Improved magnetic particle tracking technique in dense gas fluidized beds

Noninvasive monitoring of multiphase flow is rapidly gaining increased interest. More specifically noninvasive particle tracking techniques have received a lot of attention in recent years to study dense granular flow. However, these techniques are usually quite expensive and require strict safety measures. An improved magnetic particle tracking (MPT) technique for dense granular flow will be presented in this article. The improvements of the analysis technique for MPT will be demonstrated and rigorously tested with a three‐dimensional system and two‐dimensional sensor system. The strengths and limitations of the MPT technique will also be reported. Finally, the results of the MPT are compared with data obtained from a combined particle image velocimetry and digital image analysis technique. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3133–3142, 2014     

Arduino-based slider setup for gas–liquid mass transfer investigations: Experiments and CFD simulations

The implementation of traditional sensors is a drawback when investigating mass transfer phenomena within microstructured devices, since they disturb the flow and reactor characteristics. An Arduino based slider setup is developed, which is equipped with a computer-vision system to track gas–liquid slug flow. This setup is combined with an optical analytical method allowing to compare experimental results against CFD simulations and investigate the entire lifetime of a single liquid slug with high spatial and temporal resolution. Volumetric mass transfer coefficients are measured and compared with data from literature and the mass transfer contribution of the liquid film is discussed.     

光学相干层析成像技术确定组织光学特性

光学相干层析成像(OCT)是近年来发展较快的一种新型成像技术,能对生物组织内部的微观结构进行高分辨率的横断面层析成像,具有快速、非侵入及高分辨率等特点,在体生物组织微观结构分析和疾病诊断等方面具有重要的应用价值.综述了采用光学相干层析成像技术确定生物组织光学特性的研究.     

动态光谱法对提高近红外无创血液成份检测精度的理论分析

近红外光谱无创血液成分检测因测量方法具有优越性,已经成为生物医学领域的研究热点之一.但除血氧以外,目前还没有进入临床应用的报道,其原因在于个体差异和测量条件对检测精度的影响.研究了一种不同于传统的新检测方法-动态光谱法可使测量精度提高.先从检测原理出发,研究了传统的近红外无创血液成分测量过程中产生误差、造成测量精度较低的因素;再分析了动态光谱法对这些因素的抑制或克服.从理论上得到了动态光谱法可以大大提高血液成分无创检测精度的结论,为基于光谱法的无创血液成分检测的临床应用提供了条件.     

脂肪乳液中物质浓度的光学低相干干涉测量

为了实现对散射介质的非接触测量,有效地提高灵敏度,提出了光学低相干干涉测量方法.采用光纤型迈克尔逊干涉结构,增加了扫描延迟线和光学外差探测电路,实现了具有光程分辨能力的干涉测量.以脂肪乳剂Intralipid为样本,通过稀释和加入染色剂的方法改变其散射和吸收特性.通过对溶液内反射信号的干涉测量和曲线拟合,研究了光程相关的干涉光信号与物质浓度的依赖关系.实验对象为散射和吸收特性相对稳定的脂肪乳剂和印度墨水混合物,其中Intralipid乳剂浓度在4%~16%之间,印度墨水浓度在0~1%之间.拟合方法引用了广义惠更斯菲涅耳(EHF)模型的解析表达式,拟合相关系数在0.98以上.实验结果与积分球测量结果进行了比较,初步验证了理论方法的可行性.     

无创神经调控技术对全麻患者术后睡眠功能紊乱影响的研究进展

无创神经调控技术是主要通过电刺激、磁刺激等对神经功能状态进行调控的一种非侵入性、安全、便捷的有效治疗手段。近年来,无创神经调控技术越来越多地被用于脑功能调控的相关研究和治疗,其在脑卒中患者的认知障碍调控、抑郁、焦虑、谵妄、失眠等神经精神疾病的治疗上都有相关研究证实。临床科室如神经内科、康复科、疼痛科等多学科都广泛运用无创神经调控这一技术,但其在围术期的应用较少,尤其是针对全麻患者术后睡眠功能紊乱的研究尚未见报道。术后睡眠功能紊乱是术后一个常见且容易被忽视的并发症,常表现为术后睡眠结构紊乱、睡眠质量下降、睡眠时长明显缩短等,全身麻醉患者术后睡眠功能更容易受影响。术后睡眠功能紊乱涉及术前、术中以及术后等很多影响因素,影响患者整个围术期甚至出院后的长期预后。     

冠心病无创检测新方法及系统设计

提出了一种基于BP型人工神经网络的冠心病无创检测新方法,并设计了相应的诊断系统.该系统对人体体表心电信号进行处理,提取与冠心病有关的特征参数(RR间期,QRS波宽度,ST段电平和斜率),结合血压及个体基本信息(性别、年龄、体质量、是否吸烟等),利用BP型人工神经网络进行冠心病的无创检测和诊断.实验结果表明该方法具有一定的可操作性和实用性.     

Thin,Millimeter Scale Fingernail Sensors for Thermal Characterization of Nail Bed Tissue

Thin, flexible, body‐worn technologies that allow precise, quantitative monitoring of physiological status are of broad current interest due to their potential to improve the cost and effectiveness of healthcare. Although the surface of the skin represents one of the most widely explored points of integration, recently developed millimeter scale wireless sensor platforms allow deployment on alternative surfaces of the body, such as the finger/toenails and the teeth. The work described here introduces a collection of ideas in materials science, device engineering and computational techniques that enables precise characterization of the thermal transport characteristics of the nail bed tissue from measurements on the surface of the nail. Systematic in vitro studies demonstrate the underlying measurement principles, the theoretical models for optimized sensor design and the associated experimental procedures for determining the thermal conductivity of the tissue. Measurements performed on human subjects highlight capabilities in tracking changes in perfusion of the nail bed tissues in response to various external stimuli.     

用于无损检测的三坐标定位控制系统

介绍了用于对物体内部进行无损伤检测的控制系统。文中给出了控制系统的总体结构及速度控制算法。该系统采用变M/T测速方法,弥补了M/T测速方法的不足,获得了很好的测速效果。