Electrode arrangement for use in a medical instrument

• US 6,673,068 B1
• Filed: 04/12/2000
• Issued: 01/06/2004
• Est. Priority Date: 04/12/2000
• Status: Expired due to Fees

• Current Assignee: Maquet Cardiovascular LLC (Getinge AB)
• Original Assignee: AFX, Inc. (Boston Scientific Corporation)
• Inventors: Berube, Dany
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US09/548,331
• Time in Patent Office: 1,364 Days
• Field of Search: 606/15, 606/21, 606/33, 606/41, 607/100-102, 607/113, 607/154, 607/156, 600/374
• US Class Current: 606/33
• 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 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/183 characterised by the type of antenna
• CPC Class Codes: A61B 2018/1861 with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]

Abstract

A medical instrument is disclosed. The medical instrument includes a pair of spaced apart and electrically isolated elongated wire electrodes positioned adjacent one another on a working member. The wire electrodes are arranged for sensing electrical activity of biological tissues inside the body of the patient. The medical instrument also includes a pair of electrically isolated electrode wires that extend through the working member. Each of the electrode wires are electrically coupled to an associated wire electrode.

Claims

1. A catheter, comprising:

an elongated flexible tubular member adapted to be inserted into a vessel in the body of a patient, and having a longitudinal axis;

a longitudinal working member carried by the flexible tubular member and located near a distal portion of the flexible tubular member, the longitudinal working member being arranged to work in a first predetermined direction laterally to the side of the flexible tubular member, the first predetermined direction extending radially from the longitudinal axis of the tubular member;

a pair of spaced electrodes for sensing electrical activity of biological tissues inside the body of the patient, the electrodes being carried by the flexible tubular member and positioned in a second predetermined direction, which is relative to the first predetermined direction, the second predetermined direction extending radially from the longitudinal axis of the tubular member, wherein the electrodes provide a reference point for determining the radial position of the working member with respect to sensed biological tissue inside the body of the patient, the reference point allowing a user to properly align the working member with biological tissues targeted for work.

2. The catheter as recited in claim 1 wherein the second predetermined direction is in substantially the same direction as the first predetermined direction.

3. The catheter as recited in claim 1 wherein the second predetermined direction is in a direction opposite the first predetermined direction.

4. The catheter as recited in claim 1 wherein the pair of electrodes are positioned distally of the working member.

5. The catheter as recited in claim 1 wherein the spaced apart electrodes are arranged to have centerlines which extend radially from the longitudinal axis of the flexible tubular member, the centerlines having an angle between them that is less than approximately 45 degrees.

6. The catheter as recited in claim 1 wherein the working member is an ablation device that is configured to create ablating energy in the first predetermined direction.

7. The catheter as recited in claim 6 wherein the ablating energy is used to create linear lesions in biological tissues inside the body of a patient, said biological tissues being selected from the group consisting of the heart, the brain, the prostate, the stomach, the liver and the intestine.

8. The catheter as recited in claim 6 wherein the catheter is suitable for use in the right atrium to ablate the isthmus between the inferior caval vein to treat type I flutter or to ablate the lateral right free wall between the superior and the inferior caval veins to treat atypical flutter.

9. The catheter as recited in claim 6 wherein the ablating energy is directed substantially perpendicular to the longitudinal axis of the tubular member.

10. The catheter as recited in claim 6 wherein the catheter is suitable for use in the right atrium to produce an ablation from the cristae terminallis to the fossae ovalis to stop any of the macro-reentry circuits in the right atrium.

11. The catheter as recited in claim 6 wherein the catheter is suitable for use to ablate the posterior wall of the left atrium to produce an ablation to link any of the pulmonary veins together to treat one of paroxysmal, recurrent atrial fibrillation or chronic atrial fibrillation.

12. The catheter as recited in claim 6 wherein the catheter is suitable for use to ablate the posterior wall of the left atrium to produce an ablation to link any of the superior pulmonary veins to the entrance of the left appendage to avoid any of the macro re-entry circuits in the left atrium.

13. The catheter as recited in claim 6 wherein the catheter is suitable for use to ablate the ventricular wall to treat ventricular tachycardia.

14. The catheter as recited in claim 1 wherein the first predetermined direction has a central axis that is disposed between the pair of spaced apart electrodes.

15. The catheter as recited in claim 1 wherein the longitudinal working member includes a proximal end and a distal end.

16. The catheter as recited in claim 1 wherein the pair of spaced apart electrodes are separated along the outer perimeter of the elongated flexible tubular member by a first distance and a second distance, the first distance being smaller than the second distance.

