(Introduction) The biological fluid distribution have been tried to measure by the electrical impedance from 1960. Extracellular fluid including blood and intracellular fluid are consists of electrolytes solution, so these are resistance element. As for the cell wall is made of fat, so it is an insulator by a capacitance. (Purpose) At present the biological fluid measurement is the only method which is large-scale MRI. Therefore, we propose that easy and consecutive measurement method. So we tried whether subcutaneous fluid volume can be measured by bioimpedance. (Result) We found that the impedance from 500kHz to 1MHz is smaller than that of at 100Hz, and impedance is smaller within 1 minute after avascularization. (Conclusion) Because of the brachial cutaneous vein diameter expanded from 0 to 1 minute after avascularization. This phenomenon is approximately agrees with this result. We think that it is possible to measure subcutaneous fluid change by bioimpedance.
