Embedded heart sounds and murmurs generator based on discrete wavelet transform

One of the most important problems of biomedical engineering is how to obtain realistic data of patients with different clinical situations because of the difficulty of finding unhealthy volunteers and getting ethical approval for any experimental test on patients. This paper presents a practical generator of heart sounds and murmurs for educational and research purposes. The developed generator produces graphical representations of normal and two diseased heart sounds; namely aortic stenosis and mitral insufficient. Three datasets of real heart sounds have been preprocessed using discrete wavelet transform, in order to reduce the noise and decompose these cardiac signals to the third approximated level based on Daubechies four-coefficient wavelet. For the design and implementation of the heart sounds generator, the ATmega 2560 microcontroller was used to produce the output of all preprocessed datasets. The developed embedded generator showed successfully different cases of the heart sounds and murmurs, allowing to be used further for evaluating new automatic classification methods of cardiac valve abnormalities.