Ring Light Research Articles

Will the increased use of ring lights during the coronavirus pandemic lead to a growing burden of macular degeneration?

The pandemic of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), has brought with it many changes in the way with live, work, and socialise. One such change is an increase in the use of videoconferencing for communication with friends, family and work colleagues, and doing presentations, while physically distancing. We demonstrate an increase in the use of ring lights during the pandemic, and argue that this increased exposure to blue light may lead to a growing burden of macular degeneration in coming years.

Non-equilibrium magnetic compression for picosecond-long X-ray pulses at a diffraction limited storage ring light source

Picosecond-long x-ray pulses of moderate intensity and high repetition rate are highly sought after by the light sources community, e.g. for time-resolved investigations of matter in the linear response regime. We investigate the upgrade of a diffraction-limited storage ring light source to a short X-ray pulse scheme. Short pulses are emitted by electron bunches magnetically compressed in the injection chain, with no impact on the simultaneous standard emission from long bunches. The ultimate performance, limits and operational aspects of the scheme are discussed in terms of soft X-ray undulator emission.

Machine vision-based gradient-boosted tree and support vector regression for tool life prediction in turning

One of the essential elements of automated and intelligent machining processes is accurately predicting tool life. It also helps in achieving the goal of producing quality products with reduced production costs. This work proposes a computer vision-based tool wear monitoring and tool life prediction system using machine learning methods. Gradient-boosted trees and support vector machine (SVM) techniques are used to predict tool life. The experimental investigation on the CNC machine is conducted to study the applicability of the proposed tool wear monitoring system. Experiments are performed using workpiece material made of alloy steel and PVD-coated cutting inserts, and flank wear is monitored. An imaging system consisting of an industrial camera, lens, and LED ring light is mounted on the machine to capture tool wear zone images. Images are then processed by algorithms developed in MATLAB®. Boosted tree methods and the SVM methodology have 96% and 97% prediction accuracy, respectively. Validation tests are carried out to determine the accuracy of proposed models. It is observed that the prediction accuracy of boosted three and SVM is good, with a maximum error of 5.89% and 7.56%, respectively. The outcome of the study established that the developed system can monitor the tool wear with good accuracy and can be adopted in industries to optimize the utilization of tool inserts.

Research and Evaluation on an Optical Automatic Detection System for the Defects of the Manufactured Paper Cups.

In this paper, the paper cups were used as the research objects, and the machine vision detection technology was combined with different image processing techniques to investigate a non-contact optical automatic detection system to identify the defects of the manufactured paper cups. The combined ring light was used as the light source, an infrared (IR) LED matrix panel was used to provide the IR light to constantly highlight the outer edges of the detected objects, and a multi-grid pixel array was used as the image sensor. The image processing techniques, including the Gaussian filter, Sobel operator, Binarization process, and connected component, were used to enhance the inspection and recognition of the defects existing in the produced paper cups. There were three different detection processes for paper cups, which were divided into internal, external, and bottom image acquisition processes. The present study demonstrated that all the detection processes could clearly detect the surface defect features of the manufactured paper cups, such as dirt, burrs, holes, and uneven thickness. Our study also revealed that the average time for the investigated Automatic Optical Detection to detect the defects on the paper cups was only 0.3 s.

Implementation Of Data Mining Sales Of Household Furniture At Smart Kitchen Shop Using The Method K-Means

Household furniture is an item that is very much in demand by many people, especially mothers, the higher the number, the more demand. To get the desired information so that a store can sort out the inventory that must be met. So it takes a prediction for the sale of furniture products that are most requested by consumers which aims to facilitate the provision of stock goods. The purpose of this research is to apply data mining to determine what products or goods are most in demand, moderately desirable, less desirable. From the various data that the authors observe at the Smart Kitchen Store, namely the Smart Kitchen Store, it is still difficult to predict product inventory in the future. With this problem, we need to group the data based on the characteristics of product sales. In the grouping process, a grouping method will be used using the K-Means Algorithm as a manual calculation method and in its implementation a data mining software using RapidMiner Studio version 7.1 will be used.The results of the study consisted of 3 clusters, namely, 42 Most Interested Products (Double Stan Hangers, Napkins, and Stainless Dish Racks), 46 Moderately Interested Products (Super Mop Floor Mops, Surpets, and Electric Grater) and 32 Less Interested Products (Shower Hood 4 stacking, Ring Light, and stainless hood). at the Smart Kitchen Store, so that the data is used as a reference for the Smart Kitchen Store to manage the stock of goods so that the store does not disappoint customers because the goods or products you want to buy are not available.

