Geddes L A, Bourland J D, Arriaga E
Cardiovasc Res Cent Bull. 1974 Jul-Sep;13(1):3-7.
The use of a catheter-tip microphone is described for the detection of heart sounds in the esophagus. The intensity and quality of the sounds differ from those detected on the precordium. Individual valve and breath sounds can be attenuated by choice of the location of the microphone in the esophagus. The acoustic shielding provided by the thorax allows presentation of heart sounds with little difficulty from acoustic feedback.
本文描述了使用导管尖端麦克风在食管中检测心音的方法。所检测到的心音强度和质量与在心前区检测到的不同。通过选择麦克风在食管中的位置，可以减弱各个瓣膜音和呼吸音。胸部提供的声学屏蔽使得呈现心音时几乎不会受到声反馈的干扰。
