A Fast Scanning Photoacoustic Microscopy Method Based On Voice Coil Motor

Photoacoustic imaging is a new medical imaging technology with rapid development in recent years. photoacoustic signal is mainly excited by pulsed laser irradiating biological tissue. this imaging method combines the merit of high-resolution of optical imaging and high penetration depth of ultrasound imaging. photoacoustic microscopy is a branch of photoacoustic imaging. It has the characteristic of high resolution, high contrast, and can image deep in biological tissue. Thus, it has a wide range of applications in the biomedical field. For high-resolution photoacoustic microscopy imaging, improving imaging speed is of great significance. For example, achieving large field fast vascular imaging and fast oxygen saturation measurement,some dynamic process can be observed and monitored by real-time 3D imaging.The main content of this paper is to discuss the build of a fast scanning optical resolution photoacoustic microscopy imaging system,including takes advantage of the current optical path of optical resolution photoacoustic microscopy, choose voice coil motor and linear motor as the core scanning component. Design and evalution of the moving stage's scanning mode,scanning timing and data acquisition card's acquisition mode. and programed a set of software which based on visual studio 2010 platforms to control the moving stages, laser, data acquisition card.After completing of the imaging system. a series of tests have been taken on the system:(1) the unidirectional repeatability test of voice coil motor shows that within the range of 1mm stroke, 10 Hz scanning frequency, the unidirectional repeatability is to±4 ?m. This imaging system is capable of one way scanning at 8 Hz over a 2mm range and up to 15 Hz over a 500 ?m one way scanning range.(2) the 2D scanning of USAF resolution target prove the rationality of scanning mode and scanning timing. And at the same time of scanning process,dynamically changing the laser energy to achieve a more uniform signal to noise ratio.(3) the balb/c mouse ear imaging verify the system's in vivo 3D imaging ability.