17. The catheter as recited in claim 1 wherein the first predetermined direction has an axis that is disposed between the spaced apart electrodes, and that is normal to the longitudinal axis of the tubular member.

18. The catheter as recited in claim 1 wherein the longitudinal working member has a longitudinal axis that is substantially parallel to the longitudinal axis of the flexible tubular member near the distal portion of the flexible tubular member.

19. An ablation device comprising:

a transmission line suitable for the transmission of electromagnetic energy;

an antenna coupled to the transmission line, the antenna being configured to create a directional electromagnetic field sufficiently strong to cause tissue ablation in a predetermined direction;

an antenna enclosure for enclosing at least a portion of the antenna;

an electrode carried by the antenna enclosure, and positioned in the predetermined direction to sense electrical activity of biological tissues.

20. The ablation device as recited in claim 19 wherein the electrode is a first wire electrode, the ablation device further comprising a second wire electrode, the first and second wire electrodes forming a pair of spaced apart and electrically isolated elongated wire electrodes positioned adjacent one another on the antenna enclosure, the wire electrodes being arranged to extend substantially parallel to one another and configured for sensing electrical activity of biological tissues.

21. The ablation device as recited in claim 20 wherein the first wire electrode and the second wire electrode are arranged to extend side by side longitudinally relative to the antenna enclosure and have centerlines which extend radially from a longitudinal axis of the transmission line, the centerlines having an angle between them that is less than approximately 45 degrees.

22. An ablation device as recited in claim 20 wherein the first and second wire electrodes are positioned distally of the antenna.

23. The ablation device as recited in claim 20 wherein the first wire electrode is electrically coupled to a first wire, and the second wire electrode is electrically coupled to a second wire, both the first wire and the second wire extending through the antenna enclosure.

24. The ablation device as recited in claim 23 wherein the first and second wires are formed from a high resistance material, the high resistance material being arranged to reduce the coupling of electromagnetic energy along the electrode wire.

25. The ablation device as recited in claim 23 wherein each of the wires are electrically coupled to an associated surface mount resistor, the surface mount resistors being arranged to reduce the coupling of electromagnetic energy between the antenna and the wire electrodes.

26. The ablation device as recited in claim 19 wherein the ablation device further includes a reflector positioned laterally to a first side of the antenna, the reflector being configured for redirecting a portion of the electromagnetic field to a second side of the antenna opposite the reflector, the antenna and reflector cooperating to produce an electromagnetic field that is sufficiently strong to cause tissue ablation.

27. The ablation device as recited in claim 26 wherein the electrode is positioned to the second side of the antenna opposite the reflector, the position coinciding with the predetermined direction such that the electrode is substantially aligned with the directional electromagnetic field.

28. The ablation device as recited in claim 19 wherein the ablation device is one of a catheter or surgical tool.

29. The ablation device as recited in claim 19 wherein the frequency of the electromagnetic field is in the microwave range.

30. The ablation device as recited in claim 19 wherein the device is suitable for use epicardially to electrically isolate the superior and inferior right pulmonary veins from the atrium to treat one of paroxysmal, recurrent atrial fibrillation, and chronic atrial fibrillation or to electrically isolate the superior and inferior left pulmonary veins from the atrium to treat one of paroxysmal, recurrent atrial fibrillation, and chronic atrial fibrillation.

31. The ablation device as recited in claim 26 wherein the antenna enclosure is configured to encapsulate the antenna and the reflector.

32. The ablation device as recited in claim 19 wherein the device is suitable for use epicardially and introduced along the transverse sinus to produce an ablation between the left and right superior pulmonary veins to treat on of paroxysmal, recurrent atrial fibrillation, and chronic atrial fibrillation.

33. The ablation device as recited in claim 19 wherein the device is suitable for use epicardially to produce an ablation between one of the left pulmonary veins to the left appendage to avoid any macro reentry circuits in the left atrium or to produce an ablation between the superior and inferior caval veins to avoid any macro reentry circuits in the right atrium.

34. The ablation device as recited in claim 19 wherein the antenna enclosure is configured to encapsulate the antenna.

35. A microwave ablation catheter, comprising:

a flexible tubular member having a lumen therein, and being adapted to be inserted into a vessel in the body of a patient;

a coaxial transmission line disposed within the lumen of the flexible tubular member, the coaxial transmission line including an inner conductor and an outer conductor suitable for the transmission of electromagnetic energy;

an antenna electrically coupled to the inner conductor of the coaxial transmission line, the antenna being positioned distally relative to the inner conductor and configured for creating an electromagnetic field;

