面向医疗监测的无线体域网MAC层关键技术研究
发布时间：2018-09-11 15:41
【摘要】：面对日益迫切的国民健康需求,研究低成本、可穿戴、可无缝融入日常生活、不受限于时间与地点的医疗监测关键技术及应用至关重要。无线体域网WBAN (Wireless Body Area Network)是由一系列低功耗、微型化、轻量级、可置于体表或植入体内、可提供实时数据、具备无线通信能力的传感节点组成的网络,为该类医疗监测提供了创新性解决方案；而MAC层涉及WBAN的能耗、可扩展性、高效通信,以及个人医疗数据的隐私性与安全性等诸多核心问题,因此本文针对WBAN的MAC层关键技术开展研究。本文按照MAC层“理论建模→协议设计→安全协议”的研究思路,从缓存容量有限状态下基于CSMA/CA机制的MAC层协议性能评估模型,低能耗、高时隙利用率、可满足异构医疗数据QoS需求的短中断混合MAC协议设计,以及基于Fuzzy Commitment的MAC层轻量级密钥协商协议设计三方面,对面向医疗监测的无线体域网MAC层关键技术进行了深入研究,并构建了以WBAN和云计算技术为支撑的实时医疗监测系统,在实际应用场景内对所研究技术进行了分析验证。本文的主要研究成果和创新点包括以下几方面：(1)提出了一种适用于非饱和条件,可对基于IEEE 802.15.6 CSMA/CA的WBAN MAC协议进行性能评估的分析模型。模型采用三维离散马尔科夫链来模拟非饱和状态下无线体域网节点的回退机制,通过求解马尔科夫链得到不同优先级节点竞争到信道资源的概率；采用嵌入式马尔科夫链分析缓存中的数据包队列,得到稳态时缓存中的数据包队列分布；基于概率母函数和利特尔法则,分别计算出数据包的平均服务时间和平均排队时延,进而得到数据包的平均时延和网络吞吐量；通过计算每个节点的能量消耗,得到整个网络的能效。通过Matlab仿真验证了理论模型的正确性,结果表明该模型可以对非饱和条件下的无线体域网MAC协议性能进行有效评估。(2)以无线体域网医疗监测为应用目标,设计了一种混合型媒体接入协议(I-MAC)。通过对超帧结构与时隙分配的设计改进,I-MAC可提高能量利用效率与时隙利用效率,并同时能保证数据的实时性与可靠性要求。I-MAC采用较长超帧结构以消除多余信标收发所需能耗,从而提高能量利用效率；并将大多数时隙分配为GTS时隙,以满足传输周期性医疗监测应用所产生大量数据的带宽需求；针对随机紧急监测数据,特殊设计了中断时隙进行传输并保证这些数据的实时性与可靠性要求。仿真结果表明,不同参数配置的I-MAC协议的能量效率、时隙利用率均高于802.15.4,且同时能够满足数据的时延要求；当每个中断周期内的随机性医疗监测数据量小于1时,I-MAC协议可显著提升无线体域网的性能,对于具有低非周期性随机数据的无线体域网,协议也具有良好的性能。(3)对体域网中基于噪声生理信号的密钥协商机制进行了系统性深入研究,其中详细分析了两种主流密钥协商技术Fuzzy Commitment和Fuzzy Vault的优势和劣势,并根据各自的特点进行了细化分类。对体域网节点与协调器间的单跳与多跳传输方式的能耗进行了细致的对比分析,指出对于体表传感节点,单跳传输更加节能,为构建低能耗的体域网密钥管理模型打下了基础。提出了一种基于Fuzzy Commitment和ECG信号的轻量级MAC层密钥协商协议。在该协议的初始化阶段,通过共享密钥产生承诺的方式避免了体域网间的互干扰,并能够抵御基于超宽带雷达遥测的新型攻击方式；在密钥协商阶段,利用时间窗机制实现了噪声生理信号的弱同步,避免了精确时间同步所带来的巨大能耗；采用了“以计算能耗代替传输能耗”的思路,利用简单的比特级运算避免了由于生理信号噪声造成的密钥协商失败所带来的协议重启,极大地节约了能量。分析表明,该协议既保障了WBAN密钥协商的低能耗需求,又提升了协议的抗攻击性能。(4)在上述研究内容的基础上,通过详细的软硬件设计及关键技术的研究,构建了以无线体域网为支撑的实时医疗监测系统。系统以多样化的医疗传感器为节点,以设计完成的智能云健康检测仪为智能协调器,实现了轻量级WBAN的快速部署,完成了人体多类医学生理指标的精准感知与监测；数据经智能处理后,通过自适应的异构网络,上传至云计算中心的医疗监测云平台,实现了云端的医疗数据智能解析、处理、存储和展示,并通过移动APP形成医疗监测的闭环,完成了健康数据的实时检测、移动查询、远程监护与诊断等功能,并通过心电数据的完整测试,证明依托无线体域网可以有效进行远程实时医疗监测,具有良好的应用价值。
[Abstract]:In the face of the increasingly urgent national health needs, it is essential to study low-cost, wearable, seamless integration into daily life, key technologies and applications of medical monitoring that are not limited to time and place. The network composed of sensor nodes with real-time data and wireless communication capabilities provides innovative solutions for this kind of medical monitoring; and the MAC layer involves many core issues such as WBAN energy consumption, scalability, efficient communication, privacy and security of personal medical data, so this paper focuses on the key technologies of the MAC layer of WBAN. According to the research idea of MAC Layer "Theoretical Modeling-Protocol Design-Security Protocol", this paper discusses the performance evaluation model of MAC Layer protocol based on CSMA/CA mechanism under limited buffer capacity, the design of short interrupt hybrid MAC protocol with low energy consumption and high slot utilization, which can meet the QoS requirements of heterogeneous medical data, and the design of Fuzzy Commitm-based MAC protocol. In this paper, the key technologies of MAC layer in wireless body area network for medical monitoring are deeply studied, and a real-time medical monitoring system based on WBAN and cloud computing technology is constructed. The research results are analyzed and verified in practical application scenarios. The innovations are as follows: (1) An analytical model for evaluating the performance of WBAN MAC protocol based on IEEE 802.15.6 CSMA/CA under unsaturated conditions is proposed. The model uses three-dimensional discrete Markov chains to simulate the backoff mechanism of nodes in wireless body area networks under unsaturated conditions. The model is obtained by solving Markov chains. The probabilities of different priority nodes competing for channel resources are analyzed by using embedded Markov chain to obtain the packet queue distribution in steady-state cache. Based on probability generating function and Littler's law, the average service time and queue delay of packets are calculated respectively, and then the packets are obtained. Mean time delay and network throughput; energy efficiency of the whole network is obtained by calculating the energy consumption of each node. The correctness of the theoretical model is validated by MATLAB simulation. The results show that the model can effectively evaluate the performance of MAC protocol in wireless body area network under unsaturated conditions. (2) The application of wireless body area network medical monitoring Aim, a hybrid media access protocol (I-MAC) is designed. By improving the design of superframe structure and slot allocation, I-MAC can improve the efficiency of energy