SYSTEM FOR DELIVERING ACOUSTIC ENERGY IN CONNECTION WITH THERAPEUTIC ULTRASOUND SYSTEMS AND CATHETERS

• US 20090163836A1
• Filed: 12/21/2007
• Published: 06/25/2009
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Original Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Inventors: Sliwa, John W.
• Granted Patent: US 8,444,579 B2
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61N 2007/0056 Beam shaping elements
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

The invention discloses a system for delivering acoustic energy to a subject in connection with high intensity focused ultrasound (HIFU) systems. In an embodiment, the system comprises an optionally disposable waveguide-attached ablation applicator coupled with an optionally re-usable waveguide, and an optional acoustic power source. The systems may comprise acoustic energy exit port intensity control, waveguide heat-sinking, and transducer operational adjustments that accommodate waveguide effects on the traversing acoustic power.

Claims

1. A system for delivering therapeutic acoustic energy to a subject, comprising:

at least one transducer for emitting at least therapeutic acoustic energy;

an acoustic waveguide including an input port and an exit port, the input port coupleable to the transducer;

an acoustic energy applicator acoustically coupled to the exit port of the waveguide, said applicator also acoustically coupleable with said subject; and

at least one acoustic energy detection sensor positioned at, in or near the applicator or waveguide exit port, the acoustic detection sensor being operably connected to the transducer,

wherein acoustic energy emitted by the transducer passes through the waveguide, and the acoustic detection sensor detects the delivered acoustic energy and provides feedback.

2. The system of claim 1, wherein the feedback permits a user of the system to perform one or more of:

assessing the acoustic energy being delivered, or about to be delivered, to a subject;

assessing acoustic energy loss in the waveguide, in the input port, in the exit port, or in the applicator;

adjusting an operational parameter of the transducer to modify an acoustic energy being delivered or which is deliverable to or through the applicator;

or correcting phase-error or amplitude to one or more sub-selements of the transducer, wherein the transducer has multiple sub-selements.

3. The system of claim 1 wherein the correction or compensation of the acoustic prevents one or more of:

a loss of therapeutic benefit,

an undesired lack of uniformity in a therapeutic benefit;

an undesired extent or lack of extent of a therapeutic benefit at at least one location;

undesirable phase errors or differences;

or undesirable amplitude errors or differences.

4. The system of claim 1 wherein the acoustic detection sensor is

mounted on, or in, the waveguide itself;

mounted on or in the acoustic energy applicator;

or

mounted in an acoustic path for energy being delivered by the system, the mounting location including possibly being on or in target tissue.

5. The system of claim 1, wherein the waveguide comprises a filler material that serves as an acoustic propagation medium.

6. The system of claim 5, wherein the filler material is a liquid, gel, paste, cream, emulsion, water or aqueous solution, flowable or flowed material or combinations thereof.

7. The system of claim 5, wherein the filler material is aqueous or is saline.

8. The system of claim 5, wherein the filler material includes at least one metallic, glass, ceramic or metal-ceramic member, fiber, wire, or cable that runs along the waveguide and along which acoustic energy propagates, the member, fiber, wire or cable having any cross-section including hollow or of variable cross-section versus distance along the waveguide.

9. The system of claim 8, wherein the filler material includes a plurality of metallic, glass, ceramic, ceramic-metal members, fibers, wires, or cables, and wherein each member, fiber, wire or cable is substantially acoustically isolated from an adjacent member, fiber, wire or cable.

10. The system of claim 1, wherein the waveguide further comprises a wall material that is one or more of the following:

porous, permeable, acoustically reflective, fully or partly gaseous, fully or partly vapor-containing, fully or partly air-saturated, or fully or partly air-infiltrated.

11. The system of claim 1, further comprising a filler material that is at least partially enclosed inside the waveguide, the filler material serving as an acoustic propagation medium, and wherein the filler material does not substantially infiltrate the wall material during acoustic power propagation along the waveguide, the wall material acting to at least radially reflect and contain the acoustical energy propagating within its interior filler material.

12. The system of claim 9, wherein the wave guide includes a porous or permeable wall material that is partially filled with air or vapor.

13. The system of claim 1, wherein the waveguide comprises a substantially unwettable wall material, and further comprising a filler material contained by the substantially unwettable wall material.

14. The system of claim 11, further comprising a vacuum coupled to the propagation medium to de-gas the propagation medium.

15. The system of claim 1, wherein the transducer includes a face that emits into the waveguide and allows for at-least one of phase-delay or intensity control across the face.

16. The system of claim 1, wherein the transducer is configured for an area-wise variation in at least one operational acoustic parameter, and the variation, at least in part, is used to correct for a degradation or distortion of the acoustic energy in the waveguide or to form an acoustic energy beam or pattern.

17. The system of claim 1, wherein the transducer comprises a multi-element or multi-segment transducer.

18. The system of claim 17, wherein an operational parameter of the transducer is varied or of different value between at least two of the transducer'"'"'s elements or segments.

