On the construction of an electronic stethoscope with real-time heart sound de-noising feature

In this paper, we investigate the aspects of constructing an electronic stethoscope with the capability to filter out heart sound from the lung sound pickups in real time. Such a capability is most useful for the clinical diagnosis of pulmonary diseases. The proposed filter design is based on the adaptive line enhancer (ALE) filter structure to be implemented in an FPGA based platform. The DE2-70 development board and Audio CODEC are used in the design. Experiments on a preliminary setup of the proposed design demonstrate its efficacy.