基于近红外光谱法的驾驶员误踩操作脑功能连接特性分析

发布时间：2018-01-27 06:58

  本文关键词： 误踩操作 近红外光谱 小波变换 脑功能连接　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：近些年随着汽车保有量的增加,年轻驾驶员的比例在逐步上升,因此道路交通安全也成为大众关注的焦点。年轻驾驶员一个最关键的问题就是误踩操作,现在电视和媒体关于驾驶员由于突发情况慌张和疲劳等因素导致驾驶员误踩加速踏板的情况已经是屡见不鲜,这种误操作无论是对车内驾驶员还是车外行人都是致命性的。在较容易发生误踩操作的驾驶员人群中,他们在日常开车的过程中发生错误的可能性要比不容易发生误踩操作人群高很多,易发生人群在脑部各区域协调性方面与正常人群相比是有差别的。因此,本文旨在通过脑功能连接的方法寻找误踩操作的脑部连接生理机理,为驾驶室防误踩效果监测及申领驾驶执照的学员重点培训提供理论依据。脑功能连接是寻找误踩操作脑部机理的主要研究方法,它能够反映脑部不同区域神经活动之间的相关性,而在低频段自发性神经信号之间存在某种连接特性。由于神经血管耦合作用的存在,神经活动与脑部血氧含量有一定的相关性,所以从血氧浓度出发,就能够很好地反应神经活动。本文是基于多通道近红外光谱法采集脑部不同区域的血氧信号,近红外方法的优点是无创、连续、实时地检测脑部微组织循环的血氧参数。信号经过预处理之后经小波变化得到其时频特性,通过计算不同通道之间的小波相位相干性值,来作为脑功能连接的评价指标。小波相位相干性值按照生理来源影响的不同可划分为六个频率频率间隔:Ⅰ,0.6-2.0 Hz;Ⅱ,0.145-0.6 Hz;Ⅲ,0.052-0.145 Hz;Ⅳ,0.021-0.052 Hz;V,0.0095-0.021Hz;Ⅵ,0.005-0.0095 Hz。本文先通过警惕任务模型验证其模拟驾驶负荷的有效性,再通过模拟驾驶器的正常驾驶与添加了突发因素和疲劳因素的任务态驾驶,在正常驾驶和任务过程中同时测量脑部血氧浓度信号,最后得出两种状态下的血氧浓度信号,信号经基于Morlet小波的小波分析方法得出不同通道信号的耦合关系,即小波相位相干性值,来评估误踩操作状态下的脑功能连接与正常驾车状态下的脑功能连接的差异性。本文研究表明得出,通过小波变换的方法可以进行时频域转化并提取出感兴趣的频率成分,单独分析其各频率成分(生理来源)在相位同步性方面对误踩操作的影响,从根本上解释了驾驶员发生误踩操作的原因,对驾驶员驾驶水平的评估提供新角度。
[Abstract]:In recent years, with the increase of vehicle ownership, the proportion of young drivers is gradually rising, so road traffic safety has become the focus of public concern. Now TV and the media about drivers due to sudden panic and fatigue and other factors leading to the driver to step on the acceleration pedal situation is common. This misoperation is fatal to both the driver inside the vehicle and the layman. They are much more likely to make mistakes in the course of their daily driving than people who are not prone to misstepping, and are different from normal people in terms of coordination across brain regions. The purpose of this paper is to find out the physiological mechanism of brain connection by using the method of brain functional connection. It provides the theoretical basis for the monitoring of the cab anti-false stepping effect and the key training for the students who apply for driving license. The brain functional connection is the main research method to find the mechanism of the misstepping operation of the brain. It can reflect the correlation between neural activities in different regions of the brain, and there is a connection between spontaneous nerve signals at low frequency. There is a certain correlation between the neural activity and the blood oxygen content in the brain, so starting from the blood oxygen concentration, the neural activity can be well reflected. This paper is based on the multi-channel near infrared spectroscopy to collect blood oxygen signals from different regions of the brain. Near-infrared method has the advantages of noninvasive, continuous, real-time detection of blood oxygen parameters of microcirculation in the brain. After pretreatment, the time-frequency characteristics of the signal are obtained by wavelet changes. By calculating the wavelet phase coherence between different channels, as the evaluation index of brain functional connection, the wavelet phase coherence value can be divided into six frequency intervals according to different physiological sources: I. 0.6-2.0 Hz; 鈪，

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