Expanding access to microneurosurgery in low-resource settings: Feasibility of a low-cost exoscope in transforaminal lumbar interbody fusion.

Less than a quarter of the world population has access to microneurosurgical care within a range of 2 h. We introduce a simplified exoscopic visualization system for low-resource settings. We purchased a 48 megapixels microscope camera with a c-mount lens and a ring light at a total cost of US$ 125. Sixteen patients with lumbar degenerative disk disease were divided into an exoscope group and a microscope group. In each group, we performed four open and four minimally invasive transforaminal lumbar interbody fusions (TLIF). We conducted a questionnaire-based assessment of the user experience. The exoscope achieved similar outcomes with comparable blood loss and operating time as the microscope. It provided similar image quality and magnification. Yet, it lacked stereoscopic perception and the adjustability of the camera position was cumbersome. Most users strongly agreed the exoscope would significantly improve surgical teaching. Over 75% reported that they would recommend the exoscope to colleagues and all users saw its great potential for low-resource environments. Our low-budget exoscope is safe and feasible for TLIF and purchasable at a fraction of the cost of conventional microscopes. It may thus help expand access to neurosurgical care and training worldwide.

Multispectral imaging of nailfold capillaries using light-emitting diode illumination.

The capillaries are the smallest blood vessels in the body, typically imaged using video capillaroscopy to aid diagnosis of connective tissue diseases, such as systemic sclerosis. Video capillaroscopy allows visualization of morphological changes in the nailfold capillaries but does not provide any physiological information about the blood contained within the capillary network. Extracting parameters such as hemoglobin oxygenation could increase sensitivity for diagnosis and measurement of microvascular disease progression. To design, construct, and test a low-cost multispectral imaging (MSI) system using light-emitting diode (LED) illumination to assess relative hemoglobin oxygenation in the nailfold capillaries. An LED ring light was first designed and modeled. The ring light was fabricated using four commercially available LED colors and a custom-designed printed circuit board. The experimental system was characterized and results compared with the illumination model. A blood phantom with variable oxygenation was used to determine the feasibility of using the illumination-based MSI system for oximetry. Nailfold capillaries were then imaged in a healthy subject. The illumination modeling results were in close agreement with the constructed system. Imaging of the blood phantom demonstrated sensitivity to changing hemoglobin oxygenation, which was in line with the spectral modeling of reflection. The morphological properties of the volunteer capillaries were comparable to those measured in current gold standard systems. LED-based illumination could be used as a low-cost approach to enable MSI of the nailfold capillaries to provide insight into the oxygenation of the blood contained within the capillary network.

Hyaluronan Modulates the Biomechanical Properties of the Cornea.

Hyaluronan (HA) is a major constituent of the extracellular matrix (ECM) that has high viscosity and is essential for maintaining tissue hydration. In the cornea, HA is enriched in the limbal region and is a key component of the limbal epithelial stem cell niche. HA is upregulated after injury participating in the formation of the provisional matrix, and has a key role in regulating the wound healing process. This study investigated whether changes in the distribution of HA before and after injury affects the biomechanical properties of the cornea in vivo. Corneas of wild-type (wt) mice and mice lacking enzymes involved in the biosynthesis of HA were analyzed before, immediately after, and 7 and 14 days after a corneal alkali burn (AB). The corneas were evaluated using both a ring light and fluorescein stain by in vivo confocal microscopy, optical coherence elastography (OCE), and immunostaining of corneal whole mounts. Our results show that wt mice and mice lacking HA synthase (Has)1 and 3 present an increase in corneal stiffness 7 and 14 days after AB without a significant increase in HA expression and absence of scarring at 14 days after AB. In contrast, mice lacking Has2 present a significant decrease in corneal stiffness, with a significant increase in HA expression and scarring at 14 days after AB. Our findings show that the mechanical properties of the cornea are significantly modulated by changes in HA distribution following alkali burn.

Lattice design for an improved angular dispersion-induced microbunching scheme

In this paper, an improved angular dispersion-induced microbunching (ADM) scheme [1] is studied to generate fully coherent soft x-ray radiation pulses in an electron storage ring light source with a limited energy modulation amplitude. This scheme releases the coupling between the dispersion function and the momentum compaction in the original ADM scheme. The lattice structure of the improved ADM is simple, which only adds a chicane following the dogleg compared to the original one. With the chicane, even higher harmonic radiation can be generated. Numerical simulation results show that soft x-ray radiation with photon energy covering the water window range can be produced.

