The Research And Application Of The Visualized Stethoscope Based On The Android Platform's Smart Phone

Current the disease of heart system is becoming the first killer to human health, and had already aroused a high degree of concern and attention. So, the early, timely and accurate diagnosis of cardiovascular disease has become an important research content. Heart sounds signal is one of the most primary physiological signals, including the physiology and the pathology information of heart each part and mutually affection between themselves. The auscultation is one of the most important ways to examine the health state of heart. It is convenient to analyze the heart sounds and extract the characteristic parameter for doctors to obtain basic information of heart and make more exact diagnosis.After analyzing and summarizing the related studies of the home and abroad, our own research group as well, applying the detection and processing technology of heart sounds signal to the Android Smartphone, the thesis has represented a preliminary design of a multi-functional Smartphone heart sound visible examination software system, which includes the gathering, storing, diagnosing, displaying, transmitting of the heart sounds signal.According to the characteristics of the heart sounds signal, a simple way utilizing average heart rate and envelop of heart sound energy to segment the heart sound with murmurs and extract features of that is proposed. By using this method, energy envelop firstly is extracted from the energy diagram of heart sound's internal energy. Then easily-identified square diagram could be gotten after signal pretreatment by setting up a threshold. Through the calculation of average heart rate, S1 and S2 are preliminarily extracted.For reasons of the limited hardware and software resources of Smartphone, further reducing calculation complexity as well, the way calculating heart sound features is being developed---locating S1 and S2, major components of heart sound signal, by means of sample binarization and calculation of heart sound features with proper window value. The improved one gets less calculation complexity and quantity, faster speed and higher accuracy, which is appropriate to be put into effect on Smartphone. As to the software, a multi-functional Smartphone heart sound visible examination software system including the gathering, storing, diagnosing, displaying, transmitting of the heart sounds signal is successfully operated on Google Android Smartphone Gl. This topic opens up a new way which unifies Smartphone and the detection and processing of the heart sounds signal, making auscultation popular, portable, and perceivable. It is an effective method to realize the prompt diagnosis of the heart system disease anytime and everywhere.