| Feature | Description |
| Time domain | Amplitude | Amplitude of the fiducial points in Figure 2 (e.g., systolic peak, diastolic peak, and dicrotic notch) | Time | Time interval between the fiducial points in Figure 2 (e.g., systolic peak, diastolic peak, dicrotic notch, and onset) | Width | Systolic width at 10%, 25%, 33%, 50%, 66%, and 75% and diastolic width at 10%, 25%, 33%, 50%, 66%, and 75%, as shown in Figure 3 | Area | Systolic area, diastolic area, and their ratios | Derivatives | Ratio of amplitude of fiducial points on first-order derivative and second-order derivative in Figure 2 |
| Frequency domain | Amplitude and frequency of the first, second, and third peaks of the frequency domain signal |
| Demographic information | Age, gender, height, weight, body mass index (BMI), etc. |
| Entropy | Shannon entropy, spectral entropy, approximate entropy, sample entropy, etc. |
| Statistical characteristics | Mean, standard deviation, skewness, kurtosis, etc. |
| Others | value, PIR, ASI, etc. |
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