混频激励生物电阻抗测量系统(英文)

Mixing frequency based bioelectrical impedance measurement

为获得同一时刻,不同频率下的生物电阻抗信息,本文采用混频激励模式,对生物电阻抗进行测量。为了提高系统的测量精度,本文在虚参考矢量方法与乘法解调技术相结合的测量方法基础上构建而成。系统设计中采用了模块化设计思路,并通过DSP实现对各个模块的控制功能。上位机软件采用VB语言编写,主要实现对下位机配置、串口通信、显示数据等功能。以阻容器件为对象,利用Agilent4294A阻抗分析仪对系统进行了标定,证明该系统具有较高精度和准确性;以人体为对象,也获得与阻抗分析仪测量结果趋势一致的生物阻抗信息。

In order to acquire the bioelectrical impedance information at different frequencies concurrently, a new measurement system was developed using a mixing frequency approach. The system design is based on the virtual reference vector method and multiplication demodulation technique. The implementation of the system hardware is a- chieved using a modular structure. A digital signal processor controls various modules in the system, and the system software realizes configuration of the digital signal processor, serial communication and data presentation, etc. A reference impedance analyzer （Agilent 4294A） is used to provide reference data in order to evaluate the developed system. Results obtained on a human body show that the system performs well in terms of functionality and accuracy.