基于超声回波信号的指端脉搏波提取

Fingertip pulse wave extraction based on ultrasonic echo signal

脉搏波可作为检测人体心血管系统生理病理状态的重要依据。为了验证用超声波测量脉搏波的可能、解决脉搏波的测量部位受限的问题,本研究提出一种从超声回波信号中提取脉搏波的方法。设计一种跟随式超声传感器,用数据采集系统采集指端超声回波信号,经过滤波、选点及小波去噪等处理后得到较为纯净的脉搏波信号;同时采集心电信号以及光电容积脉搏波信号作为参考信号。结果表明,可以从提取的指端脉搏波中准确地获取心率;与同步测得的光电容积脉搏波数据相关系数大部分在0.8以上;波形中的重搏前波、重搏波等细节部分也能明显地表现出来。本研究提出的方法实现了从指端超声回波信号中获取完整可靠的脉搏波信号,为日后获取不同部位的脉搏信号提供了基础。

The pulse wave can be used as an important basis for detecting the physiological and pathological states of the human cardiovascular system.In order to verify the possibility of detecting pulse waves with ultrasound and to solve the problem of restricted sites for pulse wave detection,a method of extracting pulse waves from ultrasonic echo signal is proposed.A following ultrasonic sensor was designed,and a data acquisition system was used to collect the ultrasonic echo signals at the fingertips.Pure pulse wave signals were obtained after filtering,point selection and wavelet denoising.Meanwhile,the electrocardiogram signals and the photoplethysmography signals were collected as reference signals.The results show that the heart rate can be accurately obtained from the extracted fingertip pulse wave,and that the correlation coefficient between the pulse wave signals and the photoplethysmography data measured at the same time is mainly above 0.8.Such details as dicrotic wave and dicrotic wavefront can also be displayed clearly.By the proposed method,a complete and reliable pulse wave signal can be obtained from the ultrasonic echo signals at the fingertips,which lays significant foundations for obtaining pulse signals from different sites in the future.