SYSTEMS AND METHODS FOR DETERMINING THE LIKELIHOOD OF ENDOCARDIAL BAROTRAUMA IN TISSUE DURING ABLATION

• US 20110144657A1
• Filed: 12/10/2010
• Published: 06/16/2011
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Original Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Inventors: Lathia, Rohan, Afonso, Valtino X., Clark, Lynn E., Geurkink, Christopher J., Dando, Jeremy D., Paul, Saurav, Byrd, Israel A., Fish, Jeffrey M., Puryear, Harry A.
• Granted Patent: US 9,095,349 B2
• Time in Patent Office: Days
• US Class Current: 606/130
• 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 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2053 Tracking an applied voltage gradient
• CPC Class Codes: A61B 2034/301 for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes
• CPC Class Codes: A61B 2090/372 Details of monitor hardware
• CPC Class Codes: A61B 5/036 by means introduced into body tracts A61B5/032 and A61B5/035 take precedence
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter

Abstract

A method and system for determining a likelihood of barotrauma occurring in tissue during the formation of a lesion therein is provided. The system includes an electronic control unit (ECU). The ECU is configured to acquire at least one value of at least one component of a complex impedance between an electrode and the tissue. The ECU is further configured to calculate an index responsive to the at least one value of the at least one complex impedance component. The index is indicative of a likelihood of barotrauma occurring in the tissue. The method comprises acquiring at least one value of at least one component of a complex impedance between an electrode and the tissue. The method further comprises calculating an index responsive to the at least one value of the at least one complex impedance component. The calculating index is indicative of a likelihood of barotrauma occurring in the tissue.

Claims

1. A system for determining a likelihood of barotrauma occurring in a tissue during the formation of a lesion in said tissue as a result of an ablation procedure being performed thereon, comprising:

an electronic control unit configured to;

acquire at least one value for at least one component of a complex impedance between an electrode and said tissue; and

calculate an index responsive to said at least one value of said at least one complex impedance component, said index indicative of a likelihood of barotrauma occurring in said tissue.

2. The system of claim 1, wherein said electronic control unit is further configured to:

acquire a value for the power applied to said tissue during the formation of a lesion in said tissue; and

calculate said index responsive to said values of said at least one complex impedance component and said power.

3. The system of claim 1, wherein said electronic control unit is configured to acquire values for first and second components of said complex impedance, and to calculate said index responsive to said values of said first and second components of said complex impedance.

4. The system of claim 3, wherein said first and second complex impedance components comprise two of a resistance between said electrode and said tissue, a reactance between said electrode and said tissue, a phase angle between said electrode and said tissue, and an impedance magnitude between said electrode and said tissue.

5. The system of claim 1, wherein said electrode comprises an ablation electrode on a radio-frequency ablation catheter.

6. The system of claim 1, wherein said tissue comprises cardiac tissue, and said barotrauma is endocardial barotrauma.

7. The system of claim 1, wherein said electronic control unit is further configured to output said index to a display device.

8. The system of claim 1, wherein said electronic control unit is further configured to evaluate said index to determine a likelihood of barotrauma occurring in said tissue.

9. The system of claim 8, wherein said electronic control unit is further configured to:

generate a signal representative of an indicator corresponding to said determination; and

output said signal to a display device.

10. The system of claim 1, wherein said at least one component of said complex impedance is reactance, and said electronic control unit is configured to calculate one of a change in reactance between a first reactance value and a second reactance value, and a slope of a line between a first reactance value and a second reactance value, wherein said one of said change in reactance and said slope comprises said index.

11. The system of claim 1, wherein said ECU is further configured to assess the stability of said electrode based on predetermined stability criteria and to calculate said index responsive to a determination by said ECU that said electrode meets said predetermined stability criteria.

