基于波形分析的多种PWV获取系统的设计

主动脉脉搏波速度(aoPWV)是心血管疾病的独立预测因子,但难以采用波形分析方法直接获取,医学界采用颈股PWV(cfPWv)、臂踝PWV(baPWV)、心股PWV(hfPWV)近似代替aoPWV.目前三种指标在国内外均有应用,但三者的差异性尚未得到深入研究.我们设计了一种无创脉搏波检测仪器,同步采集心电、心音和多路脉搏...     

基于超声回波信号的指端脉搏波提取

脉搏波可作为检测人体心血管系统生理病理状态的重要依据。为了验证用超声波测量脉搏波的可能、解决脉搏波的测量部位受限的问题,本研究提出一种从超声回波信号中提取脉搏波的方法。设计一种跟随式超声传感器,用数据采集系统采集指端超声回波信号,经过滤波、选点及小波去噪等处理后得到较为纯净的脉搏波信号;同时采集心电信号以及光电容积脉搏波信号作为参考信号。结果表明,可以从提取的指端脉搏波中准确地获取心率;与同步测得的光电容积脉搏波数据相关系数大部分在0.8以上;波形中的重搏前波、重搏波等细节部分也能明显地表现出来。本研究提出的方法实现了从指端超声回波信号中获取完整可靠的脉搏波信号,为日后获取不同部位的脉搏信号提供了基础。     

脉搏波速度在高血压病早期干预中的临床意义

目的探讨脉搏波传导速度（PWV）与高血压病早期干预的相关性及其相关因素。方法应用脉搏波速度自动测量系统对104例健康人和397例高血压病患者进行肱动脉-踝动脉脉搏波传导速度（baPWV）检测。结果高血压患者的脉搏波传导速度显著高于健康人（P〈0.01）。年龄是影响健康人大动脉弹性功能最主要的因素,年龄、收缩压和脉压与高血压患者的大动脉弹性功能密切相关。结论脉搏波传导速度是敏感反映高血压大动脉弹性的重要指标,年龄、收缩压和脉压是影响baPWV值的主要因素,可作为心血管疾病的一个危险信号,以指导早期预防干预。     

基于心电信号的脉搏波形特征点提取

为寻求一种精确的脉搏波特征提取方法,提取更多的脉搏波形特征,揭示心电脉搏在时域上的相关性,使用MP425数据采集卡和LabVIEW构成的数据采集系统同步采集ECG信号和脉搏波信号,对ECG信号和脉搏波信号进行分析和处理,采用能量算子法检测心电信号R波;基于同步采集的ECG和脉搏波信号,提出一种应用ECG信号的R波和T波来提取Pulse wave的重搏波和峰值的方法.经过分析与实验验证,该方法能准确找到脉搏波波峰和重搏波位置,并具有较强的抗干扰能力,为研究心电脉搏之间的关系提供了一种新的方法.     

基于心电-脉搏波的心血管疾病识别研究

为实现心血管疾病的早期筛查,降低心血管疾病临床检测的成本。本研究基于上肢脉搏波传导速度（PWV）及脉搏波相关血液动力学基础理论,采集了总计51人的脉搏波与心电信号数据,提取了包括3种PWV和脉搏波特征参数总计16个特征参数,将不同的PWV与脉搏波特征组成3个样本特征数据集,分别建立了基于K近邻学习（KNN）和支持向量机（SVM）的心血管疾病识别模型。KNN模型分类准确率为66.28%,SVM模型分类准确率为84.3%,并通过对比不同PWV对模型性能的影响,确定了用于血管评估的最优脉搏波传导速度pwvm。研究表明基于SVM建立的分类模型对心血管疾病识别有一定可靠性,为低成本的心血管疾病早期筛查提供了新思路,也为穿戴式心血管系统监测提供了基础。     

