Table 1.

Comparison of vital-sign sensing techniques.

Technology	Sensitivity	Sensing Style	System Complexity	Power Consumption
Accelerometer	Low	Wearable	Low	Low
Piezoelectric device	Low	Contact	Low	Low
Electrocardiography (ECG)	High	Contact	High	Low
Photoplethysmography (PPG)	High	Wearable	High	High
Pulse radar	High	Wearable	High	High
CW radar	High	Non-contact	High	Medium
SIL bistatic radar	High	Wearable	Low	Low