ABSTRACT
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 processing techniques, such as waveform modeling and pattern recognition.