The disclosed invention uses two sensors to capture the heartbeat and environmental noises of an occupant of a vehicle or hospital bed. One of the sensors is placed on a seat or bed frame adjacent the occupant. A second sensor is placed remotely from the occupant, on a vehicle floor, or remote portion of the bed frame. A signal conditioning module is attached to the first and second sensors for detecting the heartbeat signal. Specialized software is used for processing the signal and decision making based upon the extracted heartbeat signal. The invention is capable of operating despite environmental noise and vibrations.