Integrated Devices for Non-Invasive Diagnostics

“Sample-in-answer-out” type integrated diagnostic devices have been widely recognized as the ultimate solution to simplify testing across healthcare systems. Such systems are equipped with advanced fluidic, mechanical, chemical, biological, and electronic components to handle patient samples without any manual steps therefore have the potential to accelerate intervention and improve patient outcomes. In this regard, the combination of integrated devices and non-invasive sampling has gained a substantial interest to further improve the comfort and safety of patients. In this Review, the pioneering developments in integrated diagnostics are covered and their potential in non-invasive sampling is discussed. The key properties of possible sample types are highlighted by addressing their relevance for the clinical practice. Last, the factors affecting the transition of integrated devices from academia to the market are identified by analyzing the technology readiness levels of selected examples and alternative remedies are explored to increase the rate of survival during this transition.     

沿面闪络用非介入式表面电位测量研究

沿面闪络是威胁气体绝缘封闭开关(GIS)安全运行的重要事故,支撑绝缘“三结合点”处的表面电场畸变易产生电荷积聚并最终演变成持续性沿面闪络。本文通过对指形电极沿面闪络装置进行非介入式表面电位测量,并通过有限元分析软件验证实验装置的可行性,在本文的仿真参数设定下,非介入式测量误差仅为2.42%。利用该实验装置对添加纳米SiO₂质量分数为2 wt%的环氧试样进行表面电位测量,升压速率为0.5 kV/5 min。当施加电压不足以引发沿面闪络时,纳米颗粒的添加引起的Maxwell-Wagner界面极化使得表面电位呈现衰减现象。当施加电压接近闪络电压时,表面电位衰减过程出现周期性回升现象,且回升现象出现的频率随施加电压升高而变快,闪络前表面电位衰减过程中的回升现象能够作为预测沿面闪络的一种信号。当施加电压为5 kV时,发生沿面闪络现象,闪络过程表现为间歇性闪络向持续性闪络的过渡。在间歇性闪络阶段,表面电位的幅值出现极性反转现象,可能与瞬间短路引起的电子沿面泄露和Maxwell-Wagner界面去极化有关。持续性闪络阶段表面电位的幅值波动相较于间歇性闪络要小且相邻闪络间期变短,说明闪络引起表面灼烧通路更易于发生沿面闪络。     

能量代谢守恒法无创血糖检测算法研究

根据能量代谢守恒法无创血糖检测的基本原理,设计出无创血糖检测探头并推导出血糖检测的数学模型。采用了多元线性回归和主分量分析方法处理数据,得出了计算血糖值的多元线性表达式,获得了对血糖值贡献最大的两个分量。实验结果显示,采用上述算法计算得出的血糖值与血糖真实值之间的相关系数R=0.86,表明了采用主分量分析和多元线性回归求解无创血糖检测模型的方法是可行的。     

Non-invasive glucose measuring apparatus based on conservation of energy method

A new non-invasive blood glucose measuring apparatus (NBGMA) made up of MSP430F149 SCM (single chip micyoco) was developed, which can measure blood glucose level (BGL) frequently, conveniently and painlessly. The hardware and software of this apparatus were designed, and detecting algorithms based on conservation of energy method (COEM) were presented. According to the law of conservation of energy that the energy derived by human body equals energy consumed by metabolism, and the relationship between convection, evaporation, radiation and the BGL was established. The sensor module was designed. 20 healthy volunteers were involved in the clinical experiment. The BGL measured by an automatic biochemical analyzer (ABA) was set as the reference. Regression analysis was performed to compare the conservation of energy method with the biochemical method, using the 20 data points with blood glucose concentrations ranging from 680 to 1 100 mg/L. Reproducibility was measured for healthy fasting volunteers. The results show that the means of BGL detected by NBGMA and ANA are very close to each other, and the difference of standard deviation (SD) is 24.7 mg/L. The correlative coefficient is 0.807. The coefficient of variation (CV) is 4% at 921.6 mg/L. The resultant regression is evaluated by the Clarke error grid analysis (EGA) and all data points are included in the clinically acceptable regions (region A: 100%, region B: 0%). Accordingly, it is feasible to measure BGL with COEM.     

心音信号分析方法及应用性研究

阐述了心音信号的产生机理、组成成分以及人体微弱心音信号检测的关键技术,介绍了心音信号处理技术在心血管疾病无创诊断中的意义,结合应用分析了经典心音信号谱分析方法的局限性,对现代心音分析中的常用的时频分析方法的特点进行了探讨,并展望了心音信号识别技术的应用与发展前景.     

