表面肌电信号的高速数据采集系统的设计

表面肌电信号不仅非常微弱,常常淹没在大量的噪声中,而且极易受到干扰,因此前置放大电路的共模抑制能力成为能否有效拾取SEMG的关键。针对前置放大电路,本文提出了一种新的"浮地技术"。经实验证明,电路在低频的KCMR改善了30dB。此外,设计的基于CY68013与AD7862的USB2.0高速数据采集系统,工作在GPIF模式,有效地采集到了人体的表面肌电信号,为后续人体上肢动作模式辨识提供了信号源。

High speed data acquisition system of SEMG

SEMG, because of its weakness, is usually buried in huge amount of noise. Also it is susceptible to disturbance. Therefore, the KCMR of preamplifier is vital to acquire valid SEMD. A new technique improving the ability to suppress common signal while enlarging differential signal, adopted in this article, is named "suspend power ground". It is proved that the KCMR at low frequency of the revised circuit goes up by 30 dB. In addition, a high speed DAQ system consisting of CY68013 and AD7862 works at GPIF mode. This system acquires SEMG effectively, which offers signal for pattern identification of limb's action.