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Standard Automated Perimetry: Determining Spatial Summation and Its Effect on Contrast Sensitivity Across the Visual Field
摘要： PURPOSE. To establish Ricco’s critical area (Ac) using the 30-2 Humphrey visual ?eld analyzer (HVFA) and thereby identify Goldmann test sizes that are within or outside complete spatial summation at all visual ?eld testing locations. We also determined the suitability of using age normative data for different test sizes. Finally, by modifying current output measures (dB values), we provide a new method that allows comparison of contrast sensitivity when testing with different Goldmann test sizes within complete spatial summation. METHODS. We used the HVFA in full threshold mode and measured thresholds for all ?ve Goldmann test sizes in 12 observers. Normative data of Heijl et al. were used for age transformation and comparison. RESULTS. All the data converted to a 50-year-old equivalent lie within 1 SD of expected variance for all test locations of the 30-2 paradigm. We established Ac values at all locations of the 30-2 paradigm and showed a systematic increase in Ac as a function of increased visual ?eld eccentricity, consistent with previous studies. Age does not appear to affect Ac or the slope of partial summation for a wide range of visual ?eld eccentricities tested using the HVFA. By equating spatial summation, we propose a new metric, dB*, that returns a uniform sensitivity value for different test sizes that are operating within complete spatial summation (i.e., follow Ricco’s law). CONCLUSIONS. We established that converting to age-equivalent thresholds and application of dB* principle advantageously allows comparison of data sets across age and test size at different locations of the visual ?eld. By identifying the Ac across the visual ?eld, it is now possible to systematically determine threshold changes across the 30-2 locations in ocular disease and further characterize the importance of testing within complete spatial summation in standard automated perimetry.
关键词： retinal eccentricity,contrast sensitivity,Ac,Ricco’s Law,Humphrey visual ?eld analyzer
更新于2025-09-04 15:30:14
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Electrochromic Switch Devices Mixing Small- and Large-Sized Upconverting Nanocrystals
摘要： The hasty progress in smart, portable, flexible, and transparent integrated electronics and optoelectronics is currently one of the driving forces in nanoscience and nanotechnology. A promising approach is the combination of transparent conducting electrode materials (e.g., silver nanowires, AgNWs) and upconverting nanoparticles (UCNPs). Here, electrochromic devices based on transparent nanocomposite films of poly(methyl methacrylate) and AgNWs covered by UCNPs of different sizes and compositions are developed. By combining the electrical control of the heat dissipation in AgNW networks with size-dependent thermal properties of UCNPs, tunable electrochromic transparent devices covering a broad range of the chromatic diagrams are fabricated. As illustrative examples, devices mixing large-sized (>70 nm) β-NaYF4:Yb,Ln and small-sized (<15 nm) NaGdF4:Yb,Ln@NaYF4 core@shell UCNPs (Ln = Tm, Er, Ce/Ho) are presented, permitting to monitor the temperature-dependent emission of the particles by the intensity ratio of the Er3+ 2H11/2 and 4S3/2 → 4I15/2 emission lines, while externally controlling the current flow in the AgNW network. Moreover, by defining a new thermometric parameter involving the intensity ratio of transitions of large- and small-sized UCNPs, a relative thermal sensitivity of 5.88% K?1 (at 339 K) is obtained, a sixfold improvement over the values reported so far.
关键词： electrochromic materials,upconverting nanocrystals,thermal sensitivity,transparent conducting electrode materials,silver nanowires
更新于2025-09-04 15:30:14
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Tunable Fano resonances in a robust quasicylindrical microresonator photonic system
摘要： The control of Fano resonances is of critical importance to opto-electronic and all-optical switching devices, light delay and storage, high sensitivity sensors, and quantum information processors. In this paper, we controllable electromagnetically induced transparency (EIT)-like and Fano resonances can be achieved in a single quasi-cylindrical microresonator (QCMR). Robust and selective excitation of localized axial modes in a high quality QCMR is firstly demonstrated. Based on this stable platform, EIT-like lineshapes can be tuned and converted into Fano resonances by vertically moving the resonator. Moreover, by horizontally scanning the resonator, the transmission spectrum exhibits periodically changed Fano-like lineshapes. It is reported for the first time that the above two kinds of Fano resonances originated from different mechanisms can work on the same mode simultaneously. Our approach, demonstrated in this work, provides a robust photonic platform for accessing, controlling, and engineering the Fano resonances.
