Modified photoplethysmography signal processing and analysis procedure for obtaining reliable stiffness index reflecting arteriosclerosis severity
This study aimed to describe a modified photoplethysmography (PPG) signal processing and
analysis procedure to obtain a more reliable arterial stiffness index (SI). Approach. Three
parameters were used to assess the PPG signal quality without prominent diastolic waves, which are
similar to a sinusoidal waveform shape. The first parameter, sinusoidal ratio (S-value), was based
on frequency-domain analysis: a higher S-value indicated the presence of PPG pulse wave with
unapparent diastolic peak. The second parameter was the time difference between systolic
peak-to-diastolic peak and the systolic peak-to-dicrotic notch. The third parameter was the
percentage of sin-like waveform in the PPG signals. The applicability of these parameters was
demonstrated in 40 participants, including 11 with apparent diastolic peaks in the PPG signals and
29 with unapparent diastolic peaks. Main results. An S-value of>3.5 indicated apparent diastolic
peaks in the PPG signals. In addition, a systolic peak-to-diastolic peak time difference>80% and a
sin-like waveform>55% may be associated with severity of vascular aging. Significance. These
parameters successfully detected low-quality PPG signals with unapparent diastolic waveform before
SI calculation, thereby ensuring the accuracy of subsequent evaluation of cardiovascular-related
disease and clinical risk stratification.
Source: Physiological Measurement - Category: Physiology Authors: Meng-Ting Wu, I-Fan Liu, Yun-Hsuan Tzeng and Lei Wang Source Type: research