The Research Of Artery Elasticity Index Based On Pulse Wave And Its Clinic Application

In China, each year there are 3 million people who died of myocardial infarction, hemorrhagic stroke and other cardiovascular diseases up to 50 percent of total Chinese deaths. Those who survive are about 75 percent of patients with varying degrees of loss of the ability to work, and for more patients the left psychological barriers affect quality of life. China's annually pay the direct cost of approximately 9.7 billion yuan for cardiovascular disease patients'hospital fees and indirect spending amounted to tens of billions. So prevention and treatment of cardiovascular diseases in China has become an important health issue.The basic pathological changes of cardiovascular disease is atherosclerosis, and early change performance of atheroscleros is reduced arterial elasticity function . Arterial elasticity sometimes called arterial compliance whose changes often occur before clinical symptoms appearing and disease is usually changes in lower organ function after clinical symptoms, such as hypertension, atherosclerosis, diabetes, coronary heart disease, etc. After carefully comparing several methods measuring artery elasticity function such as PWV, AI, the large and small artery elasticity index C₁ and C₂, and AOCS , we choose C₁ , C₂ .Because C₁ C₂ especially C₂ can reflect small artery elasticity function and artery endothelial function that other ways, for example PWV, are impossible to achieve. The only instrument in the world which can measurement C₁ and C₂ is the American DO-2020, and all the information about C₁ and C₂ is about the application of DO-2020. About how to acquire the parameters C₁ and C₂ there is no report.In this paper radial waveform is acquired by YF/XGYD-II as research object. The algorithm procedures of C₁ and C₂ is written by LabVIEW after deeply study on the artery double elasticity cavity model. There are four important steps: choosing the optimal wave by wavelet, determining diastolic periodic position, guessing initial values of model parameters, and curve fitting using the famous Levenberg-Marquarat method. And we also do clinical trials, the results are like this: the values of C₁ and C₂ are 15.2±4.0ml/mmHg*10 and 6.7±2.9ml/mmHg*100; and the value of female is significantly lower than male; after 7 days the repeat trial shows that the absolutely margin is related to the first test value of C₁ and C₂ and the larger the first value of C₁ and C₂, the larger the margin. But if do log transformation, the gap will disappear. These results prove our method is basically correct and reliable.