A portable multifunctional electronic stethoscope based on STM32 embedded microprocessor is designed and manufactured. Different types of microphones is compared

and an OB4015 L is selected for the stethoscope application. The structure of the auscultation head is optimized by using finite element simulation

and then an embedded system is built to realize real-time auscultation

storage and playback of heart sounds

volume control and other functions. The collected signals can be further sent to the host computer for waveform display and storage through Bluetooth or serial port. The device has a bandwidth of 600 Hz

which covers the frequency range of the heart sound signal

and an amplification up to 11 times with a signal-to-noise ratio of 51 d B. The device has a portable design with a diameter of 6. 5 cm and a weight of 122 g. Compared with the traditional mechanical stethoscopes

the electronic stethoscope can not only realize the auscultation function and clearly reflect the weak biological signals of human body

but also has unique advantages in digitalization and intelligentization.