基于USB接口的三道生理信号检测仪电路设计

Circuit Design of a USB-based Three Channels Physiological Apparatus

介绍了用于心电、心音、胸阻抗信号测量的三道生理信号检测仪的硬件电路设计,着重描述了三种信号的放大、滤波、串行A/D转换及USB接口电路,前置放大使用了仪表放大器结构提高电路的共模抑制比,采用对消方法有效地抑制了电路中的各种共模干扰,设计了专门用于消除50 Hz工频干扰的50 Hz陷波器。实测表明,所检测到的三道生理信号都能满足临床应用,达到了设计要求。

This paper presents the measuring principle for three kinds of physiological signals, namely electrocardiogram, heart sound and impedance cardiography. We also propose a hardware circuit design of a three - channels physiological apparatus for measuring the aforementioned signals. In this paper, we emphasize on sampling, magnifying and sieving these three physiological signals. In particular, we take advantage of instrument amplifier structure to promote KCMR of the circuit. In addition, we design a band reject filter in order to eliminate 50Hz power frequency noise. Our experiments demonstrate that three physiological signals can satisfy clinical application.