Built-in Light Source Research Articles

Impact of different lighting conditions on the tooth-shade selection using intra-oral scanners: An in-vitro study

ObjectivesTo evaluate the accuracy in tooth shade selection under various lighting conditions using different devices, including a color spectrophotometer (CSP) and two intra-oral scanners (IOS: IOS-1 and IOS-2). MethodsTooth shade measurements were performed on a standardized shade guide (16 shades, A1-D4) using CSP, IOS-1 and IOS-2. These evaluations were carried out under three lighting conditions: (1) DL - device light source only, (2) RL - DL plus room light, and (3) CL - RL plus dental-chair light. Each shade was measured ten times per lighting condition with each device by a single investigator. Shade detection accuracy was defined as the percentage of matches to the known shade. Logistic regression models were used for statistical analyses (α = 0.05). ResultsA total of 1440 measurements were conducted. Lighting conditions of increasing intensity significantly decreased the shade detection accuracy of the devices (CSP: RLvsDL, p > 0.9999, Odds Ratio (OR) = 1; CLvsDL, p = 0.0726, OR = 0.6053, IOS-1: RLvsDL, p < 0.0001, OR = 0.2862; CLvsDL, p < 0.0001, OR = 0.05239 and IOS-2: RLvsDL, p = 0.0002, OR = 0.376; CLvsDL, p < 0.0001, OR = 0.1908). CSP, IOS-1, and IOS-2 had shade detection accuracies of 43.75 %, 74.38 %, and 59.38 % respectively under DL. In RL, IOS-1 and IOS-2 dropped to 50.63 % and 40.63 %, respectively; CSP remained unchanged. Under CL, the accuracy dropped for all devices (CSP: 35.63 %, IOS-1: 20.63 %, IOS-2: 28.75 %). Additionally, the devices demonstrated higher accuracy when measuring shade A compared to shades B, C, and D. ConclusionsThe findings of this in vitro study concluded that the accuracy of tooth shade detection was more reliable, particularly for individuals with shade A, when spectrophotometers and intraoral scanners were used with only their built-in light source. Further purpose-built clinical studies are required to confirm these findings in a clinical context.

MobileOne-YOLO: Improving the YOLOv7 network for the detection of unfertilized duck eggs and early duck embryo development - a novel approach

Unfertilized duck eggs and early dead embryo eggs can significantly harm normally developing embryo eggs if not detected and removed in a timely manner. The traditional light-illumination technique currently used for this purpose is inefficient, time-consuming, and labor-intensive, making it unsuitable for modern farms and hatcheries. To address this issue, this study focuses on duck eggs incubated for a period of 10 days. This paper introduces a newly developed duck egg image acquisition device that incorporates a duck egg suction lifter with a built-in light source. The device is designed based on the incubation process and has the potential for rapid implementation in actual production. Furthermore, this study describes an improved algorithm for identifying unfertilized duck eggs and early dead embryo eggs based on the YOLOv7 network. The algorithm incorporates the use of MobileOne as a replacement for YOLOv7′s backbone network and lightweight operations applied to the YOLO head. The test results demonstrate that the MobileOne-YOLO achieves 98.10% detection accuracy, 98.55% recall, 97.79% mAP50, 98.55% precision, and 142.8 FPS in the test set images. In comparison, the original YOLOV7 also achieves 98.10% detection accuracy, 97.10% recall, 97.86% mAP50, 100.00% precision, and 101.2 FPS. The MobileOne-YOLO network maintains the same level of detection accuracy as the YOLOV7 network while achieving significantly improved detection speed. The technical method proposed in this study meets the actual production requirements in terms of detection accuracy and speed. Moreover, the image acquisition method adopted in this study is based on the incubation process, making it readily applicable to production practice. This study provides a new foundation for the subsequent development of intelligent detection equipment for identifying unfertilized duck eggs and early dead embryo eggs.

