Table 3.

Performance comparison for combinations of input signals without attention model and with attention. The 95% confidence interval is indicated below the error of the proposed model.

Model	Input	SBP (mmHg)				DBP (mmHg)
		RMSE	MAE	SD	${\mathbf{R}}^{\mathbf{2}}$	RMSE	MAE	SD	${\mathbf{R}}^{\mathbf{2}}$
CNN+Bi-GRU	ECG	7.02	5.51	4.66	0.24	5.16	4.06	3.45	0.27
	PPG	6.88	5.34	4.60	0.28	5.73	4.45	4.09	0.14
	BCG	7.24	5.59	5.03	0.20	5.29	4.06	3.71	0.22
	ECG, PPG	5.83	4.46	4.06	0.46	4.74	3.70	3.37	0.38
	ECG, BCG	6.74	5.30	4.60	0.31	4.82	3.74	3.27	0.34
	PPG, BCG	6.44	4.86	4.50	0.36	5.04	3.88	3.62	0.27
	ECG, PPG, BCG	5.87	4.51	4.14	0.48	4.73	3.71	3.39	0.40
CNN+Bi-GRU +Attention (proposed model)	ECG, PPG, BCG	5.42 [1.97, 8.87]	4.06 [1.53, 6.59]	4.04	0.52	4.30 [0.94, 7.72]	3.33 [0.61, 6.05]	3.42	0.49