At Electronica in Munich Germany next month, Plessey Semiconductors Ltd. will reveal more details on the use of its electric potential integrated circuit (EPIC) sensor technology in a system for detecting driver fatigue.
Tests by the company engineers indicate that more than 95 percent of heart beat peaks were detected during a 10-minute trial based on a variety of driving conditions.
Licensed for commercial use by Plessey from the University of Sussex, EPIC measures changes in an electric field in a way similar to a magnetometer, taking advantage of the fact that human body and its motions affect the electrical field. The sensor design can be used to detect heart beats and other nerve and muscle activity with or without dry contact, by making use of capacitive coupling to transmit an ECG signal through normal clothing or seat cover fabric.
The Plymouth, England based firm has used the technology to monitor heart rate variability from which it is possible to tell whether a driver is becoming sleepy. This is best achieve, company engineers say, through the use of an array of sensors built into a seat back.
The optimal sensing location can then be chosen, regardless of the driver's height and build. Movement noise is minimized by placing the sensors away from the shoulders on the lower part of the seat back.
Evaluation kits are now available for car manufacturers and suppliers and include a seat pad with a six-sensor array on the seat back and a ground plane on the base as well as an interface box with a USB output to display and recording software.