Study On Evaluation Method Of Cardiovascular System Based On Noninvasive Detection Of Blood Pressure And Pulse Wave Of Limbs

Noninvasive detection technology of cardiovascular disease has been applied on clinical,but many patients are still not undetected and delay the treatment period due to the fact that the early clinical symptom of cardiovascular disease is not obvious.In addition,the current evaluation index and methods of cardiovascular function have failed to form a complete evaluation system,which lead to the poor execution of the application on health management and disease warning of cardiovascular.Therefore,this paper aims to create the cardiovascular system noninvasive evaluation method based on limbs blood pressures and pulse.The main research includes three aspects,research on noninvasive detecting algorithm of cardiovascular system based on limbs blood pressures and pulse,research on cardiovascular disease risk factors by clinical epidemiological cross-sectional study,and research on cardiovascular health evaluation system based on the fuzzy mathematics method and noninvasive index.Noninvasive evaluation methods of cardiovascular function can service the early check-up of cardiovascular disease broadly.The specific research contents were as follows.(1)Research on noninvasive detection algorithm of the cardiovascular system based on limbs blood pressures and pulse.This paper proposed a noninvasive detection algorithm on the base of radial artery nonlinear pulse wave theory.Mathematical models were established between pressure of ankle artery and brachial artery and pulse wave velocity,between wave velocity and pressure gradient,between pressure gradient and the blood flow in algorithm.Numerical solution of the limbs blood flow was calculated by numerical analysis in different time of cardiac cycle.The correction coefficients of limb blood flow were calculated by medical statistics analysis.A blood flow equation was fitted out in different time of cardiac cycle,then the average blood flow and blood flow were calculated.Cardiovascular function parameters were derived on the base of average blood flow.Consistency of cardiovascular function parameter was tested by Bland-Altman analysis between calculated value and clinical experimental data.Calculation results showed that the brachial artery blood flow was within the clinic reference scope,and ankle artery blood flow was higher than brachial artery blood,which is accorded with the practice of clinical.Consistency of cardiovascular function parameter was verified between calculated value and clinical experimental data.The noninvasive detection algorithm based on limbs blood pressures and pulse can also be used to calculate the cardiovascular function parameter,and it can be used in cardiovascular noninvasive detection.(2)Research on risk factors of cardiovascular disease based on clinical epidemiological cross-sectional study.The staff of Beijing University of Technology were as the research object.Limbs blood pressures,pulse waves and cardiac hemodynamic parameters were collected using cluster random sampling in resting.The statistical analysis of research object was completed by cross-sectional study.Cardiovascular function evaluation index was proposed according to the cross-sectional study,and it was helpful for the construction of cardiovascular noninvasive evaluation system.The results were as follows.1)Age,body mass index(BMI)and blood pressure were the main affecting factors of cardiovascular function parameters.2)There was no statistically significant difference for majority cardiovascular function parameters and limbs blood pressures for people of the same age but different gender.There was statistically significant difference for 14 cardiovascular function parameters except the functional index of Left ventricular and left ventricular end diastolic pressure in different age groups,and cardiovascular function parameters declined with age except total peripheral resistance.3)Hypertension with atherosclerosis had a larger influence for cardiovascular function in the same age,while the same kind of disease had a larger influence for cardiovascular function with age,which was not ruled out the cardiovascular physiological function decrease with age.4)Cardiovascular function parameters(cardiac pumps blood,cardiac diastolic and blood vessel elasticity)had statistically significant difference with limbs blood pressures,cardiovascular function parameters reduced with age except total peripheral resistance,and blood pressure parameters increased with age except the ankle brachial index.A part of the cardiovascular function parameter had statistically significant difference with limbs blood pressures between different groups,there was still statistically significant difference after excluding hypertension,but the correlation coefficient reduced or even disappeared.5)The detection rate of cardio-ankle vascular index(CAVI)was higher than stethoscopy in hypertension for elderly people older than 60 years,and the difference was statistically significant.In conclusion,age,BMI and blood pressure were the main affecting factors of cardiovascular function parameters,age was an uncontrollable factor,hypertension was the predictive risk factors for cardiovascular function parameters.Limbs blood pressure differences could evaluate the health of the cardiovascular function,and prompt the doctor to pay more attention to limbs blood pressures for the aged especially systolic blood pressure changes between arms.The detection rate of CAVI was higher than stethoscopy in hypertension for elderly people older than 60 years,and the further examination should be advised for patients when the CAVI was higher than 8.35.(3)Research on cardiovascular health evaluation system based on noninvasive index and fuzzy mathematics.Cardiovascular function evaluation indexes were established based on the risk factor of cardiovascular function parameters.Twelve indicators weights were completed using the analytic hierarchy process(AHP).Membership function,evaluation matrix set and comprehensive appraisal matrix of evaluation system were established using the fuzzy mathematics.Early warning and assessment of cardiovascular health system was preliminarily realized by Matlab software.In conclusion,noninvasive detection algorithm can be used to calculate the cardiovascular function parameters based on blood pressure and pulse wave of limbs.Therefore,the algorithm accomplished the noninvasive detection of cardiovascular function.Noninvasive detection indicators of cardiovascular function were built based on epidemiological statistical analysis and the international accepted risk factors for cardiovascular disease,and scientific mathematical methods were applied to implement cardiovascular health comprehensive evaluation based on these indicators.The completion of these two points was to realize the noninvasive detection,prediction and assessment of cardiovascular health.It could provide a noninvasive,convenient,economical and practical tests method of early examination of cardiovascular health for all people.