CORRELATION OF CARDIAC ELECTRICAL MAPS WITH BODY SURFACE MEASUREMENTS

• US 20080058657A1
• Filed: 08/28/2007
• Published: 03/06/2008
• Est. Priority Date: 09/06/2006
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Bar-Tal, Meir, Schwartz, Yitzhack, Porath, Joshua
• Granted Patent: US 9,370,312 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6805 Vests

Abstract

A reliable endocardial map is obtained by constructing a matrix relationship between a small number of endocardial points and a large number of external receiving points using a multi-electrode chest panel. Inversion of the matrix yields information allowing the endocardial map to be constructed. Subsequent maps are obtained noninvasively using the multi-electrode chest panel, applying new electrical signals to the matrix relationship, and again inverting the matrix to generate new endocardial electrical maps.

Claims

1. A method for generating an electrical map of a heart of a living subject, comprising the steps of:

inserting a probe into a chamber of the heart, said probe having at least one electrode;

emitting electrical signals from said electrode from at least one transmission point within the heart;

receiving said emitted electrical signals in at least one receiving point;

locating said receiving point relative to said at least one transmission point;

determining a functional relationship between said emitted electrical signals and said received electrical signals;

receiving electrophysiological signals at new receiving points; and

applying said functional relationship to said electrophysiological signals to obtain an endocardial electrical map.

2. The method according to claim 1, wherein said functional relationship is a measured inverted lead field matrix.

3. The method according to claim 2, further comprising the steps of:

acquiring an anatomic image of a thorax of said subject;

using said anatomic image preparing a finite element model of said thorax having parameters, said finite element model having a calculated inverted lead field matrix; and

adjusting said parameters to conform said calculated inverted lead field matrix to said measured inverted lead field matrix.

4. The method according to claim 1, further comprising the step of withdrawing said probe from said subject prior to performing said steps of receiving electrophysiological signals and applying said functional relationship.

5. The method according to claim 1, wherein said at least one receiving point is external to said subject.

6. The method according to claim 1, wherein said at least one receiving point is internal to said subject.

7. The method according to claim 1, wherein said probe has at least two electrodes and emitting electrical signals is performed by time multiplexing said electrical signals using different subsets of said electrodes.

8. The method according to claim 1, wherein said probe has at least two electrodes and emitting electrical signals is performed by frequency multiplexing said electrical signals using different subsets of said electrodes.

9. The method according to claim 1, wherein said electrode is a unipolar electrode.

10. The method according to claim 1, wherein said electrode is a bipolar electrode.

11. The method according to claim 1, wherein said steps of emitting electrical signals, receiving said emitted electrical signals, and determining a functional relationship are performed with respect to a predetermined phase of a respiratory cycle of said subject.

12. The method according to claim 1, wherein said steps of emitting electrical signals, receiving said emitted electrical signals, and determining a functional relationship, are performed with respect to a predetermined phase of a cardiac cycle of said subject.

13. A method for generating an electrical map of a heart of a living subject, comprising the steps of:

inserting a catheter into a chamber of the heart, said catheter having a first location sensor and at least one electrode;

emitting electrical signals from said electrode at a plurality of transmission points within the heart;

receiving said emitted electrical signals at a plurality of receiving points that are external to said subject;

locating said receiving points relative to said transmission points;

determining a measured lead field matrix to define a linear matrix relationship between said emitted electrical signals and said received electrical signals;

calculating an inverted lead field matrix from said measured lead field matrix;

receiving electrophysiological signals at said receiving points; and

applying said inverted lead field matrix to said electrophysiological signals to obtain an endocardial electrical map.

14. The method according to claim 13, wherein said step of locating said receiving points comprises:

associating said receiving points with a second location sensor; and

reading said first location sensor and said second location sensor to determine a difference therebetween.

15. The method according to claim 13, wherein said catheter has at least two electrodes and emitting electrical signals is performed with different subsets of said electrodes.

16. The method according to claim 13, wherein said electrode is a unipolar electrode.

17. The method according to claim 13, wherein said electrode is a bipolar electrode.

18. The method according to claim 13, wherein said step of receiving said emitted electrical signals is performed by determining impedances between said receiving points and subsets of said transmission points.

19. The method according to claim 13, wherein said step of receiving said emitted electrical signals is performed by measuring signals produced by electrical dipoles that are generated among said subsets of said transmission points.

20. The method according to claim 13, wherein said steps of emitting electrical signals, receiving said emitted electrical signals, determining a measured lead field matrix, and calculating an inverted lead field matrix are performed with respect to a predetermined phase of a respiratory cycle of said subject.

21. The method according to claim 13, wherein said steps of emitting electrical signals, receiving said emitted electrical signals, determining a measured lead field matrix, and calculating an inverted lead field matrix are performed with respect to a predetermined phase of a cardiac cycle of said subject.

22. The method according to claim 13, further comprising the steps of:

acquiring an anatomic image of a thorax of said subject;

using said anatomic image preparing a finite element model of said thorax having parameters, said finite element model having a calculated lead field matrix; and

adjusting said parameters to conform said calculated lead field matrix to said measured lead field matrix.

23. The method according to claim 13, wherein said step of calculating an inverted lead field matrix comprises regularizing said measured lead field matrix by removing a null space of said inverted lead field matrix.

24. A system for imaging a heart in a living subject, comprising:

an imaging device;

a signal generator; and

a processor linked to a torso vest for clothing said subject, said torso vest comprising a plurality of receivers and a first position sensor, said processor being linked to said imaging device, said signal generator and to a mapping catheter adapted for insertion into said heart, said mapping catheter having a mapping electrode, said processor operative to read said first position sensor to locate said mapping electrode with respect to said receivers, said processor operative to cause said signal generator to transmit electrical signals sequentially to said mapping electrode, and said mapping electrode sequentially emits said electrical signals from different transmission points in said heart, wherein said emitted electrical signals are transferred to said processor via said receivers as received electrical signals, said processor further operative to determine a measured lead field matrix that defines a linear matrix relationship between said emitted electrical signals at respective locations thereof and said received electrical signals, calculate an inverted lead field matrix from said measured lead field matrix, and apply said inverted lead field matrix to process electrophysiological signals of said subject that are received at said receivers to generate an endocardial electrical map from said electrophysiological signals, and to display said endocardial electrical map on said imaging device.

25. The system according to claim 24, wherein said mapping catheter has at least two mapping electrodes and said signal generator is operative to produce said emitted electrical signals by sequentially conveying said electrical signals to different subsets of said mapping electrodes.

26. The system according to claim 24, processor is operative to determine said measured lead field matrix at a predetermined phase of a respiratory cycle of said subject.

27. The system according to claim 24, processor is operative to determine said measured lead field matrix at a predetermined phase of a cardiac cycle of said subject.

28. The system according to claim 24, wherein said processor is operative to accept an anatomic image of a thorax of said subject, and to using said anatomic image to prepare a finite element model of said thorax having parameters, said finite element model having a calculated lead field matrix, and to adjust said parameters to conform said calculated lead field matrix to said measured lead field matrix.

29. The system according to claim 24, wherein said processor is operative to calculate said inverted lead field matrix by regularizing said measured lead field matrix by removing a null space of said inverted lead field matrix.