Design Of Detection Instrument Of Brainstem Auditory Evoked

Auditory evoked brainstem response signal is generated in the auditorynerve, the detection of auditory evoked brainstem response signal can not onlyjudge the function of human hearing is normal or not but also able locate thehearing function effectively the lesions. At present, brain stem auditory evokedsignal detecting equipment of domestic market monopolized by foreigncompanies, and the price is expensive. So this thesis designed an auditory evokedbrainstem response signal detector which has multi-functions and cost-effective.This thesis based on the in-depth study of the characteristics of auditoryevoked brainstem responses, According to the auditory brainstem response signalis weak, strong mutation caused signal extraction difficult, design thepreamplifier circuit with high input impedance, low noise,extracting the EEGsignal by median filtering method in the early stage, DB6wavelet combined withcoif3wavelet late auditory evoked EEG de-noising, feature extraction based oncosine summation algorithm for auditory evoked brainstem response signal. Atthe aspect of hardware system, the stimulating sound generating unit includes adigital to analog conversion circuit, an audio amplifying circuit and a soundprobe, signal acquisition and processing unit includes brain electrode, preamplification circuit, the two stage amplifier circuit, filter circuit, main amplifiercircuit, signal acquisition circuit, in addition also has a communication unit, adata storage unit, a clock circuit unit, a power supply unit, a printing unit.The auditory evoked brainstem response signal detector can be connectedwith a computer. This thesis uses the detector to demonstrate the feasibility of thedesign.