A group of Japanese researchers are developing a medical app designed to record and analyze heart sounds and murmurs, using just an external microphone.

Auscultation is a highly technical and subjective bedside skill that can only be mastered through repeated practice. Additional tools for honing that skill, both for trainees and clinicians in practice, could be helpful. We’ve previously covered the Eko device, which can connect any stethoscope to a smartphone enabling recording, sharing, and visualization. Here, Mamorita et al from Kitasato University, developed a medical app that records and, more importantly, helps visualize heart sounds and murmurs on a smartphone, using an external microphone.

Phonocardiograms have been around for more than 50 years. Medical trainees are probably more familiar with them as diagrams that help visualize what different murmurs, reflective of different valvular heart diseases, will sound like when laying the stethoscope on the patient’s chest.

Mamorita et al, from Kitasato University in Japan, developed a medical app designed to capture phonocardiograms using a smartphone. In this study, they used sounds captured through either an external microphone connected to a smartphone or an external microphone alone.

They tested their app on 26 different heart sounds on a human patient simulator. The most intriguing finding of this study is how similar the waveforms generated by the external microphone alone were to those generated with a stethoscope across numerous types of valvular heart disease. While there could be educational value here, helping trainees link the waveforms they saw in textbooks to what they are actually hearing, the diagnostic value is intriguing. We can’t help but wonder whether, with the right reference dataset and analytics, such a medical app could be developed into a low cost screening tool for valvular heart disease.