Time-domain characterization of a wireless ECG system event driven A/D converter

Abstract

Heart strokes are one of the leading cause of global deaths. In order to prevent such strokes, a variety of wearable devices have been proposed recently. These are based on the wireless Electrocardiogram (ECG) acquisition, analysis and transmission. An efficient acquisition, analysis and transmission of such signals can be achieved by adapting the system activity according to the input signal local characteristics. In this context, an event driven analog-to-digital converter (ADC) based on level-crossing sampling scheme (LCSS) is designed for the ECG acquisition. The analog-to-digital (A/D) conversion error is a vital parameter to characterize its performance. It implicitly provides information about the ADC effective resolution. In this context, a novel method is proposed to measure the conversion error in time domain of the designed level-crossing ADC (LC-ADC). In the aim of acquiring the desired conversion precision, a criterion for properly choosing the system parameters is also discussed.