Long afterglow phosphor driven g-C3N4 photocatalyst for continuous water purification under light and dark conditions

An important issue in photocatalysis is the light required to carry out the catalytic reaction, so maintaining photocatalytic reaction activity in the dark has been the ultimate target of expanding photocatalytic technology. Herein, we report a photocatalyst g-C3N4/SrAl2O4:Eu2+,Dy3+ through a strategy that couples the energy-storing and light-releasing properties of long afterglow materials and the light-absorbing properties of photocatalytic materials. g-C3N4/SrAl2O4:Eu2+,Dy3+ is able to effectively degrade methyl orange in water under visible light using molecular oxygen in the air, but it maintains significant methyl orange degradation activity after the light is turned off, as if SAO acts as a built-in light source in it. The photocatalytic degradation mechanism is investigated by active species capture experiments, which shows that superoxide radicals (•O2−), hydroxyl radicals (•OH), holes (h+), and singlet oxygen (1O2) generate during the photocatalytic process. Among them, •O2− is the relatively predominantly acting reactive species. This study exemplifies the design of a continuously working photocatalyst with conceptual value for light storage, which provides ideas for practical energy and environmental system applications.

Ultracompact fluorescence smartphone attachment using built-in optics for protoporphyrin-IX quantification in skin.

Smartphone-based fluorescence imaging systems have the potential to provide convenient quantitative image guidance at the point of care. However, common approaches have required the addition of complex optical attachments, which reduce translation potential. In this study, a simple clip-on attachment appropriate for fluorescence imaging of protoporphyrin-IX (PpIX) in skin was designed using the built-in light source and ultrawide camera sensor of a smartphone. Software control for image acquisition and quantitative analysis was developed using the 10-bit video capability of the phone. Optical performance was characterized using PpIX in liquid tissue phantoms and endogenously produced PpIX in mice and human skin. The proposed system achieves a very compact form factor (<30 cm3) and can be readily fabricated using widely available low-cost materials. The limit of detection of PpIX in optical phantoms was <10 nM, with good signal linearity from 10 to 1000 nM (R2 >0.99). Both murine and human skin imaging verified that in vivo PpIX fluorescence was detected within 1 hour of applying aminolevulinic acid (ALA) gel. This ultracompact handheld system for quantification of PpIX in skin is well-suited for dermatology clinical workflows. Due to its simplicity and form factor, the proposed system can be readily adapted for use with other smartphone devices and fluorescence imaging applications. Hardware design and software for the system is made freely available on GitHub (https://github.com/optmed/CompactFluorescenceCam).

Next-generation on-chip plasmonic tweezer with a built-in light source

We are proposing next-generation lab-on-a-chip plasmonic tweezers with a built-in optical source that can be activated electrically. The building block of these tweezers is composed of an Au/p+-InAs/p+-AlAs0.16Sb0.84 Schottky diode, with a circular air-hole opened in the Au layer. Under an appropriate forward bias, the interband optical transitions in InAs, acting as a built-in optical source that can excite the localized surface plasmons (LSPs) around the edge of the hole. Numerical simulations show that the LSPs mode penetrates a chamber that is filled with water and electrically isolated from the top gold layer, providing the gradient force components desired for trapping the target nanoparticles suspended in the water. Moreover, we show that tweezers with air-holes of radius 90 nm under an applied bias of −1.6 V, can trap polystyrene nanoparticles of radius as small as 93 nm. The proposed structure provides a new platform for developing the next-generation compact on-chip plasmonic tweezers with no need for any external optical pump.

Modifying Mie Resonances and Carrier Dynamics of Silicon Nanoparticles by Dense Electron-Hole Plasmas

The strongly localized electric field achieved at the Mie resonances of a silicon nanoparticle enables the generation of a large carrier density, which offers us the opportunity to manipulate the linear and nonlinear optical properties of silicon nanoparticles by optically injecting a dense electron-hole plasma. Here, we show that the dense electron-hole plasma created in a silicon nanoparticle significantly modifies the complex dielectric constant of silicon, which in turn leads to wavelength shift and amplitude change in the magnetic dipole resonance. We demonstrate that the maximum wavelength shift of the magnetic dipole resonance can be revealed by exploiting the hot-electron luminescence emitted by the silicon nanoparticle, which acts as a built-in light source with a broad bandwidth and a short lifetime. We demonstrate that the quantum efficiency of the hot-electron luminescence of silicon nanoparticles can be enhanced a factor of more than 5 through the injection of a dense electron-hole plasma. More interestingly, an acceleration of the radiative recombination process is found at high carrier densities. Our findings are helpful for understanding the modification of Mie resonances in silicon nanoparticles induced by the dense electron-hole plasmas and useful for designing silicon-based photonic devices.

