Estimation of contact force of catheter expandable assembly

Patent metadata

Field	Value
Publication number	US-2025099041-A1
Application number	US-202318373308-A
Country	US
Kind code	A1
Filing date	Sep 27, 2023
Priority date	Sep 27, 2023
Publication date	Mar 27, 2025
Grant date	—

Abstract

A system includes a medical probe and a processor. The medical probe includes a shaft for insertion into a cavity of an organ of a patient; an expandable assembly fitted at a distal end of the shaft, wherein the expandable assembly has elastic properties; a position sensing element mounted on the distal end of the shaft; and at least one distal position sensing element on a distal end of the expandable assembly. The processor senses relative location of each of the at least one distal position sensing element and the proximal position sensing element; determines deflection of the expandable assembly based on the relative location; relates the deflection to the contact force applied on the expandable assembly; and provides an indication of the contact force on a display.

First claim

1 . A system, comprising:
a medical probe, comprising:
a shaft for insertion into a cavity of an organ of a patient;
an expandable assembly fitted at a distal end of the shaft, wherein the expandable assembly has elastic properties;
a position sensing element mounted on the distal end of the shaft; and
at least one distal position sensing element on a distal end of the expandable assembly; and
a processor, which is configured to:
sense relative location of each of the at least one distal position sensing element and the proximal position sensing element;
determine deflection of the expandable assembly based on the relative location;
relate the deflection to the contact force applied on the expandable assembly; and
provide an indication of the contact force on a display.

2 . The system according to claim 1 , wherein each of the proximal position sensing element and the at least one distal position sensing element is an electromagnetic coil (EMC).

3 . The system according to claim 2 , wherein a controller is configured to:
apply a driving signal in a given frequency to one of the proximal EMC and the at least one distal EMC; and receive and process output at the given frequency by the other of the proximal EMC and the at least one distal EMC to determine relative location of each of the at least one distal position sensing element and the proximal position sensing element.

4 . The system according to claim 3 , wherein each of the EMCs is configured to sense magnetic fields generated by a magnetic source external to the patient and output respective signals indicative of a position in a 3D coordinate system of a position traction system, and wherein the driving signal has a frequency different from the frequencies used by the magnetic source external to the patient.

5 . The system according claim 3 , and comprising an amplifying circuit fitted on the catheter, the circuit configured to amplify the output at the given frequency by the other of the proximal EMC and the at least one distal EMC.

6 . The system according to claim 2 , wherein the distal end of the shaft includes three EMCs that are non-parallel oriented one with respect to the others, and wherein the processor is configured to detect, by processing the output from the three EMCs, at least one of an axial compression of the expandable assembly and an angular deflection of the expandable assembly relative to the distal end of the shaft.

7 . The system according to claim 2 , wherein the at least one distal EMC is embedded in a respective electrode disposed on a spline. #

8 . The system according to claim 2 , wherein the distal end ( 46 ) of the shaft ( 44 ) comprises at least two EMCs ( 29 ) that are parallel and displaced for one another on the shaft ( 44 ).

9 . The system according to claim 1 , and comprising a memory configured to store relationship between position sensing elements output and contact force based on empirical data and wherein the processor is configured to use the empirical data to relate position sensing elements output to contact force.

10 . The system according to claim 1 , wherein the expandable assembly is a basket assembly formed with a plurality of splines.

11 . A method, comprising:
inserting a shaft of a medical probe into a cavity of an organ of a patient, the probe comprising (i) an expandable assembly fitted at a distal end of the shaft, wherein the expandable assembly has elastic properties, (ii) a position sensing element mounted on the distal end of the shaft, and (iii) at least one distal position sensing element on a distal end of the expandable assembly;
sensing relative location of each of the at least one distal position sensing element and the proximal position sensing element;
determining deflection of the expandable assembly based on the relative location;
relating the deflection to the contact force applied on the expandable assembly; and providing an indication of the contact force on a display.

12 . The method according to claim 11 , wherein each of the proximal position sensing element and the at least one distal position sensing element is an electromagnetic coil (EMC).

13 . The method according to claim 12 , further comprising
applying a driving signal in a given frequency to one of the proximal EMC and the at least one distal EMC; and receiving and processing output at the given frequency by the other of the proximal EMC and the at least one distal EMC to determine relative location of each of the at least one distal position sensing element and the proximal position sensing element.

14 . The method according to claim 13 , wherein each of the EMCs is configured to sense magnetic fields generated by a magnetic source external to the patient and output respective signals indicative of a position in a 3D coordinate system of a position traction system, and wherein the driving signal has a frequency different from the frequencies used by the magnetic source external to the patient.

15 . The method according to claim 13 , and comprising amplifying the output from the three EMCs using an amplifying circuit fitted on the catheter.

16 . The method according to claim 12 , wherein the distal end of the shaft includes three EMCs that are non-parallel oriented one with respect to the others, and wherein the processor is configured to detect, by processing the output from the three EMCs, at least one of an axial compression of the expandable assembly and an angular deflection of the expandable assembly relative to the distal end of the shaft.

17 . The method according to claim 12 , wherein the at least one distal EMC is embedded in a respective electrode disposed on a spline. #

18 . The method according to claim 12 , and comprising storing relationship between EMCs output and contact force based on empirical data and using the empirical data to relate EMCs output to contact force.

19 . The method according to claim 12 , wherein the expandable assembly is a basket assembly formed with a plurality of splines.

Assignees

• Biosense Webster Israel Ltd

Inventors

• Govari Assaf
• Altmann Andres Claudio
• Sinitsky Ilya
• Schechtman Alexander
• Fuchs Amit
• Beeckler Christopher Thomas
• Keyes Joseph Thomas
• Khan Ishan

Classifications

• A61B18/1492

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

• A61B5/6858

  with a distal basket, e.g. expandable basket · CPC title

• A61B5/062

  using magnetic field · CPC title

• A61B5/287

  Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS] · CPC title

• A61B5/367

  Electrophysiological study [EPS], e.g. electrical activation mapping or electro-anatomical mapping · CPC title