# US 12,594,038 B2 · Estimation of contact force of catheter expandable assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,594,038 B2 - Document ID: US12594038B2 - Status: Granted - Kind: B2 - Application number: 18/373,308 - Filed: 2023-09-27 - Published: 2025-03-27 - Granted: 2026-04-07 - Earliest claimed: 2023-09-27 - Assignees: Biosense Webster (Israel) Ltd. - Applicants: Biosense Webster (Israel) Ltd. - Inventors: Assaf Govari; Andres Claudio Altmann; Ilya Sitnitsky; Alexander Shechtman; Amit Fuchs; Christopher Thomas Beeckler; Joseph Thomas Keyes; Ishan Khan - Web page: https://patentgrep.com/patent/US12594038B2 ## CPC - A61B 5/065: {Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe} - A61B 5/6885: {Monitoring or controlling sensor contact pressure} - A61B 5/062: {using magnetic field} - A61B 5/287: Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS] - A61B 5/367: Electrophysiological study [EPS], e.g. electrical activation mapping or electro-anatomical mapping - A61B 5/6843: {Monitoring or controlling sensor contact pressure} - A61B 5/6858: {with a distal basket, e.g. expandable basket} - A61B 5/6859: {with multiple distal splines} - A61B 18/1492: {having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence)} - A61B 5/063: {using impedance measurements} - A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)} - A61B 2034/2051: {Electromagnetic tracking systems} - A61B 2090/064: {for measuring force, pressure or mechanical tension} - A61B 2090/065: {for measuring contact or contact pressure} - A61B 2562/0223: Magnetic field sensors - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## 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. ## Claims ### Claim 1 A system, comprising: a medical probe, comprising: a shaft for insertion into a cavity of an organ of a patient; a proximal position sensing element mounted on the distal end of the shaft; an expandable assembly fitted at a distal end of the shaft, the expandable assembly including: a cage that is configured to be deformable with elastic properties, the cage configured supporting plurality of electrodes thereon; a plurality of electrodes mounted on the cage; and at least one distal position sensing element mounted on a distal end of the cage; 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; determine contact force applied on the expandable assembly based on the elastic properties of the cage that is pre-defined and deflection of the expandable assembly; and provide an indication of the contact force on a display. ### Claim 2 (depends on 1) 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). ### Claim 3 (depends on 2) 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 position sensing element and the at least one distal position sensing element; and receive and process output at the given frequency by the other of the proximal position sensing element and the at least one distal position sensing element to determine relative location of each of the at least one distal position sensing element and the proximal position sensing element. ### Claim 4 (depends on 3) The system according to claim 3, wherein each of the proximal position sensing element and the at least one distal position sensing element 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 tracking system, and wherein the driving signal, has a frequency different from frequencies used by the magnetic source external to the patient. ### Claim 5 (depends on 3) The system according claim 3, further comprising an amplifying circuit fitted on the medical probe, 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. ### Claim 6 (depends on 2) 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 compute 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 based on the output from the three EMCS. ### Claim 7 (depends on 2) The system according to claim 2, wherein the at least one distal EMC is embedded in an electrode of the plurality of electrodes. ### Claim 8 (depends on 2) 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). ### Claim 9 (depends on 1) The system according to claim 1, further 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. ### Claim 10 (depends on 1) The system according to claim 1, wherein the cage is a basket formed with a plurality of splines and wherein the plurality of electrodes is mounted on the plurality of splines. ### Claim 11 A method, comprising: receiving a first signal from a proximal position sensing element, wherein the proximal position sensing element is mounted on a distal end of a shaft of medical probe; receiving a second signal from at least one distal position sensing element of an expandable assembly, wherein the expandable assembly includes a cage that is configured to be deformable with elastic properties, a plurality of electrodes mounted on the cage, and the at least one distal position sensing element, the expandable assembly fitted on the distal end of the shaft; sensing relative location of each of the at least one distal position sensing element and the proximal position sensing element based on the first signal and the second signal; determining deflection of the expandable assembly based on the relative location; relating the deflection to the contact force applied on the expandable assembly based on the elastic properties of the cage; and providing an indication of the contact force on a display. ### Claim 12 (depends on 11) 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). ### Claim 13 (depends on 12) The method according to claim 12, further comprising: applying a driving signal in a given frequency to one of the proximal position sensing element and the at least one distal position sensing element; and receiving and processing output at the given frequency by the other of the proximal position sensing element and the at least one distal position sensing element to determine relative location of each of the at least one distal position sensing element and the proximal position sensing element. ### Claim 14 (depends on 13) The method according to claim 13, wherein each of the proximal position sensing element and the at least one distal position sensing element 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 tracking system, and wherein the driving signal has a frequency different from frequencies used by the magnetic source external to the patient. ### Claim 15 (depends on 13) The method according to claim 13, further comprising amplifying the output from the at least one distal position sensing element using an amplifying circuit fitted on the medical probe. ### Claim 16 (depends on 12) 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 method further comprises computing 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 based on the output from the three EMCs. ### Claim 17 (depends on 12) The method according to claim 12, wherein the at least one distal EMC is embedded in an electrode of the plurality of electrodes. ### Claim 18 (depends on 12) The method according to claim 12, further 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. ### Claim 19 (depends on 12) The method according to claim 12, wherein the cage is a basket formed with a plurality of splines.