Development and applicability of a smartphone torch based emergency light source for microscopy.

Modern microscopes are equipped with built-in illuminator. However, during a power outage, microscopy is not possible with extra mirror system if an alternative light source is not available. Smartphone torch can serve as a light source. Holding it under the microscope is difficult when both hands are engaged in microscopy. The aim of the study was to develop a stand for smartphone torch and to check the applicability of smartphone torch-based light source in microscopy. A stand was made with cardboard for keeping the smartphone on it. An optical diffuser was made with white polyethylene plastic. Smartphone with the stand and optical diffuser can serve as a soft light source. A convenient sample of 16 faculty member rated 11 slides first under the microscope with its built-in light source and then twice with the new device as a light source on 10-point Likert type scale. Applicability of the device was checked by validity and reliability by Intraclass Correlation Coefficients (ICC) with α = 0.05. The raters were able to examine the slides under the microscope with the new devices as a light source. An overall score (11 slides, 16 observers) for the image quality was 9.36 ± 0.86 (range 6-10). Interrater, intrarater, and test-retest ICC were 0.939 (P < 0.001), 0.853 (P = 0.003), and 0.889 (P < 0.001) respectively which indicate "good" to "excellent" level of reliability. Developed smartphone torch stand with an optical diffuser can serve as an emergency light source in microscopy. This may be a useful tool for settings with a frequent power outage.

Use of the No-Touch Saphenous Vein Harvesting Technique via Small Incisions.

There are substantial data in support of improved patency using the no-touch (NT) saphenous vein (SV) harvesting technique. However, wound complications correlated with such are more significant than those associated with the skeletonized technique. To solve this, we introduced the use of the electrothermal bipolar vessel sealing device via small incisions. In this study, a cordless retractor with a built-in LED light source was utilized. The NT-SV graft was harvested with a pedicle of surrounding tissue approximately 5 mm in size and attached to the main trunk. The intima, tunica media, adventitia, and vasa vasorum appeared normal by histological analysis. Our technique combines the potential advantages of a minimally invasive endoscope approach using bipolar electrothermy and the improved patency of a NT-SV.

A "Missile-Detonation" Strategy to Precisely Supply and Efficiently Amplify Cerenkov Radiation Energy for Cancer Theranostics.

Cerenkov radiation (CR) from radionuclides can act as a built-in light source for cancer theranostics, opening a new horizon in biomedical applications. However, considerably low tumor-targeting efficiency of existing radionuclides and radionuclide-based nanomedicines limits the efficacy of CR-induced theranostics (CRIT). It remains a challenge to precisely and efficiently supply CR energy to the tumor site. Here, a "missile-detonation" strategy is reported, in which a high dose of p-SCN-Bn-deferoxamine-porphyrin-PEG nanocomplex (Df-PPN) is first adminstered as a CR energy receiver/missile to passively target to tumor, and then a low dose of the 89 Zr-labeled Df-PPN is administrated as a CR energy donor/detonator, which can be visualized and quantified by Cerenkov energy transfer imaging, positron-emission tomography, and fluorescence imaging. Based on homologous properties, the colocalization of Df-PPN and 89 Zr-Df-PPN in the tumor site is maximized and efficient CR energy transfer is enabled, which maximizes the tumor-targeted CRIT efficacy in an optimal spatiotemporal setting while also reducing adverse off-target effects from CRIT. This precise and efficient CRIT strategy causes significant tumor vascular damage and inhibited tumor growth.

Smartphone supported backlight illumination and image acquisition for microfluidic-based point-of-care testing.

