An Active Noise Control Stethoscope

The objective of the proposed work is to develop an electronic stethoscope that enables emergency medical personnel to check vital signs in the presence of high background noise levels. Often physicians in military vehicles and other noisy environments are unable to auscultate. The relevant stethoscope audio signal becomes unintelligible when masked by prohibitively loud noises. The proposed electronic stethoscope will allow physicians to clearly hear sounds used to monitor the lung, heart, and blood pressure of patients. The design of the electronic stethoscope incorporates active noise control and adaptive digital signal processing technology. A functional breadboard prototype has already been developed for removing cyclical or repetitive noise. During Phase I of the project, the software used by the controller will be combined with previously developed algorithms for cancelling (non-eriodic) noise. A detailed cost analysis of the targeted commercial project will be made. Several specific noisy environments of interest will be simulated in the laboratory. Demonstrations of the activ enoise control gbreadboard prototype will be given to stethoscope manufacturing companies in an effort to obtain a contingency commitment for follow-on support and licensing at the completion of Phase II.