Research On Non-invasive Measurement System Of Blood Pressure And Arterial Stiffness

Cardiovascular disease, one of the serious diseases harms the human health, isnamed as the first killer of human health in the 21st century by World HealthOrganization. The formation of the disease is long and it is essentially caused by thestructural or functional abnormity of the blood vessel. It begins with the sub-healthystate while a series of cardiovascular parameters, such as blood pressure, vesselstiffness and so on, have begun to change. Therefore, early detection of thesecardiovascular parameters can forecast the cardiovascular disease. The issueresearches about the measurement methods of blood pressure and arterial stiffness todesign a non-invasive portable blood pressure and vascular hardness testing systemused in day-to-day family health care. Paper includes algorithm study on bloodpressure and arterial stiffness, the design of measurement system and related clinicalverifytrials.Research takes vessel pulse-wave theory, the methodology of cardiovascularfluid dynamics and Windkessel Model as the basis, takes arterial stiffness index (ASI)as an indicator of the standard of atherosclerosis (AS) in the vessel, and usesOscillometric method to measure it. When the measurement system is designed,characteristics of the pulse wave are well considered to improve the accuracy andconsistency. So, to process the signal, filters and amplifiers are used in hardwareindicator, anti-jamming methods, smooth are used in the software design. The designcan not onlyuse in the experiment, but also in future product design.To identify the accuracy and repeatability of system performance, clinical trialsare operated. The results showed that the value of the vessel stiffness index tested bythe designed system is well related to the index gived by color Doppler Sonography,the correlation coefficient is greater than 0.6. ASI can well point out the trend of thevascular atherosclerosis. Paper also uses the results of the color Doppler Sonographyto identify ASI threshold and grades. So the system can monitor the human dailyatherosclerosis condition and give an earlywarning when necessary.In addition, the primary study of atherosclerosis testing based on pulse wavemethod is conducted in the issue too. The feasibility of the use of pulse wavecharacteristics parameters K and vascular expansion coefficient ETK derived frompulse wave parameters to identify the atherosclerosis degree is discussed. The related experiment proved that K can better express the arteries atherosclerosis condition.