单词first heart sound
un.: 第一心音
第一心音
The results showed that the first heart sound energy fraction were significantly different in the normal group and the heart murmur group.
试验结果表明，在正常组和返流性心脏杂音组间，第一心音能量分数存在显著性差异。
The first heart sound is caused by the closure of the atrioventricular valves and so marks the beginning of ventricular systole.
第一心音的原因是关闭房室瓣膜等标志着心室收缩。
Frequency Detection of the First Heart Sound Based on Wavelet Transformation
基于小波变换的第一心音频率检测