生物电阻抗测量系统中同时多频混合激励源的设计

摘要

为了满足对生物体内不同组织、器官同一时间阻抗测量的需求,设计了一种同时多频混合激励信号产生电路系统,系统包括单片机控制的直接数字式频率合成(DDS)信号模块,电压控制电流源(VCCS)模块等主要硬件电路,并给出了核心设计电路;经测试:当激励源频率范围为10Hz～1MHz时,其输出电流最大相对偏差为0.74％,实验结果表明所设计的同时多频激励源带负载能力强、抗干扰性能好,满足生物电阻抗测量系统的要求.%To measure the impedance of different tissues and organs at the same time, this paper designs a Multi-frequency-one-time (MFOT) Current Source based on the microcontroller controlled the Direct Digital Synthesizer (DDS) and the Voltage Controlled Current Source (VCCS) . The core circuits are proposed. The maximum relative deviation of MFOT Current Source is 0. 74% between 10Hz and 1MHz. This design satisfies the requirement of biological electrical impedance measurement system with powerful capacity of bearing load and good anti-interference ability.