TABLE 4.

Average group importance levels of PTTs and PPG features for blood pressure estimation.

Feature	SBP	Feature	DBP
PTTrm	0.1670	DT	0.2190
SYSAREA	0.1281	DIAAREA	0.1392
PTTrf	0.0889	HR	0.0886
FAS	0.0841	K	0.0884
AS	0.0778	FAS	0.0621
DT	0.0738	DS	0.0548
PIR	0.0637	AS	0.0542
DIAAREA	0.0579	PIR	0.0488
PW	0.0574	SYSAREA	0.0474
K	0.0419	FDS	0.0371
HR	0.0390	PTTrp	0.0367
AT	0.0357	PTTrf	0.0362
DS	0.0315	PW	0.0357
PTTrp	0.0278	AT	0.0267
FDS	0.0253	PTTrm	0.0250

Abbreviations and detailed definitions shown in Table 1.