Mamorita Noritaka, Arisaka Naoya, Isonaka Risa, Kawakami Tadashi, Takeuchi Akihiro
Department of Medical Informatics, School of Allied Health Sciences, Kitasato University, Sagamihara, Japan.
Cardiology. 2017;137(3):193-200. doi: 10.1159/000466683. Epub 2017 Apr 26.
Auscultation is one of the basic techniques for the diagnosis of heart disease. However, the interpretation of heart sounds and murmurs is a highly subjective and difficult skill.
To assist the auscultation skill at the bedside, a handy phonocardiogram was developed using a smartphone (Samsung Galaxy J, Android OS 4.4.2) and an external microphone attached to a stethoscope.
The Android app used Java classes, "AudioRecord," "AudioTrack," and "View," that recorded sounds, replayed sounds, and plotted sound waves, respectively. Sound waves were visualized in real-time, simultaneously replayed on the smartphone, and saved to WAV files. To confirm the availability of the app, 26 kinds of heart sounds and murmurs sounded on a human patient simulator were recorded using three different methods: a bell-type stethoscope, a diaphragm-type stethoscope, and a direct external microphone without a stethoscope. The recorded waveforms were subjectively confirmed and were found to be similar to the reference waveforms.
The real-time visualization of the sound waves on the smartphone may help novices to readily recognize and learn to distinguish the various heart sounds and murmurs in real-time.
听诊是心脏病诊断的基本技术之一。然而，心音和杂音的解读是一项主观性很强且困难的技能。
为辅助床边听诊技能，利用智能手机（三星Galaxy J，安卓操作系统4.4.2）和连接在听诊器上的外置麦克风开发了一种便捷的心音图仪。
安卓应用程序使用了Java类“AudioRecord”“AudioTrack”和“View”，分别用于记录声音、重放声音和绘制声波。声波实时可视化，同时在智能手机上重放，并保存为WAV文件。为确认该应用程序的可用性，使用三种不同方法记录了人体患者模拟器上发出的26种心音和杂音：钟型听诊器、膜型听诊器以及不带听诊器的直接外置麦克风。对记录的波形进行主观确认，发现其与参考波形相似。
智能手机上声波的实时可视化可能有助于新手轻松实时识别并学会区分各种心音和杂音。
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