Design And Implement Of A High-Resolution Photoacoustic Microscopy System And In Vivo Imaging With The System

Photoacoustic imaging is a new type of imaging technology developed in recent years.Its principle is the photoacoustic effect.It also has the advantages of high resolution of optical imaging technology and large penetration depth of ultrasound imaging,and can provide high-resolution,high-contrast images.This has opened up a new direction for imaging in physical medicine.The existing photoacoustic microscope systems have certain deficiencies,such as the scanning speed and resolution cannot be taken into account when the imaging is performed in a large range,and the stability of the system operation needs to be improved.This article demonstrates a set of high-resolution photoacoustic microscope systems,including hardware and control systems.The hardware components were selected and introduced,and the hardware system was built.According to the experimental requirements,the control system was written based on LabVIEW,which mainly included the control program of the electrophoresis stage,the control of the laser,and the data acquisition and pre-acoustic signal acquisition.Process it and integrate it into a control interface.After the photoacoustic microscopy system was constructed,the lateral resolution,signal-to-noise ratio,and scanning speed of the system were tested using a 7?m diameter carbon fiber sample.Tests have shown that the system can obtain high-detailed images of carbon fiber,with a lateral resolution of the imaging system of 1.7 ?m;and a stable and rapid imaging of a 5 mm x 5 mm area with an imaging time of approximately 5 minutes.The system then performed a series of in vivo imaging experiments on mice under anesthesia.Imaging the mouse's ear microvascular network,the imaging quality is good,the image contrast is high,and the opening and closing of the microvascular network can be observed through imaging.At the same time,for each mouse,a series of imaging was performed at intervals of 5 minutes for 14 consecutive groups.Ten mice were performed in total for ten experiments.We extracted two indicators of blood vessel intensity and blood vessel density from the photoacoustic images obtained from the experimental collection.The statistical results obtained from the ten groups of experiments showed that after 65 minutes,the blood vessel intensity and density increased by 42.7±8.6%and 28.6±12.2%,respectively.The experimental results show that the high-resolution photoacoustic microscopy system can effectively image the microvessels and has a good application prospect in the future biomedical sciences.Finally,this article summarizes some of the remaining deficiencies in the system,and also gives some perspective on the direction in which future photoacoustic microscopy systems can be developed.