PS25201A/B

Data Sheet 291841 issue 3

PLESSEY SEMICONDUCTORS LTD

TAMERTON ROAD | ROBOROUGH | PLYMOUTH | DEVON | PL6 7BQ

5

APPLICATION OF THE ECG SENSOR

Because of the large coupling capacitance to the body (around 250pF) the EPIC sensor’s internal electrometer can

be used in differential mode to recover true surface potential ECG signals from the surface of the skin. A typical

ECG signal at the surface of the skin is 1mV p-p.

Vdiff

Fig. 7 Differential measurement of body (skin) surface potential to produce ECG trace

Fig. 8 Comparison of two vectors from a pair of EPIC sensors (top)

and two conventional Ag/AgCl electrodes (bottom)