共查询到10条相似文献,搜索用时 125 毫秒
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体域网(BAN)的研究在远程医疗及远程医疗服务方面起着重要的作用,由于无线传感器节点附着在人体表面,人体不可避免地会吸收可能有害的电磁波,因此,对人体处于BAN网络下的SAR值的研究变得格外重要.而由于BAN中通信距离很短,电磁波沿身体表面传播的通道与普通的无线信道不同,需要建立适用于BAN网络环境的计算模型.以FDTD有限时域差分法为依托,建立三维矩形人体组织网格模型以及三维站立式人体网格模型,采用半波偶极子天线在贴近人体皮肤表面处对矩形人体组织模型与站立式人体模型在不同频率下的SAR值进行仿真,得到了在0.9 GHz,2.4 GHz,5 GHz 3种频率下人体SAR值. 相似文献
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Callejón MA Roa LM Reina-Tosina J Naranjo-Hernández D 《IEEE transactions on information technology in biomedicine》2012,16(1):159-165
Intrabody communication (IBC) is a technique that uses the human body as a transmission medium for electrical signals to connect wireless body sensors, e.g., in biomedical monitoring systems. In this paper, we propose a simple, but accurate propagation model through the skin based on a distributed-parameter circuit in order to obtain general expressions that could assist in the design of IBC systems. In addition, the model is based on the major electrophysiological properties of the skin. We have found the attenuation and dispersion parameters and they have been successfully compared with several published results, thus showing the tuning capability of the model to different experimental conditions. Finally, we have evaluated different digital modulation schemes in order to assess the tradeoffs between symbol rate, bit error rate, and distance between electrodes of the skin communication channel. 相似文献
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考虑人体电特性的建模是对人体进行电磁生物效应研究的基础,提出了一个可以用于计算人体输入阻抗的新的人体电路模型;基于该电路模型给出了在人体圆柱模型下的输入阻抗计算方法。并用试验证明,据此计算出来的人体阻抗会随曝露系统的维数增加而减小,反映出功率吸收的现实。应用该模型分析人体阻抗变化,可有益于人体健康状态信息的获取,为进行医学诊断提供帮助。 相似文献
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人体信道路径损耗计算对植入式通信链路预估具有重要意义。文章利用有耗媒质的电磁场边界条件、反射和透射定理并引入切向等效波阻抗定义,推导出平面波向人体斜入射时各人体组织分界面上的入射角、透射角、反射系数、透射系数、切向等效波阻抗以及各人体组织中的电磁合成波,提出了一种基于平面波向多层有耗媒质斜入射的人体信道远场路径损耗解析模型。然后以植入在肌肉为例,计算了TM波和TE波在5个常用工业通信频率以不同角度斜入射的人体信道电磁场分布与路径损耗,结果显示,电磁波在入射面的反射是影响人体信道路径损耗的关键因素,当频率在1.4 GHz附近时总路径损耗最小,TM波性能优于TE波,且当入射角小于等于30°时,总路径损耗基本保持不变。最后采用COMSOL Multiphysics建立了有限元仿真模型验证解析模型,二者结果高度吻合,最大误差仅为0.039,有力证明了解析模型的正确性和有效性。 相似文献
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《IEEE transactions on information technology in biomedicine》2009,13(6):933-945
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Rong Yu Yan Zhang Chen Gao Chujia Huang Ruchao Gao 《Mobile Networks and Applications》2011,16(6):733-744
We study the potential of cognition and cooperation in Body Area Networks (BANs). On one hand, most BAN-based applications
involve end-to-end transmission across heterogenous networks. Cognitive communication has been known to be an effective technology
for addressing network heterogeneity. On the other hand, a BAN is normally required to provide reliable communications and
operate in a very low power level to conserve energy and reduce the electromagnetic radiation impact on human body. Cooperative
communication has been known to enhance the transmission reliability and maintain low transmission power. However, the joint
cognitive and cooperative mechanism has not been investigated yet in the literature. In this paper, we propose a network architecture
for cognitive and cooperative communications in BANs. An intelligent mobile device is introduced as either a cognitive gateway
to interconnect heterogenous networks; or a cooperative relay node to achieve transmission diversity. Two cooperative transmission
schemes, Energy-conserved Cooperative Transmission and Reliability-driven Cooperative Transmission, are presented for different
applications that have distinct energy consumption or reliability requirement. Optimization problems are formulated to optimally
allocate power in the cooperative transmission. Results indicate that cooperative transmission schemes can significantly decrease
Bit Error Rate (BER) and reduce energy consumption, compared to the non-cooperative schemes. The BER gain is over one order
in the high SNR region, while the energy consumption can save up to 50% in the low BER region. 相似文献
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Wireless body area network (WBAN) is a new enabling system with promising applications in areas such as remote health monitoring and interpersonal communication. Reliable and optimum design of a WBAN system relies on a good understanding and in-depth studies of the wave propagation around a human body. However, the human body is a very complex structure and is computationally demanding to model. This paper aims to investigate the effects of the numerical model's structure complexity and feature details on the simulation results. Depending on the application, a simplified numerical model that meets desired simulation accuracy can be employed for efficient simulations. Measurements of ultra wideband (UWB) signal propagation along a human arm are performed and compared to the simulation results obtained with numerical arm models of different complexity levels. The influence of the arm shape and size, as well as tissue composition and complexity is investigated. 相似文献