基于单个颈动脉压力波形获取主动脉脉搏波速度的可行性研究

目的评估基于单个颈动脉压力波形分解以获取主动脉脉搏波速度(aortic pulse wave velocity,ao PWV)的可行性,验证该方法是否适用于动脉硬化的早期筛查。方法研究对象为53名无明显心血管病的健康人群[男性22人,女性31人,(58.6±13.7)岁]。利用压力传感器同步获取颈动脉和股动脉脉搏波形,计算颈股动脉脉搏波传导时间(carotid-femoral pulse transit time,cf PTT)和传导速度(carotid-femoral pulse wave velocity,cf PWV)。利用阻抗分析技术将颈动脉压力波形分解为前向波和反向波。通过对前向波和反向波进行相关分析获得主动脉脉搏波传导时间(aortic pulse transit time,ao PTT)和传导速度(aortic pulse wave velocity ao PWV)。评估ao PTT与cf PTT以及ao PWV与cf PWV之间的相关性和一致性。结果基于单个颈动脉压力波形分解获得的ao PTT与实测的cf PTT显著相关(r=0.624,P0.001),组内相关系数为0.621;ao PWV与cf PWV之间的相关系数为0.476(P0.001),组内相关系数等于0.452。老年人(年龄≥60岁,29人)ao PWV与cf PWV间的相关性显著低于中青年人(0.267 vs 0.549,P0.001)。结论基于单个颈动脉压力波形分解获取ao PWV与实测的cf PWV之间只具有中度的相关性和一致性,且在老年人中相关性更低。该方法可能不适用于老年人的ao PWV检测。     

基于血管弹性腔模型的脉搏波发生器的现场可编程门阵列设计与实现

脉搏波中包含着人体心血管系统的生理和病理信息,已有的脉搏波检测设备对心血管疾病的临床诊断与治疗有很大帮助。为实现对脉搏波检测设备性能指标的测试,需要获得准确的波形;然而,现有的信号发生器不能提供精确对应多种生理、病理状态的脉搏波输入信号。本文基于弹性腔理论设计了一种脉搏波发生器,对心血管系统进行建模,得到四种不同阻力条件下波形输出,同时添加噪声选择、设置信噪比(SNR)等功能。由于需要系统具有便携、动态响应好、可扩展性强、低功耗等特点,所以本文采用了现场可编程门阵列(FPGA)作为硬件开发平台,在可编程片上系统(SOPC)开发流程下,完成了脉搏波生成算法设计、外围存储器及用户接口控制。通过液晶屏和触摸屏,用户可通过输入关键参数设定想要的脉搏波,在液晶屏上显示波形,同时输出低电压电压模拟信号。本文设计的脉搏波发生器结构简单,为脉搏波的教学与科研以及采集与诊断设备的检测提供了解决方案。     

脉搏波自动采集系统关键技术的研究

目前的脉搏波波形采集分析系统需要人为干预,其自动化程度低,且受人为因素影响比较大。本文结合心血管血流动力学参数的无创检测理论,利用光调制技术、单波提取以及基线漂移实时滤除等信号处理技术,设计了自动化程度较高的脉搏波自动采集分析系统,实现了脉搏波信号的增益自动调节、波形自动识别、基线漂移的实时滤除及波形的有效性自动判定。此脉搏波自动采集分析系统实现了脉搏波波形的自动采集,且无需人为干预,适宜在社区和家庭中应用。     

一种可监测人体脉搏波的汽车方向盘辅助装置

目的脉搏波的波形特征与心血管疾病密切相关。本文拟设计一种安装在汽车方向盘上的能独立实时监测脉搏波信号的辅助装置,在驾驶员无意识下获取其血流动力学的相关信息,为监测健康状况提供数据支持。方法该装置利用置于方向盘套表面的反射式脉搏波光电传感器采集脉搏波信号。经过滤波、放大和A／D转换,利用嵌于方向盘助力器内的配套装置对脉搏波信号进行数字处理,实现对脉搏波信号周期的确定、心率和平均动脉压数据的计算,以及信号和数据的存储。最后将处理后的脉搏波波形、心率数据及平均动脉压显示在配套装置的液晶显示屏上,还可通过配套装置中的SD卡接口进行数据传输及存储。结果经受试者实际测试,传感器能够准确测出手指脉搏波并输出,使得方向盘套和助力器具有测量脉搏波、心率及平均动脉压的功能。结论该汽车方向盘辅助器可为用户实时监测脉搏波、心率和平均动脉压,帮助使用者实时监测自己的健康状况。     

