Design And Implementation Of A Photoacoustic Microscopy Imaging System Based On Pulsed Diodes

Since the end of the 20 th century,the photoacoustic imaging technology has been rapidly developed since the photoacoustic effect has once again entered the people's sight.With the revolutionary development of various types of lasers,photoacoustic imaging technology has been able to achieve such encouraging research results.The reason why photoacoustic technology causes such high attention is firstly because photoacoustic imaging is an imaging method based on absorption,which relies on the absorption intensity of tissue for different wavelengths to form the contrast of the image.Secondly,photoacoustic imaging technology Involved in two areas,including optics and acoustics,tissue scattering of light is the imaging depth of pure optical imaging is difficult to achieve a satisfactory degree,while the contrast of pure ultrasound imaging depends on the density difference between different tissues,which passes The ultrasonic transmitting device generates ultrasonic waves and injects into the interior of the tissue,and inverts and calculates the information in the tissue by detecting the ultrasonic echo.For photoacoustic imaging,since the ultrasonic signal is generated by the tissue absorption light,and then the ultrasonic signal is received,It effectively avoids the shortcomings of the above two imaging methods,which combines the high contrast of pure light imaging(depending on the absorption distribution)and the imaging depth of pure acoustic imaging(depending on the difference in tissue density),which is the high level of photoacoustic imaging.Contrast and dependence on the characteristics of light absorption,it has become one of the hotspots of medical imaging technology research at home and abroad.The technology is expected to become the analysis and research,monitoring and subcutaneous even a powerful tool for in vivo diagnosis of the cause of the mechanism.In this paper,the research background and basic principles of photoacoustic imaging technology are briefly introduced.The time domain and frequency domain characteristics are analyzed.The construction methods and system structures of several common photoacoustic imaging techniques are introduced.Several typical semiconductor-based lasers are introduced.The structure,construction mode and mechanism of the photoacoustic imaging system,and the starting point of the contentstudied in this paper,based on the design of the photoacoustic microscopy imaging system of the semiconductor laser with strong absorption band of the vascular component,the semiconductor Lasers have the characteristics that traditional solid-state lasers cannot achieve,such as compact size,low price,good stability,and high reliability.At present,semiconductor lasers have become the hotspot of photoacoustic imaging technology as the excitation source of photoacoustic imaging systems.One of the directions.In the construction platform of the experimental platform,LabVIEW is used as the control software platform of the whole imaging system,and the two aspects of the reconstruction program are written by MATLAB.The photoacoustic microscopy imaging of the 3D electric displacement platform and the PCI8520 data acquisition card data acquisition system is completed.The design and implementation of the system verified the stability and feasibility of the system through experiments on carbon fiber precursors,hair,etc.,and verified the photoacoustic imaging ability of the subcutaneous blood vessels in the abdomen of mice.The photoacoustic imaging technology of the laser realizes the high-contrast rapid detection of human subcutaneous capillaries,and has made theoretical and experimental feasibility verification work.