Hemispherical Surface Defect Classification of Valve Core with a Noval Semi-supervised Learning

Background: In the industrial manufacturing process, manually labeling enough datasets is time-consuming, which hinders the training and deployment of defect detection models. Therefore, automatic defect detection and its classification is the premise of industrial production quality. Objectives: The study mainly discusses about the detection of the Hemispherical Surface of the valve core by machine vision method. Methods: The paper put forward a novel semi-supervised algorithm to detect the Hemispherical Surface of the Valve Core. Under the condition of the lack of labeled datasets, the paper used labeled and unlabeled samples for model training. This thesis proposed, for the first time, using the Mean Teacher semisupervised learning framework and then making changes to the model; firstly, this paper proposed to use the Stochastic Weight Average (SWA) algorithm to update the weight of the teaching model to enhance this model’s generalization ability. Furthermore, in order to select reliable datasets and calculate the consistency loss, this study also proposed an Uncertainty Filter (UF) method. Thirdly, the selection of hard-ware equipment, since the hemispherical surface is anisotropic, ring light source is used, which can lit the surface from top to bottom. Results: Experimental results show that in two different conditions, the classification accuracy can raise. On one hand, under the condition of training with a small amount of labeled datasets, the proposed semi-supervised learning model can achieve a classification accuracy of 90.51%; whereas, under the condition of the semi-supervised learning mechanism and a large amount of unlabeled datasets, the accuracy increases from 93.7% to 98.1%. Conclusion: This paper uses hemispherical metal surface as the dataset for the first time, and also innovatively optimizes the semi-supervised model. On the other hand, experimental comparative analysis indicates that the model proposed in this paper is significantly better than the comparison model, which lays the basic position for the defect detection of the hemispherical surface’s metal. At the same time, the novel semi-supervised algorithm can also be used to detect other metal part’s hemispherical surfaces.

Superradiant transfer of quantized orbital angular momentum between light and atoms in a ring trap

The authors present a non-trivial quantum regime based on superradiant transfer of discrete orbital angular momentum between light and ultracold atoms trapped in a ring. Tuning the ring and pump light parameters, specific angular momentum states can be efficiently populated and light with orbital angular momentum different from that of the pump can be generated.

Expanding Access to Microneurosurgery in Low-Resource Settings: Feasibility of a Low-Cost Exoscope in Transforaminal Lumbar Interbody Fusion

Abstract Objectives Less than a quarter of the world population has access to microneurosurgical care within a range of 2 hours. We introduce a simplified exoscopic visualization system to achieve optical magnification, illumination, and video recording in low-resource settings. Materials and Methods We purchased a 48 megapixels industrial microscope camera with a heavy-duty support arm, a wide field c-mount lens, and an LED ring light at a total cost of US$ 125. Sixteen patients with lumbar degenerative disk disease were divided into an exoscope group and a conventional microscope group. In each group we performed four open and four minimally invasive transforaminal lumbar interbody fusion procedures. We further conducted a questionnaire-based assessment of the user experience. Results The overall user experience was positive. The exoscope achieved similar postoperative improvement with comparable blood loss and operating time as the conventional microscope. It provided a similar image quality, magnification and illumination. Yet, the lack of stereoscopic perception and the cumbersome adjustability of the camera position and angle resulted in a shallow learning curve. Most users strongly agreed that the exoscope would significantly improve surgical teaching. Over 75% reported they would recommend the exoscope to colleagues and all users saw its great potential for low-resource environments. Conclusion Our low-budget exoscope is technically non-inferior to the conventional binocular microscope and purchasable at a significantly lower price. It may thus help expand access to neurosurgical care and training worldwide.

An Image-Based Data-Driven Model for Texture Inspection of Ground Workpieces.

Nowadays, the grinding process is mostly automatic, yet post-grinding quality inspection is mostly carried out manually. Although the conventional inspection technique may have cumbersome setup and tuning processes, the data-driven model, with its vision-based dataset, provides an opportunity to automate the inspection process. In this study, a convolutional neural network technique with transfer learning is proposed for three kinds of inspections based on 750–1000 surface raw images of the ground workpieces in each task: classifying the grit number of the abrasive belt that grinds the workpiece, estimating the surface roughness of the ground workpiece, and classifying the degree of wear of the abrasive belts. The results show that a deep convolutional neural network can recognize the texture on the abrasive surface images and that the classification model can achieve an accuracy of 0.9 or higher. In addition, the external coaxial white light was the most suitable light source among the three tested light sources: the external coaxial white light, the high-angle ring light, and the external coaxial red light. Finally, the model that classifies the degree of wear of the abrasive belts can also be utilized as the abrasive belt life estimator.

