Portable acoustic holography systems for therapeutic ultrasound sources and associated devices and methods

Patent metadata

Field	Value
Publication number	US-9588491-B2
Application number	US-201313894333-A
Country	US
Kind code	B2
Filing date	May 14, 2013
Priority date	May 14, 2012
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

The present technology relates generally to portable acoustic holography systems for therapeutic ultrasound sources, and associated devices and methods. In some embodiments, a method of characterizing an ultrasound source by acoustic holography includes the use of a transducer geometry characteristic, a transducer operation characteristic, and a holography system measurement characteristic. A control computer can be instructed to determine holography measurement parameters. Based on the holography measurement parameters, the method can include scanning a target surface to obtain a hologram. Waveform measurements at a plurality of points on the target surface can be captured. Finally, the method can include processing the measurements to reconstruct at least one characteristic of the ultrasound source.

First claim

We claim:

1. A method of characterizing an ultrasound source using acoustic holography, the method comprising:
obtaining a transducer geometry characteristic, a transducer operation characteristic, and a holography system measurement characteristic,
wherein obtaining the transducer geometry characteristic comprises obtaining at least one of an aperture size, planar or curvature characteristic, orientation, or shape of a radiating transducer;
instructing a control computer to determine holography measurement parameters;
based on the holography measurement parameters, scanning a target surface to capture waveform measurements at a plurality of points on the target surface;
using the waveform measurements to define a measured hologram at the target surface; and
processing the measured hologram to reconstruct at least one characteristic of the ultrasound source.

2. The method of claim 1 wherein scanning the target surface comprises scanning a two-dimensional target surface, and wherein processing the measured hologram to reconstruct at least one characteristic of the ultrasound source comprises reconstructing three-dimensional acoustic field characteristics of the ultrasound source.

3. The method of claim 1 wherein obtaining a transducer operation characteristic comprises obtaining at least one of a linear, nonlinear, pulsing, continuous, spatial extent, Q-factor, or operating frequency characteristic of a radiating transducer.

4. The method of claim 1 wherein obtaining a holography system measurement characteristic comprises obtaining at least one of a size of a hydrophone sensing region, a hydrophone bandwidth, a geometry of a test tank, a liquid temperature in the test tank, or a reference position relative to a transducer at which the hydrophone is initially located.

5. The method of claim 1 wherein instructing the control computer to determine holography measurement parameters comprises instructing the control computer to determine at least one of a scanning position, a scanning extent, or a step size of a hologram sensor; a duration of measurement acquisition of a data recorder; or a duration or amplitude of excitation of the ultrasound source.

6. The method of claim 1 wherein scanning the target surface comprises continuously scanning the target surface.

7. A method of characterizing an ultrasound source using acoustic holography, the method comprising:
obtaining a transducer geometry characteristic, a transducer operation characteristic, and a holography system measurement characteristic,
instructing a control computer to determine holography measurement parameters;
based on the holography measurement parameters, scanning a target surface to capture waveform measurements at a plurality of points on the target surface;
using the waveform measurements to define a measured hologram at the target surface; and
processing the measured hologram to reconstruct at least one characteristic of the ultrasound source,
wherein processing the measured hologram to reconstruct a characteristic of the ultrasound source comprises using the hologram to define a boundary condition of the ultrasound source.

8. The method of claim 7 wherein processing the measured hologram comprises applying at least one of a Rayleigh integral, a Helmholtz-Kirchoff integral, a Khokhlov-Zabolotskaya-Kuznetsov equation, or a Westervelt equation.

9. The method of claim 1 wherein characterizing the ultrasound source comprises characterizing an acoustic field generated by the ultrasound source in uniform or nonuniform media.

10. A method of characterizing an ultrasound source using acoustic holography, the method comprising:
obtaining a transducer geometry characteristic, a transducer operation characteristic, and a holography system measurement characteristic,
instructing a control computer to determine holography measurement parameters;
based on the holography measurement parameters scanning a target surface to capture waveform measurements at a plurality of points on the target surface;
using the waveform measurements to define a measured hologram at the target surface; and
processing the measured hologram to reconstruct at least one characteristic of the ultrasound source,
wherein processing the measured hologram to reconstruct a characteristic of the ultrasound source comprises determining at least one of an acoustic output power of the ultrasound source or a radiation force that would occur if an acoustic beam from the ultrasound source impinged on a particular physical target.

11. The method of claim 10 , further comprising using radiation force in conjunction with an independent radiation force balance measurement to calibrate a hydrophone's sensitivity at a single frequency.

12. A method for calibrating a hydrophone, the method comprising:
using an uncalibrated hydrophone to measure a hologram for a source operating in continuous-wave mode at a specified output level;
making a radiation force balance measurement of the source using a physical target;
using the measured hologram to calculate a radiation force on the physical target as a function of hydrophone sensitivity; and
calculating a hydrophone sensitivity by equating the radiation force balance measurement with the radiation force calculation based on the measured hologram.

13. The method of claim 12 wherein the using the uncalibrated hydrophone to measure the hologram comprises:
obtaining a transducer geometry characteristic, a transducer operation characteristic, and a holography system measurement characteristic;
instructing a control computer to determine holography measurement parameters; and
based on the holography measurement parameters, obtaining a hologram.

14. The method of claim 12 wherein making the radiation force balance measurement of the source using a physical target comprises making a radiation force balance measurement under identical pulse waveform conditions for which the hologram was measured.

15. A holography system, comprising:
an ultrasound source;
a hologram sensor; and
a physical computer-readable storage medium having stored thereon, computer-executable instructions that, if executed by a computing system, cause the computing system to perform operations comprising:
determining holography measurement parameters;
receiving data related to a geometry characteristic, an operation characteristic, and a measurement characteristic of the holography system;
instructing the hologram sensor to measure acoustic waveforms generated by the ultrasound source; and
generating one or more of the acoustic propagation projections, radiation force calculations, or true power calculations based on a combination of the acoustic waveforms and the characteristics.

16. The holography system of claim 15 wherein the ultrasound source comprises a waveform generator, an amplifier, and a transducer.

17. The holography system of claim 15 wherein the hologram sensor comprises one or more of a two-dimensional array of independent hydrophones, a one-dimensional array of independent hydrophones in conjunction with a repeatable source and a positioner that is automated in at least one dimension, or a single hydrophone in conjunction with a repeatable source and a positioner that is automated in at least two dimensions.

18. The holography system of claim 15 , further comprising:
an acoustic medium through which ultrasound waves travel from the ultrasound source; and
a thermometer configured to obtain a temperature of the acoustic medium.

Assignees

• Univ Washington Through Its Center For Commercialization

Inventors

• Sapozhnikov Oleg A
• Bailey Michael R
• Kaczkowski Peter J
• Khokhlova Vera A
• Kreider Wayne

Classifications

• G01N29/0663

  by acoustic holography (acoustical holography per se G03H3/00) · CPC title

• A61B8/00

  Diagnosis using ultrasonic, sonic or infrasonic waves · CPC title

• G03H3/00 Primary

  Holographic processes or apparatus using ultrasonic, sonic or infrasonic waves for obtaining holograms; Processes or apparatus for obtaining an optical image from them (G03H1/22 takes precedence) · CPC title

• Y10S359/901

  Acoustic holography · CPC title