Heartbeat detection is a brand new feature incorporating very sensitive sensors and sophisticated software to detect if there is a human being in the car when the car is locked and should be empty. The main reason to introduce such a system was to detect if a child, for example was inadvertently left in the car. It might also be useful to detect hidden car occupants.
Anti-theft systems and immobilizers use accelerometers to detect the motion of the car, when it is locked. The sensors used are low cost two-axis sensors. By combining anti-theft system with accurate heart beat sensor, the reliability of these systems can be enhanced.