utilization and slot utilization, and ensure the real-time and reliability requirements of data. I-MAC uses a longer superframe structure to eliminate the energy consumption required for redundant beacon transceiver and receiver, thereby improving the efficiency. Most of the time slots are allocated to GTS slots to meet the bandwidth requirement of transmitting large amounts of data generated by periodic medical monitoring applications. The interrupt slots are designed to transmit the random emergency monitoring data and ensure the real-time and reliability of the data. The simulation results show that different parameters are allocated. The energy efficiency and slot utilization of the I-MAC protocol are higher than 802.15.4, and can satisfy the data delay requirement at the same time. When the amount of randomized medical monitoring data in each interrupt cycle is less than 1, the I-MAC protocol can significantly improve the performance of wireless body area network. For wireless body area network with low aperiodic random data, the protocol is also used. (3) The mechanism of key agreement based on noisy physiological signals in body area network is studied systematically and deeply. The advantages and disadvantages of two main key agreement technologies, Fuzzy Commitment and Fuzzy Vault, are analyzed in detail, and their respective characteristics are classified. The energy consumption of single-hop and multi-hop transmission modes is analyzed in detail. It is pointed out that single-hop transmission is more energy-efficient for body surface sensor nodes, which lays a foundation for constructing low-energy key management model of WAN. A lightweight MAC layer key agreement protocol based on Fuzzy Commitment and ECG signal is proposed. In the key agreement stage, the weak synchronization of noise physiological signals is realized by using time window mechanism, which avoids the huge energy consumption caused by precise time synchronization. Computational energy consumption replaces transmission energy consumption. Simple bit-level operation is used to avoid the protocol restart caused by the failure of key agreement caused by physiological signal noise, which greatly saves energy. On the basis of describing the research contents, a real-time medical monitoring system based on wireless body area network (WMAN) is constructed through detailed software and hardware design and key technology research. The system takes a variety of medical sensors as nodes and the designed intelligent cloud health detector as an intelligent coordinator. The rapid deployment of lightweight WBAN is realized. After intelligent processing, the data is uploaded to the cloud platform of medical monitoring in cloud computing center through adaptive heterogeneous network, which realizes intelligent analysis, processing, storage and display of medical data in cloud, and forms a closed loop of medical monitoring through mobile APP. Real-time detection, mobile query, remote monitoring and diagnosis functions, and through the complete test of ECG data, prove that relying on wireless body area network can effectively carry out remote real-time medical monitoring, with good application value.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN92
，
本文编号：2237119
[Abstract]:In the face of the increasingly urgent national health needs, it is essential to study low-cost, wearable, seamless integration into daily life, key technologies and applications of medical monitoring that are not limited to time and place. The network composed of sensor nodes with real-time data and wireless communication capabilities provides innovative solutions for this kind of medical monitoring; and the MAC layer involves many core issues such as WBAN energy consumption, scalability, efficient communication, privacy and security of personal medical data, so this paper focuses on the key technologies of the MAC layer of WBAN. According to the research idea of MAC Layer "Theoretical Modeling-Protocol Design-Security Protocol", this paper discusses the performance evaluation model of MAC Layer protocol based on CSMA/CA mechanism under limited buffer capacity, the design of short interrupt hybrid MAC protocol with low energy consumption and high slot utilization, which can meet the QoS requirements of heterogeneous medical data, and the design of Fuzzy Commitm-based MAC protocol. In this paper, the key technologies of MAC layer in wireless body area network for medical monitoring are deeply studied, and a real-time medical monitoring system based on WBAN and cloud computing technology is constructed. The research results are analyzed and verified in practical application