Plessey develops sensor solution to monitor driver fatigue

The EPIC sensor uses capacitive coupling and can measure ECG through clothing and seat cover fabric, rather than requiring skin contact. By monitoring a parameter called Heart Rate Variability (HRV) – a measure of how stable the heart rate is from beat to beat – the sensor can tell when the driver is starting to become sleepy. An array of sensors are built into the seat back so that an optimal sensing location can be chosen, regardless of the driver's height and build. Movement noise is said to be minimised by placing the sensors away from the shoulders on the lower part of the seat back. The system uses a capacitive driven ground plane, which can also be placed under the seat cover fabric on the base of the seat, to produce a completely hidden system. The company says the system is immune to electrical noise sources within the car. Plessey's tests show that more than 95% of heart beat peaks were detected during a ten minute trial over a variety of driving conditions.