Accuracy of FreeStyle Libre flash glucose monitoring in patients with type 2 diabetes who migrated from highlands to plains

BACKGROUND The FreeStyle Libre flash glucose monitoring(FGM)system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose.Due to its increased usage in clinics,the number of studies investigating its accuracy has increased.However,its accuracy has not been investigated in highland populations in China.AIM To evaluate measurements recorded using the FreeStyle Libre FGM system compared with capillary blood glucose measured using the enzyme electrode method in patients with type 2 diabetes(T2D)who had migrated within 3 mo from highlands to plains.METHODS Overall,68 patients with T2D,selected from those who had recently migrated from highlands to plains(within 3 mo),were hospitalized at the Department of Endocrinology from August to October 2017 and underwent continuous glucose monitoring(CGM)with the FreeStyle Libre FGM system for 14 d.Throughout the study period,fingertip capillary blood glucose was measured daily using the enzyme electrode method(Super GL,China),and blood glucose levels were read from the scanning probe during fasting and 2 h after all three meals.Moreover,the time interval between reading the data from the scanning probe and collecting fingertip capillary blood was controlled to<5 min.The accuracy of the FGM system was evaluated according to the CGM guidelines.Subsequently,the factors influencing the mean absolute relative difference(MARD)of this system were analyzed by a multiple linear regression method.RESULTS Pearson’s correlation analysis showed that the fingertip and scanned glucose levels were positively correlated(R=0.86,P=0.00).The aggregated MARD of scanned glucose was 14.28±13.40%.Parker's error analysis showed that 99.30%of the data pairs were located in areas A and B.According to the probe wear time of the FreeStyle Libre FGM system,MARD_(1 d) and MARD_(2-14 d) were 16.55%and 14.35%,respectively(t=1.23,P=0.22).Multiple stepwise regression analysis showed that MARD did not correlate with blood glucose when the largest amplitude of glycemic excursion(LAGE)was<5.80 mmol/L but negatively correlated with blood glucose when the LAGE was≥5.80 mmol/L.CONCLUSION The FreeStyle Libre FGM system has good accuracy in patients with T2D who had recently migrated from highlands to plains.This system might be ideal for avoiding the effects of high hematocrit on blood glucose monitoring in populations that recently migrated to plains.MARD is mainly influenced by glucose levels and fluctuations,and the accuracy of the system is higher when the blood glucose fluctuation is small.In case of higher blood glucose level fluctuations,deviation in the scanned glucose levels is the highest at extremely low blood glucose levels.

Hepatitis C virus core antigen testing: Role in diagnosis, disease monitoring and treatment

While hepatitis B virus(HBV)screening relies on hepatitis B surface antigen to confirm HBV infection since the early days of hepatitis B disease management,hepatitis C virus(HCV)infection screening is based on anti-HCV testing which does not discriminate active from past infection.Thus to confirm infection HCV RNA testing has been required;recently a HCV core antigen assay became widely commercially available which could serve to confirm infection.That assay is less sensitive than current HCV RNA assays,but as more than 50%of anti-HCV positive persons will be HCV core antigen positive,HCV core antigen testing can be a cost effective and reflex test to confirm HCV infection in anti-HCV positive individuals and will be easier as it can be applied on the same platform.For treatment monitoring,more data need to be generated,but the early data available at present suggest that HCV core antigen may be an alternative to HCV RNA monitoring.With direct antivirals,HCV core antigen could even be superior to HCV RNA testing,as direct antivirals might already prevent virus formation when HCV core antigen is still produced and thereby correlates better with eventual viral clearance.

Optical Surface Monitoring系统跟踪运动靶区的位置精度和剂量精度验证

目的:评估Optical Surface Monitoring System(OSMS)测量靶区运动的几何精度和使用OSMS跟踪运动靶区放疗时的剂量精度。方法:①分别使用OSMS与锥形束CT监测腹部模体的位置,通过移动治疗床使模体产生位移和旋转,对比二者对模体位置的测量结果;②用呼吸运动平台搭载MatriXX二维电离室阵列,测量不同跟踪阈值时模体内相对剂量,分别与计划剂量分布对比,分析不同跟踪阈值时计划验证的gamma通过率。结果:OSMS和锥形束CT系统对模体平移和旋转预设偏移的测量结果差异很小,使用OSMS门控技术时OSMS的阈值越小gamma通过率越高,相对剂量分布与计划剂量的一致性也越好。结论:OSMS系统对模体表面位置监测精度高,可以应用到实际放射治疗的辅助摆位。使用OSMS门控技术跟踪运动靶区可以提高靶区的剂量精度,而且对患者不附加任何电离辐射,适合应用于分次间的辅助摆位和分次内的靶区跟踪。

