摘要
从头顶记录到的脑干听觉诱发电位的原始信号信噪比很低。一般情况下,需要1000～2000次刺激后的响应进行相干平均才能得到较满意的结果。这么多的刺激次数,使检查时间较长及人体可能产生生理上的疲劳反应,造成检查误差。根据脑干诱发电位背景噪声有时变的功率和时变的功率谱分布,本文提出分频段最优加权平均提取脑干诱发电位。原始的诱发响应信号按频率分成几个频段的子信号,对每一子信号采用使信噪比最高的最优加权平均,实际处理的结果表明,分频段最优加权平均比常规的相干平均可减少刺激次数三分之二以上,取得了满意的结果。
<ABSTRACT>
Signal-to-noise ratio (SNR ) of original signal recorded on scalp
during electrical response audiometry is very low, conventional coherent
averaging for extracting BAEP requires a large number (1000-2000 ) of
response to auditory stimulation and physiological fatigue effect.
Considering the background noise having time-varying and power with specifra
distribution, this paper presents a frequertcy-band optimal weighted
averaging. The frequency spectrum of signal is divided into several frequency
bands,the highest SNR being obtained by using time-varying optimal weighted
averaging in each band. The processing results indicate that the number of
samples is reduced to 2/3 of that of conventional coherent averaging.
出处
《中国生物医学工程学报》
EI
CAS
CSCD
北大核心
1990年第1期1-12,共12页
Chinese Journal of Biomedical Engineering
基金
中国科学院科学基金资助的科研课题
关键词
脑干
最优加权平均
听觉
诱发电位
Audiometers
Noise, Spurious Signal
Signal to Noise Ratio
