Biomedical Data Acquisition Systems Based on Sigma-Delta Analogue-to- Digital Converters.

摘要

The high resolution of recent sigma-delta analog-to-digital converters (ADCs) has made possible the direct acquisition of a wide range of biomedical data. Such ADCs allows creating universal systems for medical research and for clinical practice. The performance of biomedical data acquisition systems is generally limited by the precision of the digital input data, which is achieved at the interface between analog and digital signals. The recent developments in digital VLSI technologies provide the practical means to implement the Sigma-Delta analog-to-digital converters (ADCs). The increasing use of digital techniques in biomedical data acquisition systems also has contributed to the recent interest in cost-effective, high precision ADCs. Sigma-delta modulation based on analog-to-digital conversion technology is a cost-effective alternative for high resolution (greater than 14 bits) converts, which can be ultimately integrated on digital signal processor ICs. This study details the use of sigma-delta ADCs in acquiring signals from electrocardiograms and electroencephalograms. ADC and software specifications for ECG and EEG signal processing are provided. A table presents frequency range, dynamic range, and comments on signal processing for electroretinogram, electrooculogram, EEG, visual evoked potentials, surface EMG, and ECG. (1 table, 3 figures, 5 refs.).