# US 2019/0167149 A1 · Magnetic sensor for tracking the location of an object > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167149 A1 - Document ID: US20190167149A1 - Status: Published application - Kind: A1 - Application number: 16/210,469 - Filed: 2018-12-05 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: St. Jude Medical International Holding S.à r.l. - Applicants: St. Jude Medical International Holding S.à r.l. - Inventors: Ryan K. Buesseler - Web page: https://patentgrep.com/patent/US20190167149A1 ## CPC - A61B 5/062: {using magnetic field} - A61B 5/063: {using impedance measurements} - A61B 5/6852: {Catheters} - A61B 5/6869: {Heart} - A61B 18/1492: {having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence)} - A61B 34/20: Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis - A61M 25/0127: {Magnetic means; Magnetic markers} - G01B 7/046: {using magnetic means} - G01B 21/042: {Calibration or calibration artifacts (G01B3/30, G01B9/02072 take precedence)} - 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 5/287: Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS] - A61B 18/1206: {Generators therefor} - A61B 90/37: {Surgical systems with images on a monitor during operation} - A61B 2018/00351: {Heart} - A61B 2018/00577: {Ablation} - A61B 2018/00791: {Temperature} - A61B 2034/2051: {Electromagnetic tracking systems} - A61B 2034/2072: {Reference field transducer attached to an instrument or patient} - A61B 2218/002: Irrigation - A61B 2560/0223: of calibration, e.g. protocols for calibrating sensors - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - 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)} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract An apparatus for emitting a field comprising a a core, a conductive winding with a first end, a second end, and an intermediate portion, where the conductive winding surrounds a portion of the core and is wound about a winding axis, a protrusion for aligning the apparatus where the protrusion is parallel with the winding axis, and a conductive connector extending from the conductive winding, wherein the conductive connector is electrically coupled with the conductive winding at the intermediate portion. ## Claims ### Claim 1 An apparatus for emitting a field comprising: a core; a conductive winding with a first end, a second end, and an intermediate portion, where the conductive winding surrounds a portion of the core and is wound about a winding axis; a protrusion for aligning the apparatus where the protrusion is parallel with the winding axis; and a conductive connector extending from the conductive winding, wherein the conductive connector is electrically coupled with the conductive winding at the intermediate portion. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the protrusion comprises a portion of the core. ### Claim 3 (depends on 1) The apparatus of claim 1, further comprising a coating surrounding a portion of the core. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the protrusion comprises a portion of the coating. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the protrusion is configured to couple with a test fixture or an optic-magnetic registration plate. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the conductive connector extends from the conductive winding at an angle that is perpendicular to the winding axis. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the conductive connector extends from the conductive winding at an angle not perpendicular to the longitudinal axis. ### Claim 8 A system comprising: a first transducer assembly with a first longitudinal axis, the first transducer assembly comprising a core, a conductive winding, and a conductive connector electrically coupled with the conductive winding, wherein the core is parallel with the first longitudinal axis; a catheter with a second longitudinal axis, wherein the catheter comprises a first sensor, and a plurality of electrodes, where a location of the second sensor is known in relation to each of the plurality of electrodes; where the first longitudinal axis of the transducer assembly is perpendicular with the second longitudinal axis of the catheter; and an electronic control unit (ECU) electrically coupled to the first transducer assembly and the first sensor and operable to do the following: (A) generate a magnetic field using the first transducer assembly; (B) measure a first signal from the first sensor, wherein the first signal varies based on a position of the first sensor along the second longitudinal axis in relation to the magnetic field generated by the first transducer assembly; (C) analyze the first signal to determine a relative position of the catheter along the second longitudinal axis based on the location of the first sensor; (D) generate a relative position information for the catheter using the analysis of the first signal. ### Claim 9 (depends on 8) The system of claim 8, further comprising an introducer, where the first transducer assembly is coupled with the introducer. ### Claim 10 (depends on 8) The system of claim 8, further comprising a fixture, where the fixture comprises a base plate; a transducer assembly receptacle allowing the transducer assembly to be coupled with the base plate; a tube with a third longitudinal axis removably coupled with the base plate, the tube comprising a closed end and an open end, wherein the open end is configured to accept a distal end of the catheter, wherein the third longitudinal axis of the tube is perpendicular to the first longitudinal axis of the transducer assembly. ### Claim 11 (depends on 8) The system of claim 8, where the catheter further comprises a second sensor and the ECU is further operable to do the following: measure a second signal from the second sensor, wherein the second signal varies based on a position of the second sensor in relation to the magnetic field generated by the first transducer assembly, evaluate the second signal to determine a characteristic of the signal for the first sensor and the second signal for the second sensor, correlate the characteristic of the signal to a position of the first sensor and the second signal to the second sensor, determine a relative position of the catheter along the second longitudinal axis based on the position of the first sensor and the second sensor. ### Claim 12 (depends on 11) The system of claim 11, wherein the characteristic of the signal comprises one or more of a change in a voltage, a change in a current, a change in a magnetic field strength, and a change in a magnetic flux density. ### Claim 13 (depends on 8) The system of claim 8, wherein the ECU is further operable to: output the relative position to a display. ### Claim 14 (depends on 8) The system of claim 8, wherein the first transducer assembly further comprises a protrusion. ### Claim 15 (depends on 14) The system of claim 14, wherein the protrusion comprises a portion of the core. ### Claim 16 A method for detecting a position of a sensor on an elongate medical device, comprising: positioning a catheter at a first location along a first longitudinal axis, emitting a field from a first transducer with a second longitudinal axis, where the first longitudinal axis is perpendicular with the second longitudinal axis, moving the catheter to a second position along the longitudinal axis, measuring a signal, by an electronic control unit (ECU) comprising a processor, at a first sensor on the catheter while moving the catheter along the longitudinal axis from the first position to the second position within the field, analyzing the signal, by the ECU, from the first sensor, and determining, by the ECU, a position data of the first sensor based on the signal. ### Claim 17 (depends on 16) The method of claim 16, further comprising: outputting, by the ECU, the position data to a display. ### Claim 18 (depends on 16) The method of claim 16, further comprising: measuring, by an electronic control unit (ECU) comprising a processor, the signal at a second sensor on the catheter while moving the catheter along the longitudinal axis, analyzing, by the ECU, the signal from the second sensor, determining, by the ECU, the position data of the second sensor based on the signal, and outputting, by the ECU, the position data to the display. ### Claim 19 (depends on 16) The method of claim 16, wherein the determining further comprises a position of the first sensor with respect to one or more electrodes proximate the sensor.