A smartphone-based image analysis system is advantageous for point-of-care testing applications. However, the processes of observation and image recording rely heavily on an external attachment that includes additional light sources. Moreover, microfluidic point-of-care devices are highly miniaturized, and can be clearly observed only under magnification. To address these issues, the present work proposes a novel imaging box for converting the built-in light source of a smartphone into uniform backlight illumination to avoid interference arising from reflections. A multi-piece orthoscopic lens is embedded in the imaging box to enable the imaging of micro-sized samples. As such, the colorimetric signal of a microchannel with a width as small as 25 µm can be faithfully recorded. Protein concentration quantification based on the bicinchoninic acid assay method was demonstrated with the proposed smartphone/imaging box system from an analysis of colorimetric signals. In addition, a microfluidic chip for conducting ABO blood typing was fabricated, and the microscopic imaging of induced blood coagulation can be clearly observed in a 3 µL sample using the proposed system. These results highlight the potential for adopting smartphone-based analysis systems in point-of-care testing applications.

Dark adaptation time in canine electroretinography using a contact lens electrode with a built-in light source.

The purpose of this study was to evaluate the dark adaptation time in canine electroretinography (ERG) using a contact lens electrode with a built-in LED. Twelve eyes of six normal laboratory beagle dogs were used and exposed to steady room light at 500 lux for 30 min for light adaption. ERG was recorded at different time points during dark adaptation in sedated and light-adapted beagles. The stimulus intensity was 0.0096 cd/m2/sec. The b-wave amplitude increased significantly until 25 min of dark adaptation, whereas no significant changes in amplitudes were observed after 30 min. Dark adaptation for more than 25 min would be necessary for accurate ERG in canine ERG using a contact lens electrode with a built-in LED.

Mass-Producible Polydimethylsiloxane (PDMS) Frontlight Unit (FLU) for Reflective Displays

A new frontlight unit (FLU) that consists of a single-body light-guide plate (LGP) with cylindrical microstructures has been proposed as a light source for reflective displays. Owing to the material properties of polydimethylsiloxane (PDMS), the proposed FLU shows high transparency and flexibility. In order to fabricate the FLU with mass production-friendly processes, simple 3-D micromachining methods were developed using thick photoresist lithography and metal electroplating. Compared with commercial FLU products, the fabricated 6-in PDMS FLU showed good optical performance with an average luminance of 5.58 nit (cd/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) and uniformity (minimum luminance divided by maximum luminance from nine positions) of 53% using four LEDs. The proposed FLU can be utilized as a built-in light source for diverse reflective displays applications.

Novel Method for Open-Access Laparoscopic Port Insertion Using the Killian Nasal Speculum: The Lister Technique

Safe insertion of the first port during laparoscopic surgery has always been problematic, from the early use of the Veress needle to the open Hasson technique. We describe a novel, safe, and well-illuminated technique of port entry using the Killian nasal speculum. This technique has been used successfully in transperitoneal laparoscopic nephrectomy as well as extraperitoneal radical prostatectomy in our department. The Killian nasal speculum has an built-in light source allowing excellent vision, and its narrow "beak" perfectly separates the fat and rectus sheath, and allows muscle splitting without the need for any other instrument or assistant. This technique has been employed in obese patients, allowing easy access, and it creates a tight, leakproof entry port. The Killian nasal speculum is available in all hospitals that offer an ear, nose, and throat service, and comes in four different sizes and lengths to suit all types of patients.

Functional Disorder of the Retina in Manganese-Deficient Japanese Quail Revealed by Electroretinography using a Contact Lens Electrode with Built-In Light Source

Manganese deficiency results in neurological and skeletal defects, together with ultrastructural disarrangement of the retina in rats. Wild birds show a range of Mn concentrations in their tissues, including the liver, raising the possibility of Mn-related disorders in the wild. Electroretinography (ERG) provides a useful noninvasive approach to evaluate visual function. This method is especially useful in birds, as objective analysis of them is very difficult, while they have well-developed vision. In this study, we carried out a convenient and reliable ERG recording using a contact lens electrode with a built-in light source (LED electrode) of Japanese quail (Coturnix coturnix japonica) fed a Mn-deficient diet. After 10 min light adaptation, single-flash and flicker cone responses were reproducibly recorded to cause an intensity-dependent increase in amplitude of both a-wave and b-wave in single-flash ERG. Mn-deficient feeding markedly decreased the Mn concentration in the liver by almost half in 3 to 6 weeks, followed by body weight loss in 13 to 15 weeks. Implicit time of a-wave and b-wave cone response by single-flash stimulation was significantly delayed in quail with a Mn depletion from 3 to 6 weeks. Every cone response of the Mn-deprived quail had a tendency to decrease amplitude. The ultrastructure of cone photoreceptor cells was disorganized by Mn deficiency, including changes in outer segment discs of photoreceptor cells. These results suggest the essential role of Mn in the integrity of the retinal function of birds.

