magnets can be distributed over the distal portion of the device. The end electrode can have openings for delivering irrigating fluid, and/or a sleeve can be provided around the tube to create an annular space for the delivering of irrigating fluid. A temperature sensor can be provided to control the operation of the catheter. A localization coil can also be included to sense the position and orientation of the catheter.

Claims

1. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive auxiliary element spaced proximally from the tip element, each of the magnetically responsive elements being separated from the adjacent element by a portion of the body that applies a torque of no more than about 0.01 N-m to resist orientation of the element with an applied magnetic field.

2. The magnetically responsive medical device according to claim 1 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

3. The magnetically responsive medical device according to claim 1 wherein at least one of the at least one auxiliary elements is smaller than the tip element.

4. The magnetically responsive medical device according to claim 1 wherein there are at least two auxiliary elements and wherein the distances between adjacent magnetically responsive elements are not all equal.

8. The magnetically responsive medical device according to claim 2 wherein there are at least two auxiliary elements, and wherein the distances between adjacent magnetically responsive elements are not all equal.

5. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive auxiliary element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, the magnetically responsive elements being sized so that, and the flexibility of the portions between the magnetically responsive elements being selected so that, that the longitudinal axis of the tip element can align within 20 degrees of a magnetic field applied in a direction substantially perpendicular to the elongate axial direction of the undeformed device.

6. The magnetically responsive medical device according to claim 5 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

7. The magnetically responsive medical device according to claim 5 wherein the at least one of the at least one auxiliary elements is smaller than the tip element.

9. The magnetically responsive medical device according to claim 5 wherein with a free length of at least about 5 cm the longitudinal axis of the tip element can align within 20 degrees of a magnetic field applied in a direction substantially perpendicular to the elongate direction of the undeformed device.

10. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, wherein (lmB/EI) for each flexible portion is greater than about 0. 1, where E is the Young'"'"'s modulus of the flexible portion, I is the bending moment of inertia of the portion, l is the length of the portion, m is the effective magnetic moment of the magnetically responsive element at the distal end of said flexible portion, and B is the applied magnetic field.

11. The magnetically responsive medical device according to claim 10 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

12. The magnetically responsive medical device according to claim 10 wherein at the at least one auxiliary element is smaller than the tip element.

13. The magnetically responsive medical device according to claim 10 wherein there are at least two auxiliary elements and wherein the distances between adjacent magnetically responsive elements are not equal.

14. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, wherein (lmB/EI) for each flexible portion is greater than about 0.1, and less than about 7, where E is the Young'"'"'s modulus of the flexible portion, I is the bending moment of inertia of the portion, l is the length of the portion, m is the effective magnetic moment of the magnetically responsive element at the distal end of said flexible portion, and B is the applied magnetic field.

15. The magnetically responsive medical device according to claim 14 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

16. The magnetically responsive medical device according to claim 14 wherein at least one auxiliary element is smaller than the tip element.

17. The magnetically responsive medical device according to claim 14 wherein there are at least two auxiliary elements and wherein the distance between adjacent magnetically responsive elements differs.

18. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, wherein the lag angle between the tip element and the applied field is less than about 20 degrees, and wherein the lag angle between each successively proximal element and the applied field is less than 35 degrees greater than the lag angle between the next most proximal angle and the applied field, when the field is applied in a direction substantially perpendicular to the elongate direction of the undeformed device.

19. The magnetically responsive medical device according to claim 18 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

20. The magnetically responsive medical device according to claim 18 wherein the at least one auxiliary element is smaller than the tip element.

21. The magnetically responsive medical device according to claim 18 wherein there are at least two auxiliary elements, and wherein the distance between adjacent magnetically responsive elements differs.

22. The magnetically responsive medical device according to claim 18 wherein with a free length of at least about 5 cm the longitudinal axis of the tip element can align within 20 degrees of a magnetic field applied in a direction substantially perpendicular to the elongate direction of the undeformed device.

23. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, wherein the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

24. The magnetically responsive medical device according to claim 23 wherein the at least one auxiliary element is smaller than the tip element.

25. The magnetically responsive medical device according to claim 23 wherein the distance between adjacent magnetically responsive elements differs.

26. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

the device having a distal end portion comprising a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, the distal portion of the device including the magnets having an effective end-to-end bending stiffness that is at least four times larger in the presence of a magnetic field applied in a direction substantially parallel to the elongate direction of the device than it is in the absence of said applied magnetic field.

27. The magnetically responsive medical device according to claim 26 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

28. The magnetically responsive medical device according to claim 26 wherein the at least one auxiliary element is smaller than the tip element.

29. The magnetically responsive medical device according to claim 26 wherein the distance between adjacent magnetically responsive elements varies.

30. The magnetically responsive medical device according to claim 26 wherein the effective end-to-end bending stiffness that is at least four times larger in the presence of a magnetic field of at least 0.08 Tesla than it is in the absence of said applied magnetic field.

34. The magnetically responsive medical device according to claim 30 wherein there are at lest two auxiliary element and wherein the distance between adjacent magnetically responsive elements varies.

31. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

the device having a distal end portion comprising a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, the size and position of the magnets and the stiffness of the flexible portions being selected so that the when the device extends trans-septally through a puncture in the septal wall of the heart from right side to left side, it can touch the anterior right lateral portions of the circumference of the Mitral Valve.

32. The magnetically responsive medical device according to claim 31 wherein all of the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

33. The magnetically responsive medical device according to claim 32 wherein the at least one auxiliary element is smaller than the tip element.

35. The magnetically responsive medical device according to claim wherein the device extends trans-septally through a puncture in the septal wall of the heart from right side to left side, it can touch the anterior right lateral portions of the circumference of the Mitral Valve, with a maximum applied field of 0.08 Tesla.

36. A magnetically guidable medical device comprising an elongate body having a proximal end and a distal end;

the device having a distal end portion comprising a magnetically responsive tip element at the distal end of the body; and

at least one magnetically responsive element spaced proximally from the tip element, each of the magnetically responsive elements being separated from adjacent elements by flexible portions of the body, the size and position of the magnets and the stiffness of the flexible portions being selected so that the distal end of the device can bend at least 180 degrees over a length of less than about 5 cm.

37. The magnetically responsive medical device according to claim 36 wherein the magnetically responsive elements are disposed within about 5 cm of the distal tip of the device.

38. The magnetically responsive medical device according to claim 36 wherein the at least one auxiliary element is smaller than the tip element.

39. The magnetically responsive medical device according to claim 36 wherein the distance between adjacent magnetically responsive elements varies.

40. The magnetically responsive medical device according to claim 36 wherein the distal end of the device can bend at least 180 degrees over a length of less than about 5 cm with an applied magnetic field of at least about 0.08 Tesla.