Sigma-delta analogue-to-digital converters for ECG signal acquisition

The high resolution of recent sigma-delta analogue to digital converters (ADCs) has made possible the direct acquisition of a range of biopotential signals. Traditionally 12 lead electrocardiogram (EGG) acquisition systems have been complex and hardware intensive. Sigma-delta ADCs have the potential to reduce the amount of hardware by about 60%, thereby reducing system cost, volume and power consumption. This paper contains an evaluation of the Analog Devices AD7716 22-bit, 4 channel sigma-delta ADC for diagnostic-quality ECG acquisition.