基于波形时域特征和动态差分阈值的脉搏波传导时间检测算法EI北大核心CSCD

针对传统脉搏波传导时间(PTT)检测方法对脉搏波(PPG)信号幅值变化敏感、计算量大等问题,提出了一种综合波形时域特征和动态差分阈值的PTT检测算法。采用动态差分阈值检测心电(ECG)信号R波,根据波形时域特征缩短脉搏波信号主波检测区间,利用R波检测脉搏波信号主波,从而计算PTT。利用美国麻省理工学院MIMIC数据库和实验室实测数据对上述算法进行验证。结果表明,该方法能够准确地提取特征点并检测出PTT,对实测和数据库样本的PTT检测准确率分别为99.1%和97.5%,效果优于传统检测方法。     

不同糖代谢状态人群的肥胖指标与动脉硬化的相关性

目的研究北京市社区不同糖代谢状态人群的肥胖指标与动脉硬化的相关性。方法用臂-踝脉搏波传导速度(baPWV)反映动脉硬化程度。对北京市石景山区两个社区大于或等于40岁居民进行体格检查,测量体重(weight)、腰围(WC)、体重指数(BMI)、腰臀比(WHR)、腰围升高比(WHtR)及标准化问卷调查、生化和糖化血红蛋白检测、75 g葡萄糖耐量实验及baPWV测量。对数据资料完整及BMI大于或等于18.5 kg/m2的9 080名人员根据75OGTT试验及糖尿病史分为NGT、IGR和DM组,分析BMI、WC、WHR、WHtR与baPWV之间的关系。结果在NGT、IGR、DM组,根据WC、WHR、WHtR分成亚组,中心型肥胖组的baPWV明显高于正常组(P0.01),在DM组内,以BMI作为肥胖标准,baPWV仅在NGT和IGR组内有统计学意义,在DM组无显著差异(P0.05)。在NGT、IGR和DM组内,中心型肥胖指标(WC、WHR、WHtR)与baPWV呈显著正相关(P0.05),BMI仅在NGT组内与baPWV呈正相关,在IGR和DM组内无明显相关(P0.05)。校正年龄、性别、心血管危险因素,通过多元回归分析发现,WHR和WHtR每增加0.1,baPWV则随之升高40.6 cm/s和55.3 cm/s。结论在糖代谢异常人群中,中心性肥胖指标(WC、WHR、WHtR)与动脉硬化呈正相关,较BMI更能反映动脉硬化程度。     

Determinants of Brachial-Ankle Pulse Wave Velocity and Carotid-Femoral Pulse Wave Velocity in Healthy Koreans

The aim of this study was to determine the normal value of brachial-ankle pulse wave velocity (baPWV) and carotid-femoral pulse wave velocity (cfPWV) according to age group, gender, and the presence of cardiovascular risk factors in healthy Koreans, and to investigate the association between PWV and risk factors such as prehypertension, dyslipidemia, smoking, and obesity. We measured an arterial stiffness in 110 normal subjects who were 20 to 69 yr-old with no evidence of cardiovascular disease, cerebrovascular accident or diabetes mellitus. The mean values of baPWV and cfPWV were 12.6 (±2.27) m/sec (13.1±1.85 in men, 12.1±2.51 in women; P=0.019) and 8.70 (±1.99) m/sec (9.34±2.13 in men, 8.15±1.69 in women; P=0.001), respectively. The distribution of baPWV (P<0.001) and cfPWV (P=0.006) by age group and gender showed an increase in the mean value with age. Men had higher baPWV and cfPWV than women (P<0.001). There was a difference in baPWV and cfPWV by age group on prehypertension, dyslipidemia, current smoking, or obesity (P<0.001). In multiple linear regression, age and prehypertension were highly associated with baPWV and cfPWV after adjustment for confounding factors (P<0.001). The present study showed that baPWV and cfPWV are associated with age, gender, and prehypertension in healthy Koreans.

