Method for ablating body tissue

• US 10,052,121 B2
• Filed: 07/20/2017
• Issued: 08/21/2018
• Est. Priority Date: 05/12/2006
• Status: Active Grant

• Current Assignee: Auris Health, Inc. (Johnson & Johnson)
• Original Assignee: VytronUS, Inc. (Johnson & Johnson)
• Inventors: Thapliyal, Hira V., Gallup, David A., Arenson, James W.
• Primary Examiner(s): Roane, Aaron
• Application Number:
  US15/654,779
• Publication Number:
  US 20170311973A1
• Time in Patent Office: 397 Days
• Field of Search: 606 27
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 17/320068 using mechanical vibrations, e.g. ultrasonic A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745
• 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 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 2017/00106 ultrasonic
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22024 with a part reflecting mechanical vibrations, e.g. for focusing
• CPC Class Codes: A61B 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

A cardiac ablation method including the following steps: inserting a treatment catheter into an atrium of a heart, the treatment catheter including an ultrasound emitter; positioning the ultrasound emitter to face heart tissue within the left atrium outside of a pulmonary vein; emitting ultrasound energy from the ultrasound emitter while rotating the ultrasound emitter about a rotation axis; and ablating heart tissue with the ultrasound energy to form a lesion outside of a pulmonary vein.

Claims

1. A method for creating a lesion in cardiac tissue, the method comprising:

positioning at a first location within a heart of a patient, an ultrasound transducer coupled to a distal portion of a catheter;

sweeping the ultrasound transducer along a first ablation path;

sensing a distance between the ultrasound transducer and the cardiac tissue,

wherein sensing occurs while the ultrasound transducer is sweeping along the first ablation path, and

wherein sensing generates an indicator signal;

checking the indicator signal to ensure that the first ablation path will result in a continuous transmural lesion; and

ablating the cardiac tissue with a beam of energy from the ultrasound transducer along the first ablation path to form the lesion,

wherein the ablation depth is dynamically controlled by varying a sweep rate of the ultrasound transducer along the first ablation path during ablation.

2. The method of claim 1, wherein the lesion is formed without contact between the ultrasound transducer and the target tissue.

3. The method of claim 1, wherein the same ultrasound transducer performs the sensing and the ablating.

4. The method of claim 1, wherein sweeping the transducer comprises one or more of bending and rotating the catheter.

5. The method of claim 1, further comprising moving the catheter to a second location with the heart, sweeping the transducer along a second ablation path, and ablating the cardiac tissue along the second ablation path.

6. The method of claim 5, wherein moving the catheter comprises one or more of inserting, retracting, bending, or rotating the catheter.

7. The method of claim 5, wherein moving the catheter comprises moving the catheter with a console and a control system coupled to the catheter.

8. The method of claim 5, wherein moving the catheter comprises one or more of moving the catheter manually and moving the catheter with a microprocessor-controlled system.

9. The method of claim 1, wherein sensing comprises operating the ultrasound transducer in a diagnostic mode and wherein ablating comprises operating the ultrasound transducer in an ablation mode.

10. The method of claim 9, further comprising converting regularly from ablation mode to diagnostic mode and from diagnostic mode to ablation mode in order to generate an updated indicator signal while ablating the cardiac tissue along the first ablation path.

11. The method of claim 10, further comprising adjusting the sweep rate along the first ablation path based on the updated indicator signal.

12. The method of claim 1, wherein sweeping the ultrasound transducer along the first ablation path comprises sweeping the ultrasound transducer at the sweep rate, wherein the sweep rate is configured to allow sufficient time for the lesion to develop during ablation.

13. The method of claim 1, wherein sensing comprises sensing at least a portion of an ultrasound beam generated by the ultrasound transducer and reflected back toward the ultrasound transducer by the cardiac tissue.

14. The method of claim 1, wherein the amplitude of the reflected ultrasound beam depends on the acoustic properties of the cardiac tissue.

15. The method of claim 1 wherein sensing further comprises one or more of determining a residual tissue depth which has not been ablated or the depth of the lesion.

16. The method of claim 15, further comprising halting ablation if the depth of the lesion the thickness of the cardiac tissue.

17. The method of claim 1, further comprising adjusting a convergence of the beam of energy so as to compensate for an attenuation of the cardiac tissue.

18. The method of claim 1, further comprising adjusting the distance between the ultrasound transducer and the cardiac tissue based on the indicator signal such that ablating the cardiac tissue along the first ablation path forms a continuous transmural lesion.

19. The method of claim 1, further comprising bending the distal portion of the catheter, wherein the catheter comprises at least one pull wire and wherein bending the distal portion of the catheter comprises actuating the at least one pull wire.

20. The method of claim 1, wherein the indicator signal comprises a color-coded display.