微波人体心动信号的研究

【作者】 方晓颖；

【导师】 尹秋艳；

【作者基本信息】 华东师范大学 ， 无线电物理， 2004， 硕士

【摘要】 近年来，生物医学信号的非接触式检测成为国内外生物医学工程领域的研究热点。随着科技的发展和人民生活水平的提高，特别是在近期，健康和生命安全设备受关注，人们对临床医学诊断手段和监护水平的要求越来越高，也越具有人性化。人体心脏运动信息的非接触式测量对临床医学诊断和护理具有重要的意义。本文的主要工作是对检测到的微波人体心动信号进行了分析和处理。文中的微波人体心动信号数据，是利用华东师大电子系和计算机系人员研制的非接触式微波人体心动测量系统，通过探测其前向散射信息，非接触人体测量得到的心动信号。 前向散射式探测系统获取的微波人体心动信号中，携带有心血管器官内部的组织运动信息和血流运动信息，这些信息如何作用于微波载波信号的调制机理非常复杂。传统上以多普勒模型来解释人体心跳对微波载波的调制，仅取用微波人体心动调制信号中的相位调制信息。然而，我们在实验的基础上发现，人体心跳运动同时也对微波载波的幅度产生规律性的影响。本文以有耗分层介质中电磁波的传播模型以及传输线端接可变电阻的模型分析了人体心跳运动对微波载波的调制，阐述了人体心跳运动对微波载波的幅、相调制机理。 认识人体心跳信号的方法主要是对心跳信号的频域分析FFT，傅立叶变换可以帮助认识人体心动波形所反映的心率情况。然而，面对人体心动波形所体现的非平稳特性，FFT的方法存在较多的局限。借鉴在心电信号和心音信号的分析中小波方法的应用，本文提出以小波的方法分析和处理微波心动信号。并在小波的基础上进行了微波心动信号的处理，滤除了叠加在心动信号上的呼吸信号和直流漂移等杂波信号。 在小波分析的基础上，本文利用统计学的方法对微波心动信号的原始波形和小波分析结果进行了相关性检测，在比较的基础上提出了对于微波心动信号的模型假设。从一个方面证明了微波人体心动信号应用于病理检测的可行性。更多还原

【Abstract】 With the improvement of the daily life, Biotechnology has been one of the most hot focuses of people’s attention and there come out many new techniques on diagnose and treatment. A forward scatter microwave telemetry developed by the staffs from the department of electronics and the department of computer science has offered a new method to measure the human cardio information. In this paper, the data acquainted on this system was brought to research and process.The information obtained by the forward scatter system schleps more information from the inner movment of human heart and vain. The information effects the microwave carrier in a quite complex way. Traditionally the Doppler theory is used to explain the modulation, and phase modulation is considered the main effection. In this paper, two more modulation model is detailed and it is pointed out that the process how the human heart movement modules the microwave carrier on voltage and phase.The method usually used in analyzing the human cardio signal is Fast Fourier Tranfrom (FFT). FFT method helps to get the heart rate, but in FFT, some particular information of heart would be discarded. Use for reference, the wavelet method is largely used in analyzing the heart signals like ECG and PCG, wavelet method is used to analyze and process the microwave cardio signals.Based on the wavelet analyze, statistics method is also adopted. The correlation coefficients are calculated to estimate the relativity in the signals obtained under different measure condition. A microwave cardio signal model is supposed.At last, the paper conclude the defect in the research work and bring forward the future research work could be expanded.更多还原