Graphical Abstract

相似文献   

Elevated arterial stiffness in postmenopausal women with osteoporosis

OBJECTIVES: Osteoporosis and increased pulse wave velocity (PWV) are cardiovascular risk factors. We investigated the relationship between PWV and bone mass in the lumbar spine in postmenopausal women. METHODS: We studied the PWV in 95 women; 38 postmenopausal women with normal spinal bone mineral density (BMD), 32 osteopenic postmenopausal women, and 25 osteoporotic postmenopausal women. The brachial-ankle PWV (baPWV) was measured using an automated device. The BMD of the lumbar spine (L2-L4) was measured using dual-energy X-ray absorptiometry. RESULTS: After adjusting for age and years since menopause, women with osteoporosis had a significantly higher baPWV than those with normal BMD (1500 +/- 220 cm/s versus 1340 +/- 215 cm/s; P < 0.05), but no significant differences in baPWV were seen between the osteoporotic and osteopenic groups or between the osteopenic and normal BMD groups. In univariate regression analysis, the baPWV was significantly negatively correlated with BMD (r = -0.450, P < 0.01), and significantly positively correlated with age (r = 0.601, P < 0.01), years since menopause (r = 0.577, P < 0.01), systolic blood pressure (r = 0.295, P < 0.01), and diastolic blood pressure (r = 0.264, P < 0.05), but was not with other variables. In multivariate regression analysis, the baPWV was significantly correlated with BMD (P < 0.05), but not with other variables. CONCLUSIONS: Postmenopausal women with osteoporosis may have elevated arterial stiffness, suggesting that osteoporotic postmenopausal women may have a higher risk of cardiovascular disease.     

Whole-body vibration attenuates the increase in leg arterial stiffness and aortic systolic blood pressure during post-exercise muscle ischemia

Exercise with whole-body vibration (WBV) decreases brachial-ankle pulse wave velocity (baPWV), a marker of systemic arterial stiffness. To examine the effect of WBV on arterial responses, 12 young men underwent three experimental trials: (1) no-exercise control (CON), (2) static squat with WBV, and (3) static squat without WBV (no-WBV). Bilateral baPWV and femoral-ankle PWV (faPWV), carotid-femoral PWV (cfPWV), augmentation index (AIx), first (P1) and second (P2) systolic peaks, aortic systolic blood pressure (aSBP), and heart rate (HR) were assessed at rest, during 4-min post-exercise muscle ischemia (PEMI) on the left thigh, and 4-min recovery. During PEMI, right faPWV increased (P < 0.05) after no-WBV and did not change after CON and WBV. Right baPWV, P2, and aSBP increased (P < 0.05) after both exercise trials, but the increase was lower (P < 0.05) after WBV than no-WBV. The increases in cfPWV (P < 0.05), AIx (P < 0.05), P1 (P < 0.01), and HR (P < 0.05) were similar in both trials during PEMI. During recovery, right faPWV and baPWV remained similar than rest after WBV and CON, but remained elevated (P < 0.05) after no-WBV. Aortic SBP, P1, and P2 remained elevated (P < 0.05) in both exercise trials during recovery, but the levels were lower (P < 0.05) than PEMI. Left faPWV and baPWV were reduced (P < 0.05) from rest in the three trials. CfPWV, AIx, and HR returned to resting levels in both exercises. WBV prevents the increases in faPWV and attenuates the increase in baPWV and aSBP induced by post-static squat muscle ischemia due to an attenuated P2 response.     

Hormone replacement therapy improves arterial stiffness in normotensive postmenopausal women

Objectives: Aortic stiffness, determined by the pulse wave velocity (PWV), is an independent marker of cardiovascular risk. PWV is mainly influenced by age-associated alterations of arterial wall structure and blood pressure (BP). To determine the impact of hormone replacement therapy (HRT) on arterial compliance in normotensive, postmenopausal women, we examined the effects of HRT on PWV. Methods: Fifty-six postmenopausal women aged 50–70 years were recruited into the present retrospective study from the patients visiting our menopause clinic. Twenty-seven women who were prescribed HRT (14 on estrogen alone and 13 on estrogen plus progestogen) for several months to 6 years and an age-matched group of 29 women not on HRT were studied (Study 1). Nine postmenopausal women were also studied before and at 4 weeks of the treatment of estrogen replacement therapy (ERT) (Study 2). Brachial to ankle PWV (baPWV), which is correlated with aortic PWV, was determined using an automatic device, BP-203PRE. Results: In Study 1, PWV was significantly correlated with age in both groups (controls: r=0.392, P=0.035; HRT group: r=0.471, P=0.013), and HRT significantly lowered the PWV value at all ages examined (Mean±S.D. of baPWV in controls: 1382.2±114.1; HRT: 1245.3±124.8, P=0.0001). In Study 2, baPWV decreased significantly after ERT (P<0.05), without a significant change in systolic BP (P=0.851). Conclusions: Estrogen appears to improve arterial compliance independently of BP within 4 weeks.     

