| Nowadays the Cardiovascular disease(CVD)is a kind of disease with the highest mortality rates in developed countries and our country.Therefore,it is very critical to carry out the early risk screening,early warning,and health managing of CVD actively.In recent years,numerous studies have shown that many cardiovascular parameters(CVPs)are closely related with CVD,and when some cardiovascular diseases(such as high blood pressure,arteriosclerosis)are in the initial stage,some CVPs,such as vascular resistance,blood pressure,blood vessels elasticity,and blood viscosity,have changed though there are no self-conscious symptoms for patients.Therefore,how to accurately achieve more CVPs with a non-invasive method has always been a hot topic of research.At present,although there are many testing instruments or equipments(such as atherosclerosis detector and blood pressure meter)for CVPs with noninvasive method,they can obtain few CVPs relatively or are too bulky to be carried.Therefore,it is not good or inconvenient for early risk screening and warning of cardiovascular disease.Based on these,this study aims to provide a new acquisition method of cardiovascular information and present its new information extraction method for obtaining more significant CVPs.In medical research field,it is an effective mean to study the structure and function of organs or tissues by stimulating them and observing their response.Through the comprehensive analysis of existing literature,the following reults can be obtained.it is possible that more CVPs with clinical values can be acquired by both stimulating blood vessels in some particular parts with noninvasive means and synchronously collecting the relative signals,which cover ECG,heart sounds,the pressure pulse wave,finger volume wave,finger double-wavelength pulse wave for blood oxygen saturation and the others.And this is expected to improve the measurement accuracy of some CVPs,such as blood pressure and pulse wave velocity(PWV).Additionally,it can provide necessary data for the study on cardiovascular models and numerical simulations.Furthermore,if there is some abnormalities in the cardiovascular system,especially on one side of subjects,the stimulus may make them more prominent or obvious.Based on these,this paper presents a new noninvasive acquisition platform and an information extraction method of cardiovascular information.The main research contents and results of this article are shown as follows:(1)A novel acquisition platform of cardiovascular information with a noninvasive method has been developed.The innovation points of this platform are mainly reflected in the following three aspects.Firstly,the information acquisition platform can effectively complete the synchronous collection of 24-channel signals related with cardiovascular when the specific stimulations are applied to blood vessels.And this is beyond the scope of the peer instruments.Secondly,in this study,the whole information acquisition is creatively divide into 22 sub-processes,which incorporate a no additional pressure,9 gradual decrease pressures and 12 constant pressures in the air belts.These subprocesses are helpful to obtain more CVPs through different external stimuli by contrastive analysis(covering among different subprocesses of the one side and between the left and right sides).These are the biggest difference from existing equipment.(2)Research on the collection process and information extraction method of cardiovascular information.Firstly,the specific collection process of cardiovascular information and the purpose of each specific process are described in detail.Secondly,this paper expounds the specific methods of extracting information from time domain and frequency.Finally,the significance and calculation method of CVPs are described in detail.CVPs calculated in this article mainly include the parameters presented by other studies and this research.Among them,the parameters mentioned in other studies include blood pressure,K value,the maximum-amplitude rate between the first heart sound and the second one,etc.And the new CVPs proposed in this study cover the ratio,,between the maximum amplitude differences of pressure pulse waves about same side during the respective whole processes that gradually reduce the air pressure is given on one side and both sides,the ratio,,between the maximum variable rate of pressure pulse waves under the same condition,the ratio,,between the maximum variable rates of pressure pulse waves about left and right side during the apiece whole subprocess that gradually reduce the air pressure is given on both sides,four new parameters related with heart sounds(_/?_/?_/?_/),four double-wavelength novel parameters about blood oxygen saturation(ROSdec ROSinc ROSmax,ROSmin),and the frequency-domain new parameters(such as the ratio of the average amplitude of 1-10 times heart rate(HR)to the maximum value),etc.The acquisition of these new parameters shows the superiority of the information acquisition and research methods.In addition,it is worth pointing out that some new CVPs,such as waPWVmcr???ROSdec?ROSinc?ROSmax?ROSmin and others,are not available in the existing detection methods.