一种评估肱动脉内皮功能的电阻抗信号检测与分析系统

Detecting and Analyzing System for Brachial Artery Endothelial Function

动脉内皮功能受损或者功能障碍是动脉硬化早期的主要表现。定量评估肱动脉内皮功能有助于及时发现心血管功能异常,从而为心脑血管疾病的早期诊断和治疗提供一定的依据。目前临床上主要采用彩色超声多普勒技术检测肱动脉血流介导扩张(FMD)来评估肱动脉内皮功能。虽然这种检测方法精确度与分辨率更高,但设备相对昂贵,操作复杂。本文提出一种基于前臂电阻抗信号的肱动脉内皮功能检测与分析系统。该系统通过检测FMD实施前后前臂的生物电阻抗信号,并运用小波分析技术对前臂生物电阻抗信号的特征参数进行分析计算,包括特征频率、绝对能量、平均幅值,以及FMD实施前后这些特征量的相对变化率。由于FMD实施前后前臂电阻抗信号的变化主要由前臂动脉管径的变化引起,因此,本文提出的前臂电阻抗信号检测与分析系统为定量评估肱动脉内皮功能提供了一种新思路。与目前临床上使用的内皮功能检测方法相比,本文提出的电阻抗信号检测与分析系统具有操作简单、经济实用、快速便捷的特点,不仅能用于家庭或社区医疗的监测,并且可以实现在线检测,为进一步研制智能可穿戴电阻抗动脉功能监测仪器提供了一定的方法学基础。

The damage or dysfunction of arterial endothelial function is the primary performance at the early stage of atherosclerosis. Quantitative evaluation of brachial artery endothelial function is helpful to discover the cardiovascular dysfunction in time, thus provides some evidence for the early diagnosis and treatment of cardiovascular and cerebrovascular diseases. To date, brachial artery endothelial function is evaluated at clinic by measuring the brachial flow-mediated vasodilation（FMD） with a Color Doppler Ultrasonography. Although the accuracy and resolution of this method are much higher, its equipment is relatively expensive, and its operation is very complicated. In this study, a detecting and analyzing system is proposed for evaluating brachial artery endothelial function based on forearm biological electrical impedance signal. By detecting forearm biological impedance signal before and after brachial FMD, the characteristic parameters of biological electro-impedance signals, including characteristic frequency, absolute energy, average amplitude and their relative alteration rate, are calculated using wavelet analysis technology. As the changes in the forearm biological electro-impedance before and after FMD are mainly caused by the changes in the brachial arterial diameter, the detecting and analyzing system of forearm biological electro-impedance signal would provide a new idea for evaluating quantitatively brachial artery endothelial function. In comparison with existing methods at clinic, the detecting and analyzing system of forearm biological electro-impedance signal is detection-simpler, cheaper, more practical and convenient, it can not only be used in the family or community medicine, but also realize on-line detection and provide with a methodology base for further development of the intelligent and wearable electrical impedance analyzer for monitoring arterial function.