Waterless coupled fast linear confocal scanning photoacoustic probe and imaging method thereof

Abstract

The invention discloses a waterless coupled fast linear confocal scanning photoacoustic probe and an imaging method. The photoacoustic probe comprises a casing, a fiber collimator, a galvanometer, a flat field scanning lens, a hollow two-dimensional translational adjustment frame,an ultrasonic coupler and an ultrasonic transducer; laseremitted from an optical fiber is collimated by the fiber collimator, reflected by the galvanometer, and then injected into the flat field scanning lens, the hollow two-dimensional translational adjustment frameand the ultrasonic coupler to reach a sample. Afterthe sample absorbs light, an acoustic signal is generated, and the acoustic signal is converted into an electrical signal by the ultrasonic transducer,transmitted to a computer processing system, andthen subjected to rapid image reconstruction through a GPU to achieve real-time imaging. The method has the advantages thathigh resolution is ensured by point excitation, fast linear confocal scanningdetection is achieved, and a waterless coupled device can achieve better effects in the application ofmatched photoacoustic microscopy instruments.

Description

technical field [0001] The invention relates to the field of photoacoustic imaging technology and devices, in particular to a fast linear confocal scanning photoacoustic probe without water coupling and an imaging method thereof. Background technique [0002] Photoacoustic imaging is a new non-invasive and non-ionizing biomedical imaging method developed in recent years. When the pulsed laser is irradiated (thermoacoustic imaging specifically refers to irradiation with radio frequency pulsed laser) into biological tissue, the light absorption domain of the tissue will generate an ultrasonic signal. We call this ultrasonic signal generated by light excitation as photoacoustic Signal. The photoacoustic signal generated by biological tissue carries the light absorption characteristic information of the tissue, and the light absorption distribution image in the tissue can be reconstructed by detecting the photoacoustic signal. Photoacoustic imaging combines the advantages of h...

AI Technical Summary

Problems solved by technology

At present, most of the photoacoustic probes use water as the coupling material, but there are many disadvantages of using water as the coupling material. One is that there should be no air bubbles in the water, and a little air bubbles will cause distortion of the photoacoustic signal, which is harmful to the imaging device. The airtightness has extremely high requirements, which is difficult to achieve in engineering; second, even if the airtightness requirements can be met, the water will become dirty and deteriorate after a certain period of time, which is unavoidable, which leads to photoacoustic imaging every time Water needs to be changed before testing

This greatly increases the cumbersome operation of photoacoustic imaging detection

[0004] In addition, traditional photoacoustic imaging systems are difficult to achieve both fast imaging and high-resolution imaging

In order to achieve fast imaging, the traditional photoacoustic imaging system uses a large spot to irradiate the sample, and uses an ultrasonic transducer array to collect signals. Although this can achieve real-time imaging, the resolution is limited by the size of the array elements, and high-resolution imaging cannot be achieved; In order to achieve high resolution, the light needs to be focused, and the resolution depends on the size of the focused spot, but when the light is focused, the light only illuminates a very small area, so light scanning is required to image the entire target area, the traditional The photoacoustic imaging system uses a motor to drive the probe or sample to move for optical scanning, but the motor has a large mass and large inertia, and it is basically impossible to achieve fast scanning. The CPU processes the data, and it is also difficult to image in real time

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