ACTIVE VOLTAGE LOCATION (AVL) RESOLUTION

• US 20190328274A1
• Filed: 04/30/2018
• Published: 10/31/2019
• Est. Priority Date: 04/30/2018
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Gliner, Vadim, Govari, Assaf, Boumendil, Alon, Altmann, Andres Claudio
• Granted Patent: US 10,722,141 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/0238 Means for recording calibration data
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; 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
• CPC Class Codes: A61B 5/063 using impedance measurements
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61N 1/08 Arrangements or circuits for monitoring, protecting, controlling or indicating for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925
• CPC Class Codes: G01R 33/0206 Three-component magnetometers

Abstract

A method includes transmitting into a heart of a patient multiple voltages using multiple respective surface-electrodes attached externally to the patient. Repeatedly per each region of a plurality of regions of the heart (i) multiple respective calibration-voltages are measured in the region; (ii) a respective partial sub-set of the surface-electrodes is selected for the region, whose corresponding calibration-voltages minimize a cost-function, wherein the cost-function includes a first term that depends on magnitudes of gradients of the measured calibration-voltages, and a second term that depends on correlations among the gradients; and (iii) the partial sub-set of surface-electrodes selected for the region, are recorded for use in a subsequent session; and, in the subsequent session, a position of a probe inserted into a given region of the heart is calculated based only on the sub-set selected for the given region.

Claims

1. A method, comprising:

transmitting into a heart of a patient multiple voltages using multiple respective surface-electrodes attached externally to the patient;

repeating per each region of a plurality of regions of the heart;

(i) measuring multiple respective calibration-voltages in the region;

(ii) selecting for the region a respective partial sub-set of the surface-electrodes whose corresponding calibration-voltages minimize a cost-function, wherein the cost-function comprises a first term that depends on magnitudes of gradients of the measured calibration-voltages, and a second term that depends on correlations among the gradients; and

(iii) recording the partial sub-set of surface-electrodes, selected for the region, for use in a subsequent session; and

in the subsequent session, calculating a position of a probe inserted into a given region of the heart, based only on the sub-set selected for the given region.

2. The method according to claim 1, wherein measuring the calibration-voltages comprises receiving location measurements from a location-measuring system that tracks a calibration-tool at multiple locations in the heart, and deriving respective relations between the multiple location measurements and respective sets of measured calibration-voltages.

3. The method according to claim 2, wherein the location-measuring system comprises a magnetic location-tracking system.

4. The method according to claim 2, wherein the location-measuring system comprises a medical imaging system.

5. The method according to claim 2, wherein calculating the position of the probe comprises:

measuring multiple investigation-voltages using the probe;

deriving an identity of the given region from the measured investigation-voltages and the derived relations; and

calculating the position of the probe, based only on the measured investigation-voltages that originate from the surface-electrode belonging to the sub-set selected for the given region.

6. The method according to claim 5, wherein calculating the position of the probe comprises calculating the position of the probe based on the selected sub-set of measured investigation-voltages and based on a respective sub-set of the derived relations.

7. The method according to claim 1, wherein transmitting the multiple voltages comprises selecting one surface-electrode to serve as common ground, and applying the voltages between one or more remaining surface-electrodes and the common ground.

8. The method according to claim 3, wherein measuring the investigation-voltages comprises measuring the investigation-voltages using one or more investigation-electrodes fitted at a distal end of the probe.

9. A system, comprising:

multiple surface-electrodes, which are attached externally to a patient and are configured to transmit multiple respective voltages into a heart of the patient;

a processor, which is configured to;

repeat per each region of a plurality of regions of the heart;

(i) receiving multiple calibration-voltages measured in the region;

(ii) selecting for the region a respective partial sub-set of the surface-electrodes whose corresponding calibration-voltages minimize a cost-function, wherein the cost-function comprises a first term that depends on magnitudes of gradients of the measured calibration-voltages, and a second term that depends on correlations among the gradients; and

(iii) recording the partial sub-set of surface-electrodes, selected for the region, for use in a subsequent session; and

in the subsequent session, calculate a position of a probe inserted into a given region of the heart, based only on the sub-set selected for the given region.

10. The system according to claim 9, wherein the processor is configured to receive multiple location measurements from a location-measuring system that tracks a calibration-tool at multiple locations in the heart, and to derive respective relations between the multiple location measurements and respective sets of measured calibration-voltages.

11. The system according to claim 10, wherein the location-measuring system comprises a magnetic location-tracking system.

12. The system according to claim 10, wherein the location-measuring system comprises a medical imaging system.

13. The system according to claim 10, wherein the processor is configured to calculate the position of the probe by:

receiving multiple measured investigation-voltages using the probe;

deriving an identity of the given region from the measured investigation-voltages and the derived relations; and

calculating the position of the probe, based only on the measured investigation-voltages that originate from the surface-electrode belonging to the sub-set selected for the given region.

14. The system according to claim 13, wherein the processor is configured to calculate the position of the probe based on the selected sub-set of measured investigation-voltages and based on a respective sub-set of the derived relations.

15. The system according to claim 9, wherein the system is configured to transmit the multiple voltages by selecting one surface-electrode to serve as common ground, and applying the voltages between one or more remaining surface-electrodes and the common ground.

16. The system according to claim 9, wherein the system is configured to measure the investigation-voltages using one or more investigation-electrodes fitted at a distal end of the probe.