Preliminary Experimental Study of Observing Acute Cerebral Hypoxia in Rabbits Using Bio-impedance Measurement Technique

摘要

The aim of this article was to study the effects of cerebral impedance and the impedance frequency characteristics with acute cerebral hypoxia in rabbits. Oxygen suffocation method was performed to establish rabbit's cerebral hypoxia. After fixing four electrodes on the anesthetized rabbit's skull, 15 rabbits' cerebral impedance of normal and hypoxia were measured by electrical impedance monitor made by Faculty of Medical Electronic Engineering, Department of Biomedical Engineering, Fourth Military Medical University. The driving current was set to 1mA at the frequency range from 100Hz to 180kHz. The cerebral impedance distinctly increased during acute cerebral hypoxia and returned after oxygen supply. Before and after acute cerebral hypoxia, two means are significantly different at the 0.05 level. The maximum change(1.90%) of the real part of impedance could be obtained at the frequency of 6.310kHz and the maximum change(1.89%) of the modulus of impedance could be obtained at the frequency of 7.854kHz, The imaginary part of impedance change was not significant. Bio-impedance measurement technique can be used as a method of early diagnosis of acute cerebral hypoxia. Different percentage of impedance change would be obtained with different frequency and the best sensitivity of impedance change could be obtained at the frequency of 6.310kHz(real part) and 7.854kHz(modulus).