Study on the Monitoring Malfunction of Water Pollution during Drought or Flood Period and Low-carbon and High-value Methodology--A Case Study of the Correlation Test of Water,Soil and Gas Pollution in Xiangxiang County

Based on the low-carbon and high-value methodology of chemical ecology and chemical informatics,combining theory and methods,taking saving,environmental protection,low carbon,high production,high value and circulation as values and aims,the relationship between human and land as a basis,ecosystem as a center,overall control as a goal and agricultural ecological engineering as a mean,environmental pollution detection,as one of bottlenecks for agricultural products and food security,should be solved firstly;through the field survey in dry years from 2009 to 2010 when drought and flood were frequent and the frequency of drought was higher than that of flood,plus the determination of surface water flow and water quantity in a small typical river basin,the correlation of local water,soil and gas in the county could be found,and the transfer of monitoring focus from water environment to atmospheric environment was possible and necessary.The study would promote the quantitative research on the correlation among water,soil and gas,and the results were in accordance with the conclusions of related studies.

A Non-Asymptotic Confidence Region with a Fixed Size for a Scalar Function Value: Applications in C-OTDR Monitoring Systems

In this paper we will investigate some non-asymptotic properties of the modified least squares estimates for the non-linear function f(λ*) by observations that nonlinearly depend on the parameter λ*. Non-asymptotic confidence regions with fixed sizes for the modified least squares estimate are used. The obtained confidence region is valid for a finite number of data points when the distributions of the observations are unknown. Asymptotically the suggested estimates represent usual estimates of the least squares. The paper presents the results of practical applications of the proposed method in C-OTDR monitoring systems.

Calibration of CO and CO2 Monitors Used in Periodic Inspection of Vehicles at Fixed Stations for Environmental Control

Global efforts for environmental cleanliness through the control of gaseous emissions from vehicles are gaining momentum and attracting increasing attention. Calibration plays a crucial role in these efforts by ensuring the quantitative assessment of emissions for informed decisions on environmental treatments. This paper describes a method for the calibration of CO/CO2 monitors used for periodic inspections of vehicles in cites. The calibration was performed in the selected ranges: 900 - 12,000 µmol/mol for CO and 2000 - 20,000 µmol/mol for CO2. The traceability of the measurement results to the SI units was ensured by using certified reference materials from CO/N2 and CO2/N2 primary gas mixtures. The method performance was evaluated by assessing its linearity, accuracy, precision, bias, and uncertainty of the calibration results. The calibration data exhibited a strong linear trend with R² values close to 1, indicating an excellent fit between the measured values and the calibration lines. Precision, expressed as relative standard deviation (%RSD), ranged from 0.48 to 4.56% for CO and from 0.97 to 3.53% for CO2, staying well below the 5% threshold for reporting results at a 95% confidence level. Accuracy measured as percent recovery, was consistently high (≥ 99.1%) for CO and ranged from 84.90% to 101.54% across the calibration range for CO2. In addition, the method exhibited minimal bias for both CO and CO2 calibrations and thus provided a reliable and accurate approach for calibrating CO/CO2 monitors used in vehicle inspections. Thus, it ensures the effectiveness of exhaust emission control for better environment.

智能传感技术在水肥一体系统中的应用研究

以进一步提升水肥一体机系统的作业效率为目标,选取智能传感的监测技术,针对整机的监测控制与信号处理展开应用设计研究。考虑水肥一体机过程作业肥液融合的均匀性及系统各模块之间的协同性功能实现,结合微分补偿的传感数据算法处理方法,进行智能传感的水肥一体机架构布局,并匹配可执行的软件控制程序及硬件实施结构,进行实地传感应用监测与灌施控制作业试验。结果表明:水肥一体机系统的数据监测准确率可达95.25%,系统故障率相对降低3.79%,监测数据准确及时,能够确保系统各环节指令得到有效的调整与反馈,进而保证灌施土壤的含水稳定率相对提升7.87%,对于作物的稳定生长与产量提升有重要的参考价值。

Differences in the system accuracy acceptability of four types of blood glucose monitoring systems against five different standards

