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Test–Retest Repeatability of Microperimetry at the Border of Deep Scotomas
摘要： PURPOSE. The purpose of this study was to examine the test–retest repeatability of microperimetric sensitivity at the border of deep scotomas. METHODS. Thirty normal participants underwent two examinations, each on the Macular Integrity Assessment (MAIA) microperimeter and on the MP-1 microperimeter (four examinations in total). A customized stimulus pattern allowed microperimetric sensitivity to be measured at the border of the optic nerve head (ONH), which acted as a model for the border of a deep scotoma—and also at the macular and peripapillary region. RESULTS. There were no significant changes in average point-wise sensitivity (PWS) values between the two examinations for all three regions using the MAIA microperimeter (P ≥ 0.262). The PWS coefficient of repeatability (CoR) was ±12.99 dB at the border of the ONH, which was significantly larger than points in the macular and peripapillary regions (P > 0.001). A significant decrease in average PWS, using the MP-1 microperimeter at the macular and peripapillary region (P < 0.001), meant that the PWS CoR could not be determined in these regions. No significant changes in average PWS were observed at the border of the ONH (P = 0.223), and the PWS CoR was ±7.52 dB in this region. CONCLUSIONS. Microperimetric test–retest repeatability at the border of a deep scotoma was worse than at other areas of normal retina, and this highlights the limitation of applying a single estimate of test–retest repeatability to determine whether significant functional decline has occurred at the border of a deep scotoma.
关键词： repeatability,test–retest,microperimetry,scotoma
更新于2025-09-19 17:15:36
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Test-retest variability of multifocal electroretinography in normal volunteers and short-term variability in hydroxychloroquine users
摘要： Purpose: To determine measurement variability of N1P1 amplitudes and the R1/R2 ratio in normal subjects and hydroxychloroquine users without retinopathy. Design: Retrospective, observational study. Subjects: Normal subjects (n=21) and 44 patients taking hydroxychloroquine (n=44) without retinopathy. Methods: Multifocal electroretinography (mfERG) was performed twice in one session in the 21 normal subjects and twice within 1 year in the hydroxychloroquine users, during which time no clinical change in macular status occurred. Main outcome measures: N1P1 amplitudes of rings R1–R5, the R1/R2 ratio, and coefficients of repeatability (COR) for these measurements. Results: Values for N1P1 amplitudes in hydroxychloroquine users were reduced compared with normal subjects by the known effect of age, but R1/R2 was not affected by age. The COR for R1–R5 ranged from 43% to 52% for normal subjects and from 43% to 59% for hydroxychloroquine users; for R1/R2 the COR was 29% in normal subjects and 45% in hydroxychloroquine users. Conclusion: mfERG measurements show high test-retest variability, limiting the ability of a single mfERG test to influence a decision to stop hydroxychloroquine; corroborative evidence with a different ancillary test is recommended in a suspicious case.
关键词： test-retest variability,hydroxychloroquine,multifocal electroretinography
更新于2025-09-19 17:15:36
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Simple geometrical modifications for substantial color intensity and detection limit enhancements in lateral-flow immunochromatographic assays
摘要： One of the ongoing challenges in lateral flow Immunochromatographic assays (LFIA), is lowering the limit of detection and enhancing their signal quality, i.e. the color intensity. There are a number of rather costly and complicated processes for this aim, such as the use of functionalized materials/membranes and additional spectroscopic readout units. Nonetheless, there are simple and easy to practice alternatives, to be uncovered by analyzing the essential parameters of immunological reactions. The color intensity of the test line is a function of analytes flow velocity and their reaction rate. Detection pad width and test line position impact the flow velocity and reaction rate kinetics, examined in this paper for the limit of detection (LOD) and test-line color intensity. Firstly, the impact of width on the LOD was examined for human chorionic gonadotropin (pregnancy biomarker). Test line color intensity was measured using five different widths of the detection pad (trapezoidal) and four different test line positions, and the trends observed were explained according to the measured evolution of the velocity along the chromatography paper. With a constant width absorbent pad, LOD was cut by half to 5 mIU/ml by using a narrowing width detection pad, which keeps the wicking velocity higher than normal strips, and compared to them, color intensity increase between 55-150%, depending on the concentration. Nevertheless, a widening detection pad might cut the color intensity up to 150%, compared to normal strips, due to a profound decline of the analyte to ligand ratio at the test line. In addition, adequately sending the test line away from the conjugate pad yields the highest possible color intensity, for up to 400% of increase, in lower concentrations and narrowing test pads. However, further distancing the test line downfalls the color intensity.
