Study On Several Key Issues Of Non-invasive Cardiovascular Detection Technology Based On Pulse Wave

Cardiovascular disease, which is named as the first killer of human health in the 21st century by World Health Organization, is one of severe diseases which harm the human health. Since the noninvasive cardiovascular detecting technology has many advantages such as free from pain and no risk of infection, it brings great improvements in pain relief and realizes the early diagnosis and therapy of cardiovascular disease. This research focuses on several key issues of non-invasive detection of cardiovascular health state based on pulse wave. The structure of the paper is arranged as follows.Firstly, the modeling theory of cardiovascular system based on system analysis method and the calculation formula of cardiovascular function parameters are introduced.Secondly, the relationship between elastic expansion coefficient of blood vessel (ETK), one of model parameters, and arteriosclerosis is studied. A new method is proposed to estimate directly the arteriosclerotic degree with ETK. Results of clinical experiment show that the correlation coefficient between ETK and results of clinical ultrasound system is 0.76, arteriosclerotic degree can be divided into 4 levels by the value of ETK.Thirdly, a method of improving the recognition precision of characteristic points of pulse wave is studied. A new recognition method of characteristic point of pulse wave is proposed with three Gaussian functions that fit the pulse wave. Results of clinical experiment show that the correlation coefficient between ETK and results of clinical ultrasound system is improved from 0.76 to 0.832 with the method, prove that the method is valid.In the end, the non-invasive cardiovascular detection system is developed based on the modeling theory of cardiovascular system with system analysis method, the system can obtain blood pressure and other cardiovascular parameters at the same time. Clinical experiment is done with the system. Results of Clinical experiments show that the repeatability error of the measuring results is the range of 1%~3%, the correlation coefficients of all measuring results from the system are greater than 0.7 with results of clinical ultrasound system, and prove the credibility of such detection system based on pulse wave.The main innovation work in this thesis mainly includes:1. A new method is proposed to estimate directly the arteriosclerotic degree with ETK, results of clinical experiment show that ETK can be as a quantized index of arteriosclerosis.2. A new recognition method of characteristic point of pulse wave is proposed based on three Gaussian functions that fit the pulse wave, results of clinical experiment show that the measurement accuracy of cardiovascular parameter can be improved.3. A non-invasive detection system for cardiovascular function parameters is developed and can obtain blood pressure and other cardiovascular parameters at the same time. Results of clinical experiments prove the credibility of such detection system based on pulse wave.