Objective:This study aimed to evaluate the system accuracy of four types of blood glucose monitoring systems(BGMSs)and explore the differences in the system accuracy acceptability of each BGMS against five different standards.Methods:The glucose measurement values obtained from four types of BGMSs(Roche Accu-Chek® Performa,Bayer Contour™ TS,Sinomedisite Glupad® H1 Plus,and Sinocare® Gold-Accu)were evaluated against the reference values obtained from the biochemical analyzer of the central laboratory.The system accuracy acceptability of each BGMS was determined using the criteria specified in five standards,namely the International Organization for Standardization(ISO)15197:2003,Clinical Laboratory Standards Institute(CLSI)POCT12-A3,ISO 15197:2013,Chinese Society of Laboratory Medicine(CSLM)consensus,and US Food and Drug Administration(FDA)guidelines.Results:From 2018 to 2022,10,980 pairs of measurement values were obtained from 366 glucose meters of four types of BGMSs.Significant correlations were observed between the glucose measurement values from the BGMSs and the reference values from the biochemical analyzer of the central laboratory.The correlation coefficient r was 0.995 for Roche Accu-Chek® Performa,0.994 for Bayer Contour™ TS,0.983 for Sinomedisite Glupad® H1 Plus,and 0.997 for SinocareR Gold-Accu.The acceptability criteria specified in ISO 15197:2003 were met by 100.00%(135/135)of the glucose meters of Roche Accu-Chek® Performa,100.00%(109/109)of Bayer Contour™ TS,81.61%(71/87)of Sinomedisite Glupad® H1 Plus,and 100.00%(35/35)of SinocareR Gold-Accu.Whereas,the acceptability criteria specified in ISO 15197:2013 were met by 99.26%(134/135)of the glucose meters of Roche Accu-Chek® Performa,88.07%(96/109)of Bayer Contour™ TS,58.62%(51/87)of Sinomedisite Glupad R H1 Plus,and 91.43%(32/35)of SinocareR Gold-Accu.Conclusions:Among the four types of BGMSs evaluated,the glucose meters of Roche Accu-Chek® Performa exhibited superior system accuracy.The system accuracy acceptability of each BGMS varied significantly against the acceptability criteria specified in the five different standards.

Design and Implementation of an IoT Based Remote Health Monitoring System

Considering the quality of life, manpower, and expenditure, an IoT-based health monitoring system has been proposed and implemented. Devices are placed on the human body to collect data, which is then uploaded to an online data server. Specialist doctors can access this data as needed, allowing them to assess the patient’s initial condition and provide advice at any time. This approach enhances the quality and reach of health services. The module, designed and installed using modern technology, minimizes latency and maximizes data accuracy while reducing delay and battery drain. An accompanying app motivates public acceptance and ease of use. Various sensors, including ECG, SpO2, gyroscope, PIR, temperature-humidity, and BP, collect data processed by an Arduino microcontroller. Data transmission is handled by a WiFi module, with ThingSpeak and Google Sheets used for data processing and storage. The system has been fully tested, and patient data from two hospitals compared with the proposed model shows 97% accuracy.

基于预知维修的小麦播种机运行监控系统设计

为了减少播种机故障频率,提升小麦播种机的播种效率和播种质量,基于预知维修对小麦播种机的运行监控系统进行了设计。系统的主要组成包括主控单片机、检测系统、显示监控系统、报警系统及电源。为了对播种机进行预知维修,将灰色模型和神经网络模型结合,建立了动态灰色神经网络模型,并进行了算法设计。为了验证小麦播种机监控系统性能和预知维修算法的有效性,对其进行了监测精度和趋势预测试验,结果表明:监测系统的监测精度较高,播种机可有效对数据趋势进行预测。

网络球型摄像机瞬时视场的单点校正水位连续测量方法

基于网络球型摄像机进行洪水监测成为当今水利建设的热点之一,摄像机需进行旋转、焦距的放大与缩小等操作,才能在多视场进行流速、水位、流量一体化监测。由于摄像机传动装置制造的缺陷,在多视场切换时会出现预置点不能准确复位的问题而产生隙动差,这给从单张影像上解析水位、流速造成较大偏差,因此本文提出一种针对水位测量的隙动差校正方法。首先对预置点的水位尺进行精确标定,得到预置点水位方程参数,并在影像上选取两个特征明显的校正点;然后在连续监测中,将瞬时视场内校正点影像坐标按线性方法校正到预置点视场校正点;最后用预置点水位方程参数计算瞬时视场水位。经现场试验测试,不同瞬时视场校正点的影像坐标最大有8像素隙动差,产生水位误差达5 cm,而经本文方法计算的水位误差约为5 mm,说明本文方法对消减隙动差的影响是显著的。

