广电行业VoIP业务发展分析

随着三网融合的大力推进,广电和电信业务的双向化发展将更加深入。在这种形式下,广电面临巨大的压力,以现有数字电视、数据业务无法与电信抗衡,广电应借助三网融合之势(政策的准入),加快对通信业务的渗透,结合有线网络的实际情况,选择自己的发展道路,推动现有业务模式的转变,开展多媒体业务,实现视频、数据、语音等多业务融合。本文阐述、分析了VoIP主流协议及广电行业VoIP业务的现状,就广电行业VoIP业务系统的规划建设、业务场景、业务发展、实施规划等提出了思路,供业内人士探讨。     

PDA及无线局域网络在医院信息系统中的应用

目的：介绍以掌上电脑为终端(PDA)的非独立式无线局域网络在医院信息系统中的应用．方法：服务器采用Windows2000 Server操作系统，数据库采用MicroSoft SQLServer 2002，后台系统基于中文WindowsXP操作系统，采用C#，NET进行开发，C／S结构；前台系统采用PDA，Windows CE 2003操作系统，IEEE802，11b无线网络，使用ADP．NET开发，B／S3层结构．建模采用Power Designer9．5；服务器与台式机之间采用星型拓普网络结构．结果：基于以掌上电脑为终端的非独立式无线局域网络开发出的医院信息系统具有强大网络漫游功能，可同时兼容无线移动数字化诊疗设备和传统诊疗设备，安全稳定，性能卓越．结论：该系统能满足我国绝大多数医院数字化建设的需要，具有广阔的应用前景．     

信息网络化无线走天下--思科无线网络解决方案在美国医院的应用

在医疗系统先进的美国，政府按照“健康保险便携与责任法案”(HIPAA)颁布的新保密标准即将施行．这些大都是患者信息的保密标准。涉及到数据传输的安全性。面对加强无线安全这个医院IT系统需要考虑的重要因素．Cisco Aironet可以为医院提供能够满足HIPAA标准的保护等级。思科Aironet系列提供了全面的无线网络解决方案。包括Cisco Aironet340／350系列无线网桥．无线网络接入点和无线网卡。Cisco Aironet 340／350系列产品兼容IEEE802．11b．其互操作性已通过无线以太网兼容性联盟(WECA)的Wi—Fi认证．它采用直序扩频技术。可以工作在2．4GHz频段．最高速率11Mbps,与固定网络的速率相差无几。     

体感诱发电位与数量化脑电图监测地氟醚全身麻醉深度的临床研究

目的探讨地氟醚吸入全身麻醉时上肢短潜伏期体感诱发电位(short latency somatosensory evokedpotentials,SL-SEP)、数量化脑电图(quantitative electroencephalography,QEEG)的变化。方法选择全麻患者30例,麻醉诱导后吸入地氟醚,依次维持呼末地氟醚浓度在0.4MAC、0.7MAC、1.0MAC、1.3MAC;分别记录麻醉过程中平均动脉压(MAP)、心率(HR)、QEEG(BIS、95%SEF、MF)和SL-SEP(LP15、LN20、LN11、AMPP15-N20、AMPN11、CCT)。结果患者HR、MAP以及皮层下电位N11的变化与吸入地氟醚浓度无明显量效关系(P>0.05);而QEEG值随吸入地氟醚的呼末浓度增高而降低(P<0.05);LP15、LN20和CCT随地氟醚呼气末浓度的增加而逐渐延长(P<0.05)。结论LP15、LN20、CCT以及QEEG各参数是监测地氟醚麻醉深度的较好指标。     

