Ablation Devices and Methods With Ultrasonic Imaging

• US 20080255449A1
• Filed: 10/14/2005
• Published: 10/16/2008
• Est. Priority Date: 10/14/2004
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: ProRhythm, Inc.
• Inventors: Sinelnikov, Yegor, Warnking, Reinhard
• Granted Patent: US 10,123,903 B2
• Time in Patent Office: Days
• US Class Current: 600/439
• 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 2017/00243 cardiac
• CPC Class Codes: A61B 2017/22024 with a part reflecting mechanical vibrations, e.g. for focusing
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/22058 reflective
• CPC Class Codes: A61B 2017/22069 Immobilising; Stabilising
• CPC Class Codes: A61B 2090/3782 transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61F 7/02 Compresses or poultices for effecting heating or cooling

Abstract

Ablation apparatus such as a catheter (10) carrying an ultrasonic ablation device (20) including an ablation transducer (42) and a balloon reflector structure (22, 24) for directing ultrasonic energy from the ablation transducer into a ring-like ablation region (A) is provided with an imaging ultrasonic transducer (86) mounted on an imaging probe (80) which may be inserted into or through a passageway (18, 65) extending through the catheter and into or through the ablation device to image the ablation region or neighboring regions. Alternatively, the imaging transducer (102, 202) may be mounted within the balloon reflector structure or distal to this structure.

Claims

1. Apparatus comprising:

(a) a structure including a catheter having a proximal end and a distal end and an expansible ablation device mounted to said catheter adjacent said distal end thereof, said ablation device having an expanded condition and a collapsed condition, a continuous passageway extending from adjacent said proximal end of said catheter to said ablation device; and

(b) an ultrasonic imaging probe including at least one imaging transducer, said probe being adapted to image structures in the vicinity of said imaging transducer, said probe having an operative condition in which said probe is positioned in said passageway and said imaging transducer is disposed adjacent said ablation device, said probe being removable from said passageway.

2. The apparatus as claimed in claim 1 wherein said structure defines a port distal to said ablation device and said passageway extends to said port.

3. The apparatus as claimed in claim 2 wherein said imaging probe is positionable in an extended position in which said imaging probe projects through said port so that said transducer is disposed distal to said ablation device.

4. The apparatus as claimed in claim 2 wherein said ablation device in said expanded condition has an axis extending generally proximally and distally, said ablation device in said expanded condition being operative to apply ablation energy in a loop-like ablation region encircling said axis, said port being disposed adjacent said axis.

5. The apparatus as claimed in claim 4 wherein said imaging transducer is rotatable about said axis.

6. The apparatus as claimed in claim 5, in which said imaging probe is movable to an interior operating position in which said imaging transducer is disposed inside of said expansible ablation device, said imaging probe being operative to image tissue surrounding said ablation device when said imaging probe is in said interior operating position.

7. The apparatus as claimed in claim 6 wherein, when said imaging probe is in said interior operating position, said imaging probe will image tissue in said ablation region.

8. The apparatus as claimed in claim 7 wherein said ablation device includes a balloon structure surrounding said axis.

9. The apparatus as claimed in claim 8 wherein said balloon structure includes an interior structure extending through said balloon and defining a portion of said passageway, at least a portion of said interior structure being substantially transparent to ultrasonic waves.

10. The apparatus as claimed in claim 9 wherein said interior structure includes one or more engagement elements for reinforcing said balloon structure, at least one of said engagement elements being substantially transparent to ultrasonic energy.

11. The apparatus as claimed in claim 9 wherein said interior structure includes a spring adapted to elongate said balloon structure during deflation of said balloon structure, and wherein said spring is substantially transparent to ultrasonic energy.

12. Apparatus comprising:

(a) a catheter having a proximal end and a distal end;

(b) an expansible ablation device mounted to said catheter adjacent said distal end thereof, said ablation device having an expanded condition and a collapsed condition, said ablation device in said expanded condition having an axis extending generally proximally and distally, said ablation device including an ultrasonic ablation transducer disposed adjacent said axis and a reflector extending around said axis, said reflector being operative to direct ultrasonic waves emitted by said transducer generally distally into a loop-like ablation region encircling said axis, and

(c) an ultrasonic imaging transducer separate from said ultrasonic ablation transducer, said ultrasonic imaging transducer being disposed adjacent said axis when said ablation device is in said expanded condition, said ablation transducer being operative to send ultrasonic waves to said reflector so that said waves are reflected generally distally by said reflector, said imaging transducer being operative to receive return waves reflected by said reflector.

13. Apparatus as claimed in claim 12 wherein said ultrasonic imaging transducer includes at least one array of imaging transducer elements encircling said axis.

14. Apparatus as claimed in claim 12 wherein said expansible ablation device includes one or more balloons, said balloons being inflated in said expanded state of said device and defining said reflector.

15. Apparatus as claimed in claim 14 wherein said one or more balloons include a structural balloon, said ablation transducer and said therapeutic transducer being disposed inside said structural balloon in said expanded state of said device.

16. A method of operating apparatus as claimed in claim 14 comprising the steps of

(i) in a calibration step, operating said ablation transducer and said imaging transducer so that said imaging transducer provides calibration signals representing return waves reflected from a wall of said structural balloon to said reflector and reflected by said reflector to said imaging transducer;

and

(ii) in an imaging step, operating said ablation transducer and said imaging transducer so that said imaging transducer provides imaging signals representing return waves reflected an imaged region outside of said structural balloon to said reflector and reflected by said reflector to said imaging transducer

17. A method as claimed in claim 16 further comprising the step of determining one or more calibration factors based on said calibration signals and applying said one or more calibration factors to said imaging signals.

18. A method as claimed in claim 16 wherein said step of operating said ablation transducer during said calibration step includes varying the frequency of excitation signals applied to said ablation transducer and monitoring said calibration signals to measure the power output by said ablation transducer at different frequencies.

19. Apparatus comprising:

(a) a catheter having proximal and distal ends;

(b) an expansible ablation device mounted to said catheter adjacent said distal end, said ablation device in said expanded condition having an axis extending generally proximally and distally, said ablation device including a balloon structure surrounding said axis and defining a reflector extending around said axis when said balloon structure is in an inflated condition;

(c) an ultrasonic ablation transducer disposed within said balloon structure, said reflector being operative to direct ultrasonic waves emitted by said transducer generally distally into a loop-like ablation region encircling said axis; and

(d) an ultrasonic imaging transducer mounted to said balloon structure distal to said ablation transducer.

20. The apparatus as claimed in claim 19 wherein said balloon structure includes a distal fitting disposed adjacent a distal extremity of the balloon structure at said axis when the balloon structure is in an inflated condition, and wherein said imaging transducer is mounted to said tip structure.

21. The apparatus as claimed in claim 19 wherein said balloon structure includes a reinforcing structure extending through the balloon structure distal to said ablation transducer and said imaging transducer is mounted to said reinforcing structure.

22. The apparatus as claimed in claim 19 wherein said imaging transducer includes an array of transducer elements encircling said axis and directed outwardly from said axis.