Dorsal mode light acoustic imaging method based on multiple phase control focusing ring array

Abstract

The invention provides a multiple phase control focus ring array-based dorsad mode optical acoustic imaging method; steps of the method are as follows: (1) the pulsed laser is used to irradiate a sample to be tested; (2) the sample to be tested or a multi-ring array detector receives optical acoustic signals by the dorsad mode of a step motor driving scan, and simultaneously acquires the data of optical acoustic signals; (3) data processing software is used to calculate the phase control of the acquired optical acoustic signals for realizing the dynamic focus mode A scan in the depth Z direction, and by the two-dimensional data scanning in the X-Y direction of the step motor point-to-point, a three-dimensional optical absorption distribution map can be synthesized by the back projection. The method has the advantages that due to the adoption of the multi-ring array detector, the super narrow aperture angle and the good direction pointing of the multi-ring array detector greatly improve the imaging resolution, and realize the focus scan imaging in both X and Y directions; due to the adoption of the calculation phase control focus technology, the signal to noise ratio of signals can be effectively improved, and the mode A dynamic focus scan imaging in the depth Z direction can be realized; due to the receiving of optical acoustic signals in the dorsad mode, the operability and the application range of the system are greatly improved.

Description

technical field [0001] The invention relates to a test measurement and imaging method, in particular to a back-mode photoacoustic imaging method based on a multi-element phased focus ring array. Background technique [0002] At present, there are three measurement modes of photoacoustic imaging: forward, side and back mode: [0003] Due to the high scattering properties of biological tissues, the applicable range of forward mode systems is very small. [0004] Lateral mode systems usually obtain the distribution of photoacoustic pressure in a certain plane by means of detector rotation scanning, sample rotation scanning, and plane linear scanning, and then deduce the spatial light absorption distribution image through a specific reconstruction algorithm. This method has a high spatial resolution, but its time resolution is low, the imaging algorithm is complex, and the spatial directionality is poor. Moreover, due to the limitation of the characteristics of the organism, th...

AI Technical Summary

Problems solved by technology

A large-aperture high-frequency focusing detector can obtain a good signal-to-noise ratio, but its focal spot and focal length limit its imaging resolution and imaging angle, and the rapid attenuation of the signal in the tissue also limits its detection depth; The electric disc detector has a very high time resolution, and the longitudinal resolution of the three-dimensional imaging can reach tens of microns, but its directivity and signal-to-noise ratio are poor; the double-ring detector has a narrow aperture angle and a certain directionality , but its small aperture makes the signal-to-noise ratio of the acquisition poor, and it cannot achieve dynamic focusing in the depth direction

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