基于PCI4732的高定位精度光声成像系统设计

为了研究光声成像技术对不同吸收体的成像性能，利用PCI4732和高精度旋转台RT-5-10,在Labview软件设计平台上开发了一套光声成像系统.系统由脉冲激光器、水浸探头和放大器等硬件组成,采集卡通过PCI总线与电脑连接.采用高分辨率滤波反投影重建算法对数据进行处理,得到较高对比度和分辨率的图像.分别采用2.25、5.00和10.00 MHz的超声探头对发丝进行试验,以验证系统的实用性.试验结果显示:采用5.00 MHz的探头比采用2.25和10.00 MHz的探头得到的发丝的图像更清晰,表明对于一定尺寸的吸收体,需要选择一定中心频率的探头,才能得到清晰的图像. 

Design of Photoacoustic Imaging System with High Positioning Accuracy Based on PCI4732

In order to research the photoacoustic imaging abilities of different absorbers,a photoacoustic imaging system was developed based on Labview software design platform coupled with PCI4732 and high positioning accuracy rotation stage RT-5-10.This system consists of a pulsed laser,an immersion probe and an amplifier and so on,and a PCI(peripheral component interconnect) bus was used to realize the connection between the PCI card and a computer.A high resolution filtered back-projection reconstruction algorithm was used to process the data and obtained high contrast and high resolution images.To verify the practicability of the developed system it was tested using human hairs as objects respectively with 2.25,5.00 and 10.00 MHz transducers.The result indicates that a 5 MHz transducer can gain clearer images than a 2.25 or 10 MHz transducer to show that certain absorber should correspond to certain frequency of transducer.