Measurement of sympathetic nerve activity with carbon fiber electrode and spectrum analysis by image processing

Abstract

A biosensor is needed to be light, strong, durable, as well as to satisfy the safety conditions against virulence, stimulation, carcinogenicity and allergic reactions. Carbon is one of the most suitable elements which has the highest blood compatibly, and have been used as an intrvascular implant material. Because of these high degree of adaptabilities, carbon is expected to apply as an in-vivo bio-sensor. In this paper, we developed a new bipolar biosensor using advanced PAN-based carbon fibers (CF). The CF electrodes have been estimated to have enough sensitivity and stability as a nerve signal detector presumably because of the high degree of affinity of carbon fiber to an organism. The CF biosensors were set on the sympathetic nerves of small test animals, and the electric signals of sympathetic nerves activity for the hepatic, the cardiac and renal were detected. The fast Fourier transform (FFT) was carried out on the signals, and the FFT power spectrums were lined up along the time axis in order to transfer to color images of the signals. It has been suggested that the images indicate the clear information from noisy original signal and evaluated to be useful, especially to analyze the influence of bleeding. It is shown that the sympathetic nerve activity of the each viscera is analyzed in detail by CF sensor combined with this image processing system.