passive physiological monitoring apparatus and method has a sensor for sensing physiological phenomenon . a converter converts sensed data into electrical signals and a computer receives and computes the signals and outputs computed data for real - time interactive display . the sensor is a piezoelectric film of polyvinylidene fluoride . a band - pass filter filters out noise and isolates the signals to reflect data from the body . a pre - amplifier amplifies signals . signals detected include mechanical , thermal and acoustic signatures reflecting cardiac output , cardiac function , internal bleeding , respiratory , pulse , apnea , and temperature . a pad may incorporate the pvdf film and may be fluid - filled . the film converts mechanical energy into analog voltage signals . analog signals are fed through the band - pass filter and the amplifier . a converter converts the analog signals to digital signals . a fourier transform routine is used to transform into the frequency domain . a microcomputer is used for recording , analyzing and displaying data for on - line assessment and for providing realtime response . a radio - frequency filter may be connected to a cable and the film for transferring signals from the film through the cable . the sensor may be an array provided in a medevac litter or other device for measuring acoustic and hydraulic signals from the body of a patient for field monitoring , hospital monitoring , transport monitoring , home , remote monitoring .