1997 R&D 100 Awards Celebrate Innovative Excellence

Searching for Hidden Hearts

The Enclosed Space Detection System detects human occupants in enclosed spaces like cars, trucks, or other vehicles to eliminate the need for physical searches. It does this by using geophones in contact with the vehicles to detect ballistocardiac shock waves, or beats of the human heart. The unit, created by teams from Lockheed Martin Energy Systems Inc., Oak Ridge, Tenn., and DOE’s Oak Ridge (Tenn.) National Laboratory, operates 10 to 250 times faster than physical searches and at 3% of the cost.

The researchers discovered that a consistently good method of extracting the features of the 2- to 16-Hz signal is to take the wavelet transform of the geophone output’s Fourier transform. Pioneering developments in the wavelet analysis, devised especially for this system, enable reliable detection of the ballistocardiac wave with inexpensive hardware.

R&D Magazine, September 1997