电阻抗断层成像技术重建方法对比研究

目的比较几种电阻抗成像(Electrical Impedance Tomography,EIT)重建算法的性能,为EIT应用于肺部实时功能成像提供参考依据。方法设计三组实验,分别用一步高斯牛顿法、反投影算法、GREIT算法和基于L1正则化的成像算法对仿真数据及人体实测数据进行图像重建。在L1正则化求解过程中采用交替方向乘子法(Alternating Direction Method of Multipliers,ADMM)。将四种算法对仿真数据与实测数据的重建图像以及评价参数进行对比分析。结果GREIT算法在无噪声重建目标的参数评价中表现最优,ADMM算法在加入噪声数据的重建中受到的影响最小,评价参数变化幅度最小,具有很好的抗干扰性能。结论GREIT算法与ADMM算法可以应用于肺部EIT重建,实现对肺部的功能成像。     

大孔树脂吸附和纯化蒲黄总黄酮的工艺研究

以主成分香蒲新苷及异鼠李素-3-O-新橙皮糖苷含量为指标，研究了HZ802非极性大孔树脂吸附和纯化蒲黄总黄酮的工艺条件。结果表明HZ802非极性大孔树脂对蒲黄总酮有良好的吸附纯化性能，其优化的工艺条件为：样品溶液的浓度为50mg／mL(生药量／体积)；树脂用量为生药量的1．5倍(质量比)；纯化先用2倍树脂柱体积的水，再用2倍树脂柱体积φ=0．2的乙醇；总黄酮的洗脱用2倍树脂柱体积φ=0．5的乙醇；吸附和洗脱流速均为2mL／min。     

舌象客观化研究及其临床观察

舌象客观化研究其中重要部分是按照国际照明标准(CIE)获得统一的各类舌色的数据。本文报道运用光谱法制作的舌色仪在临床观察中具有稳定性能好，分辨率高的特点。其舌色色度坐标参数稳定，重复精度达0.005；取样时间短，仅为0.3秒，避免因舌体抖动而取样的偏移。研制的样机为非接触式，防止交叉感染．可与通用计算机配合进行数据处理。临床上对4种舌色和5种舌苔颜色共1660例进行测定，获得舌色分类的数据。     

GPRS移动心电监护仪的研制与应用

目的:应用GSM移动通讯网的通用分组无线业务(GPRS)通讯平台,实现心电图信号的远程、无线传送。方法:通过对心电信号采集软硬件的设计,移动发送模块的选择,将心电数据发送到心电监护中心。结果:无线发送前后的心电图数据准确,波形无失真。结论:实现了院外患者心电信号的远程监护和及时诊断。     

帕金森患者构音障碍的语音特征分析

目的 分析帕金森患者构音障碍的语音特征。方法 2019年2月至2020年5月于成都医学院附属医院神经内科征募帕金森疾病(PD)患者28例作为试验组,征募正常健康人26例作为对照组。所有受试者在安静的环境下,进行语音学测试;使用矩阵实验室(MATLAB)提取音频参数。结果 试验组男性患者与对照组平均基频(mean f0)、最大基频(max f0)、抖动频率(jitter)、信噪比(hnr)和持续发音时间(duration)比较,差异有统计学意义(P<0.05);试验组女性患者与对照组结束基频(end f0)和duration比较,差异有统计学意义(P<0.05)。结论 PD患者语音变化对早期识别PD具有重要价值。     

BIS和AAI在小儿七氟烷麻醉深度监测中的应用价值

目的:通过观察小儿七氟烷麻醉过程中脑电双频谱指数(BIS)、听觉诱发电位指数(AAI)及血流动力学随呼气末七氟烷浓度(ETSEV)改变时的变化情况,从而客观评价BIS和AAI在小儿七氟烷麻醉深度监测中的准确性。方法:选择ASAⅠ或Ⅱ级、年龄3~12岁拟择期在腹腔镜下行腹股沟斜疝高位结扎术的患儿40例。所有手术皆采用气管插管全身麻醉,术中通过调节七氟烷吸入浓度维持ETSEV于0.6最低肺泡有效浓度(MAC)、1.0MAC和1.4MAC并记录在不同七氟烷浓度状态下的BIS、AAI、平均动脉压(MAP)和心率(HR)。结果:与麻醉前相比,ETSEV为0.6MAC时,BIS、AAI、MAP和HR显著降低(P<0.01);与0.6MAC时的BIS、AAI、MAP和HR相比,1.0MAC和1.4MAC时显著降低(P<0.01);1.0MAC与1.4MAC时各项指标无显著变化(P>0.05)。结论:当ETSEV由0.6MAC向1.4MAC逐渐升高的过程中,BIS、AAI和MAP呈下降趋势,二者具有显著相关性,BIS和AAI可以作为小儿七氟烷麻醉深度监测的有效参考指标。     