关键词： Lateral Flow Immunochromatographic Assays,Trapezoidal Geometry,Limit of Detection,Detection Pad,Capillary Flow Velocity,Porous Medium,Color Intensity,Test Line Displacement
更新于2025-09-19 17:15:36
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An Easily Fabricated Linear Piezoelectric Actuator Using Sandwich Longitudinal Vibrators With Four Driving Feet
摘要： A piezoelectric actuator using three sandwich longitudinal vibrators is proposed and tested. The two horizontal vibrators are parallel to each other and orthogonal to the vertical vibrator. The ends of the two horizontal vibrators serve as the four driving feet. The actuator has a simple fabricating process, which will shorten the period of fabrication. Two modes of the actuator are used to get the elliptical trajectories on the driving feet. The frequencies of the two modes are tuned to be about 21.60 kHz with modal analysis by the finite element method (FEM). The operating principle is also examined with transient analysis by FEM. A prototype is fabricated and its vibration characteristics are verified by using a scanning laser Doppler vibrometer. The prototype shows the best mechanical performance with the optimum working frequency and phase difference of 18.50 kHz and 60°, respectively. The typical output of the prototype is a no-load speed of 439.41 mm/s, a maximum thrust of 40 N, and a maximum power of 5.01 W at the voltage of 200 VP?P. The mechanical characteristics of the prototype show that the exciting voltages can be used for the speed control due to the approximately linear relationship between them.
关键词： resonant state,vibration test.,Linear piezoelectric actuator,sandwich longitudinal vibrators
更新于2025-09-19 17:15:36
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Interlaboratory comparison about feasibility of insoluble particulate matter test for injections with reduced test volume in light obscuration method
摘要： Insoluble particulate matter test for injections in pharmacopoeia is mandatory for parenteral drug products. In this test using light obscuration, four measurements of at least 5-mL are required. Since therapeutic protein injections of low dosage volumes are getting more popular, reduction of test volumes is desired. In this collaborative study, the impact of lower measurement volume on the accuracy and precision of particle count was evaluated using 2, 5, 10, and 25-μm polystyrene count standards for the validity of test with reduced sample volumes. Good accuracy (3000 particles/mL ± 10%) was obtained at all measurement volumes, and the inter-run variability (RSD) was the same levels between 5 and 1 mL. Although the inter-run variability increased at 0.2 mL, it was below 5%. These results indicated that light obscuration method can be used with 5 mL–0.2 mL, and that it is feasible for monitoring particles ≥2 μm.
关键词： Sub-visible particulate,Quality control,Reduced-volume method,Insoluble particulate matter test,Light obscuration
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) - Madrid, Spain (2018.10.1-2018.10.5)] 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) - Automatic Fall Risk Assessment for Challenged Users Obtained from a Rollator Equipped with Force Sensors and a RGB-D Camera
摘要： Fall risk assessments provide a useful tool to prevent morbidity and mortality provoked by falls. Nowadays, these assessments are usually performed manually by the medical staff. This approach has three main drawbacks: i) it is time consuming, so it is only performed a few times per volunteer during their rehabilitation process; ii) it requires supervision by medical staff, so assessment at home or preferred environments is not feasible; and iii) fall risk is evaluated in a global way, so imminent fall risk is not available for decision making in assistive navigation. In this paper we propose an imminent fall risk estimator for rollator's users that can be automatically obtained on the fly. Its main advantages are: i) it can be used in everyday conditions in any environment; ii) it does not require assistance of medical staff; and iii) it is suitable for a variety of users with minimal configuration changes. We have validated our estimator with a set of volunteers (n=10) presenting different physical and cognitive disabilities. Although the number of volunteer is limited, results show that our estimator is coherent to two traditional, well accepted assessments: the Tinetti Mobility Test and the walking speed.
