一种新型的基于四电极结构的生物电阻测量方法

提出了一种成本低而且精度高的人体阻抗测量系统。测量电路采用四电极结构，使每个电极模拟人体皮肤电阻，分别与人体的赤足接触，利用单片机产生50kHz的正弦波信号，经过四电极以及与其接触的人体后形成电压降，再经过信号放大电路处理，最终实现人体阻抗的测量。系统有效降低了产品的成本，克服了接触阻抗以及空间电磁波的干扰，试验结果与理论值证明了测量方法具有高精度、高稳定性和准确性。

A New High Precision Measurement of Biological Impedance

The purpose of this study is to develop a low-cost and high accuracy impedance measurement system of the human body. We construct the measurement circuit with four-electrode structure; the 4 electrodes can simulate the resistance of human skin, when bare feet have contact with them. The microcontroller generates 50kHz sine wave signals through the four electrodes and the finally the current will go to the human body, the voltage drop will be created and then through the signal amplification circuit, we can ultimately achieve the body impedance. This method effectively reduces not only the cost of the product, but also the interference from contact resistance and the electromagnetic wave, this system has been used for test with man or bio-impedance simulator, the results of this measurement are compared with the theoretical value, it demonstrated that, its stability and accuracy are very good.