葡萄糖浓度对THz频段血液光学特性的影响

无创性血糖检测仍是糖尿病患者护理安全舒适的现实科学任务。本文研究了血糖光学特性与血糖浓度之间的相关性。用时域THz光谱研究了全血在0.3~0.5 THz频率范围内的透射谱。在注射胰岛素后的短时间内,由同一糖尿病患者产生了生物样品。得到了血液光学特性的频散特性。基于频散,给出了血糖浓度与折射率和介电常数的关系式。这项工作是复杂研究的一部分,重点是无创葡萄糖测量技术的发展。记录血糖水平与血液光学参数之间的依赖关系,使得将来可以使用反射光谱技术进行无创血糖水平检测。     

Optical Glucose Monitoring Based on Femtosecond Two-Color Pulse Interferometry

We demonstrate the potential of femtosecond two-color pulse interferometry for in vitro optical glucose monitoring, by dispersion of the group refractive index in a glucose solution sample with respect to a red-color light and a blue-color light. By comparison with femtosecond one-color pulse interferometry, the basic performance of the present system with regard to sensitivity, quantitativeness, and tolerance to surrounding disturbances, is evaluated. The resulting accuracy and precision of glucose determination are 77 and 118mg/dl for 10-mm-sample-thickness, respectively. This near-common-path configuration of the two-color pulse light provides good stability to fluctuations of sample temperature, which is important in clinical applications. Considering the performance of femtosecond two-color pulse interferometry as an optical glucose sensor, a suitable measurement site for in vivo optical glucose monitoring is discussed.     

Progress in Boronic Acid-Based Fluorescent Glucose Sensors

Effective management of diabetes relies on the frequent monitoring of blood glucose concentrations. The current approach of blood sampling and glucose concentration determination in vitro) presents many problems. Therefore, there is a drive for the development of non-invasive and continuous monitoring of glucose concentrations. The use of implanted glucose fluorescent sensors represents a promising approach. Due to its strong interaction with diol moieties, the boronic acid group often plays a critical role in the design of such glucose sensors. This paper reviews the progress in this area during the last ten years.     

基于安卓平台的糖尿病监护系统的研究及实现

基于目前针对糖尿病的研究主要集中在健康管理及血糖浓度监测方面,在糖尿病病情控制方面并不乐观的现状,设计开发了一套能够实时监护老年患者注射药物情况的远程家庭医疗系统。该系统由智能检测硬件系统,手机客户端和WEB信息管理端组成,不仅可以解决独孤老人时常忘记注射胰岛素的问题,也有利于解决我国老年患者糖尿病监护难的问题,同时也能提醒青壮年实时携带注射针剂盒,缓解糖尿病并发症的发生。通过实时实验测试,该糖尿病监护系统可靠、稳定,且具有良好的实际应用价值。     

论无创血糖监测的红外光谱方法(特邀)

介绍了无创血糖监测的几种光学方法以及红外光谱法用于无创血糖监测的优势。分析了无创血糖监测红外光谱法的主要问题,包括光在人体组织中的复杂传播;葡萄糖吸收信号微弱,且与人体中其它生化成分吸收光谱重叠;人体组织背景吸收干扰严重等。总结了无创血糖监测红外光谱法的最新进展,给出抑制人体组织背景吸收干扰的方法,并认为组织液可代替血液用于血糖水平的测量。展望了该领域未来研究趋势,主要涉及精确描述光子在组织中的传输、测量皮肤表皮内或表皮与真皮浅层光谱信息,以及提高光谱仪器信噪比,建立葡萄糖吸收带定标模型。     

New applications for ultrasonic sensors in process industries

Today, sophisticated instruments and algorithms used for process control allow the efficient production of substances with the quality guaranteed to the customer. However, production and management techniques are changing. This article aims to analyze trends resulting from those changes from the point of view of ultrasonic sensors. The focus will be on plant asset management. One part of plant asset management is maintenance management. Its goal is cost saving by avoiding unexpected shutdowns of single components or the complete plant. However, new maintenance concepts like condition-based or predictive maintenance require reliable methods of condition monitoring. This article will discuss these new applications for ultrasonic sensors. A new ultrasonic measurement based on acoustic emission analyses for condition monitoring of high pressure process pumps is introduced and economic benefits for the user are discussed.     

