# US 11,439,337 B2 · Mapping of atrial fibrillation

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- Number: US 11,439,337 B2
- Document ID: US11439337B2
- Status: Granted
- Kind: B2
- Application number: 16/895,606
- Filed: 2020-06-08
- Published: 2020-09-24
- Granted: 2022-09-13
- Earliest claimed: 2016-03-31
- Assignees: Biosense Webster (Israel) Ltd.
- Applicants: Biosense Webster (Israel) Ltd.
- Inventors: Richard P. M. Houben; Meir Bar-Tal; Yaniv Ben Zriham; Roy Urman; Shmuel Auerbach
- Web page: https://patentgrep.com/patent/US11439337B2

## CPC

- A61B 5/287: Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
- A61B 5/0036: {including treatment, e.g., using an implantable medical device, ablating, ventilating}
- A61B 5/349: Detecting specific parameters of the electrocardiograph cycle
- A61B 18/12: by passing a current through the tissue to be heated, e.g. high-frequency current
- A61B 18/1206: {Generators therefor}
- A61B 18/1492: {having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence)}
- A61B 5/0044: {for the heart}
- A61B 5/341: Vectorcardiography [VCG]
- A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)}
- A61B 5/743: {Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots}
- A61B 2018/00351: {Heart}
- A61B 2018/00636: {Sensing and controlling the application of energy}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

Electroanatomic mapping is carried out by inserting a multi-electrode probe into a heart of a living subject, recording electrograms from the electrodes concurrently at respective locations in the heart, delimiting respective activation time intervals in the electrograms, generating a map of electrical propagation waves from the activation time intervals, maximizing coherence of the waves by adjusting local activation times within the activation time intervals of the electrograms, and reporting the adjusted local activation times.

## Claims

### Claim 1

A method comprising:
inserting a probe into a heart of a living subject, the probe having a plurality of electrodes;
modeling at least a portion of the heart as a mesh with vertices, each vertex representing an electrode, each vertex formed by a plurality of connected triangles, each triangle having a triangle velocity vector, each vertex having a plane normal thereto onto which its triangle velocity vector is projected to generate a projected velocity vector, and each vertex having a vertex velocity vector based on an average of all projected velocity vectors of the connected triangles;
corresponding locations of respective electrodes of the plurality of electrodes to respective vertices of the mesh;
recording electrograms from the respective electrodes of the plurality of electrodes concurrently at the respective locations of the corresponding locations of respective electrodes in the heart, the electrograms comprising readings of the electrodes, each reading being from the group consisting of trusted readings, each with a fixed Local Activation Time (LAT) obtained from a respective maximum negative slope, and unreliable readings, each with an adjustable LAT that falls within a respective time window with upper and lower limits derived from a time incidence of peak and valley demarcating a slope on which the adjustable LAT is defined;
generating an activation map from the trusted and unreliable readings of the group;
transforming the activation map into a map of electrical propagation waves, comprising:
segmenting the electrograms into a series of frames filled with the fixed and adjustable LATs based on vertex velocity vectors of corresponding vertices of the mesh;
for the vertices of the mesh corresponding to electrodes with unreliable readings that fall within respective time windows, determining velocity deviation angles based on their vertex velocity vectors, wherein a velocity deviation angle is defined as an angle between a pair of projected vertex velocity vectors;
adjusting the LATs of the electrodes with unreliable readings that fall within respective time windows by minimizing the velocity deviation angles;
reporting adjusted LATs; and
ablating tissue of the heart based on adjusted LATs to modify the electrograms.

### Claim 2 (depends on 1)

The method of claim 1, wherein the minimizing the velocity deviation angles includes adjusting the LATs of electrodes with readings that fall within their respective time windows.

### Claim 3 (depends on 1)

The method of claim 1, further comprising defining blocked waves by maximizing the velocity deviation vector.

### Claim 4 (depends on 1)

The method of claim 1, wherein the conduction velocity is based on LATs of a center electrode and neighboring electrodes with respect to a selected area of the portion of the heart being modeled.

### Claim 5 (depends on 4)

The method of claim 4, wherein the generating an activation map includes region growing the mesh by generating the activation map to include the neighboring electrodes.

### Claim 6 (depends on 1)

The method of claim 1, wherein the minimizing the velocity deviation angles is iterative until a difference between a prior velocity deviation angle and a minimized velocity deviation angle is greater than a predetermined tolerance.

### Claim 7 (depends on 1)

The method of claim 1, wherein time windows are defined by earlier and later slopes of the slopes on which the LATs are defined.

### Claim 8

An apparatus, comprising:
a probe having a plurality of electrodes and adapted for insertion into a heart of a living subject; and
a processor configured to receive electrical signals from the electrodes and to perform the acts of:
modeling at least a portion of the heart as a mesh with vertices, each vertex representing a respective electrode, each vertex formed by a plurality of connected triangles, each triangle having a triangle velocity vector, each vertex having a plane normal thereto onto which its triangle velocity vector is projected to generate a projected velocity vector, and each vertex having a vertex velocity vector based on an average of all projected velocity vectors of the connected triangles;
corresponding locations of respective electrodes of the plurality of electrodes to respective vertices of the mesh;
recording electrograms from the respective electrodes of the plurality of electrodes concurrently at the respective locations of the corresponding locations of respective electrodes in the heart, the electrograms comprising readings of the electrodes, each reading being from the group consisting of trusted reading, each with a fixed Local Activation Time (LAT) obtained from a respective maximum negative slope, and unreliable readings, each with an adjustable LAT that falls within a respective time window with upper and lower limits derived from a time incidence of peak and valley demarcating a slope on which the adjustable LAT is defined;
generating an activation map from the trusted and unreliable readings of the group;
transforming the activation map into a map of electrical propagation waves, comprising:
segmenting the electrograms into a series of frames filled with the fixed and adjustable LATs based on vertex velocity vectors of corresponding vertices of the mesh;
for the vertices of the mesh corresponding to electrodes with unreliable readings that fall within respective time windows, determining velocity deviation angles based on their vertex velocity vectors, wherein a velocity deviation angle is defined as an angle between a pair of projected vertex velocity vectors;
adjusting the LATs of the electrodes with unreliable readings that fall within respective time windows by minimizing the velocity deviation angles;
reporting adjusted LATs; and
ablating tissue of the heart based on adjusted LATs to modify the electrograms.

### Claim 9 (depends on 8)

The apparatus of claim 8, wherein the minimizing the velocity deviation angles includes adjusting the LATs of electrodes with readings that fall within their respective time windows.

### Claim 10 (depends on 8)

The apparatus of claim 8, further comprising defining blocked waves by maximizing the velocity deviation vector.

### Claim 11 (depends on 8)

The apparatus of claim 8, wherein the conduction velocity is based on LATs of a center electrode and neighboring electrodes with respect to a selected area of the portion of the heart being modeled.

### Claim 12 (depends on 11)

The apparatus of claim 11, wherein the generating an activation map includes region growing the mesh by generating the activation map to include the neighboring electrodes.

### Claim 13 (depends on 8)

The apparatus of claim 8, wherein the minimizing the velocity deviation angles is iterative until a difference between a prior velocity deviation angle and a minimized velocity deviation angle is greater than a predetermined tolerance.

### Claim 14 (depends on 8)

The apparatus of claim 8, wherein time windows are defined by earlier and later slopes of the slopes on which the LATs are defined.