Intracardiac tracking system

• US 9,474,467 B2
• Filed: 04/20/2015
• Issued: 10/25/2016
• Est. Priority Date: 04/02/2008
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Rhythmia Medical, Inc. (Boston Scientific Corporation)
• Inventors: Harlev, Doron, Eldar, Rotem, Badics, Zsolt
• Primary Examiner(s): Stice, Paula J
• Application Number:
  US14/690,571
• Publication Number:
  US 20150223726A1
• Time in Patent Office: 554 Days
• Field of Search: 600508-509, 600512-515, 600/547
• US Class Current: 1/1
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2562/0214 Capacitive electrodes
• CPC Class Codes: A61B 2562/04 Arrangements of multiple sensors of the same type
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/063 using impedance measurements
• CPC Class Codes: 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
• CPC Class Codes: A61B 5/068 using impedance sensors
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/343 Potential distribution indication
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence

Abstract

In general, in one aspect, a method is disclosed for determining information about a position of an object. The method includes: (i) causing current to flow between each of three or more sets of current-injecting electrodes on a first catheter inserted into an organ in a patient'"'"'s body, the organ having a periphery (ii) in response to current flow caused by each set of current injecting electrodes, measuring an electrical signal at each of one or more measuring electrodes located on one or more additional catheters inserted into the organ in the patient'"'"'s body and (iii) determining the position of each of one or more of the measuring electrodes on the additional catheters relative to the first catheter based on the measured signals from the one or more measuring electrodes.

Claims

1. A method comprising:

causing current to flow between each of three or more sets of current-injecting electrodes on a first catheter inserted into an organ in a patient'"'"'s body, the organ having a periphery;

in response to current flow caused by each set of current injecting electrodes, measuring electric signals at each of multiple measuring electrodes on the first catheter and measuring an electrical signal at each of one or more measuring electrodes on one or more additional catheters inserted into the organ in the patient'"'"'s body;

determining location information for the three or more sets of current-injecting electrodes on the first catheter;

determining a position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter based on the measured signals for the measuring electrodes on the first catheter and the one or more additional catheters; and

determining a position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to a fixed reference point based on an independent tracking system.

2. The method of claim 1, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter includes associating each measured signal with at least one of a homogeneous component that depends on the relative position of each signal measuring electrode with respect to each set of current injecting electrodes, and an inhomogeneous component associated with the periphery of the organ.

3. The method of claim 1, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to a fixed reference point based on an independent tracking system includes tracking positions of the first catheter in the organ relative to the fixed reference point using the independent tracking system.

4. The method of claim 1, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to a fixed reference point based on an independent tracking system includes tracking positions of at least one of the one or more additional catheters in the organ relative to the fixed reference point using the independent tracking system.

5. The method of claim 1, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter comprises an optimization technique that minimizes collective differences between each of the measured signals and an estimate for each of the respective measured signals as a function of the relative position between each of the measuring electrodes on the first and the one or more additional catheters and the sets of current-injecting electrodes on the first catheter and a change in conductivity at the periphery.

6. The method of claim 1, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter comprises an optimization technique that minimizes collective differences between each of the measured signals and an estimate for each of the respective measured signals as a function of the relative position between each of the measuring electrodes on the first and the one or more additional catheters and the sets of current-injecting electrodes on the first catheter and an estimate for conductivity inside the organ.

7. The method of claim 1, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter comprises an optimization technique that minimizes collective differences between each of the measured signals and an estimate for each of the respective measured signals as a function of the relative position between each of the one or more measuring electrodes on the one or more additional catheters and the sets of current-injecting electrodes on the first catheter.

8. The method of claim 1, further comprising using the multiple measuring electrodes on the first catheter to measure cardiac signals.

9. The method of claim 1, further comprising using the multiple measuring electrodes on the first catheter and the one or more measuring electrodes on the one or more additional catheters to measure cardiac signals.

10. A method comprising:

causing current to flow between each of three or more sets of current-injecting electrodes on a first catheter inserted into an organ in a patient'"'"'s body, the organ having a periphery;

in response to current flow caused by each set of current injecting electrodes, measuring electric signals at each of multiple measuring electrodes on the first catheter and measuring an electrical signal at each of one or more measuring electrodes on one or more additional catheters inserted into the organ in the patient'"'"'s body;

determining location information for the three or more sets of current-injecting electrodes on the first catheter; and

determining a position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter based on the measured signals for the measuring electrodes on the first catheter and the one or more additional catheters, the determination associating each measured signal with a homogeneous component that depends on a relative position of a corresponding measuring electrode from the one or more additional catheters with respect to each set of current injecting electrodes.

11. The method of claim 10, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter includes associating each measured signal with an inhomogeneous component associated with the periphery of the organ.

12. The method of claim 10, comprising determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to a fixed reference point based on an independent tracking system.

13. The method of claim 12, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to a fixed reference point based on an independent tracking system includes tracking positions of at least one of the first catheter in the organ relative to the fixed reference point using the independent tracking system, and at least one of the one or more additional catheters in the organ relative to the fixed reference point using the independent tracking system.

14. The method of claim 10, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter comprises an optimization technique that minimizes collective differences between each of the measured signals and an estimate for each of the respective measured signals as a function of the relative position between each of the measuring electrodes on the first and the one or more additional catheters and the sets of current-injecting electrodes on the first catheter and a change in conductivity at the periphery.

15. The method of claim 10, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter comprises an optimization technique that minimizes collective differences between each of the measured signals and an estimate for each of the respective measured signals as a function of the relative position between each of the measuring electrodes on the first and the one or more additional catheters and the sets of current-injecting electrodes on the first catheter and an estimate for conductivity inside the organ.

16. The method of claim 10, wherein determining the position of each of one or more of the one or more measuring electrodes on the one or more additional catheters relative to the first catheter comprises an optimization technique that minimizes collective differences between each of the measured signals and an estimate for each of the respective measured signals as a function of the relative position between each of the one or more measuring electrodes on the one or more additional catheters and the sets of current-injecting electrodes on the first catheter.

17. The method of claim 10, comprising at least one of:

measuring cardiac signals with the multiple measuring electrodes on the first catheter; and

measuring cardiac signals with the one or more electrodes on the one or more additional catheters.

18. A system comprising:

a first catheter configured for insertion into an organ in a patient'"'"'s body and comprising multiple measuring electrodes and three or more sets of current injecting electrodes;

one or more additional catheters configured for insertion into the organ in the patient'"'"'s body and comprising one or more measuring electrodes;

an electronic control system coupled to the first catheter and the one or more additional catheters and configured to cause current to flow between each set of current-injecting electrodes and to measure electrical signals, generated by the current flow from each set of current injecting electrodes, at each of the multiple measuring electrodes on the first catheter and at each of the one or more measuring electrodes on the one or more additional catheters; and

a processing system coupled to the electronic system and configured to determine location information for the three or more sets of current-injecting electrodes on the first catheter and determine a position of each of the one or more measuring electrodes relative to the current-injecting electrodes of the first catheter based on the measured signals from the multiple measuring electrodes on the first catheter and the one or more measuring electrodes.

19. The system of claim 18, wherein the processing system is configured to determine the position of each of the one or more measuring electrodes on the one or more additional catheters relative to a fixed reference point based on an independent tracking system.

20. The system of claim 18, wherein the processing system is configured to associate each measured signal with at least one of a homogeneous component that depends on the relative position of each signal measuring electrode with respect to each set of current injecting electrodes, and an inhomogeneous component associated with the periphery of the organ.