The determination of dark adaptation time using electroretinography in conscious Miniature Schnauzer dogs

The optimal dark adaptation time of electroretinograms (ERG's) performed on conscious dogs were determined using a commercially available ERG unit with a contact lens electrode and a built-in light source (LED-electrode). The ERG recordings were performed on nine healthy Miniature Schnauzer dogs. The bilateral ERG's at seven different dark adaptation times at an intensity of 2.5 cd·s/m2 was performed. Signal averaging (4 flashes of light stimuli) was adopted to reduce electrophysiologic noise. As the dark adaptation time increased, a significant increase in the mean a-wave amplitudes was observed in comparison to base-line levels up to 10 min (p < 0.05). Thereafter, no significant differences in amplitude occured over the dark adaptation time. Moreover, at this time the mean amplitude was 60.30 ± 18.47 µV. However, no significant changes were observed for the implicit times of the a-wave. The implicit times and amplitude of the b-wave increased significantly up to 20 min of dark adaptation (p < 0.05). Beyond this time, the mean b-wave amplitudes was 132.92 ± 17.79 µV. The results of the present study demonstrate that, the optimal dark adaptation time when performing ERG's, should be at least 20 min in conscious Miniature Schnauzer dogs.

Development of a Trigger-On Indicator for a Weed Sensing Spray Unit

Intermittent spray systems that automatically spray only when weeds are present have been commercially available since 1992 and can significantly reduce herbicide usage by 50 to 90% as compared to broadcast applications (2). The Weedseeker (NTech Industries, Ukiah, Calif.) is one such system that utilizes optics to detect the presence of weeds. The system works by exploiting the fact that chlorophyll selectively absorbs red wavebands of light and reflects near-infrared light (1). Each sensor unit has its own built-in light source and a sensor that detects the light reflected back to the unit over a 12-inch-wide field of view. When the sensor detects an increase in the ratio of near-infrared to red light above the base threshold level, a solenoid valve is activated to spray the weed. Although the sensor unit reliably detects the presence of green plants (2), a major drawback with the current design is that it doesn't provide any feedback to the user when one of the spray units is actively spraying. This is problematic, particularly on wide-boom, multi-sensor-unit sprayers since each sensing unit is calibrated independently in the field prior to spraying from the reflectance of the ground surface beneath it whenever the calibration button is pushed. If one of the sensing units is calibrated when the sensor is over a weed, the unit will not detect weeds of similar size or smaller when spraying. Also, because the sensing unit is sensitive to background reflectance, if one of the sensors is calibrated when it is positioned over a spot of ground that is not characteristic of the rest of the field, the unit will ghost fire and spray when weeds are not present. Either scenario is undesirable, but likely to occur since recalibration is necessary several times during the day due to changes in ambient light and field conditions. To overcome this problem, a trigger-on indicating device was developed to help the operator determine that the sensor units are operating correctly. The Weedseeker unit has a small LED on the back of the unit that illuminates whenever the unit is spraying. The device developed utilizes a phototransistor to detect when the LED is illuminated and activate a super-bright LED that is visible from the tractor cab (Fig. 1). The circuit designed includes a resistor and a NPN transistor that function to prevent low levels of light from activating the super-bright LED (Fig. 2). All electronic components are encased in a waterproof BUD box and attached to a Weedseeker sensor via Velcro and zip ties (Figs. 1 and 3). An opaque, nontranslucent flexible rubber washer is used to seal the phototransistor from ambient light and dust (Fig. 1). Power is supplied by two 1.5-V, AA batteries. Fig. 1. Trigger-on indicator assembly for Weedseeker sensor unit.

