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Impact of light conditions on reading ability following multifocal pseudophakic corrections
摘要： Purpose: To examine the impact of light intensity and temperature on reading performance following bilateral pseudophakic multifocal presbyopic correction. Patients and methods: This is a prospective clinic-based trial conducted at the Department of Ophthalmology in the University Hospital of Alexandroupolis, Greece. Three groups of patients were formed (G1: patients with bilateral bifocal implantation, G2: patients with bilateral trifocal implantation, and control group: patients with bilateral pseudophakic monofocal implantation). Reading ability was quantified with the Greek version of MNREAD chart with minimal reading speed at 80 words/min for the following light intensities (25, 50, and 75 Foot-Candles [FC]) and temperatures (3,000, 4,000, and 6,000 K). Preferred light conditions for reading were assessed, as well. ClinicalTrials.gov Identifier: NCT03226561. Results: Control group demonstrated significantly lower reading ability at all light combinations with maximal ability at 75 FC and 6,000 K (0.58±0.18 logMAR). Bifocal group presented a light-dependent reading ability that ranged from 0.45±0.08 logMAR (25 FC and 3,000 K) to 0.40±0.11 logMAR (75 FC and 4,000 or 6,000 K). Trifocal participants presented the best reading ability that was light intensity-independent; however, their performance was reduced at 6,000 K. G1 and G2 preferred primarily intermediate light temperature, while control participants preferred cold light temperature. Conclusion: Multifocal pseudophakic corrections improve reading ability; however, they present variable efficacy according to the light conditions.
关键词： presbyopia,Kelvin,trifocal,Foot-Candles,bifocal,light intensity
更新于2025-09-23 15:23:52
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The utility of infrared thermography for evaluating lameness attributable to bacterial chondronecrosis with osteomyelitis
摘要： Bacterial chondronecrosis with osteomyelitis (BCO) is a leading cause of lameness in broilers. Infrared thermography (IRT) is a noninvasive technique for measuring infrared radiation from an object and can be used to evaluate clinical health. Two replicated studies compared the effect of light intensity on broilers grown on a wire flooring model that experimentally increased their susceptibility to and incidence of BCO lameness. Day-of-hatch male broiler chickens were placed into 6 pens on wood shavings litter, and at 1 wk one of 3 light intensity treatments (2, 5, or 10 lux) was allotted. At 4 wk half of the population from each pen was moved to a pen with wire flooring and the same light intensity. At 1, 4, 5, and 8 wk, an IRT image of the legs of 5 clinically healthy broilers from each pen was taken. The right and left proximal femora and tibiae of sound and lame broilers were scored for femoral head necrosis (FHN) and tibial head necrosis (THN) lesion severity. There were minimal effects of light intensity and flooring. In Study 1, but not Study 2, broilers on wire flooring weighed less on day 38 (P = 0.007) and days 57 to 58 (P = 0.003) compared to those on litter. The proportion of broilers that became lame on wire flooring was 52% in Study 1 and 14% in Study 2. The proportion of sound broilers from litter and wire flooring pens with subclinical signs of BCO in their right or left proximal growth plates was over 45% for FHN and 92% for THN, and lame broilers had more severe (P < 0.0001) FHN and THN compared to sound broilers. IRT surface temperatures of the hock joint, shank, and foot were consistently lower (P < 0.0001) in broilers that became lame when compared to sound. Therefore, IRT surface temperatures of broiler leg regions may be useful for detecting lesions attributed to BCO.
