Three-dimensional cavitation quantitative imaging method for microsecond-resolution cavitation spatial-temporal distribution

Patent metadata

Field	Value
Publication number	US-10332250-B2
Application number	US-201515115682-A
Country	US
Kind code	B2
Filing date	Jan 26, 2015
Priority date	Dec 27, 2014
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A three-dimensional cavitation quantitative imaging method for a microsecond-resolution cavitation spatial-temporal distribution includes steps of: after each wide beam detection, moving an array transducer by one unit; waiting until the cavitation nuclei distribution backs to an initial state, then detecting the cavitation by the wide beam detection with same cavitation energy incitation, so as to obtain a spatial series of two-dimensional cavitation raw radio frequency data corresponding to different placing positions of the array transducer; then changing the cavitation energy source duration, time delays between energy source incitation and the wide beam transmitted by the array transducer, and time delays between the pulsating pump and energy source incitation, so as to obtain a temporal series of two-dimensional cavitation raw radio frequency data; and then obtaining a microsecond-resolution three-dimensional cavitation spatial-temporal distribution image and a cavitation micro bubble concentration quantitative Nakagami parametric image.

First claim

What is claimed is:

1. A three-dimensional cavitation quantitative imaging method for a microsecond-resolution cavitation spatial-temporal distribution, comprising steps of: using a wide beam to detect cavitation activity for two-dimensional cavitation raw radio frequency data obtained; after cavitation detection by the wide beam, moving an array transducer for the wide beam detection by one unit perpendicular to a placing direction of the array transducer; waiting until a cavitation nuclei distribution returns to an original state thereof, then detecting the cavitation by the wide beam detection with the same cavitation energy incitation, so as to obtain a spatial series of two-dimensional cavitation raw radio frequency data with the array transducer placed at different unit positions; and then obtaining a three-dimensional cavitation image and a cavitation micro bubble concentration quantitative three-dimensional image by combining wide beam minimum variance adaptive beamforming, Nakagami parametric imaging, and a three-dimensional reconstruction algorithm.

2. The three-dimensional cavitation quantitative imaging method, as recited in claim 1 , wherein a cavitation generator comprises an energy source and a synchronous signal generator; a cavitation detector comprises the array transducer which is programmable and transmits the wide beam, and a parallel channel data acquisition and storage unit; wherein the synchronous signal generator generates a synchronous signal so as to respectively control the energy source and the array transducer; the energy source generates energy which induces cavitation bubbles, and the energy generated by the energy source is continuously adjustable; the array transducer transmits the wide beam for detecting the cavitation, and a cavitation echo signal obtained is acquired and stored by the parallel channel data acquisition and storage unit.

3. The three-dimensional cavitation quantitative imaging method, as recited in claim 1 , specifically comprising steps of: beamforming the two-dimensional cavitation raw radio frequency data by a wide beam minimum variance adaptive beamforming algorithm, so as to obtain a spatial series of the two-dimensional cavitation radio frequency data at the different placing positions of the array transducer; and then obtaining a spatial series of two-dimensional cavitation distribution images based on the spatial series of the two-dimensional cavitation radio frequency data; and as the spatial series of beamformed radio frequency data in three-dimensional space are required, using the three-dimensional reconstruction algorithm to reconstruct the three-dimensional cavitation distribution image, so as to obtain the three-dimensional cavitation image.

4. The three-dimensional cavitation quantitative imaging method, as recited in claim 1 , specifically comprising steps of: beamforming the two-dimensional cavitation original radio frequency data by a wide beam minimum variance adaptive beamforming algorithm, so as to obtain a spatial series of the two-dimensional cavitation radio frequency data at the different placing positions of the array transducer; processing the spatial series of the two-dimensional cavitation radio frequency data with Nakagami parametric extraction, so as to obtain a spatial series of two-dimensional cavitation concentration quantitative images; and as the spatial series of the two-dimensional cavitation concentration quantitative images in three-dimensional space are required, using the three-dimensional reconstruction algorithm to reconstruct the three-dimensional cavitation concentration quantitative image, so as to obtain the cavitation micro bubble concentration quantitative three-dimensional image.

5. The three-dimensional cavitation quantitative imaging method, as recited in claim 4 , wherein the Nakagami parametric extraction comprises steps of:
1) de-noising two-dimensional cavitation radio frequency data rf:
a) selecting a background signal area with a certain size, and calculating an average energy P of the background signal area;
b) respectively superimposing a first random Gauss white noise n 1 and a second random Gauss white noise n 2 , both having the average energy P , on the rf , so as to obtain S 1 and S 2 ; and
c) calculating a correlation coefficient of the S 1 and the S 2 , and giving a threshold Th; threshold-processing the correlation coefficient and then weighting with the rf for obtaining rf denoise :

rf
denoise

=

{

rf
,

corrcoef
⁡

(

S
1

,

S
2

)

>
Th

0
,

corrcoef
⁡

(

S
1

,

S
2

)

≤
Th

(
1
)

wherein corrcoef (S 1 , S 2 ) is the correlation coefficient of the S 1 and the S 2 ;
2) processing the rf denoise with Hilbert demodulation, so as to obtain an envelope signal R; and
3) calculating a Nakagami parameter:

m
=

[

Assignees

• Univ Xi An Jiaotong

Inventors

• Wan Mingxi
• Ding Ting
• Hu Hong
• Yang Miao
• Guo Shifang

Classifications

• G06T12/30

  Image post-processing, e.g. metal artefact correction · CPC title

• G06T2200/04

  involving 3D image data · CPC title

• G06T7/60

  Analysis of geometric attributes · CPC title

• G01N2291/02433

  Gases in liquids, e.g. bubbles, foams · CPC title

• G01N29/265

  by moving the sensor relative to a stationary material · CPC title