Methods, systems and devices are provided for reducing the amount of data, processing andor power required to analyze hemodynamic signals such as photoplethysmography signals, pressure signals, and impedance signals. The airbag includes a left half airbag to be deployed on a left side of an occupant and a right half airbag to be deployed on a right side of the occupant. A memory coupled to the communication server stores noise information and cross-channel-coupling information for the first subscriber line and the second subscriber line. The sensor unit receives instructions to change operating parameters andor control external devices.