关键词： infrared thermography,wire flooring,lameness,bacterial chondronecrosis with osteomyelitis,light intensity
更新于2025-09-23 15:23:52
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Intensity output and effectiveness of light curing units in dental offices
摘要： Background: The aims of the study were measuring the light intensity of light curing units used in Qazvin’s dental offices, determining the relationship between the clinical age of these units and their light intensity, and identifying the reasons for repairing them. Material and Methods: In this cross-sectional study, the output intensity of 95 light curing devices was evaluated using a radiometer. The average output intensity was divided up into four categories (less than 200, 200-299, 300-500, and more than 500 mW/cm2). In addition, a questionnaire was designed to obtain information mainly about the type, clinical age, and frequency of maintenance of the units and the reasons for fixing them. Data were analyzed using Kolmogorov-Smirnov, chi-squared, and t-tests (p < 0.05) on SPSS 24. Results: A total of 95 light curing units were examined, with 61 (64.2%) of them being of the LED type and 34 (35.8%) of the QTH type. While average light intensity in LED units was significantly higher than in QTH devices, the two device types were not significantly different regarding desirable light intensity (i.e., ≥ 300 mw/cm2). A negative correlation was observed between clinical age and light intensity. In addition, bulb replacement in QTH devices was over three times as much as in LED units. Also, repairing QTHs was more than twice as much frequent as fixing LEDs. The most common reason for repair was the breakage of the tip of the device. Conclusions: The light intensity of LED units is significantly higher than that of QTH devices, and the frequency of repairing in QTHs was significantly more than in LEDs. Furthermore, light intensity decreases with aging, and dentists should regularly monitor the conditions of light units.
关键词： Light curing unit,dental equipment,radiometer,light intensity,dental offices
更新于2025-09-23 15:22:29
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Investigation on Near-Infrared Quantitative Detection based on Heteromorphic Sample Pool
摘要： To enhance the detection precision of samples with scattering characteristics by near infrared spectroscopy (NIRS), this study developed a heteromorphic sample pool and established the related 2D light intensity acquisition system, which can simultaneously acquire multi-path exit light adsorption and scattering information of the samples under test. The Intralipid-20% phantom solutions in 34 samples with different concentrations were detected, while one-dimensional (1D) exit light intensity distributions and two-dimensional (2D) exit light intensity distributions on the surface of the samples were analyzed and modeled using partial least squares. In contrast with the prediction results based on the modeling method of 1D exit light intensity distribution, the modeling method of 2D exit light intensity distribution exhibits more favorable results; specifically, correlation coefficient enhanced by 2.48%, while root mean square error reduced by 6.89%. The experimental results demonstrate that using heteromorphic sample pool can effectively achieve NIRS-based detection precision and speed of chemical components in the solutions with scattering characteristics, which can provide important references for high-throughput and high-precision detection of turbid media in analytical chemistry.
关键词： two-dimensional (2D) light intensity distribution,heteromorphic sample pool,near-infrared spectrum
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - High Intensity Focused Ultrasound (HIFU) Combines Optical Coherence Tomography(OCT) for Biological Tissue Treatment and Evaluation
摘要： Light intensity focused ultrasound (LIFU) is an early stage medical technology that is in various stages of development to treat a range of disorders including super?cial diseases. Optical coherence tomography (OCT) is a rapid development imaging technique in recent ten years, which is a good way to monitor the tissue structure of super?cial diseases. In this study, OCT system is used to monitor the tissue structure of super?cial diseases during LIFU treatment. During the treatment, LIFU was performed on the lesion area of the sample with different energy levels for different times: 5s, 10s, 15s, 20s, 25s, 30s, respectively. During the treatment, the OCT system was working to monitor the tissue structure. The results showed that the light intensity of the lesion area increased with the treatment time, and the structure of the tissue changed. This study provides a new method for monitoring the treatment of super?cial diseases with LIFU.