关键词： walking speed,Tinetti Mobility Test,on-board sensors,fall risk assessment,rollator
更新于2025-09-19 17:15:36
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A luminescent terbium metal-organic framework for highly sensitive and selective detection of uric acid in aqueous media
摘要： As the final product of purine metabolism, uric acid (UA) existing in urine and serum plays an important role in the body's metabolism, immunity and other functions. However, it is still difficult to sense UA in practice. Herein, a new terbium metal–organic framework (Me2NH2)2[Tb2(L)2]·(H2O)6 (ZJU-158-Tb, ZJU=Zhejiang University, L= 1-(3,5-dicarboxylatobenzyl)-3,5-pyrazole dicarboxylic acid )for luminescent sensing of UA was designed and synthesized. It exhibits highly sensitive and selective detection to UA in aqueous solutions with a quite low detection limit of 7 nM by a luminescence turn-down phenomenon. Furthermore, the practical test papers made by ZJU-158-Tb possess fast monitoring ability for abnormal UA levels in artificial urine and serum through distinct color change, which could be even distinguished by the naked eye.
关键词： uric acid,Metal-organic frameworks,test paper.,fluorescence sensor
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Waikoloa Village, HI (2018.6.10-2018.6.15)] 2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC) - Test Platform for Photovoltaic Systems with Integrated Battery Energy Storage Applications
摘要： We present a hybrid simulation and a real-time test platform for developing control systems for photovoltaic (PV) inverters with integrated battery energy storage (BES). The platform consists of a dual-stage single-phase PV inverter system, DC coupled with a full-bridge grid connected inverter, which emulates the charge regulator and battery bank. The real-time control of the two power electronic converters is implemented in a Simulink/dSpace platform, together with the real-time simulation model of the battery pack. The input power can be provided by either a high performance PV emulator or by a physical PV array. The platform enables real-time testing of PV+BES control systems and energy management systems (EMS), for a variety of battery technologies, which can be modelled in detail and emulated by the full-bridge grid connected inverter. Such flexibility is difficult to achieve with real BES systems, due to electrical safety and cost constrains of high power charge regulators and battery packs.
关键词： Energy storage,Test equipment,Battery Emulator,Photovoltaic systems
更新于2025-09-19 17:15:36
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The Development of Accelerated Life Test Method of Multi-Layer Nano Thin Film Glass for Electric Automobiles
摘要： According to expansion of electric automobiles, the multi-layer nano thin film glass with heating source is researched to retain safety driving for winter. Generally, the tungsten wire is used as a heating source of electric automobile glass. Due to its low visibility, silver (Ag) particles are researched for years. Ag is widely used as a material of heater in the automobile industry since it has relatively high heat and electrical conductivities. However, the multi-layer nano thin film glass using Ag particles is under development stage and is not verified in the field, so recall and claim can be raised. In this study, we will find the potential failure mechanism of the multi-layer nano thin film glass based on the properties, and then suggest accelerated life test method to verify 15 years in the automobile application.
关键词： Electric automobiles,Multi-layer nano thin film glass,Accelerated life test,Windshield glass,Failure mechanism
更新于2025-09-19 17:15:36
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Ultraviolet Digital Image Correlation for Molten Thermoplastic Composites under Finite Strain
摘要： The thermostamping process used to fabricate thermoplastic prepreg composites is widely studied due to its use in several applications in the automotive and aerospace industries. In recent years, different constitutive mechanical models and new numerical techniques have been proposed to simulate this process. However, from an experimental point of view, no substantial progress has been recorded on the experimental methods used for the characterisation of thermostamped thermoplastic prepreg composites. Moreover, there is currently no experimental protocol to visualize or analyse deformation fields at temperatures above the melting point of a material during the characterisation process. The knowledge of these fields allows precision modelling of the mechanical behaviour of this type of material. Therefore, the aim of this paper is to propose a new experimental protocol that uses a digital image correlation method, which faces constraints such as light reflections on either the yarns or the molten thermoplastic matrix. The proposed solution uses an ultraviolet light source and a photoluminescent powder to make the speckle pattern. This approach avoids any visible reflections, since the sample itself is the visible light source.
关键词： Thermoplastic composite materials,Shear field measurement,Ultraviolet DIC,Bias extension test
更新于2025-09-19 17:15:36