# US 2022/0032009 A1 · Catheter with serially connected sensing structures and methods of calibration and detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0032009 A1 - Document ID: US20220032009A1 - Status: Published application - Kind: A1 - Application number: 17/493,711 - Filed: 2021-10-04 - Published: 2022-02-03 - Earliest claimed: 2012-12-31 - Assignees: Biosense Webster (Israel) Ltd. - Applicants: Biosense Webster (Israel) Ltd. - Inventors: Jeffrey L. Clark; George Kamin; Mark Stanley - Web page: https://patentgrep.com/patent/US20220032009A1 ## CPC - A61M 25/0127: {Magnetic means; Magnetic markers} - A61B 5/05: Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves (measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24) - A61B 5/062: {using magnetic field} - 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 5/6852: {Catheters} - A61B 5/72: {Signal processing specially adapted for physiological signals or for diagnostic purposes} - A61B 18/1206: {Generators therefor} - A61B 18/1492: {having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence)} - A61B 5/6885: {Monitoring or controlling sensor contact pressure} - A61B 2018/00357: {Endocardium} - A61B 2018/00577: {Ablation} - A61B 2034/2051: {Electromagnetic tracking systems} - A61B 2090/065: {for measuring contact or contact pressure} - A61M 2025/0002: {with a pressure sensor at the distal end} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A catheter is responsive to external and internal magnetic field generators for generating signals representing position and pressure data, with a reduced number of sensing coil leads for minimizing lead breakage and failure. The catheter includes a flexible joint with pressure sensing and position coils, at least pair of a pressure sensing coil and a position coil are serially connected. Methods of calibrating a catheter for position and pressure sensing, and detecting magnetic field interference with one catheter by another catheter or other metal or ferrous object advantageously use signals between two sets of sensors as a “back up” or “error check”. ## Claims ### Claim 1 A catheter for use with a catheterization system having a plurality of external magnetic field generators, each generating a position-data magnetic field, comprising: a flexible tubing; and a distal section adapted for engagement with patient tissue, the distal section having: a proximal portion, a distal portion and a flexible joint between the proximal portion and the distal portion; an internal magnetic field generator positioned in one of the proximal and distal portions, the internal magnetic field generator generating a pressure-data magnetic field; three first sensing coils and two second sensing coils positioned in the other of the proximal and distal portions, one of the three first sensing coils and the two second sensing coils adapted to sense the pressure-data magnetic field and generate signals representative of data relating to pressure exerted on the distal section when engaged with tissue, the other of the three first sensing coils and the two second sensing coils adapted to sense each of the position-data magnetic fields and generate signals representative of data relating to position of the distal section, each of the three first sensing coils being generally parallel with a longitudinal axis of the other of the proximal and distal portion and being located in a first axial section of the other of the proximal and distal portion at different azimuthal angles about the longitudinal axis, and the two second sensing coils being located in a second axial section of the other of the proximal and distal portion at different azimuthal angles about the longitudinal axis; a first lead serially connecting one of the three first sensing coils and one of the two second sensing coils; a second lead serially connecting a second one of the three first sensing coils and a second one of the two second sensing coils; and a third lead connected to a third one of the three first sensing coils. ### Claim 2 (depends on 1) The catheter of claim 1, wherein the flexible joint includes a resilient member adapted to allow axial displacement and angular deflection between the proximal and distal portions of the distal section. ### Claim 3 (depends on 1) The catheter of claim 1, wherein the system includes a signal processor adapted to receive signals from the first, second and third leads. ### Claim 4 (depends on 1) The catheter of claim 1, wherein the three first sensing coils are spaced azimuthally 120 degrees apart from each other at a same radial distance from the longitudinal axis. ### Claim 5 (depends on 1) The catheter of claim 1, wherein the two second sensing coils are spaced azimuthally 120 degrees apart from each other. ### Claim 6 (depends on 1) The catheter of claim 1, wherein the two second sensing coils are spaced azimuthally 120 degrees apart from each other and relative to one of the three first sensing coils at a same radial distance from the longitudinal axis. ### Claim 7 (depends on 1) The catheter of claim 1, wherein first sensing coils are elliptical. ### Claim 8 (depends on 1) The catheter of claim 1, wherein the second sensing coils are cylindrical. ### Claim 9 (depends on 1) The catheter of claim 1, wherein the three first sensing coils are aligned with a Z axis and each of the two second sensing coils are orthogonal to each other and to at least one of the three first sensing coils. ### Claim 10 (depends on 1) The catheter of claim 1, wherein the internal magnetic field generator is a transmitting coil axially aligned with a longitudinal axis of the catheter. ### Claim 11 (depends on 9) The catheter of claim 9, wherein the three first sensing coils are aligned with the internal magnetic field generator. ### Claim 12 A catheter for use with a catheterization system having at least three external magnetic field generators, each generating a position-data magnetic field, comprising: a flexible tubing; and a distal section adapted for engagement with tissue, the distal section having: a proximal portion, a distal portion and a flexible joint between the proximal portion and the distal portion; an internal magnetic field generator positioned in the distal portion, the internal magnetic field generating a pressure-data magnetic field; three pressure sensing coils positioned in the proximal portion, each configured to sense the pressure-data magnetic field and generate signals representative of data relating to pressure exerted on the distal section when engaged with tissue, each of the three pressure sensing coils being generally parallel with a longitudinal axis of the proximal portion and being located in a first axial section of the proximal portion at different azimuthal angles about the longitudinal axis; two position sensing coils positioned in the proximal portion, each configured to sense each position-data magnetic field and generate signals representative of data relating to position of the distal section, the two position sensing coils being located in a second axial section of the proximal portion at different azimuthal angles about the longitudinal axis; a first lead serially connecting one of the three pressure sensing coils and one of the two position sensing coils; and a second lead serially connecting a second one of the three pressure sensing coils and a second one of the two position sensing coils; and a third lead connected to a third one of the three pressure sensing coils. ### Claim 13 (depends on 12) The catheter of claim 12, wherein the flexible joint includes a resilient member adapted to allow axial displacement and angular deflection between the proximal and distal portions of the distal section. ### Claim 14 (depends on 12) The catheter of claim 12, wherein the catheterization system includes a signal processor adapted to receive signals from the first, second and third leads. ### Claim 15 (depends on 12) The catheter of claim 12, wherein each magnetic field is distinguishable by one or more of the group consisting of frequency, phase and time. ### Claim 16 (depends on 12) The catheter of claim 12, wherein the three pressure sensing coils are spaced azimuthally 120 degrees apart from each other at a same radial distance from the longitudinal axis. ### Claim 17 (depends on 12) The catheter of claim 12, wherein the two position sensing coils are spaced azimuthally 120 degrees apart from each other. ### Claim 18 (depends on 12) The catheter of claim 12, wherein the two position sensing coils are spaced azimuthally 120 degrees apart from each other and relative to one of the three pressure sensing coils at a same radial distance from the longitudinal axis. ### Claim 19 (depends on 12) The catheter of claim 12, wherein the three pressure sensing coils are cylindrical. ### Claim 20 (depends on 12) The catheter of claim 12, wherein the two position sensing coils are elliptical.