用于生物阻抗测量的混频激励电流源

Mixing Frequency Excitation Current Source Used in Bioelectric Impedance Measuring System

通过分析生物阻抗测量系统的需求,设计了一种应用于生物阻抗测量的混频激励电流源。该电流源不仅频率和幅值可控,控制精度高,而且具有良好的模块化特点,可以方便地嵌入到其他系统中。同时还采用了EEPROM对电流源的配置信息进行存储,使电流源具备上电时自动进行配置的功能。此外,电流源还可以根据上位机的指令和数据,进行扫频输出,自动产生不同频率成分的混频信号。给出了相应的硬件设计及软件控制流程。

A mixing frequency excitation current source is designed according to the analysis of requirements of the bioelectric impedance measuring system. Frequency and amplitude of the current source can be controlled with high precision. A characteristic of modularization makes it easy to be embedded in other systems. As configure information is stored in EEPROM, the current source is configured automatically when electrified. According to instructions and data from PC, the current source can produce scanning frequency signal that is mixing frequency signal and contains different frequency elements. The corresponding hardware design and control flow of software are brought forward.