(3)Test results and discussion.This part is carried out in three stages.Firstly,the cardiovascular information about a subject was collected by the platform.The results of the extracted parameters about each cardiac cycle in every process were exhibited in detail,and they also were discussed.Secondly,the information of 92 subjects were acquired by the platform.According to the distribution of age,the information of eight typical subjects was selected from the 92 subjects to be analyzed,and some important analysis results were expounded and discussed comprehensively.Thirdly,18 volunteers of three age groups were organized and compared with clinical tests,and the results were compared and analyzed.And all results of the three stages were shown as follows:1)The platform can effectively control the pressure of six air belts placed on the two-side arms,wrists and ankles,and can synchronously collect 24 dynamic signals during the 22 effective processes.And it has a good stability and reliability.2)For every subjects,this platform not only can effectively extract information according to the 22 sub-processes separately,also can comprehensively analyze the important information of the relative parts.Additionally,the personal basic information and some important information of comprehensive analysis can be summarized to provide a convenience for facilitating the further excavation of cardiovascular information by other softwares.3)The analysis results of the collected cardiovascular information about the single subject suggested that the application of this platform and the information extraction method proposed in this study can obtain more CVPs.Among them,some are relatively stable and some are changed regularly under some specific stimulation conditions.For example,in each analysis period,the time from R wave of the electrocardiogram to the maximum variable rate(MVR)of the 8-channel signals has a good stability.Under the same stimulation condition,the distributions of many time-and-frequency domain parameters about each signal on the left and right sides of the subject have a good consistency.When the pressure is given on one-side arm or wrist,the double-wavelength direct current(DC)signals of the other-side finger blood oxygen saturation will produce obvious change over time,and the change of amplitude and rate maybe reflect the regulation about blood supply of the left and right arm of the human body itself.etc.4)The collectted information and analysized results about the eight typical subjects indicate:The first,baPWVmcr,which was calculated through the time from R wave to positive MVR of pressure pulse wave has a better stability,and has an incremental trend along with the age increasing,which is in accordance with the change trend of brachial-ankle pulse wave velocity(baPWV).Second,in the sub-process 1(SP1),the distribution of the ratio of the average amplitude to the maximum one of the volumetric wave signals in the frequency domain at vicinity of each time heart rate maybe well reflect the condition of vascular sclerosis.Third,the same air-belt pressure produces different influence on the pressure pulse of different subjects,and these differences should be related with blood flow and blood vessel elasticity of the subjects,so some new cardiovascular parameters are likely to be obtained through the analyzing these differences.5)The test results of clinical comparison tests reveal:a)The baPWVmcr and waPWVmcr prosposed in this study have a good stability,and which are consistent with baPWV measured in clinical BP-203RPE III,but it is more convenient to measure waPWVmcr.In addition,the ABI and heart rate measured in this study are basically in accord with the ABI and heart rate tesed by BP-203RPE II.The systolic and diastolic blood pressure gainded by this study are also basically the same as that acquired by OMRON HEM-8102A.These confirm that the performance of the cardiovascular information acquisition platform advanced in this study is stable,reliable,and the information extraction method is feasible and correct.b)The value of some new parameters raised in this paper is related to some abnormalities of the subjects,which is worthy of further study about their clinical significance.For instance,the baPWV of the subject 6 is an unusually large in the same age group,while her many new parameters(TP?TP?and RA,etc.)take on abnormalities;The larger differences of the multiple new parameteres(the maximum amplitude and the average amplitude of one time HR,t of one time HR,the ratio of the energy from 0.5 to 6.5 times HR and total energy during some processes,etc.)about pulse wave of arms,wrists and fingers of subject 4 exist between left and right sides,and which indicate that her the vascular elasticity or blood flow in the left and right sides of the upper limbs is significantly different.Mild aortic valve closure of subject 13and 17 is not complete,their new parameter,_/,is bigger than other subjects.But the values of other two new parameters,_/?_/,of heart sounds are relatively larger for the subjects 13,and which suggests that there are other problems with her.In summary,the new noninvasive acquisition platform of cardiovascular information in this paper can give corresponding stimulation to vessel effectively and collect 24-channel dynamic signals synchronously.Furthermore,many CVPs can be extracted by proposed method,and some of them Some new parameters are worthy of further study.So,it not only can be used to further study on the inner relationships among ECS,heart sound signal,pulse signal and the others,but also can be applied to research on the relationships among CVPs,CVD and the collected signals.Meanwhile,a new model of data analysis is expected to be established on the basis of comparison with more clinical detection results.And the platform also can provide necessary data for the study of cardiovascular model and the others.Additionally,the signal acquisition platform can also provide a theoretical and practical foundation for developing a more effective,noninvasive,safe and reliable cardiovascular function test system or device that based on the internet of things and is suitable for the community hospitals and families. |
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