Methods and devices for generating high-amplitude and high-frequency focused ultrasound with light-absorbing materials

Patent metadata

Field	Value
Publication number	US-9601103-B2
Application number	US-201314057019-A
Country	US
Kind code	B2
Filing date	Oct 18, 2013
Priority date	Oct 19, 2012
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A high-frequency light-generated focused ultrasound (LGFU) device is provided. The device has a source of light energy, such as a laser, and an optoacoustic lens comprising a concave composite layer with a plurality of light absorbing particles that absorbs laser energy, e.g., carbon nanotubes, and a polymeric material that rapidly expands upon exposure to heat, e.g., polydimethylsiloxane. The laser energy is directed to the optoacoustic lens and thus can generate high-frequency (e.g., ≧10 MHz) and high-amplitude pressure output (e.g., ≧10 MPa) focused ultrasound. The disclosure also provides methods of making such new arcuate optoacoustic lenses, as well as methods for generating and using the high-frequency and high-amplitude ultrasound, including for surgery, like lithotripsy and ablation.

First claim

What is claimed is:

1. A high-frequency light-generated focused ultrasound (LGFU) device, comprising:
a source of light energy; and
an arcuate optoacoustic lens comprising a composite layer that comprises a plurality of light absorbing particles and a dielectric material having a coefficient of volume thermal expansion greater than or equal to about 1×10 −5 ×K −1 ; wherein when the light energy is directed to the arcuate optoacoustic lens it is capable of generating focused ultrasound having a frequency of greater than or equal to about 10 MHz and an output pressure of greater than or equal to about 1 MPa.

2. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the arcuate optoacoustic lens is a concave lens.

3. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the arcuate optoacoustic lens has a geometrical design with an f-number (f#) of less than or equal to about 1.

4. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the composite layer has a depth of optical absorption less than or equal to about 30 μm.

5. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the light absorbing particles absorb greater than or equal to about 50% to less than or equal to about 100% of the light energy directed at the optoacoustic lens.

6. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the light absorbing particles comprise carbon nanotubes, graphene oxide, or combinations thereof.

7. The high-frequency light-generated focused ultrasound (LGFU) device of claim 6 , wherein the light absorbing particles are coated with an electromagnetic absorption material comprising gold.

8. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the dielectric material is a polymer comprising polydimethylsiloxane.

9. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the optoacoustic lens has a focal spot of about 75 μm in a lateral dimension and about 400 μm in an axial dimension, when the source of light energy is a laser having a pulse width less than or equal to about 10 ns, a repetition rate of greater than or equal to about 10 Hz, and greater than or equal to about 10 mJ of laser energy per pulse.

10. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the coefficient of volume thermal expansion greater than or equal to about 5×10 −4 K −1 .

11. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the light absorbing particles are axially shaped particles.

12. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein composite layer is substantially free of carbon black particles.

13. The high-frequency light-generated focused ultrasound (LGFU) device of claim 1 , wherein the output pressure of the focused ultrasound is greater than or equal to about 40 MPa.

14. A method of generating a high-frequency and high-amplitude focused ultrasound, the method comprising:
directing light energy at an arcuate optoacoustic lens that comprises a composite layer comprising a polymeric material and a plurality of light absorbing particles, wherein the composite layer has a depth of optical absorption less than or equal to about 30 μm, to generate a focused ultrasound having a frequency of greater than or equal to about 10 MHz and an output pressure of greater than or equal to about 1 MPa.

15. The method according to claim 14 , wherein the arcuate optoacoustic lens is a concave lens having a geometrical design with an f-number (f#) of less than or equal to about 1.

Assignees

• Univ Michigan Regents

Inventors

• Guo Lingjie Jay
• Baac Hyoung Won

Classifications

• G10K11/32

  characterised by the shape of the source · CPC title

• G10K11/36 Primary

  Devices for manipulating acoustic surface waves (electro-acoustic amplifiers H03F13/00; networks comprising electro-acoustic elements H03H9/00) · CPC title

• B06B1/00 Primary

  Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency · CPC title