Analysis of Electromagnetic Exposure in Wireless Power Transfer System for Endoscopic Micro-robot

A wireless power transfer system for endoscopic micro-robot operating at 36 kHz is presented in this paper. The issue of patient＇ s health and safety regarding exposure to the electromagnetic field is addressed. The specific absorption rate and current density can be used to investigate the electromagnetic influences on the biological tissues surrounded by the wireless power launching coil. In view of this purpose, the limited close-ound solenoid electromagnetic model is built, the relationship between the electric intensity and the specific absorption rate and current density is deduced, and the simulation experiments are done. Experimental results show that the values of SAR and current density related to different tissue catalogs are all very small and do not exceed their own limits respectively when the resonance frequency of operation is 36 kHz.     

基于QinQ＋Portal认证技术在校园无线网中的应用

基于对陕西师范大学校园网络现状分析,介绍了QinQ技术和Portal认证技术的相关理论,设计并部署了基于QinQ和Portal认证技术的无线控制器与无线AP结合的无线网络方案,以期对其他学校和单位有所借鉴。     

Traditional vs wireless intragastric pH monitoring: are the two techniques comparable?

Background Few data are available comparing intragastric pH measured with the traditional catheter‐based and the more recent wireless system (Bravo), and also comparing intraesophageal and intragastric pH during reflux events. Aims of our study were to elucidate these points. Methods Eleven subjects with functional dyspepsia underwent placement of a Bravo capsule 9 cm below the squamo‐columnar junction (SCJ) and of a dual‐electrode catheter, so that the distal electrode was located 9 cm below and the proximal one 6 cm above the SCJ. Key Results The wireless system showed lower intragastric pH than the traditional catheter in the postprandial period (median 2.2 wireless vs 2.7 catheter, P < 0.05) but not in the whole 24 h. Moreover, during the 24 h, minimum intraesophageal pH during reflux events was lower than the simultaneous pH in the gastric body recorded using the catheter (2.2 vs 2.4, P < 0.01) and in the postprandial period lower than the one recorded using both techniques (2.3 vs 2.8 wireless and 3.2 catheter, P < 0.001). Conclusions & Inferences (i) after meals, in the 1st 2 h postprandial pH in the gastric body is significantly lower when measured with the wireless capsule than with the traditional catheter, presumably because of less buffering by food in proximity of the mucosa, (ii) during reflux events intraesophageal pH is lower than pH in the gastric body, in accordance with the notion of greater intragastric acidity in the subcardial region.     

Wireless amplified NMR detector for improved visibility of image contrast in heterogeneous lesions

To demonstrate the capability of a wireless amplified NMR detector (WAND) to improve the visibility of lesion heterogeneity without the use of exogenous contrast agents, a cylindrically symmetric WAND was constructed to sensitively detect and simultaneously amplify MR signals emitted from adjacent tissues. Based on a two‐leg high‐pass birdcage coil design, this WAND could be activated by a pumping field aligned along the main field (B₀), without perturbing MR signal reception. Compared with an equivalent pair of external detectors, the WAND could achieve more than 10‐fold gain for immediately adjacent regions. Even for regions with 3.4 radius distance separation from the detector's cylindrical center, the WAND was at least 1.4 times more sensitive than an equivalent pair of surface arrays or at least twice as sensitive as a single‐sided external surface detector. When the WAND was inserted into a rat's rectum to observe adjacent tumors implanted beneath the mucosa, it could enhance the detection sensitivity of lesion regions, and thus enlarge the observable signal difference between heterogeneous tissues and clearly identify lesion boundaries as continuous lines in the intensity gradient profile. Hyperintense regions observable by the WAND existed due to higher levels of blood supply, which was indicated by a similar pattern of signal enhancement after contrast agent administration. By better observing the endogenous signal contrast, the endoluminal WAND could characterize lesions without the use of exogenous contrast agents, and thus reduce contrast‐induced toxicity.     

Totally Implantable Wireless Ultrasonic Doppler Blood Flowmeters: Toward Accurate Miniaturized Chronic Monitors

Totally implantable wireless ultrasonic blood flowmeters provide direct-access chronic vessel monitoring in hard-to-reach places without using wired bedside monitors or imaging equipment. Although wireless implantable Doppler devices are accurate for most applications, device size and implant lifetime remain vastly underdeveloped. We review past and current approaches to miniaturization and implant lifetime extension for wireless implantable Doppler devices and propose approaches to reduce device size and maximize implant lifetime for the next generation of devices. Additionally, we review current and past approaches to accurate blood flow measurements. This review points toward relying on increased levels of monolithic customization and integration to reduce size. Meanwhile, recommendations to maximize implant lifetime should include alternative sources of power, such as transcutaneous wireless power, that stand to extend lifetime indefinitely. Coupling together the results will pave the way for ultra-miniaturized totally implantable wireless blood flow monitors for truly chronic implantation.     

生命体征检测仪与电子病历数据库对接的设计与实现

本文介绍了将电子生命体征检测仪和无线网络技术用于记录病人体温、脉搏、呼吸及血压的三测单数据并传入电子病历数据库的设计思路和实现步骤。     

基于3G/4G无线网络的区域急救系统的设计

本文阐述了一套基于3G/4G无线网络的区域性急救系统的设计过程。该系统以医院急诊科为救治中心,依托专网专线和3G/4G通信网络建立,集成了数字化智能救护车系统、急救现场手提箱系统和区域性急救医疗信息系统。该系统的应用可以有效地提高院前医疗急救水平,提升应急突发事件的紧急救援处置能力,缩短院前急救时间,提高抢救成功率。