【摘要】 本文介绍了一种具有防噪功能的微音器和一个具有材高共模抑制比的放大电路，能有效地减少各种嗓声和干扰对心音信号的影响。同时介绍了一种用软件分频方式控制数据采集频率的方法。结果表明，本系统可采集到信噪比较高的心音图。更多还原

【Abstract】 This paper describes a microphone possessing the ability for anti-noise and an amplification circuitpossessing very high CMRR(Common Mode Rejection Ratio).The influences of various noises and disturbancesupon the heart sound signals are reduced effectively.In addition,a method is described that data acquisition fre-quency is controled by dividing frequency in software. The results show that a phonocardiogram possessing highsignal-to-noise ratio can be obtained on a microcomputer.更多还原