scenarios. The innovations are as follows: (1) An analytical model for evaluating the performance of WBAN MAC protocol based on IEEE 802.15.6 CSMA/CA under unsaturated conditions is proposed. The model uses three-dimensional discrete Markov chains to simulate the backoff mechanism of nodes in wireless body area networks under unsaturated conditions. The model is obtained by solving Markov chains. The probabilities of different priority nodes competing for channel resources are analyzed by using embedded Markov chain to obtain the packet queue distribution in steady-state cache. Based on probability generating function and Littler's law, the average service time and queue delay of packets are calculated respectively, and then the packets are obtained. Mean time delay and network throughput; energy efficiency of the whole network is obtained by calculating the energy consumption of each node. The correctness of the theoretical model is validated by MATLAB simulation. The results show that the model can effectively evaluate the performance of MAC protocol in wireless body area network under unsaturated conditions. (2) The application of wireless body area network medical monitoring Aim, a hybrid media access protocol (I-MAC) is designed. By improving the design of superframe structure and slot allocation, I-MAC can improve the efficiency of energy utilization and slot utilization, and ensure the real-time and reliability requirements of data. I-MAC uses a longer superframe structure to eliminate the energy consumption required for redundant beacon transceiver and receiver, thereby improving the efficiency. Most of the time slots are allocated to GTS slots to meet the bandwidth requirement of transmitting large amounts of data generated by periodic medical monitoring applications. The interrupt slots are designed to transmit the random emergency monitoring data and ensure the real-time and reliability of the data. The simulation results show that different parameters are allocated. The energy efficiency and slot utilization of the I-MAC protocol are higher than 802.15.4, and can satisfy the data delay requirement at the same time. When the amount of randomized medical monitoring data in each interrupt cycle is less than 1, the I-MAC protocol can significantly improve the performance of wireless body area network. For wireless body area network with low aperiodic random data, the protocol is also used. (3) The mechanism of key agreement based on noisy physiological signals in body area network is studied systematically and deeply. The advantages and disadvantages of two main key agreement technologies, Fuzzy Commitment and Fuzzy Vault, are analyzed in detail, and their respective characteristics are classified. The energy consumption of single-hop and multi-hop transmission modes is analyzed in detail. It is pointed out that single-hop transmission is more energy-efficient for body surface sensor nodes, which lays a foundation for constructing low-energy key management model of WAN. A lightweight MAC layer key agreement protocol based on Fuzzy Commitment and ECG signal is proposed. In the key agreement stage, the weak synchronization of noise physiological signals is realized by using time window mechanism, which avoids the huge energy consumption caused by precise time synchronization. Computational energy consumption replaces transmission energy consumption. Simple bit-level operation is used to avoid the protocol restart caused by the failure of key agreement caused by physiological signal noise, which greatly saves energy. On the basis of describing the research contents, a real-time medical monitoring system based on wireless body area network (WMAN) is constructed through detailed software and hardware design and key technology research. The system takes a variety of medical sensors as nodes and the designed intelligent cloud health detector as an intelligent coordinator. The rapid deployment of lightweight WBAN is realized. After intelligent processing, the data is uploaded to the cloud platform of medical monitoring in cloud computing center through adaptive heterogeneous network, which realizes intelligent analysis, processing, storage and display of medical data in cloud, and forms a closed loop of medical monitoring through mobile APP. Real-time detection, mobile query, remote monitoring and diagnosis functions, and through the complete test of ECG data, prove that relying on wireless body area network can effectively carry out remote real-time medical monitoring, with good application value.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN92
，
本文编号：2237119
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