检测细胞代谢气体成分诊断肺癌的方法

提出了一种在细胞水平进行肺癌病理气体检测和早期诊断的方法,分析了肺癌细胞新陈代谢产物中特征性挥发性有机气体成分（VOCs）.采用固相微萃取 气相色谱（SPME-GC）气体检测装置来检测多种目标细胞的VOCs.选取13例肺癌病人手术切除后的肺癌组织和癌旁组织进行培养和电镜观察.通过对比不同类型肺癌细胞、肺癌细胞与同体正常肺部细胞、肺癌细胞与其他包括支气管上皮细胞、味蕾细胞、成骨细胞、脂肪粒细胞培养液中的VOCs,证明了肺癌细胞培养液中存在的特征性VOCs是肺癌细胞新陈代谢的产物,可以作为判定特定肺癌细胞的依据,为电子鼻呼吸诊断提供了重要依据.     

一种基于多参量隐马尔可夫模型的负荷辨识方法

由于电力需求侧负荷形态各异、特性多变,种类繁多,采用传统方法进行负荷辨识时存在识别率不高、模型建立困难、难以推广应用等问题。为此,基于智能负荷控制器(SRLC)的用电参数检测功能和非侵入式负荷监测(NILM)原理,提出一种基于多参量隐马尔可夫模型(MPHMM)的负荷辨识方法。该方法采用4个负载特性参数(电流、有功功率、无功功率、功率因素)作为模型的观测向量,通过模型学习和多次迭代计算,求得与MPHMM模型隐藏状态相匹配的观测序列的最大输出概率和最优状态序列,再采用辅助判别算法对结果进行修正,完成对负荷的最终辨识。通过搭建实验平台对所提方法进行验证。结果表明,该方法辨识准确率可达95%以上,特别是对小功率负荷具有较好的识别效果。     

用于检测皮瓣移植术后血红蛋白浓度的多方位反射式无创测试系统

血红蛋白浓度作为衡量皮瓣移植手术部位恢复状 况的重要指标,能较好地反映血液流通状态。目前 常见的术后血运监测方法限于对皮肤温度、颜色和肿胀程度等物理观察和经验诊断,或仅通 过血氧饱和度 粗略判断,未见对血红蛋白浓度的实时监测。本文设计并搭建了一种用于检测皮瓣移植术后 血红蛋白浓度 的多方位反射式无创测试系统,通过对样本数据的采集分析引入修正系数,实现了血红蛋白 浓度的无创检 测。实验结果表明,6名志愿者连续10次测量结果的标准偏差较小; 40组测量值与真值的相关性良好;皮 肤加热后采集的血红蛋白浓度对温度变化灵敏,说明系统具有较好的稳定性、精确性和有效 性。项目组将 与河南大学淮河医院合作,对皮瓣移植术后患者的血红蛋白浓度进行临床检测,进一步校准 数据并研发小 型化便携式测量仪器,为术后护理提供更加可靠的依据。     

一种低功耗无创血糖仪设计与性能测试

结合反离子电渗抽取原理,设计了一款基于MSP430F1611芯片的低功耗血糖仪,配合自制的三电极葡萄糖传感器,实现对组织液葡萄糖的无创抽取和低浓度葡萄糖的检测.该仪表采用MSP430F1611作为主芯片,对其它功能模块进行了低功耗设计,在3.7 V工作电压下最大工作电流降低至17.31 mA.设计了模拟实验和动物实验验证了该仪表的反离子电渗抽取和对低浓度葡萄糖的检测能力.仪表在模拟皮肤电阻阻抗小于80 kΩ时,可实现恒流抽取,当大于80 kΩ时,可实现恒压抽取.动物实验结果表明,可进行反离子电渗和检测.在葡萄糖浓度5~200 μmol/L范围内,仪表的响应电流与葡萄糖浓度呈现良好的线性关系,线性相关系数为0.9979,检测灵敏度达到15.619 nA(μmol/L)-1.仪表为动物实验研究奠定基础.     

血糖检测技术研究进展

血糖是临床上分析病人是否患糖尿病的重要参考指标之一。本文对有创、微创和无创检测三种检测血糖的方法作了阐述,并进行了展望,指出闭环无创胰岛素泵集成系统和半闭环有创胰岛素泵集成系统是今后血糖检测技术研究的主要方向。