Development of a novel pulse wave velocity measurement system: Using dual piezoelectric elements

The aim of this study is to develop a painless system of measuring the brachial-ankle arterial pulse wave velocity (baPWV) without compression cuffs. The PWV reflects the compliance of the artery and is measured for the early diagnosis of arteriosclerotic vascular diseases. However, the conventional baPWV system, which measures four cuff pressures simultaneously, easily causes circulation block and tightening pain at the extremities. In addition, approximately 15 min are required to stabilise the blood pressure for re-examination. Therefore, we developed a novel baPWV measurement system using dual piezoelectric sensor elements. The principle of this high-sensitivity pressure pulse detection system is based on adding the two in-phase outputs from the coaxially arranged dual piezoelectric sensor. As our system facilitates the measurement of the baPWV by detecting the pulsation of an artery using sensors fixed on the skin where the pulse is palpable, it does not cause pain and reduces examination time. The coefficients of correlation between the baPWV values obtained from the conventional and present methods were 0.93 (right side) and 0.90 (left side). The results suggest that our system can be used to measure the baPWV without pressure cuffs as accurately as the conventional method.     

Non-invasive assessment of carotid PWV via accelerometric sensors: validation of a new device and comparison with established techniques

Purpose

Carotid pulse wave velocity (PWV) is considered as a surrogate marker for carotid stiffness and its assessment is increasingly being used in clinical practice. However, at the moment, its estimation needs specific equipment and a moderate level of technical expertise; moreover, it is based on a mathematical model. The aim of this study was to validate a new system for non-invasive and model-free carotid PWV assessment based on accelerometric sensors by comparison with currently used techniques.

Methods

Accelerometric PWV (accPWV) values were obtained in 97 volunteers free of cardiovascular disease (age 24–85 years) and compared with standard ultrasound-based carotid stiffness parameters, such as carotid PWV (cPWV), relative distension (relD) and distensibility coefficient (DC). Moreover, the comparison between accPWV measurements and carotid-femoral PWV (cfPWV) was performed.

Results

Accelerometric PWV evaluations showed a significant correlation with cPWV measurements (R = 0.67), relD values (R = 0.66) and DC assessments (R = 0.64). These values were also significantly correlated with cfPWV evaluations (R = 0.46). In addition, the first attempt success rate was equal to 76.8 %.

Conclusions

The accelerometric system allows a simple and quick local carotid stiffness evaluation and the values obtained with this system are significantly correlated with known carotid stiffness biomarkers. Therefore, the presented device could provide a concrete opportunity for an easy carotid stiffness evaluation even in clinical practice.     

不同年龄段临界高血压人群大动脉弹性的临床研究

目的探讨不同年龄段临界高血压人群大动脉弹性的变化。方法应用科林BP-203RPEII（VP-1000）动脉弹性测定仪检测大动脉弹性,即脉搏波传导速度（PWV）。对210例临界高血压人群进行PWV检测;同时,检测189例理想血压（BP〈120/80mmHg）的PWV进行对照。评价临界高血压人群大动脉弹性的变化。结果 210例临界高血压人群年龄〈40岁、40～岁、50～岁、〉60岁组男性的PWV分别为（902±102）cm/s、（973±113）cm/s、（1045±152）cm/s、（1221±185）cm/s,各年龄组女性PWV分别为（915±114）cm/s、（945±136）cm/s、（1038±168）cm/s、（1215±201）cm/s,男女各年龄组两两比较差异均有统计学意义（P〈0.05）,显示PWV随年龄增大而增加。与理想血压人群相比,临界高血压人群PWV较高,差异有统计学意义（P〈0.05）。结论临界高血压人群与理想血压人群相比大动脉弹性已有下降,这种改变随年龄增大而加重。