Ultrasoic Simulation Model Of Detecting Carotid Pulse Wave Velocity Based On QA Method

With the continuous development of the national economic society,the material living standards of the public will also continue to improve.At the same time,the morbidity of cardiovascular and cerebrovascular disease,such as hypertension,hyperlipemia and coronary disease,has been increasing.And the mortality induced by cardiovascular and cerebrovascular disease also shows an increasing trend.Studies indicate that arteriosclerosis is the main reason for the occurrence and development of such diseases.Pulse wave velocity(PWV)can be used to quantitatively reflect the degree of arterial sclerosis,which could be further used for the evaluation of the disease condition,so it is significant to detect PWV accurately for the effective prevention and treatment of cardiovascular disease.Ultrasound is widely used in medical diagnostic technology since it is noninvasive,repeatability and without strict requirements for the detection conditions and the environment.Many scholars have systematically studied the use of the transit time(TT)method to detect local PWV,but there are few reports with regard to the flow area(QA)method based on ultrasound radio frequency signals.In order to systematically carry out detection of local PWV based on QA method,it is necessary to provide an effective detection data source.Therefore,this study utilizes the Field II ultrasound software toolkit to develop an ultrasound simulation model for the detection of PWV of carotid arterial based on QA method.At first this study simulates the normal blood vessel velocity profile and the wall pulsation of carotid artery,and then presents the simulation model of blood vessel which includes blood flow and wall pulsation based on ultrasound radio frequency signals.The specific processes are as follows,using the ultrasonic Doppler to obtain the velocity of the tube axis,calculating the pressure gradient in the vessel to obtain the blood flow velocity profile,using the QA method to process the data of the blood flow velocity and the wall pulsation according to the default value of PWV.Meanwhile,the scattering point models of intravascular blood flow and the vessel wall are established according to the velocity profile and the curve of the wall pulsation,respectively.Then the scattering models of the vessel wall and the blood flow are integrated into a complete vessel model which is used to simulate the ultrasound radio frequency signals by Field ?.In the experiment,the ultrasound radio frequency signals are processed to obtain the curve of the wall pulsation and the velocity profile of the blood flow.The changes of blood flow and the cross-sectional area are calculated to obtain the value of PWV which are used to compare with the default value.The results show that the blood flow velocity profile and curve of the wall pulsation obtained by processing the ultrasound radio frequency signals accord with the theoretical value well and the normalized relative error of the PWV estimation is 0.11 ±0.02,which prove the validity of the Q A model.This study provides an effective means for systematically conducting the detection of local PWV based on QA method.