关键词： Monitoring,Optical coherence tomography,Tissue structure,Super?cial diseases,Light intensity focused ultrasound
更新于2025-09-23 15:22:29
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Differences between Motile and Nonmotile Cells of Haematococcus pluvialis in the Production of Astaxanthin at Different Light Intensities
摘要： Haematococcus pluvialis, as the best natural resource of astaxanthin, is widely used in nutraceuticals, aquaculture, and cosmetic industries. The purpose of this work was to compare the differences in astaxanthin accumulation between motile and nonmotile cells of H. pluvialis and to determine the relationship between the two cells and astaxanthin production. The experiment design was achieved by two different types of H. pluvialis cell and three different light intensities for an eight day induction period. The astaxanthin concentrations in nonmotile cell cultures were significantly increased compared to motile cell cultures. The increase of astaxanthin was closely associated with the enlargement of cell size, and the nonmotile cells were more conducive to the formation of large astaxanthin-rich cysts than motile cells. The cyst enlargement and astaxanthin accumulation of H. pluvialis were both affected by light intensity, and a general trend was that the higher the light intensity, the larger the cysts formed, and the larger the quantity of astaxanthin accumulated. In addition, the relatively low cell mortality rate in the nonmotile cell cultures indicated that the nonmotile cells have a stronger tolerance to photooxidative stress. We suggest that applying nonmotile cells as the major cell type of H. pluvialis to the induction period may help to enhance the content of astaxanthin and the stability of astaxanthin production.
关键词： photooxidative stress,light intensity,astaxanthin,Haematococcus pluvialis
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE PES/IAS PowerAfrica - Cape Town, South Africa (2018.6.28-2018.6.29)] 2018 IEEE PES/IAS PowerAfrica - Efficient Energy Management System Using Pir Sensor
摘要： In most developing countries like Nigeria, the demand for electrical energy outweighs the supply. Negative economic and environmental impacts are also associated with its generation, transmission, and consumption. As a result there is need for the available energy to be efficiently managed. This project designed and implemented a microcontroller based energy saver and management system. The design of the energy saver and management system was aimed at coordinating the manner of use of electrical appliances, thereby reducing energy consumption in electrical appliances (such as fan and light) and devising a means of reducing the need for human intervention in the control of electrical appliances in a residential building. The project consists of a PIC microcontroller that utilizes a PIR sensor to detect occupants’ presence in the building; it also has a light intensity detection unit used to determine the level of ambient lighting as well as a temperature sensor to determine ambient temperature. The control signal from the microcontroller was used to operate the load driver circuit to switch the appliances on or off. The results show that the designed system can reduce the level of energy consumption effectively and efficiently.
关键词： load driver circuit,appliances,temperature sensor,light intensity detection,PIC microcontroller,Energy saver and Management system
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Auckland, New Zealand (2019.5.20-2019.5.23)] 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Waveguide Joint Design and Validation for use in Acoustic Vector-corrected Network Analysers
摘要： Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.
关键词： low-cost camera,light spectrum,light intensity,Photoplethysmographic image
更新于2025-09-23 15:21:01
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High-Performance Photovoltaic Hydrogen Sensing Platform with a Light-Intensity Calibration Module
摘要： Although battery-free gas sensors (e.g., photovoltaic, or triboelectric sensors) have been recently appeared to resolve the power consumption issue of conventional chemiresistors, severe technical barriers remain. Especially, their signals varying with ambient conditions such as light intensity confines the utilization of the sensors. Insufficient sensing performances (low response and slow sensing rate) of the previous battery-free sensors are also an obstacle for practical use. Herein, a photovoltaic hydrogen (H2) sensing platform having constant sensing responses regardless of light condition is demonstrated. The platform consists of two photovoltaic units: (1) a palladium (Pd)-decorated n-IGZO/p-Si photodiode covered with a microporous zeolitic imidazolate framework-8 (ZIF-8) film and (2) the same device configuration without the Pd catalyst as a reference to calibrate the base current of the sensor (1). The platform after calibration yields accurate response values in real-time regardless of unknown irradiance. Besides, the sensing performances (e.g., sensing response of 1.57 × 104% at 1% H2 with a response time < 15 s) of our platform is comparable with those of the conventional resistive H2 sensors, which are unprecedented results in photovoltaic H2 sensors.
关键词： zeolitic imidazolate framework,hydrogen sensor,battery-free gas sensor,light-intensity calibration module,photovoltaic gas sensor
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Wavelength-selective beam deflector based on Fano-resonant metasurface
摘要： Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.
关键词： Photoplethysmographic image,light intensity,light spectrum,low-cost camera
更新于2025-09-23 15:19:57