PULMONARY VEIN ISOLATION GAP FINDER

• US 20170128128A1
• Filed: 09/19/2016
• Published: 05/11/2017
• Est. Priority Date: 11/06/2015
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Saba, Eitan Moshe, Bar-Tal, Meir, Ludwin, Doron Moshe, Izraeli, David
• Granted Patent: US 10,588,692 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 18/1206 Generators therefor
• 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 2017/00053 Mapping
• CPC Class Codes: A61B 2018/00375 Ostium, e.g. ostium of pulmonary vein or artery
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00791 Temperature
• 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 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation

Abstract

A gap between a plurality of ablation sites in a heart that hinders electrical propagation therethrough is found by projecting the locations of the sites in a 3-dimensional coordinate system onto a simulation plane, identifying a set of shortest 3-dimensional paths that correspond to 2-dimensional connections between pairs of the projected locations of the sites, and reporting a gap as a longest one of the set.

Claims

1. A method, comprising the steps of:

ablating a plurality of sites in a heart of a living subject, the sites having respective locations in a 3-dimensional coordinate system;

projecting the locations of the sites onto a simulation plane;

identifying a set of shortest 3-dimensional paths that correspond to 2-dimensional connections between pairs of the projected locations of the sites, the 3-dimensional paths having respective lengths; and

reporting a gap as a longest one of the 3-dimensional paths.

2. The method according to claim 1, further comprising the steps of:

defining a source and a destination,

projecting the source and the destination onto the simulation plane, wherein the projected locations of the sites lie between the projected source and the projected destination on the simulation plane;

randomly generating 2-dimensional paths on the simulation plane extending from the projected source to the projected destination and having passages between two of the projected locations of sites, the passages having respective sizes; and

for each of the 2-dimensional paths determining a minimum size of the passages thereof, wherein reporting a gap comprises reporting the largest minimum size of the 2-dimensional paths.

3. The method according to claim 2, wherein the projected locations of the sites lie on an ellipse of best fit, wherein a portion of the projected locations of the sites lie outside the ellipse, further comprising enlarging the ellipse to include all of the projected locations of the sites.

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

modeling a portion of the heart as a triangular mesh comprising mesh nodes and ablation points, respective ablation points having a nearest mesh node;

from the mesh nodes preparing a grid graph having graph nodes that are connected by undirected edges;

representing the ablation points on the grid graph as corresponding graph nodes of the nearest mesh node thereof; and

using the corresponding graph nodes as the projected locations of the sites in the step of generating 2-dimensional paths.

5. A method, comprising the steps of:

ablating a plurality of sites in a heart of a living subject, the sites having respective locations in a 3-dimensional coordinate system;

building a tree graph from all of the locations of the sites, the tree graph having edges and defining a path constructed of shortest segments between pairs of the sites;

selecting a source, wherein the tree graph has a loop that winds about the source, the loop describing a gap between two of the ablation sites; and

reporting a shortest edge in the tree graph that can close the gap as a gap size.

6. The method according to claim 5, further comprising selecting additional sources and iterating the step of building a tree graph using the additional sources.

7. An apparatus, comprising:

a probe adapted for insertion into contact with a heart in a body of a subject, the probe having a location sensor and an electrode on a distal portion of the probe;

an ablation power generator;

a processor linked to the location sensor, and arranged cooperatively with the ablation power generator for performing the steps of;

ablating a plurality of sites in the heart, the sites having respective locations in a 3-dimensional coordinate system;

projecting the locations of the sites onto a simulation plane;

identifying a set of shortest 3-dimensional paths that correspond to 2-dimensional connections between pairs of the projected locations of the sites, the 3-dimensional paths having respective lengths; and

reporting a gap as a longest one of the 3-dimensional paths.

8. The apparatus according to claim 7, wherein the processor is operative for performing the steps of:

defining a source and a destination,

projecting the source and the destination onto the simulation plane, wherein the projected locations of the sites lie between the projected source and the projected destination on the simulation plane;

randomly generating 2-dimensional paths on the simulation plane extending from the projected source to the projected destination and having passages between two of the projected locations of the sites, the passages having respective sizes; and

for each of the 2-dimensional paths determining a minimum size of the passages thereof, wherein reporting a gap comprises reporting the largest minimum size of the 2-dimensional paths.

9. The apparatus according to claim 8, wherein the projected locations of the sites lie on an ellipse of best fit, wherein a portion of the projected locations of the sites lie outside the ellipse, further comprising enlarging the ellipse to include all of the projected locations of the sites.

10. The apparatus according to claim 8, wherein the processor is operative for performing the steps of:

modeling a portion of the heart as a triangular mesh comprising mesh nodes and ablation points, respective ablation points having a nearest mesh node;

from the mesh nodes preparing a grid graph having graph nodes that are connected by undirected edges;

representing the ablation points on the grid graph as corresponding graph nodes of the nearest mesh node thereof; and

using the corresponding graph nodes as the projected locations of the sites in the step of generating 2-dimensional paths.

11. An apparatus, comprising:

a probe adapted for insertion into contact with a heart in a body of a subject, the probe having a location sensor and an electrode on a distal portion of the probe;

an ablation power generator;

a processor linked to the location sensor, and arranged cooperatively with the ablation power generator for performing the steps of;

ablating a plurality of sites in the heart, the sites having respective locations in a 3-dimensional coordinate system;

building a tree graph from all of the sites, the tree graph having edges and defining a path constructed of shortest segments between the respective locations of pairs of the sites;

selecting a source, wherein the tree graph has a loop that winds about the source, the loop describing a gap between two of the ablation sites; and

reporting a shortest edge in the tree graph that can close the gap as a gap size.

12. The apparatus according to claim 11, wherein the processor is operative for selecting additional sources and iterating the step of building a tree graph using the additional sources.