本文介绍了一种基于过采样技术的低成本非接触式生理信号的高精度采集系统.由于传统采样ADC精度较低,而高精度采样ADC成本较高,本文采用过采样技术实现低成本、高精度数据采集系统的搭建.过采样是用采样速度换取数据精度的技术,因此,对于微弱生命信号的采集,过采样技术具有非常明显的优势.本文主要通过信号的信噪比与动态范围两个参数来系统地量化比较传统采样与过采样技术之间的优劣性.通过使用过采样技术,生理信号的采样量化噪声降低约40dB,提升了系统分辨率和动态范围.同时,本文实现了生理参数的非接触采集,使系统实用性有了较大提高.
This paper describes a high precision non-contact physiological signal acquisition system using oversampling technology, which sacrifices sampling rate for achieving a higher accuracy. As we known, due to the low resolution of tradi- tional ADC and the high cost of high-resolution ADC, oversampling technology is used to achieve a high precision data ac- quisition in this paper. This technology has been remerged to be studied due to its advantage in the acquisition and analysis of weak biomedical signals by using biomedical wireless sensor networks. In this paper, the traditional sampling and the oversampling technologies were compared by quantifying the parameters of signal-to-noise ratio and dynamic range through simulations and experimental measurements. Oversampling technology reduces the quantization noise about 40dB, in other word, the signal-to-noise increases 40dB, which has great improvement in the acquisition system for physiological signals.