Analysis of heart sounds and murmurs by digital signal manipulation

grantor: University of TorontoThis thesis involves the development and preliminary testing of a device for the collection and analysis of heart sounds, with a specific focus on heart murmurs. The device was based on a PC and was programmed using the National Instruments LabVIEW programming language. Modularity and ease of development and distribution were facilitated through this choice of apparatus. The first instrument which was programmed was the Heart Sound Simulator. This was originally developed as a signal source for the testing of the subsequent modules of the program. However, the opportunity to use it as a teaching tool was also recognized, giving this instrument a dual purpose. The heart sound analysis routines begin with data acquisition, for which an existing module was adapted. A Selective Auscultation instrument was programmed to add flexibility to the standard physician's auscultation process. Frequency content estimation of heart sounds and murmurs was facilitated through a Spectral Analysis module. Finally, research into murmur sound isolation was made in the programming of the Signal Subtraction module. Program validation was done using the Heart Sound Simulator, normal, non-pathologic data and pathological data. Results were encouraging, especially with the data manipulation modules. Further developments may be done to improve the performance of the spectral analysis module. Finally, the murmur isolation routine gave some positive indications, but further work is necessary for producing a robust instrument.M.H.Sc