Investigation of acoustic spectrum in a simplified model of aortic valve stenosis

In classifying heart murmurs, a qualitative approach is usually employed where the “pitch” and “volume” of the murmur is identified by a medical professional. The production of this sound is a result of the narrowing, or stenosis, of the aortic valve. This study aims to provide a quantitative assessment of a narrowing in a pulsing flow, modeled after the heart and aortic valve. It is desirable to find a non-invasive technique to assess the severity of aortic valve stenosis. Utilizing dynamic similarity to match our model with the healthy human heart, a set of 3D-printed restrictions will be tested at varying Reynolds numbers to assess the intensity of the acoustic spectrum. These model restrictions span the range of a healthy aortic valve to a severely restricted valve, and the Reynolds numbers are varied to match the corresponding flow associated with these restrictions. Through a spectral analysis of a sound signal obtained by a contact microphone, a relationship between the dominant frequencies and the narrowness/flow conditions will be formed and investigated. This will form a basis for future understanding of the severity of actual heart murmurs in relation to their acoustic signatures.