Method and system for gap detection in ablation lines

Patent metadata

Field	Value
Publication number	US-11484359-B2
Application number	US-201715799254-A
Country	US
Kind code	B2
Filing date	Oct 31, 2017
Priority date	Oct 31, 2017
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

Described herein is a method and system for gap detection in ablation lines. Microelectrodes are implemented at a distal tip of a catheter to provide localized gap detection along an ablation line. A pacing protocol is used to sequence through each of the microelectrode pairs for a tissue location. If living tissue is present, the pacing signal travels through the living tissue to pulse the heart. An operator will see a capture signal and know that there is a gap in the ablation line. The ablation electrode is then used to ablate the tissue in the gap. Pacing and ablation are therefore performed at the same place without the need to switch between instruments and/or catheters. In an implementation, a force sensor can automate the pacing protocol by determining which microelectrode pair is contacting the tissue. Moreover, signaling between microelectrode pairs can determine contact between the catheter and the tissue.

First claim

What is claimed is:

1. A method for gap detection in an ablation line using a catheter comprising a tip including a plurality of microelectrodes configured to deliver a bipolar pacing signal to tissue and an impedance transducer configured to detect a capture signal, the method comprising:
in a first placement of the catheter, placing the catheter along the ablation line at a first tissue location;
in the first placement, transmitting a first pacing signal between a first two of the plurality of microelectrodes, to deliver the first pacing signal to tissue at the first tissue location;
in the first placement, receiving a first capture signal from the impedance transducer if the first pacing signal pulses the heart;
in the first placement, transmitting a second pacing signal between a second two of the plurality of microelectrodes to deliver the second pacing signal to tissue at the first tissue location;
in the first placement, receiving a second capture signal from the impedance transducer if the second pacing signal pulses the heart; and
in the first placement, if the first capture signal is received, ablating the tissue at the first tissue location with the impedance transducer;
in the first placement, if the second capture signal is received, ablating the tissue at the first tissue location with the impedance transducer.

2. The method of claim 1 , further comprising:
determining which of the plurality of microelectrodes is in contact with tissue at the first tissue location.

3. The method of claim 2 , wherein determining is performed using a force sensor to automatically detect which of the microelectrodes is in contact with tissue at the first tissue location.

4. The method of claim 2 , wherein determining is performed using a thermocouple to automatically detect which of the plurality of microelectrodes is in contact with tissue at the first tissue location.

5. The method of claim 2 , further comprising:
transmitting a third pacing signal between a third two of the plurality of microelectrodes at the first tissue location without moving the catheter away from the first tissue location.

6. The method of claim 5 , further comprising:
placing the catheter at a second tissue location if no two of the plurality of microelectrodes is in contact with tissue at the first tissue location.

7. The method of claim 2 , further comprising:
using signaling between the microelectrodes to determine if the catheter is in contact with tissue at the first tissue location.

8. The method of claim 1 , further comprising: upon receiving a capture signal from the impedance transducer, displaying an indication of the capture signal to a user.

9. A system for gap detection in an ablation line, comprising:
a catheter including a plurality of microelectrodes and an impedance transducer, the catheter configured for a first placement along the ablation line at a first tissue location;
a processing device in communication with the plurality of microelectrodes and the impedance transducer, the processing device configured to:
in the first placement, transmit a first bipolar pacing signal between a first two of the plurality of microelectrodes;
in the first placement, receive a first capture signal via the impedance transducer if the first pacing signal pulses the heart;
in the first placement, transmit a second bipolar pacing signal between a second two of the plurality of microelectrodes to deliver the second pacing signal to tissue at the first tissue location; and
in the first placement, receive a second capture signal if the second pacing signal pulses the heart;
in the first placement, if the first capture signal is received, cause the impedance transducer to ablate tissue at the first tissue location, and
in the first placement, if the second capture signal is received, cause the impedance transducer to ablate tissue at the first location.

10. The system of claim 9 , wherein the processing device further comprises:
a pacing signal unit configured to:
in the first placement, determine which of the plurality of microelectrodes is in contact with tissue at the first tissue location; and
in the first placement, implement a pacing protocol comprising transmitting a sequence of successive respective pacing signals between corresponding successive, respective pairs of the plurality of microelectrodes in contact with tissue at the first tissue location, and for each successive respective pair in the sequence, determining whether or not a corresponding capture signal is received from the impedance transducer, thereby testing for presence of living tissue at the first tissue location.

11. The system of claim 10 , further comprising: a force sensor in communication with the pacing signal unit, the force sensor configured to automatically detect which of the plurality of microelectrodes is in contact with tissue at the first tissue location.

12. The system of claim 10 , further comprising:
a thermocouple in communication with the pacing signal unit, the thermocouple configured to detect which of the plurality of microelectrodes is in contact with tissue at the first tissue location.

13. The system of claim 10 , wherein the processing device is further configured to transmit a third pacing signal via a third two of the plurality of microelectrodes to deliver the third pacing signal to tissue at the first tissue location.

14. The system of claim 9 , wherein the processing device is further configured to use signals between the microelectrodes to determine which of the plurality of microelectrodes is in contact with the tissue at the first tissue location.

15. The system of claim 9 , further comprising: a display for displaying the capture signal to a user.

16. A catheter for use in gap detection and configured for a first placement along an ablation line at a first tissue location, the catheter comprising:
an impedance transducer disposed at a distal tip of the catheter;
a plurality of microelectrodes positioned about the distal tip of the catheter;
wherein a first two of the plurality of microelectrodes is configured to deliver a first bipolar pacing signal to tissue at the first tissue location in the first placement, such that in the first placement the impedance transducer detects a capture signal if the first pacing signal pulses the heart, and if the first pacing signal does not pulse the heart, the impedance transducer does not detect a capture signal;
wherein a second two of the plurality of microelectrodes is configured to deliver second bipolar pacing signal to tissue at the first tissue location in the first placement, such that the impedance transducer detects a capture signal in the first placement if the second pacing signal pulses the heart, and if the second pacing signal does not pulse the heart the impedance transducer does not detect a capture signal;
thereby determining a location for ablation in the first placement;
and
if the impedance transducer detects a capture signal while the catheter is at the first tissue location, the impedance transducer is configured to perform in the first placement, an ablation of tissue at the first tissue location;
wherein detection and ablation is performed with only one placement of the catheter between sending the first pacing signal and performing the ablation.

17. The catheter of claim 16 , further comprising:
a force sensor configured to automatically detect which of the microelectrodes is in contact with tissue.

18. The catheter of claim 16 , further comprising:
a thermocouple configured

Assignees

• Biosense Webster Israel Ltd

Inventors

• Berman Dror
• Pressman Assaf

Classifications

• A61N1/371

  Capture, i.e. successful stimulation · CPC title

• A61B5/6885

  Monitoring or controlling sensor contact pressure · CPC title

• A61B18/1492 Primary

  having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence) · CPC title

• A61B2018/126

  bipolar · CPC title

• A61N1/056

  Transvascular endocardial electrode systems · CPC title