Electroretinography Using Contact Lens Electrode with Built-In Light Source in Dogs

Electroretinography (ERG) is an effective method for the diagnosis of retinal disease. In the dog, dependable ERG recording is difficult without the use of an expensive device like a Ganzfeld full-field stimulator. The International Society for Clinical Electrophysiology of Vision has defined the standard flash stimulus condition (SF) and evaluation of the retina using the b/a ratio in humans. In dogs, evaluation using the b/a ratio has not been reported, whereas the intensity of SF has been defined. In this study, we performed a convenient ERG recording method using a contact lens electrode with a built-in light source (LED-electrode), and confirmed SF as reported previously. ERG recordings were performed on 15 healthy beagle dogs under sedation. We performed bilateral ERG at 12 different intensities after 30 min dark adaptation. After 10 min light adaptation, we recorded single flash cone and flicker cone response using the SF determined in this study. In this study, SF of 3.0 cd/m(2)/sec (6,000 cd/m(2), 0.5 msec) resulted in b/a=2. The intensity for rod response that recorded only the b-wave was 0.0096 cd/m(2)/sec (80 cd/m(2), 0.12 msec). We could achieve ERG for each response easily and smoothly under sedation, and without general anesthesia. Using an LED-electrode, we could perform more quantitative and reproducible ERG examinations than with traditional methods. We propose that the b/a ratio is the most useful parameter in ERG reporting for evaluating retinal function.

Comparison of Techniques for In Situ Nondamaging Measurement of Solar Reflectances of Low-Slope Roof Membranes

With the implementation of the Energy Star Roof Products Program by the U.S. Environmental Protection Agency and the U.S. Department of Energy, techniques are especially needed that yield in situ measurements of the average solar reflectance of roof surfaces without damage to them. This paper presents results of limited field surveys with two types of instruments that permit such measurements. Solar reflectances on a scale from 0 to 1 were obtained by the established laboratory technique for five samples covering the range exhibited by low-slope roofs and coating systems for them. Based on these results, the average bias for one instrument, a portable solar spectrum reflectometer using a built-in light source, was +0.003. The maximum bias for the five samples was ±0.02. Scatter of readings over a roof area with this instrument depends upon characteristics of the specific surface. Scatter can be as little as ±0.001 but is typically more than ±0.02. The other instrument uses a pyranometer and is operated by recording the responses when the pyranometer faces the sun and when it is inverted facing the surface of interest. The reflectance is the ratio of the response when inverted to the response facing the sun. For a variety of roof surfaces, the average of readings with both instruments agreed within 95%confidence intervals of ±0.02 to ±0.06, calculated as ±tċs.d., where t is the t-statistic for the number of measurements and s.d. is the measurement standard deviation.

The Endo-Mirror, a New Instrument for Ophthalmic Surgery Requiring Visualization of the Ciliary Sulcus

Safely suturing a posterior chamber intraocular lens (PC-IOL) to the ciliary sulcus requires a means of visualizing the ciliary sulcus, since it cannot be viewed directly with the operating microscope. We, therefore, created several trial instruments consisting of a mirror with a built-in light source, which we call an endo-mirror, designed for observing the area behind the iris. Using these instruments, we were able satisfactorily to view the ciliary sulcus and suture a PC-IOL to it, first in a number of animal eyes, and then, using an endo-mirror incorporating the best features of the trial versions, in actual clinical cases.

Continuous, real-time, noninvasive monitor of blood pressure: Penaz methodology applied to the finger.

The finger blood pressure monitor measures blood pressure continuously and noninvasively by means of a technique described by J. Penaz. The size of the artery is measured when its internal pressure (arterial pressure) equals the external pressure. (At this point, transmural pressure equals zero and the arterial wall is said to be "unloaded.") This unloaded condition is maintained by continuous, automatic adjustments of external pressure on the artery, adjustments that are made simultaneously with and parallel to intraarterial pressure variations. The external pressure then constantly equals internal pressure (arterial blood pressure) and is reported by the monitor as values for systolic, mean, and diastolic pressure. A finger cuff with a built-in light source and detector is used to measure finger artery size, and an inflatable bladder is used to apply the external pressure to the artery. The monitor is microprocessor based; algorithms determine the unloaded artery size approximately every minute and automatically correct for changes possibly induced by smooth muscle contraction or relaxation, and a high-speed electropneumatic servo control system enables automatic calibration and adjustment.