摘要
目的研究长时间静坐下小腿的电阻抗参数随着时间的变化情况。方法以系统优化设计思想为目标 ,构造出了能够实现长时间地监测组织电阻抗特性变化情况的双CPU硬件系统。 7个正常人腿部不动地静坐 1h,基于四电极法测出左小腿的电阻抗谱。依据被测组织的Ri Cm Re 等效电路模型 ,根据复平面上的阻抗轨迹 ,利用迭代式最小二乘法曲线拟合 ,得到细胞内和细胞外的阻抗以及细胞膜的膜电容。结果对于静坐条件下工作负荷加重时 ,细胞内液电阻Ri 增加较大 ,细胞外液电阻Re 有微小增加。结论这些实验结果与利用下肢阻抗的模型描述的理论解释非常吻合 。
Objective To study changes of the electrical parameters in the lower limbs after long sitting. Method In order to optimize the whole system, a practical hardware system was built with double CPUs, used to monitor the changes of the impedance of the tissues. In the experiment the electrical impedance of objects in left shanks were measured, when they were sitting still for 1 h. Based on R i C m R e equivalent circuit model of measured tissue and four electrode method, the trace of the impedance on the complex plane fit with the iterative least square curve. According to the fitted curve the intracellular and extracellular resistances as well as the membrane capacitance were obtained. Result During sitting,the intracellular resistance increased significantly while the extracellular resistance minimaly increased with an increase of the work load. Conclusion The experimental results agree well with the theoretical explanation, using impedance model to represent the lower limbs. Therefore, the model parameters of electrical bio impedance can be used for distinction of different physiological conditions of the tissues.
出处
《航天医学与医学工程》
CAS
CSCD
北大核心
2004年第1期44-48,共5页
Space Medicine & Medical Engineering
关键词
电阻抗
模型
参数
迭代式最小二乘拟合法
坐姿
下肢
electrical impedance
models
parameters
iterative least square curve fitting method
sitting position
lower lambs