A Privacy Preservation Secure Cross Layer Protocol Design for IoT Based Wireless Body Area Networks Using ECDSA Framework

Internet of Things (IoT) provides the collection of devices in different applications in which Wireless Body Area Network (WBAN) is placed an crucial role. The WBAN is a wireless sensor network consisting of sensor nodes that is collected from IoT which is implanted in the human body to remotely monitor the patient’s physiological signals without affecting their routine work. During emergency situations or life-threatening situations there is a need for a better performance to deliver the actual data with an efficient transmission and there is still a challenge in efficient remote monitoring. So, in this paper an application for cross layer protocol design architecture of Elliptic Curve Digital Signature Algorithm (ECDSA) has been proposed. It replaces the protocol architecture of WBAN (IEEE 802.15.6), WMAN (IEEE 802.16), and 3G, WLAN (IEEE 802.11) or wired networks. The lightweight secure system provides secure data transmission and access control mechanisms by using ECDA-based proxy signature algorithm. The efficiency of the system is implemented using simulation models that were developed using NS-2, and the results obtained shows an optimum solution in terms of delay, PDR, throughput, jitter, packet transmission time, dropping ratio and packet delivery. The viability of the methodology proposed is illustrated by the response.     

A Simulation Study of TaMAC Protocol using Network Simulator 2

A Wireless Body Area Network (WBAN) is expected to play a significant role in future healthcare system. It interconnects low-cost and intelligent sensor nodes in, on, or around a human body to serve a variety of medical applications. It can be used to diagnose and treat patients with chronic diseases such as hypertensions, diabetes, and cardiovascular diseases. The lightweight sensor nodes integrated in WBAN require low-power operation, which can be achieved using different optimization techniques. We introduce a Traffic-adaptive MAC protocol (TaMAC) for WBAN that supports dual wakeup mechanisms for normal, emergency, and on-demand traffic. In this letter, the TaMAC protocol is simulated using a well-known Network Simulator 2 (NS-2). The problem of multiple emergency nodes is solved using both wakeup radio and CSMA/CA protocol. The power consumption, delay, and throughput performance are closely compared with beacon-enabled IEEE 802.15.4 MAC protocol using extensive simulations.     

Throughput and delay analysis of IEEE 802.15.6-based CSMA/CA protocol

The IEEE 802.15.6 is a new communication standard on Wireless Body Area Network (WBAN) that focuses on a variety of medical, Consumer Electronics (CE) and entertainment applications. In this paper, the throughput and delay performance of the IEEE 802.15.6 is presented. Numerical formulas are derived to determine the maximum throughput and minimum delay limits of the IEEE 802.15.6 for an ideal channel with no transmission errors. These limits are derived for different frequency bands and data rates. Our analysis is validated by extensive simulations using a custom C+?+ simulator. Based on analytical and simulation results, useful conclusions are derived for network provisioning and packet size optimization for different applications.     

