目的 为了用无创测得的局部肌肉组织的电阻抗频谱评估失血性休克的程度，需要确定无创测量电极系统中电极间距 这一个关键因素。方法 参照大鼠股二头肌厚度数据，设计了3种兼具无创和有创测量的电极头，无创测量电极间距分别为 1.83、2.67、3.5 mm，有创测量电极间距均为2.67 mm；以新鲜离体的10份猪里脊肉为测量对象，对测量阻抗模值进行欧氏 距离分析及Cole-Cole曲线拟合，对比拟合误差。结果 无创测量电极间距为2.67 mm时，无创测量的模值频谱更接近有创测 量的模值频谱，而且该间距下无创测量数据拟合成Cole-Cole曲线的效果更好。结论 以被测肌肉组织的厚度的1/6为无创电 极间距时，测得的电阻抗频谱数据接近于等间距有创方式测得的电阻抗频谱数据。

Objective It is necessary to determine the electrode distance in noninvasive electrode system, so as to assess the degree of hemorrhagic shock with noninvasive measurement of the electrical impedance spectrum of local muscle tissue. Methods According to the thicknesses of biceps femoris of rats, three kinds of probes with both noninvasive and invasive electrode arrays were designed. The electrode distances of noninvasive measurements were 1.83, 2.67 and 3.5 mm respectively, while the invasive measuring electrode distances were 2.67 mm. Ten fresh pork fillets were taken as the object for measurement. The differences of measurements were analyzed by Euclidean distance and the fitting errors were analyzed in the process of Cole-Cole curve fitting with the noninvasive measurements. Results The measured results were closer to the invasive measurements and the corresponding Cole- Cole curve fitting error was better when the electrode distance of noninvasive was 2.67 mm. Conclusion The measured impedance spectrum data is close to the invasively measured data with the same electrode distance when use 1/6 of the thickness of the measured muscle tissue as the non-invasive electrode distance.