有效保留血液容积图(PPG)波形信息的新方法

A Novel Method for Effectively Preserving PPG Pulse Waveform Information

目的减少血液容积图脉冲信号提纯处理的信息损失。方法提出了一种新的血液容积图(PPG)脉冲波形提纯技术———截尾/外推技术,其核心是以信号中无关紧要部分的失真为代价,换取信号中最重要部分的波形形状模式不受改变。与通常使用的时间尺度归一化技术相比,所提出的技术保证了信号能量的相干积累。结果实验数据的分析和比较证实了此技术在较大的心率变化范围内能够保持PPG脉冲波形的主要时域特征不受影响,尤其是PPG信号一阶导数(dPPG)的主峰形状和宽度以及二重脉搏凹坑的位置信息。结论该方法减少了PPG脉冲信号提纯时的信息损失,为下一步应用高级信号处理手段如波形建模和模式识别等打下了基础。

Objective To reduce information loss in the refining processing of photoplethysmographic （PPG） pulse waveform. Method A novel PPG pulse waveform refining processing technique, named truncation/extrapolation technique was proposed. The key point of the proposed technique was to preserve the shape pattern of the most significant parts of the waveform at the expense of the distortion of the insignificant part. Thus, as compared with the conventional time-normalization method, the proposed technique ensured the accumulation coherent of the signal energy could be. Result Waveform analysis and comparison of experimental data between two methods verified the effectiveness of the proposed method in maintaining the most significant time domain features of the pulse waveform over a relatively wide range of the heart rate change, especially the shape and width of the dominant peak and the position of the dicrotic notch of the first derivative of PPG（dPPG）. Conclusion The proposed method reduces the information loss in PPG pulse waveform refining processing, thus helps further processing of the PPG signal using some advanced signal pro- cessing techniques, such as waveform modeling and pattern recognition.