摘要
胎心音检测在胎儿监护中占有极其重要的地位。胎心音的主要频率范围集中在60～180Hz，因此在对信号进行A／D采样之前，应先设计滤波电路，滤除50Hz工频的谐波分量以及母体噪音。滤波电路采用0PA2277双运放芯片，设计具有正反馈的双T型陷波器滤除工频谐波，利用巴特沃斯滤波原理设计高通滤波器和低通滤波器滤除母体噪音。通过Multisim软件对所设计的陷波电路和滤波电路进行频响特性仿真，得到的频响特性曲线表明：所设计电路可成功滤掉工频干扰和母体噪音干扰。
The detecting fetal heart sound plays an important role in monitoring fetal. The major frequency range of the fetal heart sound focus on 60～180 Hz. Before sampling the fetal heart sound, it is need to design filter circuit to percolate the syntonic of 50 Hz power frequency and the noise of the matrix. The filter fireuit uses chip OPA2277. A double-T frame trap filter which contains a positive feedback is designed percolate syntanic of power frequency. Base on Butterworth function a high-pass and a low-pass filter is designed to percolate the noise of matrix. Simulation of the frequency response characteristic by the software Muhislm indicate that the filter could percolate the power frequency and the noise of matrix.
出处
《传感器与微系统》
CSCD
北大核心
2006年第12期46-47,共2页
Transducer and Microsystem Technologies
基金
国家自然科学基金资助项目(69972160)
关键词
胎心音
陷波器
巴特沃斯滤波器
fetal heart sound
trap filter
Butterworth filter