Multiple-Scattering-Free Optical Glucose Monitoring Based on Femtosecond Pulse Interferometry

We have designed a novel multiple-scattering-free optical glucose monitoring system based on femtosecond pulse interferometry. The glucose concentration is determined by a time-of-flight method, while multiple-scattering light is rejected by a coherence gate. The resultant accuracy and precision were 94.7 and 24.5 mg/dl, respectively, for physiological-equivalent glucose concentrations in a scattering medium of 1.0% intralipid solution, while the accuracy and precision for a reference sample containing no scattering medium were 65.3 and 23.8 mg/dl, respectively. Comparing these results, we conclude that the proposed method is effective for glucose measurement in a scattering medium.     

Classification of diabetes and measurement of blood glucose concentration noninvasively using near infrared spectroscopy

Developing noninvasive blood glucose monitoring method is an to immense need to alleviate the pain and suffering of diabetics associated with the frequent pricking of skin for taking blood sample. A hybrid algorithm for multivariate calibration is proposed to improve the prediction performance of classification of diabetes and measurement of blood glucose concentration by near infrared (NIR) spectroscopy noninvasively. The algorithm is based on wavelet prism modified uninformative variable elimination approach (WP-mUVE) combined with least squares support vector machine (LSSVM), named as WP-mUVE-LSSVM. The method is successfully applied to diabetic classification experiment (in vivo) and blood glucose concentration measurement experiment (in vivo) respectively. Human tongue is selected as the measuring site in this study. To evaluate effectiveness of pretreatment method and quality of calibration models, several usually used pretreatment methods and kernel functions of LSSVM are introduced comparing with our method. Higher quality data is obtained by our pretreatment method owing to the elimination of varying background and noise of spectra data simultaneously. Better prediction accuracy and adaptability are obtained by LSSVM model with radial basis kernel function. The results indicate that WP-mUVE-LSSVM holds promise for the classification of diabetes and measurement of blood glucose concentration noninvasively based on human tongue using NIR spectroscopy.     

基于谱分解的无创血糖检测新方法研究

糖尿病是一种表现为高血糖的糖代谢异常疾病,如果血液中的葡萄糖水平长时间保持非常低或非常高,则可能导致包括组织损伤、中风、心脏病、失明和肾衰竭等严重疾病。根据世界卫生组织（WHO）的数据,目前全球约有4.5亿糖尿病患者。随着糖尿病患者的数量增加,对于血糖检测仪器的需求也日益迫切,由于目前普及的有创侵入式血糖检测仪器会给患者带来不便和疼痛,甚至会引发感染,长此以往会给病人带来不可避免的生理及心理压力,因此实现无创血糖检测具有重要的临床应用价值。光电容积脉搏波(PPG)包含丰富的人体心血管生理病理信息,针对于时域难以观察的PPG信号中与血糖浓度变化相关的频谱信息,提出基于谱分解的无创血糖检测新方法,利用连续小波变换（CWT）对脉搏波信号进行分解,从对应尺度和细节分量的频谱中获取与血糖浓度值变化相关的频谱分量幅值信息,研究发现PPG信号频谱分量幅值的变化与血糖浓度变化值之间存在较高的相关性,通过口服葡萄糖耐糖实验(OGTT)对检测的血糖浓度值与获取的相关PPG信号频谱分量幅值进行偏最小二乘回归建模,并对建立的模型进行评估,校正集的最大RMSEC为12.47 mg·dL-1即0.69 mmol·L-1,预测集的最大RMSEP为6.21 mg·dL-1即0.35 mmol·L-1,模型的血糖浓度预测值与参考值之间的一致率为96.00%。OGTT实验结果表明,采用谱分解法可以有效分离出血糖分子基团振动特征吸收光谱,血糖频谱分量建模可以最大程度地减小生理变异性和各种环境条件的影响。模型的预测结果符合国家检测标准（＞95%）。克拉克网格误差分析结果表明,该方法检测的结果可以用于患者日常血糖监测。     

Overview of CMOS image sensor use in molecular diagnostics

CMOS sensors comprise an important tool in bioscientific applications. This review focuses on CMOS sensor-based molecular diagnostics of DNA, protein, and metabolic molecules. Herein, gene sequencing, DNA–DNA hybridization, single nucleotide polymorphisms (SNP), protein interactions, peptide interactions, antigen–antibody (Ag–Ab) interactions, as well as glucose and cholesterol monitoring using CMOS sensors are discussed along with existing experimental outcomes. CMOS sensor based electrochemical, optical, impedance, dual, continuous, and label-free analysis and their related integration techniques are explained. Moreover, we describe the utilization of a CMOS chip in microarray fabrication, assay platform development, and transducer incorporation for molecular diagnostics. Furthermore, CMOS sensor-based point-of-care (POC) applications, other biological analyses, and the role of nanoparticles in biomolecular sensing are discussed. Future directions include information about the novel integration of CMOS sensor-based molecular diagnostic devices with a central focus towards enhancement of POC approaches. This review is helpful in creating highly sensitive, cheaper, and user-friendly biomedical devices with modern dimensions.     