19. The system of claim 18, wherein the varied or different value parameter is any of amplitude, phase, frequency, or excitation waveform.

20. The system of claim 16, wherein the area-wise variation is provided based in part from feedback from at least one acoustic detection sensor and, at least in part, corrects or adjusts for an acoustic degradation or distortion.

21. The system of claim 1 wherein the filler material is at least one selected from the group consisting of:

a convected or pumped heat-transfer medium, the convection being forced or natural;

a circulated medium;

a degassed medium;

a medium recirculated within or along the waveguide, and

a medium contained by one or more membrane-like members that can pass acoustical energy.

22. A system for delivering therapeutic acoustic energy to a subject, comprising:

a transducer;

a flexible acoustic waveguide, the waveguide including an input port, and an exit port, and an acoustic detection sensor operably connected to the acoustic transducer; and

an acoustic energy applicator connected to the applicator and in acoustic communication with said subject,

wherein acoustic energy emitted by the transducer passes through the waveguide;

the acoustic detection sensor situated in the region of the waveguide exit port or applicator detects the acoustic energy and provides feedback regarding the acoustic energy to the transducer, and the transducer is configured to compensate for detected degradation, distortion or non-optimal state in the acoustic energy supplied to the applicator,

wherein the waveguide is re-usable, and the acoustic energy applicator attaches to the waveguide and is preferably disposable.

23. The system of claim 22, wherein the acoustic detection sensor is used to perform at least one function selected from the group consisting of:

adjusting one or more emitter powers or operational parameters of at least one emitter portion in order to negate waveguide output power variation;

adjusting one or more emitter phases among segments of a multisegment transducer to preserve or obtain a desired phase pattern

adjusting treatment time to negate effects of variation in waveguide output power; and

adjusting a treatment dose parameter to negate effects of variation in waveguide output power.

24. The system of claim 22, wherein the waveguide further comprises a filler material that actively or passively cools the waveguide.

25. The system of claim 24, wherein the filler material is flowable and actively cools the waveguide, said filler material being circulated through at least the waveguide at least once.

26. The system of claim 22, wherein the preferably disposable energy applicator attached to the waveguide further comprises at least one selected from the group consisting of:

a coupling gel or coupling flowable material in an interface between the applicator and the waveguide;

a coupling means between the waveguide and the energy applicator;

an applicator propagation medium that is flowed; and

a connection to the waveguide through which the acoustic medium flows in the energy applicator.

27. The system of claim 22, wherein the applicator comprises one selected from the group consisting of:

a flexible diaphragm through which the acoustic energy flows;

a porous wall liner;

a permeable wall liner;

an acoustically reflective lens;

an acoustically reflective mirror;

an acoustic power sensor to monitor delivered acoustic energy to a point in or on the face of said applicator; and

an illuminator.

28. A system for delivering therapeutic acoustic energy to a subject, comprising:

a multisegment or multielement acoustic transducer, the acoustic transducer capable of an area-wise variation in at least one operational acoustic parameter, said variation being used to maximize delivered power through the waveguide, to prevent degradation of acoustic power losses in the waveguide or to obtain a desired energy pattern;

a flexible acoustic waveguide, the waveguide comprising an input port and an exit port;

an acoustic detection sensor situated at or near the waveguide exit port or applicator and being operably connected to the acoustic transducer;

a filler material that provides cooling for the waveguide; and

an acoustic energy applicator connected to the applicator and in acoustic communication with said subject,

wherein the emitted acoustic energy passes through the waveguide to the applicator,;

the acoustic detection sensor detects the acoustic energy and provides feedback regarding the acoustic energy to the transducer, such that if the exit power or power uniformity is different from a desired delivered or deliverable power uniformity, at least one transducer segment operational parameter is changed to maintain the selected exit port power or power uniformity.

29. A device for delivering acoustic energy to a subject, comprising:

an acoustic waveguide that includes an input port, an exit port,

an acoustic detection component that can be operably connected to a transducer;

an acoustic energy applicator, wherein the acoustic energy applicator is preferably disposable.

30. The device of claim 29, wherein the waveguide is re-usable.

31. A method of delivering a predetermined dose or pattern of acoustic energy to a subject, comprising:

providing an acoustic-energy producing transducer;

operably connecting the transducer to an acoustic waveguide, wherein the waveguide includes an input port, an exit port, and is operably connected to the transducer;

providing an acoustic energy applicator operably connected to the waveguide and in acoustic communication with said subject;

providing an acoustic energy detection sensor situated at or near the waveguide exit port or applicator;

providing power to the transducer to emit a pre-selected acoustic energy or energy pattern through the waveguide, through the exit port and the applicator, to said subject; and

monitoring the acoustic detection sensor, wherein said acoustic detection sensor detects the acoustic energy and provides feedback regarding the acoustic energy to the transducer, and the transducer is configured to compensate for detected degradation or distortion in the acoustic energy supplied to the applicator to maintain or achieve a selected exit port power or pattern.