Table 2.

Correlation coefficients (r) comparing pulse transit time (PTTs) from established and proposed methods, and direction of linear regression.

	$\left|r\right|$ (mean ± SD)	Regression Slope	$\left|r\right|\ge 0.6$
EST_P~OPP	0.65 ± 0.14	Negative	8
EST_F~OPP	0.05 ± 0.18	N/A a	0
EST_P~OPF	0.68 ± 0.07	Negative	11
EST_F~OPF	0.23 ± 0.11	Positive	0
EST_P~OFP	0.86 ± 0.06	Positive	12
EST_F~OFP	0.60 ± 0.09	Positive	5
EST_P~OFF	0.57 ± 0.15	Positive	4
EST_F~OFF	0.76 ± 0.12	Positive	11

^a N/A indicates no consistent direction.