关键词： high sensitivity sensors,opto-electronic devices,electromagnetically induced transparency,Fano resonances,quasi-cylindrical microresonator
更新于2025-09-04 15:30:14
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Improving the sensitivity of <i>J</i> coupling measurements in solids with application to disordered materials
摘要： It has been shown previously that for magic angle spinning (MAS) solid state NMR the refocused INADEQUATE spin-echo (REINE) experiment can usefully quantify scalar (J) couplings in disordered solids. This paper focuses on the two z filter components in the original REINE pulse sequence, and investigates by means of a product operator analysis and fits to density matrix simulations the effects that their removal has on the sensitivity of the experiment and on the accuracy of the extracted J couplings. The first z filter proves unnecessary in all the cases investigated here and removing it increases the sensitivity of the experiment by a factor ～1.1–2.0. Furthermore, for systems with broad isotropic chemical shift distributions (namely whose full widths at half maximum are greater than 30 times the mean J coupling strength), the second z filter can also be removed, thus allowing whole-echo acquisition and providing an additional √2 gain in sensitivity. Considering both random and systematic errors in the values obtained, J couplings determined by fitting the intensity modulations of REINE experiments carry an uncertainty of 0.2–1.0 Hz (～1?10 %).
关键词： solid state NMR,disordered materials,REINE experiment,J coupling,sensitivity improvement
更新于2025-09-04 15:30:14
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Quasi-Distributed Fabry-Perot Optical Fibre Sensor for Temperature Measurements
摘要： This paper presents a simulation and an experimental quasi-distributed Fabry–Perot optical fibre sensor for temperature measurements implemented on a serial array using a combined frequency division multiplexing and wavelength division multiplexing arrangement. Quasi-distributed fibre sensors have been of great interest in the industry for the monitoring of power transformers, jet engines, and furnaces. This paper is aimed at providing theoretical results for a quasi-distributed sensor system made of 25 local sensors imprinted on a serial array of the single mode fibre whereby the local sensors are of weak reflectivity. In addition, a sensor system of nine quasi-distributed local sensors is experimentally tested and a sensitivity of 10 pm/oC and a resolution of 0.125°C are obtained. Its higher resolution, higher spatial distribution, and ability to measure temperature at different points simultaneously make it a very attractive temperature sensor.
关键词： Fabry-Perot,resolution,weak reflectivity,sensitivity
更新于2025-09-04 15:30:14
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Clinical Results and Optical Quality of Diffractive Multifocal Intraocular Lens
摘要： Purpose: To compare postoperative clinical outcomes, optical quality, and patient satisfaction between two types of diffractive multifocal intraocular lens (IOL, Acri Lisa 366D and Acrysof ReSTOR +3.00 D). Methods: In a total of 68 eyes, one of two diffractive multifocal IOL (Acri Lisa 366D and Acrysof ReSTOR +3.00 D) was implanted after cataract extraction. Visual acuity was measured postoperatively at one week, 1 month, and 6 months. Contrast sensitivity, wavefront aberration, and visual function were determined via questionnaire at postoperative 1 month. Results: Intermediate visual acuity of Acri Lisa 366D and Acrysof ReSTOR at 6 months were 0.31 ± 0.14, and 0.24 ± 0.11 (log MAR), respectively. At 6 months, near and distant visual acuity results showed no significant differences between the two groups. The photopic contrast sensitivity of Acri Lisa 366D at 6 cycles/degree was 55.36 ± 7.40 and showed significant differences with Acrysof ReSTOR (47.25 ± 9.67). The mesopic contrast sensitivity values of Acri Lisa 366D and Acrysof ReSTOR were 40.26 ± 11.38 and 28.97 ± 10.45, respectively, and the spherical aberration values were 0.037 ± 0.039 μm and 0.105 ± 0.066 μm. The spherical aberration of Acri Lisa 366D was significantly lower than that of Acrysof ReSTOR. Total and high order aberration, coma, and trefoil show no significant differences between the two groups. Conclusions: The Acri Lisa 366D multifocal IOL showed better contrast sensitivity and spherical aberration compared to Acrysof ReSTOR multifocal IOL, which had an effective intermediate visual acuity.
关键词： Contrast sensitivity,Multifocal intraocular lens,Patient satisfaction,Spherical aberration
更新于2025-09-04 15:30:14
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Achieving enhanced pH sensitivity using capacitive coupling in extended gate FET sensors with various high-K sensing films
摘要： Sensing properties of various high-k sensing membrane, such as SnO2, HfO2, ZrO2, and Ta2O5, in dual gate extended-gate field-effect transistor (EGFET) were investigated. By adapting the dual-gate structure, high sensitivity exceeding the conventional Nernstian limit on sensitivity (59.15 mV/pH at 25 °C) was realized due to capacitive coupling effect. As a results, it was confirmed that dual-gate EGFET with Ta2O5 sensing membrane which has high permittivity shows the highest sensitivity of 478.0 mV/pH as well as excellent hysteresis voltage and drift rate characteristics.
关键词： Glass EG detector,Dual gate poly-Si TFT transducer,High-k membrane,Highest sensitivity,Capacitive coupling,EGFET pH sensor
更新于2025-09-04 15:30:14