Methods and apparatus for utilizing impeller-based rotationally-scanning catheters

Patent metadata

Field	Value
Publication number	US-9833217-B2
Application number	US-34711608-A
Country	US
Kind code	B2
Filing date	Dec 31, 2008
Priority date	Dec 31, 2008
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

An ablation catheter includes a tubular catheter body having a lumen, a tip portion, a liquid inlet, at least one liquid outlet, a liquid flow path defined between the liquid inlet and the liquid outlet, and an ablation element mounted on the tip portion of the catheter body. A rotationally-scanning ultrasound assembly is disposed within the lumen of the catheter body adjacent the tip portion. The ultrasound assembly includes an ultrasound transducer having an active face, an acoustic mirror acoustically coupled to the active face of the ultrasound transducer, and an impeller positioned in the liquid flow path and operably coupled to at least one of the ultrasound transducer and the acoustic mirror to impart rotational motion thereto when a liquid flows through the impeller.

First claim

What is claimed is:

1. A catheter comprising:
a tubular catheter body, configured for insertion into a body, the tubular body having a tip portion and a lumen;
a rotationally-scanning ultrasound assembly disposed adjacent the tip portion, the rotationally-scanning ultrasound assembly comprising an ultrasound transducer having an active face; and
a drive assembly including an impeller operably coupled to the rotationally-scanning ultrasound assembly such that a liquid flowing through the impeller imparts rotational motion to the ultrasound assembly,
wherein the lumen of the catheter body includes a plurality of outlet ports extending through a wall of the catheter body adjacent the tip portion, wherein the liquid flowing through the impeller, is configured to be exhausted in vivo through the plurality of outlet ports.

2. The catheter according to claim 1 , wherein the impeller is operably coupled to the ultrasound transducer to impart rotational motion to the ultrasound transducer.

3. The catheter according to claim 1 , wherein the ultrasound assembly further comprises an acoustic mirror adapted to be acoustically coupled to the active face of the ultrasound transducer via an acoustic coupling medium.

4. The catheter according to claim 3 , wherein the acoustic coupling medium comprises the liquid flowed through the impeller.

5. The catheter according to claim 3 , wherein the impeller is operably coupled to the acoustic mirror to impart rotational motion to the acoustic mirror.

6. The catheter according to claim 5 , wherein the ultrasound transducer is non-rotating.

7. The catheter according to claim 3 , wherein the acoustic mirror is positioned proximally of the ultrasound transducer.

8. The catheter according to claim 3 , wherein the acoustic mirror is positioned distally of the ultrasound transducer.

9. The catheter according to claim 1 , wherein the ultrasound assembly further comprises an acoustic lens adapted to be acoustically coupled to the active face of the ultrasound transducer via an acoustic coupling medium.

10. The catheter according to claim 1 , wherein the impeller includes a central passageway to accommodate at least one electrical wire routed through the lumen.

11. The catheter according to claim 1 , wherein two or more of an impeller blade rake angle, a liquid flow rate, and a liquid pressure are selected or controlled such that the impeller rotates at between about 10 rpm and 20 rpm when the liquid flows into the impeller.

12. The catheter according to claim 1 , wherein the tip portion of the catheter body includes an ablation element.

13. The catheter according to claim 12 , wherein the ablation element is an RF ablation element.

14. The catheter according to claim 1 , wherein the ultrasound assembly is oriented to provide a visualization field adjacent the tip portion of the catheter body.

15. The catheter according to claim 1 , wherein the ultrasound assembly is slidably mounted within the lumen of the tubular catheter body.