基于红光波段冠层SIF降尺度的小麦条锈病遥感监测

为减弱冠层几何结构等因素对传感器探测到的冠层日光诱导叶绿素荧光(Solar-induced chlorophyll fluorescence, SIF)的影响,探讨了条锈病胁迫下红光波段荧光(Red SIF,RSIF)的响应特性,并以RSIF为自变量构建了小麦条锈病遥感监测的线性回归(Simple linear regression, SLR)及非线性回归(Non-linear regression, NLR)模型。结果表明:叶片尺度RSIF在小麦条锈病遥感监测中具有较大优势,其与小麦条锈病病情严重度(Severity level, SL)间相关系数较远红光波段SIF(Far-red SIF,FRSIF)提高13.2%,以叶片尺度RSIF为自变量构建的SLR及NLR模型预测D_(SL)与实测D_(SL)之间R^(2)较FRSIF分别增加9.8%、38.9%,RMSE分别降低23.1%、36.4%。此外,降尺度处理能够提高RSIF监测小麦条锈病的精度,叶片尺度RSIF与D_(SL)之间R^(2)较冠层尺度增加126.3%,以叶片尺度RSIF为自变量构建的SLR和NLR模型预测D_(SL)与实测D_(SL)间R^(2)较冠层尺度分别提高114.3%和233.3%,RMSE分别降低16.7%、15.4%。本文提出方法可提高小麦条锈病遥感监测精度,同时对其它胁迫的遥感监测具有一定的参考价值。

基于累加式实时串并联变换算法的机械故障声学监测方法

针对基于物联网(IoT)的冲压机床故障监测问题,为了降低冲压机床故障监测的计算复杂度,并提高其低频识别的精度,提出了一种无需机器学习技术的实时性机械故障声学监测方法,即基于累加式实时串并联变换算法的机械故障声学监测方法。首先,研究了物联网场景中冲压机床声学低频分析的必要性,并给出了声学信号的表达式;然后,针对频率轴上多个周期信号重叠导致参数估计较为困难的问题,提出了一种累加式实时串并联变换算法,将输入的采样序列馈入多个具有不同输出端口的串并转换器,从累加的波形中检测出最大绝对值,并进行了比较;最后,通过样本时隙划分,将累加式实时串并联变换算法应用于机械故障监测;通过仿真和冲压机床实机测试,对累加式实时串并联变换算法和实时性机械故障声学监测方法的有效性进行了验证。研究结果表明:在无需大量信号样本的情况下,使用累加式实时串并联变换算法有利于提高低频带的识别精度;在直方图相关性方面,累加式实时串并联变换算法和Morlet小波变换具有相同的性能,且均明显优于短时傅立叶变换;同时,尽管累加式实时串并联变换算法需要的加法总数比Morlet小波变换多2.5倍,但是乘法总数减少了20447%,大幅减少了计算的复杂度。

电力电缆局放在线监测神经网络自动识别精度的提升方法

为了尽可能降低电缆线路局放在线监测系统装置运行中对局放信号识别的误判误报的可能性,对局放的判读机理和识别精度进行了改进和提升。基于现场运行系统回收的数万个疑似电缆内部局放的告警记录数据进行了分析分类,对判别程序中沿用的局放自动逻辑判别程序追加了相间信号相关性过滤程序,对既有的神经网络在构造上作了优选优化,对神经网络学习数据的前置处理进行了改进。对改进提升后的局放判别程序采用了包括现场记录,模拟信号发生器和人工局放模型加电压实验的3种局放数据进行检验。结果表明,改进提升后的局放判别程序不但能够使现场的非局放告警数据的告警率降低到5%的期待水平,同时也提高了识别人工模拟产生的各种类型局放信号的准确性,大大降低了局放在线监测系统误判误报的可能性。

基于多源遥感数据与模型对比的冬小麦土壤含水量区域监测研究

实时、精准的土壤水分含量监测是农业用水管理的基础,探究冬小麦土壤水分反演的最优模型对于提高农业用水效率和可持续发展均具有重要的意义。本研究以河南省鹤壁市浚县冬小麦种植区域的土壤水分含量为研究对象,采用无人机遥感数据、卫星遥感数据、田间采样数据,分别运用温度植被干旱指数模型、水云模型和改进的水云模型3种方法,进行土壤含水量反演对比分析与最优模型选择。结果表明,3种方法中10 cm深度的反演精度均高于20 cm,且R^(2)均大于0.4。其中采用改进的水云模型方法在10 cm深度的R^(2)为0.7055、RMSE为0.0209,20 cm深度的R^(2)为0.5069、RMSE为0.0271,优于水云模型和温度植被干旱指数的反演效果。因此,改进的水云模型是一种适合用于麦田土壤水分反演的方法,它能够提供较高的反演精度。