An Ultra Low-power and Traffic-adaptive Medium Access Control Protocol for Wireless Body Area Network

Wireless Body Area Network (WBAN) consists of low-power, miniaturized, and autonomous wireless sensor nodes that enable physicians to remotely monitor vital signs of patients and provide real-time feedback with medical diagnosis and consultations. It is the most reliable and cheaper way to take care of patients suffering from chronic diseases such as asthma, diabetes and cardiovascular diseases. Some of the most important attributes of WBAN is low-power consumption and delay. This can be achieved by introducing flexible duty cycling techniques on the energy constraint sensor nodes. Stated otherwise, low duty cycle nodes should not receive frequent synchronization and control packets if they have no data to send/receive. In this paper, we introduce a Traffic-adaptive MAC protocol (TaMAC) by taking into account the traffic information of the sensor nodes. The protocol dynamically adjusts the duty cycle of the sensor nodes according to their traffic-patterns, thus solving the idle listening and overhearing problems. The traffic-patterns of all sensor nodes are organized and maintained by the coordinator. The TaMAC protocol is supported by a wakeup radio that is used to accommodate emergency and on-demand events in a reliable manner. The wakeup radio uses a separate control channel along with the data channel and therefore it has considerably low power consumption requirements. Analytical expressions are derived to analyze and compare the performance of the TaMAC protocol with the well-known beacon-enabled IEEE 802.15.4 MAC, WiseMAC, and SMAC protocols. The analytical derivations are further validated by simulation results. It is shown that the TaMAC protocol outperforms all other protocols in terms of power consumption and delay.     

A Novel Medium Access Control Protocol with Low Delay and Traffic Adaptivity for Wireless Body Area Networks

IEEE 802.15.4 technology provides one solution for low-rate short range communications. Based on the integrated superframe structure of IEEE 802.15.4, a novel low-delay traffic-adaptive medium access control (LDTA-MAC) protocol for wireless body area networks (WBANs) is proposed in the paper. In LDTA-MAC, the guaranteed time slots (GTSs) are allocated dynamically according to the traffic load. At the same time, the active portion of superframe is kept to be a reasonable duration to decrease the energy consumption of the network devices. Moreover, for the successful GTS requests, the related data packets are transmitted in the current superframe instead of waiting more time to reduce the average packet delay. Simulations are conducted to evaluate the network performance and verify our protocol design. Comparing with IEEE 802.15.4, the results reveal LDTA-MAC accommodates more devices access to the network and reduces the packet delay obviously without the cost of more energy consumption.     

Performance Analysis of IEEE 802.15.6 CSMA/CA Protocol for WBAN Medical Scenario through DTMC Model

The newly drafted IEEE 802.15.6 standard for Wireless Body Area Networks (WBAN) has been concentrating on a numerous medical and non-medical applications. Such short range wireless communication standard offers ultra-low power consumption with variable data rates from few Kbps to Mbps in, on or around the proximity of the human body. In this paper, the performance analysis of carrier sense multiple access with collision avoidance (CSMA/CA) scheme based on IEEE 802.15.6 standard in terms of throughput, reliability, clear channel assessment (CCA) failure probability, packet drop probability, and end-to-end delay has been presented. We have developed a discrete-time Markov chain (DTMC) to significantly evaluate the performances of IEEE 802.15.6 CSMA/CA under non-ideal channel condition having saturated traffic condition including node wait time and service time. We also visualize that, as soon as the payload length increases the CCA failure probability increases, which results in lower node’s reliability. Also, we have calculated the end-to-end delay in order to prioritize the node wait time cause by backoff and retransmission. The user priority (UP) wise DTMC analysis has been performed to show the importance of the standard especially for medical scenario.     

TraPy-MAC: Traffic Priority Aware Medium Access Control Protocol for Wireless Body Area Network

