Abstract

SILVA BUSTILLOS, Ricardo José  and  GARATE PIRELA, Juan José. Bioelectronic interface development to establish communication with electric neuronal populations. Rev. Fac. Ing. UCV [online]. 2013, vol.28, n.4, pp.35-47. ISSN 0798-4065.

The project presents a modular system for bioelectric signal acquisition from neuronal populations, signals conditioning and recording, and the assessment of the results using signal processing methods. The acquisition stage of the design consisted on the development of electrodes (made from “ITO”) using sputtering and thermal evaporation techniques. It was observed that the sputtering technique produced better results in terms of composition of the films, transparency and electrical conductivity. The conditioning step and pre-processing of the signal is represented by a differential amplifier with a bandpass filter with low cutoff frequency (100 Hz) and baseline correction, a fourth-order Butterworth filter switched capacitor to set the upper cutoff frequency (2 kHz) and an electrical isolation amplifier with high accuracy. Through a temporal and spectral analysis of the behavior of the circuit, it fulfilled the defined requirements (high common mode rejection, triboelectric effect removal, and bandwidth between 100 and 2 kHz). The processing stage of the information is based on the decomposition of the signal using mathematical methods based on wavelet transform. Using low pass filters banks, it was determined that the highest-level decomposition of each wavelet provides information on the magnitude of neuronal activity while applying high-pass filter banks certain noisy signal components were highlighted allowing the elimination of such disturbances.

Keywords : Neurons; Acquisition; ITO; Amplifier; Wavelets.

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