Confinement or movement of an object using focused ultrasound waves to generate an ultrasound intensity well

Patent metadata

Field	Value
Publication number	US-11580945-B2
Application number	US-202016740320-A
Country	US
Kind code	B2
Filing date	Jan 10, 2020
Priority date	Sep 5, 2014
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

A method includes transmitting a focused ultrasound wave into a medium to form (i) an ultrasound intensity well within the medium that exhibits a first range of acoustic pressure and (ii) a surrounding region of the medium that surrounds the ultrasound intensity well and exhibits a second range of acoustic pressure that exceeds the first range of acoustic pressure. The method further includes confining an object within the ultrasound intensity well. Additionally, an acoustic lens is configured to be acoustically coupled to an acoustic transducer. The acoustic lens has a varying longitudinal thickness that increases proportionally with respect to increasing azimuth angle of the acoustic lens. Another acoustic lens is configured to be acoustically coupled to an acoustic transducer. The acoustic lens includes a plurality of segments. Each of the plurality of segments has a varying longitudinal thickness that increases proportionally with respect to increasing azimuth angle of the segment.

First claim

The invention claimed is:

1. A device for treating an object in a body, comprising:
a phased array acoustic transducer comprising a plurality of transducer elements arranged in a first space;
one or more processors; and
a computer-readable medium storing instructions that, when executed by the one or more processors, cause the acoustic transducer to perform functions comprising:
transmitting an ultrasound wave axially away from a first space and into a medium to form (i) an ultrasound intensity well in a second space within the medium that exhibits a first range of acoustic pressure and (ii) a surrounding region in the second space of the medium that surrounds the ultrasound intensity well and exhibits a second range of acoustic pressure that exceeds the first range of acoustic pressure, wherein the second space is axially offset from the first space; and

treating the object by the ultrasound intensity well.

2. The device of claim 1 , wherein the computer-readable medium includes further instructions to cause the acoustic transducer to perform the function of moving the object by moving the ultrasound intensity well.

3. The device of claim 1 , wherein the computer-readable medium includes further instructions to cause the acoustic transducer to perform the function of confining the object.

4. The device of claim 1 , and wherein the plurality of transducer elements are circumferentially arranged about the central opening.

5. The device of claim 4 , wherein the acoustic transducer comprises a central opening.

6. The device of claim 5 , wherein the central opening has a diameter of about 11 mm.

7. The device of claim 4 , wherein the acoustic transducer has a diameter of about 75 mm.

8. The device of claim 4 , wherein the plurality of transducer elements includes m elements, and wherein each of the transducer elements transmits a component of the ultrasound wave that is phase shifted by 2πL/m radians with respect to an adjacent transducer element, where L is a nonzero integer.

9. The device of claim 1 , wherein the acoustic transducer is configured to emit the ultrasound wave at a frequency between 20 kHz and 10 MHz.

10. The device of claim 1 , wherein the intensity well has a circular shape.

11. The device of claim 1 , wherein the first range of acoustic pressure corresponds to 0-0.3 MPa, and wherein the second range of acoustic pressure corresponds to 0.3-0.7 MPa.

12. The device of claim 1 , wherein the device further comprises a lens configured for transmitting the ultrasound wave, and wherein a thickness of the lens is uneven in a direction of the ultrasound wave.

13. The device of claim 1 , wherein transmitting the ultrasound wave comprises:
transmitting a first component of the ultrasound wave through an acoustic lens at a first azimuth angle θ=θ 1 , wherein the acoustic lens imparts a first phase shift L*θ 1 to the first component, wherein L is a nonzero integer; and
transmitting a second component of the ultrasound wave through the acoustic lens at a second azimuth angle θ=θ 2 , wherein the acoustic lens imparts a second phase shift L*θ 2 to the second component.

14. The device of claim 13 , wherein the acoustic lens has a varying longitudinal thickness that increases proportionally with respect to increasing azimuth angle of the acoustic lens.

15. The device of claim 13 ,
wherein at the first azimuth angle θ=θ 1 the acoustic lens has a first longitudinal thickness A*L*θ 1 +B, wherein A and B are nonzero positive numbers, and
wherein at the second azimuth angle θ=θ 2 the acoustic lens has a second longitudinal thickness A*L*θ 2 +B.

16. A method for treating an object in a body, comprising:
emitting an ultrasound wave by a phased array acoustic transducer comprising a plurality of transducer elements arranged in a first space;
transmitting the ultrasound wave axially away from the first space and into a medium;
forming (i) an ultrasound intensity well in a second space within the medium that exhibits a first range of acoustic pressure, wherein the second space is axially offset from the first space;
forming (ii) a surrounding region in the second space of the medium that surrounds the ultrasound intensity well and exhibits a second range of acoustic pressure that exceeds the first range of acoustic pressure; and
treating the object by the ultrasound intensity well.

17. The method of claim 16 , further comprising moving the object by moving the ultrasound intensity well.

18. The method of claim 16 , further comprising confining the object by the ultrasound intensity well.

19. The method of claim 16 , and wherein the plurality of transducer elements are circumferentially arranged about the central opening.

20. The method of claim 16 , wherein the acoustic transducer is configured to emit the ultrasound wave at a frequency between 20 kHz and 10 MHz.

21. The method of claim 16 , wherein the acoustic transducer is configured to emit the ultrasound wave at a frequency of about 1.5 MHz.

22. The method of claim 16 , wherein the first range of acoustic pressure corresponds to 0-0.3 MPa, and wherein the second range of acoustic pressure corresponds to 0.3-0.7 MPa.

Assignees

• Univ Washington

Inventors

• Maxwell Adam D
• Sapozhnikov Oleg A
• Kreider Wayne
• Bailey Michael R

Classifications

• G10K11/346

  using phase variation · CPC title

• G10K11/008 Primary

  Arrays of transducers (seismic streamers, see G01V1/20) · CPC title

• A61B17/225

  for extracorporeal shock wave lithotripsy [ESWL], e.g. by using ultrasonic waves · CPC title

• A61B17/2255

  Means for positioning patient, shock wave apparatus or locating means, e.g. mechanical aspects, patient beds, support arms or aiming means · CPC title

• G10K11/30 Primary

  using refraction, e.g. acoustic lenses · CPC title