兔脑缺氧对脑阻抗影响的实验研究

目的：研究家兔脑缺氧时脑阻抗的定性变化，并优选最佳的电阻抗测量频率特性。方法：采用第四军医大学医学电子工程教研室研制的阻抗监护仪，将激励电流的幅度设为1．25mA，频率分别设为1、5、10、50、100和150kHZ，对兔短时缺氧和恢复供氧过程的脑部电阻抗变化过程进行监测。结果：兔脑短时缺氧过程中，脑阻抗明显升高，恢复供氧后．阻抗恢复初始状态。相同实验条件、不同激励频率的测量结果表明：在5kHz频率点，这一过程的阻抗值变化率最大（1．7％），具有显著性差异（P〈0．001），有统计学意义。结论：采用电阻抗成像技术对脑缺氧进行监测是可行的，同时采用不同的测量频率会得到不同的脑部电阻抗变化量，在所选测量频率点中．5kHZ时可以获得最高的脑缺氧灵敏度。

Experimental Study of Effects of Cerebral Anoxia on Cerebral Impedance in Rabbits

Objective To study the changes of cerebral impedance and the impedance frequency characteristics of the rabbit with cerebral anoxia. Methods Before and after cerebral impermanent anoxia, the cerebral impedance was measured by electrical impedance tomography monitor made by Department of Medical Electronic Engineering, Faculty of Biomedical Engineering, Fourth Military Medical University. The prompting current was set to 1.25 mA at the frequency of 1 kHz, 5 kHz, 10 kHz, 50 kHz, 100 kHz, 150 kHz. Results The cerebral impedance distinctly increased after cerebral impermanent anoxia and came back after oxygen was administrated. At the frequency of 5 kHz, the percentage of impedance change was the most obvious（1.7%） and the two means was significantly different at the 0.001 level. C, oneluaion Electrical impedance technique can be used as the method for early diagnosis of cerebral impermanent anoxia. Different percentage of impedance change is obtained with different measure frequencies and the best sensitivity of cerebral anoxia impedance can be obtained at the frequency of 5 kHz.Chinese Medical Equipment Journal, 2010,31 （4） ： 1-3]