Systems and methods for creating lesions in body tissue using segmented electrode assemblies

• US 6,241,724 B1
• Filed: 02/21/1996
• Issued: 06/05/2001
• Est. Priority Date: 10/19/1993
• Status: Expired due to Term

• Current Assignee: EP Technologies Incorporated (Boston Scientific Corporation)
• Original Assignee: EP Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Amirana, Omar M., Swanson, David K., Fleischman, Sidney D., Houser, Russell A.
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US08/604,192
• Time in Patent Office: 1,931 Days
• Field of Search: 606/41, 606/49, 606/34, 607/99, 607/113, 607/116, 607/119, 607/122, 600/374
• US Class Current: 606/41
• 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 2017/00101 using an array of thermosensors
• CPC Class Codes: A61B 2017/00455 Orientation indicators, e.g. recess on the handle
• CPC Class Codes: A61B 2018/1417 Ball
• CPC Class Codes: A61B 2018/1497 Electrodes covering only part of the probe circumference
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61N 1/0565 Electrode heads
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals

Abstract

A multiple electrode array for ablating tissue carries at least two electrode segments that are circumferentially spaced from each other. Insulation electrically isolates the separated electrode segments from each other. Signal wires attached to the separated electrode segments convey ablating energy independently to the separated electrode segments. Because of its segmented structure, the array can place only one of the electrode segments in contact with tissue at one time. Because each segment is electrically isolated, and because each segment is independently served by its own signal wire, a physician can operate an ablation energy generator to selectively channel the ablation energy only to the segment actually contacting the tissue.

Claims

1. A system for ablating tissue in a body, comprising:

a guide body having a distal end,

a multiple electrode array carried on the distal end of the guide body comprising

a support body having an axis,

at least first and second electrodes on the support body, the electrodes being circumferentially spaced from each other about the body axis, said body being adapted to be oriented generally parallel to the surface of said tissue when at least one of said electrodes is in contact with said tissue and at least one of said electrodes is in contact with a blood pool adjacent to said tissue,

an insulator on the support body for electrically isolating the separated electrodes from each other,

first and second wires attached to the separated electrodes for conveying ablating energy independently to the separated electrodes, and

a controller electrically coupled to the first and second wires for conveying ablating energy to the one of the electrodes which is in contact with the tissue while not conveying energy to the other of the electrodes which is in contact with said blood pool.

2. A system according to claim 1

wherein the separated and electrically isolated electrodes comprise at least three circumferentially spaced electrodes.

3. A system according to claim 1

wherein the separated and electrically isolated electrodes comprise at least four circumferentially spaced electrodes.

4. A system according to claim 1,

further including an orientation sensor on the support body the orientation sensor configured for sensing the orientation of the separated and electrically isolated electrodes relative to the tissue and for generating an orientation signal,

wherein the controller conveys ablating energy at least in response to the orientation signal.

5. A system according to claim 4,

wherein the orientation sensor includes a switch within the support body that contacts one of the electrodes when the one electrode contacts tissue while not contacting the remaining electrodes not in contact with tissue, and

a sensor to determine contact between the switch and the one electrode, the sensor configured to generate the orientation signal which identifies among the electrodes the one electrode that contacts tissue.

6. A system according to claim 5,

wherein the controller conveys ablating energy only to the one electrode identified as contacting tissue.

7. A system according to claim 4,

wherein the orientation signal identifies among the electrodes which of the electrodes are contacting tissue and which of the electrodes are not contacting tissue, and

wherein the controller conveys ablating energy to the electrodes identified as contacting tissue while not conveying ablating energy to the electrodes identified as not contacting tissue.

8. A system for ablating tissue in a body comprising:

a guide body having a distal end,

a support body, having an axis, carried on the distal end of the guide body,

a first electrode on the support body, first electrode and electrically isolated from the first electrode,

a first conductor coupled to the first electrode for conveying ablating energy to the first electrode,

a second conductor coupled to the second electrode for conveying ablating energy to the second electrode independently of the first electrode,

a first temperature sensor associated with the first electrode for sensing temperature conditions adjacent the first electrode,

a second temperature sensor associated with the second electrode for sensing temperature conditions adjacent the second electrode,

a comparator coupled to the first and second temperature sensors for comparing the temperature conditions adjacent the first and second electrodes and, based thereon, identifying which of the first and second electrodes is contacting tissue and which of the first and second electrodes is not contacting tissue, and

a controller coupled to the comparator and to the first and second conductors for conveying ablating energy to whichever one of the first or second electrodes is contacting tissue as identified by the comparator.

9. A system according to claim 8

wherein the controller does not convey ablating energy to whichever one of the first and second electrodes is not contacting tissue as identified by the comparator.

10. A system for ablating tissue in a body comprising:

a guide body having a distal end, and

a multiple electrode array carried on the distal end of the guide body, the multiple electrode array comprising;

a support body having an axis,

at least first and second electrodes on the support body, the electrodes being circumferentially spaced from each other about the body axis, the body being adapted to be oriented generally parallel to the surface of the tissue when the electrodes are placed in contact with the tissue, at least one of the electrodes contacting the tissue and at least one of the electrodes being in contact with a blood pool adjacent the tissue,

an insulator on the support body for electrically isolating the electrodes from each other, and

a plurality of conductors for conveying ablating energy independently to the electrodes,

the system further comprising;

an orientation sensor on the support body for sensing the orientation of the electrodes relative to the tissue and generating an orientation signal indicative thereof, and

a controller responsive to the orientation signal and electrically coupled to the conductors for conveying ablating energy to one of the electrodes which is in contact with the tissue while not conveying ablating energy to the other of the electrodes which is in contact with the blood pool,

the orientation sensor including;

a pressure sensor associated with each of the electrodes for sensing contact pressure adjacent the associated electrode, and

a comparator coupled to the pressure sensors for comparing the contact pressures sensed adjacent the electrodes and generating the orientation signal based on the comparison.

11. A system according to claim 10

wherein the controller conveys ablating energy only to whichever ones of the electrodes are contacting tissue as identified by the comparator.

12. A method of ablating tissue in a body, comprising the steps of:

introducing a multiple electrode array into the body, the multiple electrode array comprising at least first and second electrodes on a support body, the electrodes being circumferentially spaced from each other about the axis of the support body,

sensing the orientation of the separated electrodes relative to the tissue and generating an orientation signal, and

conveying ablating energy to one of the electrodes while not conveying ablating energy to another one of the electrodes in response at least in part to the orientation signal.

13. A method of ablating tissue in a body, comprising the steps of:

introducing a multiple electrode array into the body, the multiple electrode array comprising at least first and second electrodes on a support body, the electrodes being circumferentially spaced from each other about the axis of the support body,

sensing the orientation of the separated electrodes relative to the tissue and generating an orientation signal that identifies which one of the electrodes contacts the tissue and which one of the electrodes does not contact the tissue, and

conveying ablating energy only to the electrodes identified as contacting the tissue and not to the electrodes identified as not contacting the tissue.