Optical monitoring of glucose concentration

A device for the monitoring of blood glucose levels is investigated. It measures the sugar concentration using the effect of the glucose on the optical refractive index. Light is transmitted along an optical fibre, and, as most of the internal rays are incident at the fibre surface at an angle less than the critical angle, the refractive index of the surrounding liquid can be calculated. The device can measure glucose concentrations with a sensitivity of better than 0.1%.     

毫米级高分辨率的混沌激光分布式光纤测温技术

近年来,随着分布式光纤传感技术在各大基础设施健康监测领域的广泛应用,人们对能够实现毫米量级精准定位和监测技术的需求日益增长.本文提出了一种基于宽线宽混沌激光的高分辨率分布式光纤测温技术.实验通过改变光反馈混沌源的偏振匹配态和反馈强度等外部参数,产生了–3 dB线宽约为7.5 GHz的宽线宽混沌激光,并在300 m传感光纤实现了空间分辨率为7.05 mm的分布式温度测量.同时,为了抑制光源线宽增加造成的布里渊增益谱恶化,在泵浦路中引入了时间门控技术,其中经脉冲调制后的泵浦光峰值功率提高了约9.5 dB,同时脉冲调制使混沌互相关锁定于脉冲持续时间内,从而布里渊增益谱的信号背景噪声比由约2.28 dB提升为4.55 dB,最终实现了空间分辨率为3.12 mm的分布式温度测量.     

Glucose-Sensitive Nanoassemblies Comprising Affinity-Binding Complexes Trapped in Fuzzy Microshells

A new design for glucose monitoring with "smart" materials based on self assembly, competitive binding, and resonance energy transfer (RET) is presented. The basic transduction principle is changing RET efficiency from fluorescein isothiocyanate (FITC) to tetramethylrhodamine isothiocyanate (TRITC), as FITC-dextran is displaced from TRITC-Concanavalin A (Con A) with the addition of glucose. Nanoscale fabrication by self-assembly of Con A/dextran into multilayer films, followed by polymer multilayers. The advantages of this approach include physical localization and separation of sensing molecules from the environment via entrapment of the biosensorelements in a semi-permeable polymeric shell, and only functional molecules are included in the sensors. To realize these nanostructures, dissolvable resin microparticles were coated with FITC-dextran+TRITC-Con A multilayers, followed by polyelectrolyte multilayers, and the core particles were then dissolved to yield hollow capsules. The nanoassembly process was studied using microbalance mass measurements, fluorescence spectroscopy, confocal fluorescence microscopy, and zeta-potential measurements. The key findings are that the specific binding between Con A and dextran can be used to deposit ultrathin multilayer films, and these exhibit changing RET in response to glucose. Fluorescence spectra of a microcapsules exhibited a linear, glucose-specific, 27% increase in the relative fluorescence of FITC over the 0-1800 mg/dL range. These findings demonstrate the feasibility of using self-assembled microcapsules as optical glucose sensors, and serve as a basis for work toward better understanding the properties of these novel materials.     

测量光学玻璃电流传感头线性双折射的新方法

线性双折射是光学(含光纤)电流传感头的重要光学参量之一,会明显影响光学电流传感器的性能,因此测量光学传感头内线性双折射的大小对于提高光学电流传感器的性能有重要意义.本文报道了一种测量光学玻璃电流传感头线性双折射的新方法,以琼斯矩阵为数学工具给出了对该方法的理论分析及测量不确定度分析,并用实验方法给出了应用实例.此方法的主要优点是弥补了以前报道过的两种测量方法暴露出的无法唯一地确定光学玻璃电流传感头线性双折射的大小,或虽然能测定双折射大小,但测量不确定度较大的不足.实验结果表明:本方法可明显地提高测量准确度.     

Current Problems and Potential Techniques in In Vivo Glucose Monitoring

Accurate in vivo monitoring of glucose concentration would be a valuable asset, particularly for management of diabetes and preterm infants during critical care. In vivo glucose monitoring devices can be divided into two categories: implanted and non-invasive. Extensive research into in vivo glucose monitoring over recent decades has not resulted in the widespread use of clinically reliable monitoring systems. For implanted devices, poor biocompatibility of the materials used for fabrication remains a major challenge, whilst progress in the commercial development of non-invasive devices is hampered by the problem of multiple interference between the detected signals and the biological components. In this review, the methods available for in in-vivo glucose monitoring are described and the associated problems are discussed.     

