基于AD5933的多通道生物电阻抗测量仪的设计与实现

Design and Implementation of Multi-Channel Bioelectrical Impedance Measurement Instrument based on AD5933

目的研究适于微重力条件下在轨应用的生物电阻抗测量方法。方法以STM32为控制中枢,以阻抗转换芯片AD5933为测量核心,进行多通道、多频生物电阻抗测量方法的研究设计,并进行通道一致性、有效性、人体试验验证。结果对64通道进行扫频测量,以第一通道为参考,多次测量相对误差可控制在2‰以内;与CHI604e生化分析仪(精度优于2‰)进行对比,测量相对误差在6‰以内;在显著度P=0.01的情况,本测量仪测量值与CHI604e测量值一致性高达0.997;对测试者的左上肢电阻RLA和右上肢电阻RRA进行30次多频测量,在P=0.01的情况,相邻两次的测量结果的相关系数高达0.994,任意两次测量结果不低于0.992。结论研制出一种支持多通道、多频的自动化测量设备。经测量分析验证,重复性和一致性较好,精度可以达到6‰。

Objective To study a bioelectrical impedance measurement method applicable to on-orbit microgravity conditions. Methods With STM32 as the control core and the impedance conversion chip AD5933 as the measurement core,a multi-channel,multi-frequency bioelectrical impedance measurement method was designed,and the channel consistency,effectiveness,and human test verification were carried out. Results The first channel is used as reference,and the relative error of multiple measurements can be controlled within 2‰in 64 channels sweep frequency test. Compared with the CHI604 e biochemical analyzer（ the precision is better than 2‰）,the relative error is within 6‰. In the case of significant degree P = 0. 01,the consistency between the measured value of this instrument and the CHI604 e measurement value is up to 0. 997. Thirty times multi frequency measurements were carried out on the tester＇s left upper limb resistance RLA and the right upper limb resistance RRA. In the case of P = 0. 01,the correlation coefficient of the two adjacent measurements reached 0. 994,and the results of any two measurements were not less than 0. 992. Conclusion The multichannel,single-frequency,multi-frequency and sweep-frequency functions were realized with this automatic measuring equipment. The measurement,analysis and verification results showed that the device had excellent repeatability and consistency,the precision of output reached a level of 0. 6‰.