Smith William A, Mogen Brian J, Fetz Eberhard E, Sathe Visvesh S, Otis Brian P
IEEE Trans Biomed Circuits Syst. 2016 Dec;10(6):1171-1180. doi: 10.1109/TBCAS.2016.2518923. Epub 2016 Apr 6.
Electrocorticography (ECoG) is an important area of research for Brain-Computer Interface (BCI) development. ECoG, along with some other biopotentials, has spectral characteristics that can be exploited for more optimal front-end performance than is achievable with conventional techniques. This paper optimizes noise performance of such a system and discusses an equalization technique that reduces the analog-to-digital converter (ADC) dynamic range requirements and eliminates the need for a variable gain amplifier (VGA). We demonstrate a fabricated prototype in 1p9m 65 nm CMOS that takes advantage of the presented findings to achieve high-fidelity, full-spectrum ECoG recording. It requires 1.08 μW over a 150 Hz bandwidth for the entire analog front end and only 7 bits of ADC resolution.
脑皮层电图(ECoG)是脑机接口(BCI)开发研究的一个重要领域。ECoG与其他一些生物电位一样,具有频谱特性,利用这些特性可实现比传统技术更优的前端性能。本文优化了此类系统的噪声性能,并讨论了一种均衡技术,该技术可降低模数转换器(ADC)的动态范围要求,且无需使用可变增益放大器(VGA)。我们展示了一款采用1p9m 65纳米互补金属氧化物半导体(CMOS)工艺制造的原型,该原型利用上述研究结果实现了高保真、全频谱的ECoG记录。整个模拟前端在150赫兹带宽上仅需1.08微瓦功率,且ADC分辨率仅需7位。