多功能便携式水库水质智能移动监测系统设计与实现

为了提高水库水质监测效率和精度,基于物联网、传感器和移动平台技术,构建了一种多功能水库水质智能移动监测系统。系统由ZigBee无线网络、Android智能移动平台、各类型传感器和上位机四部分组成。不仅具有良好的人机交互体验功能,还具有便携性和可移植性,同时可大大降低系统开发成本,能够实现对水温、pH、电导率、水位等多个参数的同时在线实时监测、数据传输、数据分析、阈值设置和报警功能。系统对水温、pH和电导率的平均监测误差分别为3.8%、1.6%和2.7%,均小于5%,精度较高,可在水库常规水质监测中予以应用。

基于特征模式识别的农田监控系统研究

针对农田监控系统中存在的识别准确度不高、数据处理效率低等问题,提出了一种基于特征模式识别的农田监控系统。对农田监控系统的功能进行了设计,包括系统整体架构设计、数据采集与传输模块设计、特征提取与模式识别算法设计,结合用户界面设计实验与结果分析,验证了所提出系统的有效性和性能优势。对农田监控系统在实际农业生产中的应用前景进行了展望,并提出了未来改进方向和研究趋势。

多路径误差对BDS-3变形监测精度的影响

为定量分析BDS-3观测值多路径误差对变形监测精度的影响,选取包含7个站点的某水利工程2022年共128 d的BDS-3监测数据,对监测站点周围树木裁剪树枝前后BDS-3观测值多路径误差、变形监测精度及二者的相关性进行研究。结果表明:1)多路径误差与BDS-3变形监测精度间存在强相关性,与其平面和高程精度的相关系数分别大于0.93和0.81;2)监测站点周围树枝裁剪后,使用B1I和B3I观测值的平均多路径误差从0.676 m、0.426 m降低至0.329 m、0.230 m,N、E、U方向的平均监测精度分别达0.9 mm、0.8 mm、1.7 mm和1.1 mm、1.0 mm、2.2 mm,较裁剪树枝前分别提高63%、69%、58%和52%、61%、48%;3)改变周围观测环境削弱多路径误差的影响后,使用B1I观测值的精度优于使用B3I观测值的精度,因此在BDS-3短基线变形监测的应用中推荐使用B1I观测值。

电厂烟气在线监测技术的精度与可靠性提升研究

文章研究了电厂烟气在线监测技术的精度与可靠性提升方法,旨在通过优化技术参数和应用先进算法提高监测系统的性能。并通过对比分析传统监测系统与优化后系统的数据,验证了新方法的有效性。优化后系统的监测精度提高了15%,数据传输可靠性提高了20%,且在不同环境条件下表现稳定。此外,应用自适应滤波算法有效减少了噪声干扰,使得监测数据的误差率降低了10%。研究表明,技术参数优化和算法应用是提升电厂烟气在线监测系统精度与可靠性的关键路径。

雷击故障下的分布式故障监测装置定位精度测试方法

分布式故障监测装置广泛应用于输电线路的故障定位领域,而产品质量参差不齐,部分厂家仅通过行波电流或者工频电流的变化进行故障定位,定位精度存在较大问题。为此,该文提出了一种兼顾行波电流和工频电流模态变化的测试方法。首先,开展了行波电流和工频电流波形的时序逻辑设计,并提出了精度测试的方法。然后,基于仿真和试验方法,对电流探头进行了选型设计。最后,研制了分布式故障监测装置测试系统,并完成了测试精度的影响因素研究。研究结果表明:测试过程中,雷击故障过渡时长小于1个周波,基本实现雷击故障波形时序的复现;电流探头A621和TRCP3000可配合进行测试,基本满足10~1000A行波电流测量的要求;两路雷电流波前时间差范围为1~100μs,实现了故障点位置的随机设定;db1测试精度优于db4,db4小波系数的鲁棒性优于db1,当信噪比大于20dB时,即可满足测试标准的要求。该研究结果可为分布式故障监测装置雷击故障下的定位精度改善提供技术支撑。