The Effect of Lighting and Photograph Exposure on Perceived Attractiveness.

To assess the effect of various lighting conditions and photograph exposures on perceived attractiveness. In the first experiment, 5 variably exposed photographs were taken of 10 subjects using a consistent lighting condition (45° superior box light). In the second experiment, 10 subjects were photographed under variable lighting conditions with consistent exposure: 1) 90° overhead box light, 2) ring light, 3) 45° superior box light, 4) built-in camera flash, 5) 2 straight on box lights, each 45° from midline, and 6) natural light. Participants were instructed to maintain a neutral expression, were placed in front of a standardized blue-gray background, and were photographed during a single session. Photographs were imported into an online survey platform (Qualtrics 2020) and displayed in random order. Volunteer survey respondents were instructed to rate the subject's attractiveness on a scale of 0 to 10. Between the two experiments, a total of 22,000 scored photographs were included in the analysis. Mixed ANOVA and pairwise comparisons with Bonferroni correction were used to compare between- and within-subject ratings. Lighting condition had a significant impact on perceived attractiveness ( p < 0.001), with the 90° overhead box light achieving lower scores and the 45° superior box light yielding greater scores of attractiveness relative to the other conditions. Photograph exposure did not have a significant impact on subjective attractiveness ( p = 1.000). Our findings suggest that perceived attractiveness is enhanced when a 45° superior box light is used for illumination, and attractiveness is reduced when 90° overhead exposure is utilized. Exposure did not play a prominent role in perceived attractiveness.

Research on Stray-Light Suppression Method for Large Off-Axis Three-Mirror Anastigmatic Space Camera.

The stray-light suppression of a large off-axis three-mirror anastigmatic space camera has been a hot topic, and this study proposes a composite stray-light suppression strategy that effectively suppresses stray light using the combination of a baffle, retaining ring, and internal antistray light measures. Additionally, the light barrier of the third mirror with a three-layered structure was designed to further optimize the composite stray-light suppression system. At the stray-light simulation analysis stage, in view of the limitations of the Torrance–Sparrow scattering analysis model, an analysis model with wide adaptability is proposed, which can be applied to the stray-light simulation analysis of large-size mirrors with rough surfaces. The simulation results indicate that the point source transmittance of the composite stray-light suppression strategy proposed in this paper is of the order of 10−5 before installing the light barrier of the third mirror, and the veiling glare index of the full field of view is less than 5.8%. After installing the light barrier of the third mirror, the point source transmittance reached the order of 10−8, and the veiling glare index of the full field of view was less than 1.31%. Moreover, the influence of the light barrier of the third mirror on the modulation transfer function of the system was less than 2.3%. The modulation transfer function test of the large-width off-axis three-mirror anastigmatic space camera in a simulated vacuum on-orbit environment was completed, and the test results indicated that the negative impact of the light barrier of the third mirror on the modulation transfer function was less than 3.6%. Moreover, an out-of-field imaging test of the space camera was conducted and the results showed that the image was clear, and the SNR reached 80 dB. The simulation and experimental results prove that the solution in this study can effectively solve the problem of stray-light suppression for large off-axis three-mirror anastigmatic space cameras.

Microsurgical Wiltse Paraspinal Approach Using a Low-Budget Exoscope.

Access to microneurosurgical care in low- and middle-income countries remains limited mainly due to a lack of equipment. High purchasing and maintenance costs hinder the use of operating microscopes in low-resource facilities. The authors present an improved version of their previously introduced low-cost exoscope to achieve high magnification and illumination in low-resource environments. The setup included a 48-megapixel two-dimensional digital microscope camera, a wide field C-mount lens, ring light, and a two-link cantilever with a screw terminal. The surgical field was projected to a portable 17.3-inch 2K resolution monitor. Ten patients underwent exoscope-assisted transforaminal lumbar interbody fusion via the Wiltse paraspinal approach. The simple construction allowed a fast and intuitive preoperative setup. The in-plane switching type display provided a clear and bright image regardless of the viewing angle. The two-link arm of the cantilever allowed smooth positioning of the camera, overcoming the cumbersome up and down movements needed to zoom in and out with the previous prototype. Industrial microscope cameras are effective low-budget alternatives to conventional operating microscopes in lumbar microdiscectomy. The improved system is superior compared to the authors' previous prototype with regard to affordability, image quality, and adjustability of position and angle.

