Systems and methods for radiometrically measuring temperature and detecting tissue contact prior to and during tissue ablation

• US 8,954,161 B2
• Filed: 06/01/2012
• Issued: 02/10/2015
• Est. Priority Date: 06/01/2012
• Status: Active Grant

• Current Assignee: Coral Sand Beach, LLC, Advanced Cardiac Therapeutics, Inc. (Medtronic Plc)
• Original Assignee: Advanced Cardiac Therapeutics, Inc. (Medtronic Plc), Meridian Medical Systems LLC
• Inventors: McCarthy, John F., Lenihan, Timothy J., Kanowsky, Eric R., Allison, Robert C.
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US13/486,889
• Publication Number:
  US 20130324993A1
• Time in Patent Office: 984 Days
• Field of Search: None
• US Class Current: 607/102
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• 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 2017/00057 Light
• CPC Class Codes: A61B 2017/0007 Pyrometers
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/0066 without feedback, i.e. open loop control
• CPC Class Codes: A61B 2018/00672 lower
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00708 switching the power on or off
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/00898 Alarms or notifications created in response to an abnormal condition
• CPC Class Codes: A61B 2018/0212 using an instrument inserted into a body lumen, e.g. catheter
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1861 with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 5/01 : Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/1405 : Devices for taking blood samples devices for taking samples of other body liquids A61B10/0045
• CPC Class Codes: A61B 5/150022 : for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/287 : Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6852 : Catheters
• CPC Class Codes: A61B 5/6886 : Monitoring or controlling distance between sensor and tissue
• CPC Class Codes: A61B 5/7405 : using sound

Abstract

The present invention provides systems and methods for radiometrically measuring temperature and detecting tissue contact during ablation. An interface module includes a first input/output (I/O) port for receiving radiometer and thermocouple signals from an integrated catheter tip (ICT) that includes a radiometer; a second I/O port for receiving ablative energy from an electrosurgical generator; a temperature display; a patient relay; a computer-readable medium storing radiometer and thermocouple parameters and instructions for causing the processor to: calculate a temperature adjacent to the ICT based on the radiometer and thermocouple signals and the parameters; causing the temperature display to display the calculated temperature; closing the patient relay to pass ablative energy from the second to the first I/O port; determining whether the ICT is in contact with tissue based on the radiometer signal. An output device indicates whether the ICT is determined to be in contact with the tissue.

Claims

1. A system for facilitating detection of contact with targeted tissue of a subject:

a catheter comprising a radiofrequency electrode and a radiometer; and

a processor configured to receive a signal from the radiometer and to provide an output indicative of contact between the radiofrequency electrode and targeted tissue of the subject based upon, at least in part, tissue properties determined from the signal received from the radiometer wherein the processor maintains the radiofrequency electrode in a deactivated condition unless contact between the radiofrequency electrode and the targeted tissue is confirmed.

2. The system of claim 1, wherein the processor is configured to regulate operation of the radiofrequency electrode based on the output indicative of the contact between the radiofrequency electrode and the targeted tissue of the subject.

3. The system of claim 1, wherein the system is operatively coupled to an electrophysiology monitoring system.

4. The system of claim 1, wherein the system is configured to provide to a user of the system confirmation of contact between the radiofrequency electrode and the targeted tissue of the subject.

5. The system of claim 4, wherein confirmation of contact is provided on a visual display or audibly.

6. The system of claim 1, further comprising an irrigation system comprising a pump in fluid communication with a fluid passage of the catheter, wherein the irrigation system is configured to selectively deliver irrigation fluid through the fluid passage of the catheter and at least one irrigation fluid port of the catheter in fluid communication with the fluid passage of the catheter during use.

7. The system of claim 1, wherein the catheter comprises an integrated catheter tip comprising a generally tubular shape and a flat distal end.

8. The system of claim 1, wherein the radiofrequency electrode and the radiometer are positioned in an integrated catheter tip at a distal end of the catheter.

9. A system for facilitating detection of contact with targeted tissue of a subject, comprising:

a processor,

wherein the processor is configured to receive a signal from a radiometer positioned at a tip along a distal end of a catheter and to provide an output indicative of contact between the tip of said catheter and targeted tissue of a subject based upon, at least in part, tissue properties determined from the signal received from the radiometer in the absence of delivery of energy to the catheter.

10. The system of claim 9, wherein the processor is configured to regulate operation of an ablation member of the catheter based on the output indicative of the contact between the tip of said catheter and the targeted tissue of the subject.

11. The system of claim 9, wherein the system is configured to provide to a user of the system confirmation of contact between the catheter tip and the targeted tissue of the subject.

12. The system of claim 11, wherein confirmation of contact is provided on a visual display or audibly.

13. The system of claim 9, further comprising an irrigation system comprising a pump in fluid communication with a fluid passage of the catheter, wherein the irrigation system is configured to selectively deliver irrigation fluid through the fluid passage of the catheter and at least one irrigation fluid port of the catheter tip in fluid communication with the fluid passage of the catheter during use.

14. A system for facilitating detection of contact with targeted tissue of a subject, comprising:

a processor,

wherein the processor is configured to receive a signal from a radiometer carried by a medical instrument and to provide an output indicative of contact between a portion of the medical instrument and targeted tissue of a subject based upon, at least in part, tissue properties determined from the signal received from the radiometer in the absence of delivery of energy to the medical instrument.

15. The system of claim 14, wherein the processor is configured to regulate operation of an energy delivery member of the medical instrument based on the output indicative of the contact between the portion of the medical instrument and the targeted tissue of the subject.

16. The system of claim 14, wherein the system is configured to provide to a user of the system confirmation of contact between the portion of the medical instrument and the targeted tissue of the subject.

17. The system of claim 14, wherein the medical instrument comprises a catheter comprising an irrigation pump in fluid communication with a fluid passage of the catheter, wherein the irrigation pump is configured to selectively deliver irrigation fluid through the fluid passage of the catheter and at least one irrigation fluid port of the catheter in fluid communication with the fluid passage of the catheter during use.

18. The system of claim 14, further comprising the medical instrument, wherein the medical instrument comprises an ablation catheter configured to deliver energy sufficient to ablate the targeted tissue upon being activated by an ablation energy source after the output indicative of contact is provided by the processor.

19. The system of claim 14, further comprising the medical instrument, wherein the medical instrument comprises an energy delivery catheter configured to deliver energy to the targeted tissue upon being activated by an energy source after the output indicative of contact is provided by the processor.