Focal point identification and mapping

Patent metadata

Field	Value
Publication number	US-9668664-B2
Application number	US-201414156903-A
Country	US
Kind code	B2
Filing date	Jan 16, 2014
Priority date	Jan 17, 2013
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A method can determine one or more origins of focal activation. The method can include computing phase for the electrical signals at a plurality of nodes distributed across a geometric surface based on the electrical data across time. The method can determine whether or not a given candidate node of the plurality of nodes is a focal point based on the analyzing the computed phase and magnitude of the given candidate node. A graphical map can be generated to visualize focal points detected on the geometric surface.

First claim

What is claimed is:

1. A system comprising:
memory to store data and machine readable instructions;
a processor to access the memory and execute the machine readable instructions, the machine readable instructions comprising:
a phase calculator programmed to compute phase values for electrical signals at each of a plurality of nodes distributed across a geometric surface corresponding to patient tissue;
a mask generator programmed to generate an activation mask for a given node of the plurality of nodes specifying a set of at least one activation time period having a beginning time and an ending time, the beginning time corresponding to when a phase value of a signal at the least one of the plurality of nodes has a given value and the ending time corresponding to when the phase value of the signal at the least one of the plurality of nodes has another value;
a candidate selector programmed to apply the activation mask to the computed phases values computed for each of the plurality nodes on the geometric surface to identify a set of focal candidate nodes;
a focal detector programmed to analyze the set of focal candidate nodes to identify a given focal candidate node corresponding to a spatial location of a focal point for the geometric surface, the focal detector further programmed to generate focal point data characterizing the identified given focal candidate node; and
a map generator programmed to generate a graphical map representing the focal point detected on the geometric surface based on the focal point data; and
a display to receive and display the generated graphical map to visualize the focal point detected on the geometric surface.

2. The system of claim 1 , wherein the focal detector further comprises an activation detector programmed to determine the activation time interval for at least a substantial portion of the plurality of nodes.

3. The system of claim 2 , wherein the activation mask is a temporal activation mask, the mask generator further to provide a magnitude activation mask that specifies a minimum magnitude for the electrical signals at each of the plurality of nodes on the geometric surface, and
wherein the candidate selector is programmed to identify the set of focal candidate nodes in response to applying both the temporal activation mask to the computed activation time intervals for each of the plurality of nodes and the magnitude activation mask to the electrical signals at each of the plurality of nodes.

4. The system of claim 2 , wherein the focal detector further comprises:
a size calculator programmed to compute a size of an activation region across the geometric surface according to which of the plurality of nodes are activated for a respective activation time in a corresponding time interval, and
wherein the focal detector is further programmed to determine whether or not each given focal candidate node is a focal point based on the computed size of the activation region for at least one time interval.

5. The system of claim 4 , wherein the focal detector further comprises:
a continuity detector programmed to provide continuity data to indicate if newly activated nodes for at least one other activation interval following the respective activation time interval are connected with the activation region that was activated for the respective activation time period,
wherein the focal detector is to determine that each given focal candidate node is a focal point based on the continuity data and based on the computed size of the activation region for the other activation time exceeding a minimum size parameter.

6. The system of claim 5 , wherein the focal detector is further programmed to determine that one of the given candidate nodes is not a focal point based on the continuity data indicating that newly activated nodes for at least one other activation interval following the respective activation time interval are unconnected with the activation region that was activated for the respective activation time period and the computed size has not changed over a predetermined time period.

7. The system of claim 1 , wherein the geometric surface comprises one of an epicardial surface, an endocardial surface or another cardiac envelope.

8. The system of claim 7 , further comprising:
a measurement system configured to measure non-invasively electrical activity for the geometric surface of the patient and provide corresponding electrical measurement data;
wherein the machine instructions further comprise a reconstruction function programmed to solving an inverse problem to compute reconstructed electrical signals, which correspond to the electrical signals, for each of the nodes on the geometric surface based on electrical measurement data and geometry data, the phase value for each of the plurality of nodes being computed based on the reconstructed electrical signals for the respective nodes.

9. The system of claim 1 , further comprising a measurement system configured to measure invasively electrical activity for the geometric surface, wherein the electrical signals for each of the plurality of nodes are derived based on the invasively measured electrical activity.

10. The system of claim 1 , further comprising a therapy system to control delivery of a therapy to a selected location on the geometric surface based on the focal point data.

11. A non-transitory computer-readable medium having instructions executable by a processor for performing a method, the method comprising:
computing phase values for signals of each of a plurality of nodes on a geometric surface region associated with tissue of a patient, a subset of the nodes surrounding a given node of the plurality of nodes defining neighboring nodes of the given node;
generating an activation mask for the given node based on an activation detected for at least one of the plurality of nodes, the activation mask specifying a set of at least one activation time period having a beginning time and an ending time, the beginning time corresponding to when phase value of a signal at the least one of the plurality of nodes has a given value and the ending time corresponding to when the phase value of the signal at the least one of the plurality of nodes has another value;
applying the activation mask to the computed phases values computed for each of the plurality nodes on the geometric surface region to identify a set of focal candidate nodes;
analyzing the set of focal candidate nodes to identify a given focal candidate node corresponding to a spatial location of a focal point for the geometric surface region;
generating focal point data characterizing the spatial location of the focal point; and
providing a graphical map to a display to visualize the focal point for the geometric surface region based on the focal point data.

12. The medium of claim 11 , wherein the ending time is a predetermined phase value that is fixed time from the beginning time.

13. The medium of claim 11 , wherein the neighboring nodes comprise an arrangement of nodes having a plurality of layers that provide a neighborhood of the nodes relative to the given node.

14. The medium of claim 13 , wherein the number of layers for each neighborhood is a programmable parameter.

15. The medium of claim 11 , wherein the method further comprises detecting the activation for at least a substantial portion of the plurality of nodes.

16. The medium of claim 11 , wherein the activation mask is a temporal activation mask,
wherein generating the activation mask further comprises setting a magnitude threshold that specifies a minimum magnitude for

Assignees

• Cardioinsight Technologies Inc

Inventors

• Zeng Qingguo
• Dubois Remi
• Jia Ping
• Bokan Ryan
• Vasudevan Venkatesh
• Ramanathan Charulatha
• Strom Maria
• George Brian P

Classifications

• G16H50/20

  for computer-aided diagnosis, e.g. based on medical expert systems · CPC title

• G16H30/40

  for processing medical images, e.g. editing · CPC title

• A61B5/0044 Primary

  for the heart · CPC title

• A61B18/1492

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

• A61B5/486

  Biofeedback (using electroencephalography [EEG] A61B5/375) · CPC title