Outlier Elimination in Rough Surface Profilometry with Focus Variation Microscopy

Rough surfaces such as metal additive manufactured surfaces are quite challenging for measurement. Artifacts caused by irregular and difficult-to-measure geometries are inevitable. Removing all the artifacts would cause a portion of surface information to be missing. Different from previous works, the postprocessing in this paper includes an additional step to eliminate artifacts based on autocorrelation functions of particular subimages instead of simply removing them. This increases the accuracy with respect to surface roughness and provides a more comprehensive view on the topography. In addition, a dome shape LED array ring light is proposed to provide all-round lighting due to the high degree of irregularity of workpiece surfaces. The experimental results obtained from FVM are validated and compared with the given roughness values of a Rubert Microsurf 329 comparator test panel as well as measurement results of a metal additive workpiece by a confocal microscope.

Manipulating the upconversion luminescence of Yb3+/Er3+ doped nanoparticles by the sheet-shaped nanocavity

Rare-earth doped upconversion luminescence is important for display and imaging field due to its narrow band, multicolor, long lifetime and high stability. However, low quantum yield of upconversion energy transfer, weak excited states absorption and slow spontaneous radiation rates lead to weak upconversion luminescence, which may dramatically limit the practical application of upconversion nanoparticles. Here, we report a metal-sheet-shaped plasmonic nanocavity consisting of gold and silver micro-sheets. It is found that the upconversion processes (including quantum yield of energy transfer, excited states absorption and spontaneous radiation rates) were enhanced by strong local electromagnetic field of the plasmonic nanocavity when RE3+ nanoparticles were filled in the plasmonic nanocavity. The significant enhancement of the luminescence and clear directional radiation were observed under 980 nm laser excitation. By adjusting the nanogap distance of the plasmonic nanocavity, we achieved a 75-fold enhancement in 654 nm emission. Benefiting from the plasmonic nanocavity, the upconversion luminescence exhibited a directional emission, which indicates the plasmonic near-field excitation contributed to the luminescence enhancement. These findings provide a candidate for ring light source and bio-imaging application.

Research on Identification Technology of Field Pests with Protective Color Characteristics

Accurate identification of field pests has crucial decision-making significance for integrated pest control. Most current research focuses on the identification of pests on the sticky card or the case of great differences between the target and the background. There is little research on field pest identification with protective color characteristics. Aiming at the problem that it is difficult to identify pests with protective color characteristics in the complex field environment, a field pest identification method based on near-infrared imaging technology and YOLOv5 is proposed in this paper. Firstly, an appropriate infrared filter and ring light source have been selected to build an image acquisition system according to the wavelength with the largest spectral reflectance difference between the spectral curves of the pest (Pieris rapae) and its host plants (cabbage), which are formed by specific spectral characteristics. Then, field pest images have been collected to construct a data set, which has been trained and tested through YOLOv5. Experimental results demonstrate that the average time required to detect one pest image is 0.56 s, and the mAP reaches 99.7%.

Development of a Novel Low-Cost Exoscope to Expand Access to Microneurosurgical Care in Low- and Middle-Income Countries

Less than a quarter of the world population has access to microneurosurgical care within a range of 2hours. We introduce a simplified exoscope system to achieve magnification, illumination, and video recording in low-resource settings. We combined an industrial microscope tube, a heavy-duty support arm, a wide-field c-mount digital microscope camera, and a light-emitting diode ring light. All parts were sterilized with ethylene oxide. We performed 13 spinal and 3 cranial surgeries with the help of the low-budget exoscope. The average preoperative setup time was 12.8minutes. The exoscope provided similar magnification and illumination like a conventional binocular microscope. It allowed operating in a comfortable posture. The field of vision ranged from 30mm-60mm. The surgical field was captured by a 16-megapixel two-dimensional camera and projected to a 55-inch high-definition television screen in real time. Image quality was similar to that of a conventional microscope although our exoscope lacked stereoscopic view. Adjusting camera position and angle was time-consuming. Thus, the benefit of the exoscope was most notable in spine surgeries where the camera remained static for most of the time. The total cost of the exoscope was approximately U.S. $750. Our low-budget exoscope offers similar image quality, magnification, and illumination like a conventional binocular microscope. It may thus help expand access to neurosurgical care worldwide. Users may face difficulty adapting to the lack of depth perception in the beginning. Prospective studies are needed to assess its usability and effectiveness compared to the microscope.