基于小波变换的激光多普勒血流信号处理研究

Research on laser Doppler blood flow signal's treatment method based on wavelet transform

激光多普勒血流量检测系统提取的光电信号中存在较大的高斯白噪声,为了消除这些噪声干扰,提取激光多普勒信号,提出了一种基于小波变换,使用Matlab中的wavelet toolbox对所得信号进行五层离散小波分解、阈值变换、消噪以及信号重构的处理方法。结果表明,该方法可有效地抑制噪声,从原始光电信号图中提取多普勒信号并对其进行分析,计算血流速度。该研究结果对后续的分析多普勒血流信号,实时检测血流量变化情况,解释血流病理含义,进而对诊断病因、指导医疗手段均有一定的参考价值。

The photoelectric signal picked-up by laser Doppler blood flow detecting system contains large white Gaussian noise. To remove this disturbance and pick-up laser Doppler signal,this paper has put forward a processing method based on wavelet transform,which contained five layer discrete wavelet decomposition,threshold transform,signal de-noising and signal reconstruction,using wavelet toolbox in Matlab.The result shows that this method can reduce the influence of noise effectively,pick-up the Doppler signal from original photoelectric signal and calculate the blood flow after analysis.The result of research has certain reference value in analyzing Doppler signal, detecting changes of blood flow in real time, explaining the pathologic meaning of blood flow,the further diagnosing and guiding the medical measurement.