Design, testing and modification of a low-cost electronic stethoscope to aid in auscultation during pneumonia diagnosis in children under five.

Abstract

The diagnosis of pneumonia relies primarily on the presented clinical signs and symptoms. One of the parameters investigated during the diagnosis is the patient’s lung sound, during which a stethoscope is used. The mechanical stethoscope is the most commonly used device by doctors, although it is faced with shortcomings such as low amplification. Digital stethoscopes are also used, but the high cost of the device limits their usage in the diagnostic process by doctors. To solve this issue, a low-cost electronic stethoscope has been developed to aid in the auscultation process. Preliminary tests on the first prototype showed fairly satisfactory results, although some modifications were needed to achieve an ideal functional device for clinical use during auscultation. The modifications to the system included a redesign of the microphone preamplifier system in order to improve the amplification of the sound signals and eliminate noise. A microcontroller unit, ATmega644 was also incorporated into the system to act as the central component, guiding the majority of the functions, such as volume control and real-time audio processing. The MCU would allow for more precise control of the filtering parameters. An audio jack port was also added to the system to allow for the use of headphones or headsets, especially when there is background noise involved. Finally, a casing for the circuit systems is also proposed, with ABS plastic being looked at as the material of choice. These modifications have the potential to improve the way pneumonia and other respiratory diseases are diagnosed during auscultation.