Improved auscultation with a stethoscope using model inversion for unknown input estimation

This paper presents a method for improved auscultation with an electronic stethoscope by estimating and removing the effects of unknown disturbance inputs. By replacing the single transducer in a stethoscope with a dual piezo transducer assembly, it is shown that an inverse dynamic mapping can be used to relate the two measured signals to original directional inputs acting on the stethoscope. Specifically, model inversion is used to estimate and remove physician handling noise from chest sound signals. An experimental test platform which uses a vibration shaker to simulate the desired auscultation signal is used to experimentally demonstrate the feasibility of the dual-piezo stethoscope approach in improving auscultation.