不同采样率对光声图像重建的影响

In Fluence of Different Sampling Rate on the Reconstruction of Photoacoustic Images

为了实现高质量的快速光声图像重建,研究了不同采样率对光声图像重建的影响。由实验表明,对于mm量级与几百μm量级的吸收体,将采样率分别调整到5~7 MHz和7~9 MHz时,其成像质量好,速度快。实验所用的光源为YAG激光器,波长为1 064nm,重复频率为20Hz,脉宽为7ns,探测器为针状的PVDF膜水听器,接收面积的直径为1mm。

In order to attain the reconstruction of photoacoustic images with high-contrast and fast noninvasive features,the effect from different sample rates was studied.The experimental results demonstrate that frequency of sample rate is about 5~7 MHz for the absorber with a few millimeter diameters,and it is 7~9 MHz for hundreds ofμm diameter absorber.A Qswitched Nd：YAG laser,which operates at 1 064 nm,was used as light source.The laser has a 7ns of pulse width and a20 Hz of repetition frequency.A needle PVDF hydrophone with 1mm diameter was used to detect photoacoustic signals.