16. An ablation catheter comprising:
a tubular catheter body, configured for insertion into a body, the tubular body comprising:
a lumen;
a tip portion;
a liquid inlet;
at least one liquid outlet extending through a wall of the catheter body; and a liquid flow path defined between the liquid inlet and the liquid outlet; an ablation element mounted on the tip portion of the catheter body; and
a rotationally-scanning ultrasound assembly disposed within the lumen of the catheter body adjacent the tip portion, the rotationally-scanning ultrasound assembly comprising:
an ultrasound transducer having an active face;
an acoustic mirror acoustically coupled to the active face of the ultrasound transducer; and
an impeller positioned in the liquid flow path and operably coupled to at least one of the ultrasound transducer and the acoustic mirror wherein the impeller is configured to impart rotational motion thereto when a liquid flows through the impeller and wherein the liquid is configured to be exhausted in vivo through the at least one liquid outlet.

17. The catheter according to claim 16 , wherein at least one of the ultrasound transducer and the acoustic mirror is oriented non-orthogonally to a central axis of the catheter body such that the ultrasound assembly provides a visualization field adjacent the tip portion of the catheter body.

18. The catheter according to claim 16 , wherein the ultrasound transducer is positioned distally of the acoustic mirror and oriented with the active face facing proximally.

19. The catheter according to claim 16 , wherein the ultrasound transducer is positioned proximally of the acoustic mirror and oriented with the active face facing distally.

20. The catheter according to claim 16 , further comprising a fluid disposed between the ultrasound transducer and the acoustic mirror to acoustically couple the acoustic mirror to the active face of the ultrasound transducer.

21. The catheter according to claim 16 , wherein the tubular catheter body comprises a material selected to minimize reflections and ringing of ultrasonic energy propagating therethrough.

22. The catheter according to claim 21 , wherein the tubular catheter body comprises polyethylene.

23. The catheter according to claim 16 , wherein the acoustic mirror and the impeller are formed as a unitary assembly.

24. The catheter according to claim 16 , wherein the acoustic mirror is affixed to the impeller.

25. The catheter according to claim 16 , wherein the at least one liquid outlet is positioned to exhaust the liquid flowing through the liquid flow path adjacent the tip portion.

26. The catheter according to claim 16 , wherein the liquid flow path includes an outlet segment between the impeller and the at least one liquid outlet, and wherein the outlet segment is configured to return the liquid flowing through the liquid flow path to a proximal end of the catheter.

27. A method of assessing tissue, comprising:
providing a catheter comprising:
a tubular catheter body having a tip portion, an ablation element mounted on the tip portion, and a lumen;
a rotationally-scanning ultrasound assembly disposed within the lumen adjacent the tip portion and including an ultrasound transducer having an active face, wherein the ultrasound assembly provides a visualization field adjacent the tip portion of the catheter body; and
an impeller operably coupled to the ultrasound assembly to impart rotational motion thereto;

placing the tip portion of the catheter adjacent tissue to be assessed;
flowing a liquid through the impeller, thereby rotating the ultrasound assembly; and
exhausting the liquid from the tubular catheter body adjacent the tip portion to irrigate the tissue to be assessed.

28. The method according to claim 27 , wherein the ultrasound assembly further comprises an acoustic mirror acoustically coupled to the active face of the ultrasound transducer and operably coupled to the impeller, and wherein the step of flowing a liquid through the impeller comprises flowing the liquid through the impeller to rotate the mirror.

29. The method according to claim 27 , further comprising monitoring a rotational position of the ultrasound assembly.

30. The method according to claim 27 , further comprising generating a three dimensional image of a tissue within the visualization fiel

Assignees

• Sliwa John W
• Ma Zhenyi
• St Jude Medical Atrial Fibrillation Div Inc

Inventors

• Sliwa John W
• Ma Zhenyi

Classifications

• A61B8/4461 Primary

  Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe · CPC title

• A61N7/022

  intracavitary · CPC title

• A61N7/02

  Localised ultrasound hyperthermia · CPC title

• A61B2090/3782

  transmitter or receiver in catheter or minimal invasive instrument · CPC title

• A61B18/18

  by applying electromagnetic radiation, e.g. microwaves · CPC title