汽车振动对驾驶员心脑功能动态调整的影响分析

发布时间：2018-10-19 16:34

【摘要】：驾驶员在驾车过程中突发脑中风,脑溢血等重大疾病,具有不可控性,容易造成重大交通事故。职业驾驶员心脑血管疾病的产生重要原因之一就是汽车在行车中产生的振动,越来越多的研究者研究汽车振动对驾驶员心脑功能动态调整的影响。基于近红外检测驾驶员脑组织血氧信号以及利用无创血压仪检测动脉血压信号,可以作为一种新型的心脑功能检测方法用于检测驾驶员心脑功能动态调整。心脑动态调整是不管血压如何变化大脑血管床都能够保持脑血流速度(脑充血)的稳定。心脑动态调整是脑血液动力学参数随血压变化的管理机制。在需要长期作业的驾驶员中,心脑动态调整能力可能随着长期振动的影响而有新减弱,造成一系列心脑血管疾病,驾驶过程中的突发脑溢血,脑中风等危险情况均与驾驶员的心脑功能动态调整受损有关。振动状态下驾驶员心脑血管参数(血压信号,血氧信号)在低频范围内的关系可以用来评估驾驶员心脑功能动态调整。相位动力学方法提供了分析脑血流动力学非线性,非稳定性信号的数学框架,而且克服了早期方法的限制和不足,对研究分析汽车振动下驾驶员心脑功能动态调整起到了很重要的作用。相位动力学分析是一种新颖的对心脑信号的分析方法,通过瞬时相位的计算相位相干性可以揭开两个信号的相干程度,它可以从相位角度来对心脑功能动态调整有一个全新的认识。通过近红外光谱法实时连续无创检测脑部组织血氧参数,对光谱信号做信号的预处理以及信号去噪处理,人体生理信号经过降低运动伪差噪声的数据处理算法预处理后,将信号中的噪音和干扰滤去或者将希望得到的频率信号滤出,获得相对理想的血氧和血压信号数据。预处理及降噪后的信号经过连续小波变换后,对脑部组织血氧信号和动脉血压信号进行小波相干性分析和相位相干性分析,分析脑组织血氧和动脉血压之间的相干性。通过统计学分析获得振动频率下相干性的显著差异性,分析差异性存在的原因,进而分析振动对驾驶员心脑功能动态调整的影响。人体心脑功能动态调整不仅仅是大脑和心脏活动在起作用,人体大脑保持稳定的血流量和氧气的供应同时受神经系统,局部血管平滑肌细胞,血管壁内皮细胞的新陈代谢活动调控,是多个系统和器官共同协调作用的结果。通过对实验结果的讨论,分析振动对人体各系统的影响,分析振动对驾驶员心脑功能动态调整的影响,为汽车振动频率的设计范围选取提供一定的理论依据。从汽车轮胎的设计,减振系统悬架的设计,以及与人体接触最多的座椅设计三方面来缓解地面传递到人体的振动,规避人体敏感振动频率,避免与对驾驶员心脑功能动态调整影响较大的振动频率形成共振,减少驾驶员在驾驶过程中突发脑中风的风险。
[Abstract]:Drivers driving in the process of sudden stroke, cerebral hemorrhage and other major diseases, with uncontrolled, easy to cause major traffic accidents. One of the important causes of cardiovascular and cerebrovascular diseases of professional drivers is the vibration produced by cars in driving. More and more researchers study the effect of vehicle vibration on the dynamic adjustment of drivers' cardio-brain function. It can be used as a new method to detect cardio-brain function dynamic adjustment based on near-infrared detection of cerebral blood oxygen signal and non-invasive blood pressure instrument to detect arterial blood pressure signal. Cerebral dynamic adjustment is that no matter how blood pressure changes, the cerebral vascular bed can maintain the stability of cerebral blood flow velocity (cerebral hyperemia). Cardio-cerebral dynamic adjustment is the management mechanism of cerebral hemodynamic parameters with changes of blood pressure. Among drivers who need to work for a long period of time, the ability of dynamic adjustment of the heart and brain may weaken with the effect of long-term vibration, resulting in a series of cardio-cerebrovascular diseases and sudden cerebral hemorrhage during driving. Stroke and other risk conditions are associated with the driver's dynamic adjustment of cardiac and brain function damage. The relationship between cardiovascular and cerebrovascular parameters (blood pressure signal, blood oxygen signal) in low frequency range can be used to evaluate the dynamic adjustment of heart and brain function. The phase dynamics method provides a mathematical framework for the analysis of nonlinear and unstable signals of cerebral hemodynamics, and overcomes the limitations and shortcomings of the earlier methods. It plays an important role in studying and analyzing the dynamic adjustment of the driver's heart and brain function under the automobile vibration. Phase dynamics analysis is a novel method for the analysis of cardiac and brain signals. The coherence of the two signals can be revealed by calculating the phase coherence of the instantaneous phase. It can have a new understanding of the dynamic adjustment of cardiac and brain function from the aspect of phase. The parameters of blood oxygen in brain tissue were continuously and continuously detected by near infrared spectroscopy (NIR). The spectral signal was pre-processed and the signal was de-noised. The human physiological signal was preprocessed by the data processing algorithm to reduce the motion pseudo-noise. The noise and interference in the signal are filtered out or the desired frequency signal is filtered out to obtain the relatively ideal signal data of oxygen and blood pressure. After continuous wavelet transform, the correlation between cerebral blood oxygen and arterial blood pressure was analyzed by wavelet coherence analysis and phase coherence analysis. Through statistical analysis, the significant difference of coherence under vibration frequency was obtained, the reason of difference was analyzed, and the influence of vibration on dynamic adjustment of driver's heart and brain function was analyzed. The dynamic regulation of human heart and brain function is not only the function of brain and heart activity, but also the steady blood flow and oxygen supply of human brain, which are simultaneously affected by the smooth muscle cells of the nervous system and local blood vessels. The regulation of vascular endothelial cell metabolism is the result of the coordination of multiple systems and organs. Through the discussion of the experimental results, the influence of vibration on human body system and the dynamic adjustment of driver's heart and brain function are analyzed, which provides a certain theoretical basis for the selection of design range of vehicle vibration frequency. From three aspects: the design of automobile tire, the design of suspension of vibration absorption system, and the design of seat which has the most contact with human body, the vibration transmitted from ground to human body can be alleviated and the sensitive vibration frequency of human body can be avoided. To avoid resonance with the vibration frequency which has a great influence on the dynamic adjustment of the heart and brain function of the driver, and to reduce the risk of sudden stroke during driving.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U491.254;R135

【相似文献】