12. An article of manufacture, comprising:

a computer-readable storage medium having a computer program encoded thereon for determining a likelihood of barotrauma occurring in a tissue during the formation of a lesion in said tissue as a result of an ablation procedure being performed thereon, said computer program including code for;

calculating an index responsive to at least one value of at least one component of a complex impedance between said tissue and an electrode.

13. The article of manufacture of claim 12, wherein said computer program includes code for evaluating said index to determine a likelihood of barotrauma occurring in said tissue.

14. The article of manufacture of claim 13, wherein said computer program includes code for:

generating a signal representative of an indicator corresponding to said determination; and

outputting said signal to a display device.

15. The article of manufacture of claim 12, wherein said at least one component of said complex impedance comprises the reactance between said tissue and said electrode, said computer program including code for calculating said index by calculating at least one of a change in reactance between a first reactance value and a second reactance value, and a slope of a line between a first reactance value and a second reactance value.

16. The article of manufacture of claim 12, wherein said computer program includes code for assessing the stability of said electrode based on predetermined stability criteria and for calculating said index responsive to a determination by said ECU that said electrode meets said predetermined stability criteria.

17. A method for determining a likelihood of barotrauma occurring in a tissue during the formation of a lesion in said tissue as a result of an ablation procedure being performed thereon, comprising the steps of:

acquiring at least one value for at least one component of a complex impedance between an electrode and said tissue; and

calculating an index responsive to said at least one value of said at least one complex impedance component, said index indicative of a likelihood of barotrauma occurring in said tissue.

18. The method of claim 17 further comprising the step of acquiring a value for the power applied to said tissue during the formation of said lesion in said tissue, and said calculating step comprising calculating said index responsive to said at least one value of said at least one complex impedance component and said value of said power.

19. The method of claim 17, wherein said step of acquiring a value for at least one component of a complex impedance comprises acquiring values for first and second components of said complex impedance.

20. The method of claim 17 further comprising the step of evaluating said index to determine a likelihood of barotrauma occurring in said tissue.

21. The method of claim 20 further comprising the steps of:

generating a signal representative of said determination; and

outputting said signal to a display device.

22. The method of claim 17, wherein said at least one component of said complex impedance is the reactance between said electrode and said tissue, and further wherein:

said acquiring step comprising the substeps of;

acquiring a first reactance value corresponding to a first point in time; and

acquiring a second reactance value corresponding to a second point in time subsequent to said first point in time; and

said calculating step comprises one of;

calculating a change in reactance value between said first and second reactance values by subtracting said first reactance value from said second reactance value, said change in reactance comprising said index; and

calculating a slope of a line between said first and second reactance values by subtracting said first reactance value from said second reactance value, subtracting said first time from said second time, and dividing said change in reactance by said change in time, said slope comprising said index.

23. The method of claim 17, wherein said method further comprises the step of assessing the stability of said electrode based on predetermined stability criteria, and said calculating step comprises calculating said index responsive to a determination by said ECU that said electrode meets said predetermined stability criteria.

24. An automated guidance system, comprising:

a catheter manipulator assembly;

a catheter associated with said catheter manipulator assembly, said catheter including an electrode associated therewith configured to deliver RF power to a tissue in a body; and

a controller configured to control at least one of the movement of the catheter and the delivery of RF power to said tissue by said electrode in response to an index calculated from at least one value of at least one component of a complex impedance between said electrode and said tissue.

25. The system of claim 24, wherein said controller is configured to control at least one of the movement of the catheter and the delivery of RF power to said tissue by said electrode in response to an index calculated from said at least one value of said at least component of said complex impedance, and a value of RF power applied to said tissue during the formation of a lesion is said tissue.

26. The system of claim 24 wherein said catheter manipulator assembly is a robotic catheter manipulator assembly including a robotic catheter device cartridge.

27. The system of claim 24 wherein said catheter further comprises a magnetic element, and said automated catheter manipulator assembly comprises a magnetic field generator configured to generate a magnetic field to control the movement of said magnetic element.