Development of Acoustically Optimized, 3D-Printed Stethoscope for Telehealth

The need for telehealth accelerated by the COVID-19 pandemic has changed the way doctors interact with patients. Recently, Internet-connected stethoscopes have been developed; however, they have not been adopted as far as many companies have hoped. The high cost of branded, high-quality stethoscopes may serve as a barrier to the adaptation, especially in low-and middle-income countries. With the above in mind, a 3D-printed stethoscope that preserves a long air column but still maintains a small form factor has been developed. Inserting a microphone into the stethoscope enables us to connect the stethoscope to our smartphone, turning it into a digital device. To take advantage of smartphone capabilities, we have also developed an Android app that enables us to record, share, and listen to heart sounds in real-time via Bluetooth headphones. Our experimental results show that the stethoscope made of thermoplastic polyurethane exhibits harmonic resonances comparable to commercially available selected acoustic stethoscopes.