Recently, Wireless Body Area Network (WBAN) has witnessed significant attentions in research and product development due to the growing number of sensor-based applications in healthcare domain. Design of efficient and effective Medium Access Control (MAC) protocol is one of the fundamental research themes in WBAN. Static on-demand slot allocation to patient data is the main approach adopted in the design of MAC protocol in literature, without considering the type of patient data specifically the level of severity on patient data. This leads to the degradation of the performance of MAC protocols considering effectiveness and traffic adjustability in realistic medical environments. In this context, this paper proposes a Traffic Priority-Aware MAC (TraPy-MAC) protocol for WBAN. It classifies patient data into emergency and non-emergency categories based on the severity of patient data. The threshold value aided classification considers a number of parameters including type of sensor, body placement location, and data transmission time for allocating dedicated slots patient data. Emergency data are not required to carry out contention and slots are allocated by giving the due importance to threshold value of vital sign data. The contention for slots is made efficient in case of non-emergency data considering threshold value in slot allocation. Moreover, the slot allocation to emergency and non-emergency data are performed parallel resulting in performance gain in channel assignment. Two algorithms namely, Detection of Severity on Vital Sign data (DSVS), and ETS Slots allocation based on the Severity on Vital Sign (ETS-SVS) are developed for calculating threshold value and resolving the conflicts of channel assignment, respectively. Simulations are performed in ns2 and results are compared with the state-of-the-art MAC techniques. Analysis of results attests the benefit of TraPy-MAC in comparison with the state-of-the-art MAC in channel assignment in realistic medical environments.     

Seamless Interworking Architecture for WBAN in Heterogeneous Wireless Networks with QoS Guarantees

The IEEE 802.15.6 standard is a communication standard optimized for low-power and short-range in-body/on-body nodes to serve a variety of medical, consumer electronics and entertainment applications. Providing high mobility with guaranteed Quality of Service (QoS) to a WBAN user in heterogeneous wireless networks is a challenging task. A WBAN uses a Personal Digital Assistant (PDA) to gather data from body sensors and forwards it to a remote server through wide range wireless networks. In this paper, we present a coexistence study of WBAN with Wireless Local Area Networks (WLAN) and Wireless Wide Area Networks (WWANs). The main issue is interworking of WBAN in heterogenous wireless networks including seamless handover, QoS, emergency services, cooperation and security. We propose a Seamless Interworking Architecture (SIA) for WBAN in heterogenous wireless networks based on a cost function. The cost function is based on power consumption and data throughput costs. Our simulation results show that the proposed scheme outperforms typical approaches in terms of throughput, delay and packet loss rate.     

A Green Media Access Method for IEEE 802.15.6 Wireless Body Area Network

It is of utmost importance to conserve battery energy to the maximum possible extent in WBAN nodes while collecting and transferring medical data. The IEEE 802.15.6 WBAN standard does not specify any method to conserve energy. This paper focuses on a method to conserve energy in IEEE 802.15.6 WBAN nodes when using CSMA/CA, while simultaneously restricting data delivery delay to the required value as specified in medical applications. The technique is to allow the nodes to sleep all the times except for receiving beacons and for transmitting data frames whenever a data frame enters an empty buffer. The energy consumed by the nodes and the average latency of data frame for periodical arrival of data are found out analytically. The analytical results are validated and also the proposed method is compared with other energy conserving schemes, using Castalia simulation studies. The proposed method shows superior performance in both device lifetime and latency of emergency medical data.     

Network Coded Cooperative Communication in a Real-Time Wireless Hospital Sensor Network

The paper presents a network coded cooperative communication (NC-CC) enabled wireless hospital sensor network architecture for monitoring health as well as postural activities of a patient. A wearable device, referred as a smartband is interfaced with pulse rate, body temperature sensors and an accelerometer along with wireless protocol services, such as Bluetooth and Radio-Frequency transceiver and Wi-Fi. The energy efficiency of wearable device is improved by embedding a linear acceleration based transmission duty cycling algorithm (NC-DRDC). The real-time demonstration is carried-out in a hospital environment to evaluate the performance characteristics, such as power spectral density, energy consumption, signal to noise ratio, packet delivery ratio and transmission offset. The resource sharing and energy efficiency features of network coding technique are improved by proposing an algorithm referred as network coding based dynamic retransmit/rebroadcast decision control (LA-TDC). From the experimental results, it is observed that the proposed LA-TDC algorithm reduces network traffic and end-to-end delay by an average of 27.8% and 21.6%, respectively than traditional network coded wireless transmission. The wireless architecture is deployed in a hospital environment and results are then successfully validated.