Audio-visual tools for computer-assisted diagnosis of cardiac disorders

The process of interpreting heart sounds is restricted by human auditory limitations. Shortcomings such as insensitivity to frequency changes, slow responses to rapidly occurring changes in acoustic signals and an inability to discriminate the presence of soft pathological sounds are the source of inaccuracies and persist even with experience. This restricts both the practice and teaching of auscultation. In this paper we propose and evaluate a suite of presentation tools for computer-assisted auscultation. We explore the use of digital signal processing techniques to slow down heart sounds while preserving frequency content, differential enhancement across frequency scales to amplify pathological disease signatures, visualization of the signal to measure changes in signal energy across time and presentation of a representative prototypical signal for the patient.