an electrically conductive reflector positioned laterally to a first side of the antenna, the reflector being electrically coupled to the outer conductor of the coaxial transmission line, the reflector being configured for redirecting a portion of the electromagnetic field to a second side of the antenna opposite the reflector, wherein a majority of the electromagnetic field is directed away from the second side of the antenna, the antenna and reflector cooperating to produce a directional electromagnetic field that is sufficiently strong to cause tissue ablation;

an antenna enclosure for encapsulating the antenna and the reflector, and being adapted to be inserted into a vessel in the body of a patient;

a first electrode disposed on the antenna enclosure and positioned to the second side of the antenna opposite the reflector, the first electrode being configured for sensing electrical activity of biological tissues inside the patient;

a first electrode wire electrically coupled to the first electrode and extending through the antenna enclosure and the flexible tubular member;

a second electrode disposed on the antenna enclosure and positioned side by side to the first electrode, the second electrode being configured for sensing electrical activity of biological tissues inside the patient, the second electrode being spaced apart and electrically isolated from the first electrode; and

a second electrode wire electrically coupled to the second electrode and extending through the antenna enclosure and the flexible tubular member.

36. The microwave ablation catheter as recited in claim 35 wherein the first and second electrodes are positioned distally of the antenna.

37. The microwave ablation catheter as recited in claim 35 wherein the first and second electrodes are positioned proximally of the antenna.

38. The microwave ablation catheter as recited in claim 35 wherein the antenna includes a proximal and distal end, and wherein the first and second electrodes are positioned between the proximal and distal end of the antenna.

39. The microwave ablation catheter as recited in claim 35 wherein each of the electrode wires are formed from a high resistance material, the high resistance material being arranged to reduce the coupling of electromagnetic energy along the electrode wire.

40. The microwave ablation catheter as recited in claim 35 wherein each of the electrode wires are electrically coupled to an associated surface mount resistor, the surface mount resistors being arranged to reduce the coupling of electromagnetic energy between the antenna and the electrode wire.

41. The microwave ablation catheter as recited in claim 40 wherein the first and second electrode wires extend through the antenna enclosure to the side of the reflector opposite the antenna.

42. The microwave ablation catheter as recited in claim 38 wherein the microwave ablation catheter is suitable for ablating internal biological tissues of the heart, the brain, the prostate, the stomach, the liver and the intestine.

43. The microwave ablation catheter as recited in claim 42 wherein the catheter is suitable for ablating cardiac tissues of the heart to treat one selected from the group consisting of type I atrial flutter, atrial fibrillation or type II atrial flutter.

44. A method for ablating biological tissues using a catheter having a longitudinal ablation component configured for transmitting directional ablative energy to a first side of the catheter in a direction substantially normal to a longitudinal axis of the catheter, and having an electrode component configured for detecting electrical signals of biological tissues, the method comprising:

introducing the catheter into a patient'"'"'s body;

monitoring electrical signals of biological tissues inside the patient'"'"'s body via the electrode component;

positioning the longitudinal ablation component in a region proximate biological tissues targeted for ablation using the monitored electrical signals;

determining the radial position of the longitudinal ablation component relative to the biological tissues targeted for ablation via the monitored electrical signals;

rotating the catheter about its longitudinal axis so that the first side of the longitudinal ablation component is facing the biological tissues targeted for ablation; and

transmitting the directional ablative energy to the first side of the longitudinal ablation component so as to cause ablation of the biological tissues targeted for ablation.

45. The method as recited in claim 44 wherein the biological tissues correspond to biological tissues of the heart, the brain, the prostate, the stomach, the liver and the intestine.

46. The method as recited in claim 45 wherein the biological tissues correspond to biological tissues of the heart, and wherein the biological tissues of the heart are ablated to treat type I atrial flutter, atrial fibrillation or type II atrial flutter.

47. The method as recited in claim 44 wherein the ablative energy is an electromagnetic field.

48. The method as recited in claim 47 wherein the frequency of the electromagnetic field is in the microwave spectrum.

49. The method as recited in claim 47 wherein the frequency of the electromagnetic field is in the infrared spectrum.

50. The method as recited in claim 47 wherein the frequency of the electromagnetic field is in the visible spectrum.

51. The method as recited in claim 47 wherein the frequency of the electromagnetic field is in the ultraviolet spectrum.

52. The method as recited in claim 44 wherein the ablative energy is cryogenic.

53. The method as recited in claim 44 wherein the ablative energy is an ultrasound pressure wave.

54. The method as recited in claim 44 wherein the ablative energy is a radiofrequency current.

55. The method as recited in claim 44 wherein the electrode component includes first and second electrodes that are positioned longitudinally at about the same position on the catheter, and that are spaced apart circumferentially about the catheter, and wherein the directional ablative energy is transmitted between the first and second electrodes.