近红外光谱无创血糖测量中背景扣除方法的研究

在近红外光谱人体血糖无创检测中,由于葡萄糖在体内含量非常低,而光谱中的噪声组成复杂且变化幅度大,从而导致测量的信噪比较低。背景扣除是提高测量信噪比的有效预处理手段之一。文章首先对常用的背景扣除方法进行了理论推导,并进一步考虑不同样品在测量过程中存在的样品本身特性变化,提出了相近背景扣除的方法,即选择与样品的光学特性变化相似的样品作为背景,能更有效地消除样品特性变化和仪器漂移的影响。并在纯吸收和散射介质中分别加入葡萄糖进行实验验证。结果表明,在血浆溶液和Intralipid-2%溶液的葡萄糖实验中,选用与样品特性更接近的样品作为背景时,葡萄糖浓度的预测精度分别提高了25.9%和40.1%。     

光谱测量在激光加工在线监测上的应用研究进展

随着现代工业的发展,复杂加工环境和对象、大动态范围、高效率和高精度激光加工需求愈加迫切,在线监测并实时优化激光加工参数是一条重要的解决途径。与此同时,激光与物质相互作用时可产生与加工参数、加工过程和目标特性密切相关的光信号和表面光学特性变化,在线测量光信号光谱可分析加工过程和状态,故光谱测量有望成为一种重要的激光加工在线监测手段。实际上,光谱测量已应用于激光焊接、激光切割和钻孔、激光清洗打磨、微纳结构制备和增材制造等几乎所有激光加工工艺,具有分辨率高和光谱信息丰富等特点。分析和总结了用于激光加工在线监测的光谱测量技术,包括等离子体光谱、反射光光谱和非线性光信号光谱等。基于单脉冲和多脉冲激光加工激发等离子体信号的光谱测量,除实现化学成分定性和定量监测外,还可以根据特征谱线相对强度变化实时调焦,根据等离子体温度监测和调控激光加工过程中与热效应相关的物理过程;作为一种无损伤且工作距离较远的监测方法,反射光光谱监测可通过测量特定波段反射光信号光谱积分功率、特征谱线和波段位置和强度来有效监测材料表面清洁度、损伤、色度和成分变化等;而在特定条件下产生的谐波信号、荧光信号和拉曼信号等非线性光信号,尽管应用场景有限,但提供了一种实现成分、焦距和材料损伤等监测的新方法。进而,展望了光谱测量在激光加工在线监测上应用的未来发展趋势,包括多种光信号的光谱协同监测与光、声、温度及图像等多种信号测量的复合监测。同时,人工智能技术与在线监测和激光加工的深入结合将进一步推动激光加工技术的智能化发展。     

Luminescence-Based Optical Fiber Chemical Sensors

A scheme for the simultaneous determination of temperature and analyte concentration for application in luminescence-based chemical sensors is proposed. This scheme is applied to an optical oxygen sensor, which is based on the quenching of the fluorescence of a ruthenium complex. Temperature measurement is performed using the excitation radiation and an absorption long-pass filter. Preliminary results are presented that show the viability of an oxygen measurement that is independent of temperature and optical power level. The possibility of self-referenced temperature measurements with semiconductor nanoparticles is also investigated. In order to optimize the sensor design, several different optical fiber probe geometries for oxygen sensing are tested and compared, including different methods of coupling radiation into the optical fiber system. Polyvinyl alcohol (PVA) and polyacrylamide membranes are tested as supports for sensor immobilization in fiber-optical pH sensing devices in aqueous solution. Some results are presented that show the feasibility of using fiber-optical pH indicators for remote monitoring.     

Luminescence-Based Optical Fiber Chemical Sensors

Abstract

A scheme for the simultaneous determination of temperature and analyte concentration for application in luminescence-based chemical sensors is proposed. This scheme is applied to an optical oxygen sensor, which is based on the quenching of the fluorescence of a ruthenium complex. Temperature measurement is performed using the excitation radiation and an absorption long-pass filter. Preliminary results are presented that show the viability of an oxygen measurement that is independent of temperature and optical power level. The possibility of self-referenced temperature measurements with semiconductor nanoparticles is also investigated. In order to optimize the sensor design, several different optical fiber probe geometries for oxygen sensing are tested and compared, including different methods of coupling radiation into the optical fiber system. Polyvinyl alcohol (PVA) and polyacrylamide membranes are tested as supports for sensor immobilization in fiber-optical pH sensing devices in aqueous solution. Some results are presented that show the feasibility of using fiber-optical pH indicators for remote monitoring.