基于直线电机的大视场快速光声显微成像系统

光声成像技术是近年来发展的一种新型的无损医学成像技术,它是以脉冲激光作为激发源,以检测的声信号为信息载体,通过相应的图像重建算法重建组织内部结构和功能信息的成像方法。该方法结合了光学成像和声学成像的特点,可提供深层组织高分辨率和高对比度的组织层析图像,在生物医学临床诊断以及在体成像领域具有广泛的应用前景。目前光声成像的扫描方式主要有基于步进电机扫描方式和基于振镜的扫描方式,本文针对目前步进电机扫描速度慢(10 mm×10 mm;0.001帧/s),振镜扫描范围小(1 mm2)的不足,发展了基于直线电机扫描的大视场快速光声显微成像系统。同一条扫描线过程中直线电机速度最高可达200 mm/s。该技术采用逐线采集光声信号的方式,比逐点采集光声信号的步进电机快800倍。该系统对10 mm×10 mm全场扫描的扫描速度为0.8帧/s。最大可扫描视场范围可以达到50 mm×50 mm。大视场快速光声显微成像系统的发展将为生物医学提供新的成像工具。

Large-field Photoacoustic Microscopy with Rapid Scanning Based on Linear Motor

Photoacoustic imaging, which was developed in recent years, is a new and noninvasive medical imaging technology. The imaging technique uses laser pulses to generate photoacoustic signal,and transmit the tissue information with ultrasonic, and reconstruct the image of tissue structure and function information with the corresponding reconstruc-tion algorithm. It combines the characteristic of optical imaging and ultrason imaging, provides high resolution and high contrast tomographic images of the deep tissue and has a wide range of applications in biomedical clinical diagnosis as well as in vivo imaging. Currently,there are two scanning modes for photoacoustic microscopy:photoacoustic microscopy system based on two-dimensional scanning galvanometer and photoacoustic microscopy system based on stepping motor. In this work, considering the limitations of the low speed of stepping motor based photoacoustic microscopy (0.001 frame/s) and small scanning scope of scanning galvanometer based photoacoustic microscopy ( <1 mm2), we devel-oped an large-field photoacoustic microscopy with rapid scanning based on linear motor. The scanning speed of this tech-nique is 200 mm/s.The technique is based on a line-by-line method to collect the photoacosutic signal, which is 800 times faster than the step-motor based photoacoustic microscopy with point-by-point gathering of photoacosutic signal. The scanning speed of this system is 0.8 frames per second in the field of 10 mm×10 mm. The maximum scan-range can reach 50 mm×50 mm. The development of the large field rapid photoacoustic microimaging system will provide new imaging tools for biomedical science.