56. An ablation device, comprising:

an ablative energy source;

an ablative energy delivery device coupled to the ablative energy source, the ablative energy delivery device having a longitudinal working member configured for delivering ablative energy sufficiently strong to cause tissue ablation in a substantially linear manner to one side of the ablative energy delivery device, the ablative energy delivery device having a cross sectional dimension that includes an outer perimeter; and

an electrode arrangement carried by the ablative energy delivery device, the electrode arrangement including a first and a second electrode

configured for sensing electrical activity of biological tissues inside the body of the patient, the first and second electrodes being separated along the outer perimeter of the ablative energy delivery device by a first distance and a second distance, the first distance being smaller than the second distance.

57. The ablation device as recited in claim 56 wherein the ratio of the second distance to the first distance is at most about 4 to 1.

58. The ablation device as recited in claim 56 wherein the second electrode is positioned adjacent to the first electrode.

59. The ablation device as recited in claim 56 wherein the first distance is between about 0.5 mm and about 2.0 mm.

60. The catheter as recited in claim 56 wherein the working member is disposed inside the outer perimeter of the ablative energy delivery device.

61. The catheter as recited in claim 56 wherein the first and second electrodes work together to provide a radial position of the ablative energy delivery device so that the ablative energy delivered by the working member during ablation is aligned with a biological tissue targeted for ablation.

62. The ablation device as recited in claim 56 wherein the longitudinal working member is configured to create a directional electromagnetic field sufficiently strong to cause tissue ablation, the ablative energy device further including a transmission line for coupling the working member to the ablative energy source, and an enclosure for enclosing at least a portion of the working member.

63. The ablation device as recited in claim 62 wherein the electrode arrangement is carried by the enclosure, and wherein the first electrode is coupled to a first wire and the second electrode is coupled to a second wire, both the first and second wires extending through the enclosure.

64. The ablation device as recited in claim 62 wherein the frequency of the electromagnetic field is in the microwave range.

65. A catheter, comprising:

an elongated flexible tubular member adapted to be inserted into a vessel in the body of a patient, and having a longitudinal axis;

an electrode arrangement carried by the flexible tubular member and configured to sense electrical activity of biological tissues, the electrode arrangement including spaced apart first and second electrodes, each of the electrodes having centerlines that extend radially from the longitudinal axis of the flexible tubular member, the centerlines having an angle between them that is less than 45 degrees; and

a working member carried by the flexible tubular member, the working member working along a central axis that is disposed between the first and second electrodes and that is normal to the longitudinal axis of the tubular member.

66. The catheter as recited in claim 65 wherein the working member is disposed inside the outer perimeter of the flexible tubular member.

67. The catheter as recited in claim 65 wherein the first and second electrodes work together to provide a radial position of the working member.

68. The catheter as recited in claim 65 wherein the working member is configured to create a directional electromagnetic field sufficiently strong to cause tissue ablation, and wherein the frequency of the electromagnetic field is in the microwave range.

69. The catheter as recited in claim 65 wherein the flexible tubular member is configured to enclose at least a portion of the working member.

70. The catheter as recited in claim 69 wherein the working member extends longitudinally, and wherein the enclosed portion of working member is substantially parallel to the longitudinal axis of the flexible tubular member.

71. The catheter as recited in claim 65 wherein the first and second electrodes extend longitudinally at the outer periphery of the flexible tubular member.

72. The catheter as recited in claim 65 wherein the first and second electrodes are positioned substantially proximate a distal end of the working member.

73. The catheter as recited in claim 65 wherein the first and second electrodes are positioned substantially proximate a proximal end of the working member.

74. The catheter as recited in claim 65 wherein the first and second electrodes are positioned between a proximal and a distal end of the working member.

75. The catheter as recited in claim 65 wherein the first and second electrodes have a length and a width, the length being substantially larger than the width.

76. The catheter as recited in claim 75 wherein the width is between about 0.25 mm and about 0.625 mm, and wherein the length is between about 0.5 mm and about 1.0 mm.

77. The catheter as recited in claim 65 wherein the first and second electrodes are parallel to the longitudinal axis of the flexible tubular member.

78. The catheter as recited in claim 65 wherein the first and second electrodes are angled relative to the longitudinal axis of the flexible tubular member.

79. The catheter as recited in claim 65 wherein the centerlines of the first and second electrodes are longitudinally offset.

80. The catheter as recited in claim 65 wherein the first and second electrodes are angled relative to one another.

81. The catheter as recited in claim 65 wherein the first and second electrodes are plates formed from stainless steel or iridium platinum.

82. The catheter as recited in claim 65 wherein the first and second electrodes are printed or deposited on the surface of the flexible tubular member.