Table 3.

Seventeen width-related PPG features.

Feature	Definition
25. Width (25%)	The width of the waveform at 25% amplitude of systolic amplitude
26. Width (75%)	The width of the waveform at 75% amplitude of systolic amplitude
27. Width (25%)/t1	The ratio of pulse width at 25% of systolic amplitude to systolic peak time
28. Width (25%)/t2	The ratio of pulse width at 25% of systolic amplitude to notch time
29. Width (25%)/t3	The ratio of pulse width at 25% of systolic amplitude to diastolic peak time
30. Width (25%)/∆T	The ratio of pulse width at 25% of systolic amplitude to ∆T
31. Width (25%)/tpi	The ratio of pulse width at 25% of systolic amplitude to pulse interval
32. Width (50%)/t1	The ratio of pulse width at 50% of systolic amplitude to systolic peak time
33. Width (50%)/t2	The ratio of pulse width at 50% of systolic amplitude to notch time
34. Width (50%)/t3	The ratio of pulse width at 50% of systolic amplitude to diastolic peak time
35. Width (50%)/∆T	The ratio of pulse width at 50% of systolic amplitude to ∆T
36. Width (50%)/tpi	The ratio of pulse width at 50% of systolic amplitude to pulse interval
37. Width (75%)/t1	The ratio of pulse width at 75% of systolic amplitude to systolic peak time
38. Width (75%)/t2	The ratio of pulse width at 75% of systolic amplitude to notch time
39. Width (75%)/t3	The ratio of pulse width at 75% of systolic amplitude to diastolic peak time
40. Width (75%)/∆T	The ratio of pulse width at 75% of systolic amplitude to ∆T
41. Width (75%)/tpi	The ratio of pulse width at 75% of systolic amplitude to pulse interval