Monochrome Digital Camera Research Articles

Novel instrumental markers of proximal scleroderma provided by imaging photoplethysmography

Objective: Instrumental identification of proximal scleroderma, which is necessary for the early diagnosis of systemic sclerosis (SSD), has not yet been developed. The aim of this study was to assess the potential diagnostic value of the imaging photoplethysmography (IPPG) method in patients with SSD. Approach: The study enrolled 19 patients with SSD and 21 healthy subjects matched by age and sex with the patients. Spatial distribution of capillary-blood-flow parameters and their dynamics was estimated in the facial area of patients and subjects. In the IPPG system, a 40 s video of the subject’s face illuminated by green polarized light was recorded with a monochrome digital camera in synchronization with the electrocardiogram. Experimental data were processed using custom software allowing assessment of an arrival time of the blood pressure wave (PAT), an amplitude of pulsatile component (APC) of the photoplethysmographic (PPG) waveform, and their variability. Main results: Our study has revealed a significant increase in PAT variability in patients with SSD compared to the control group: 52 ± 47 ms vs 24 ± 13 ms (P =0.01). Similarly, the variability of the PPG-pulse shape was larger in patients with SSD: 0.13 ± 0.07% vs 0.09 ± 0.02% (P < 0.001). In addition, patients with scleroderma showed a significantly greater degree of asymmetry of the APC parameter than the control group: 17.7 ± 9.7 vs 7.9 ± 5.0 (P < 0.001). At the same time, no correlation was found between the PPG waveform parameters and either the form or duration of the disease. Also, no relationship between the characteristics of the PPG waveform and the modified Rodnan skin score was found. Significance: Novel instrumental markers found in our pilot study showed that the IPPG method can be used for diagnosing SSD in the early stages of the disease.

Development of the interscutularis model as an outcome measure for facial nerve surgery

IntroductionAnimal models for the study of facial paralysis have been well developed, but concern has arisen regarding the accuracy of eye closure and whisker movement as outcome measures due to new data regarding interconnectivity between facial nerve branches and autonomic innervation. The posterior auricular nerve (PAN) is an isolated branch of the facial nerve which has been confirmed as the sole motor innervat or of the interscutularis muscle. This study was designed to develop a model for facial nerve palsy utilizing the PAN and interscutularis muscle. MethodsA custom-made automated video capture system was built into a poly methyl methacrylate cage using a high definition monochrome digital camera and image sensor to record the animal as it drank from a water feeder. A copper floor pad and copper collar around the water feeder were connected to an electrical circuit for automatic saving of the video recording 10 s prior to and 30 s following the drinking event. A pre-operative baseline recording of ear movement during drinking was captured. Female YFP-16 mice at 6 weeks were assigned to sham (Sh, n = 5), nerve excision (Ex, n = 10), or nerve crush (Cr, n = 10) groups with all interventions performed on the right PAN. Sh mice were irrigated with 10 ml normal saline as were the Ex and Cr mice following operative intervention. In Ex mice, a 3 mm section of the PAN was sharply excised and nerve gap was confirmed with fluorescent microscopy. In Cr mice, the PAN was crushed 3 mm from the origin of the facial nerve trunk with size 5 jeweler’s forceps for two periods of 20 s. Post-operative video recordings were collected on post-operative days (POD) 1, 10, 20, and 30. To determine the change in ear movement, the right ear was graphically compared to the left control side. ResultsSh animals exhibited a statistically significant reduction in ear movement at POD01 compared to other POD recordings (p < 0.05), but no significant change in right ear movement following POD05. Ex animals had a significant reduction in right ear movement at all PODs in comparison to the left ear (p < 0.05) with no significant change in right ear movement during the study period (p = 0.94). Cr animals showed a significant reduction in right ear movement compared to the left at POD01, POD10, and POD20 (p < 0.05). At POD30, there was no significant difference between ear movement on either side (p = 0.35). There was a significant change in right ear movement during the data collection period (p < 0.05). ConclusionThe results show that significant differences were demonstrated between the experimental groups and that significant changes within the crush group were identifiable making this an acceptable model to develop as an accurate outcome measure following rodent facial nerve surgery.

High-Throughput Synthesis and Characterization of Eu Doped Ba xSr2- xSiO4 Thin Film Phosphors.

High-throughput techniques have been employed for the synthesis and characterization of thin film phosphors of Eu-doped Ba xSr2- xSiO4. Direct synthesis from evaporation of the constituent elements under a flux of atomic oxygen on a sapphire substrate at 850 °C was used to directly produce thin film libraries (415 nm thickness) of the crystalline orthosilicate phase with the desired compositional variation (0.24 > x > 1.86). The orthosilicate phase could be synthesized as a pure, or predominantly pure, phase. Annealing the as synthesized library in a reducing atmosphere resulted in the reduction of the Eu while retaining the orthosilicate phase, and resulted in a materials thin film library where fluorescence excited by blue light (450 nm) was observable by the naked eye. Parallel screening of the fluorescence from the combinatorial libraries of Eu doped Ba xSr2- xSiO4 has been implemented by imaging the fluorescent radiation over the library using a monochrome digital camera using a series of color filters. Informatics tools have been developed to allow the 1931 CIE color coordinates and the relative quantum efficiencies of the materials library to be rapidly assessed and mapped against composition, crystal structure and phase purity. The range of compositions gave values of CIE x between 0.17 and 0.52 and CIE y between 0.48 and 0.69 with relative efficiencies in the range 2.0 × 10-4-7.6 × 10-4. Good agreement was obtained between the thin film phosphors and the fluorescence characteristics of a number of corresponding bulk phosphor powders. The thermal quenching of fluorescence in the thin film libraries was also measured in the temperature range 25-130 °C: The phase purity of the thin film was found to significantly influence both the relative quantum efficiency and the thermal quenching of the fluorescence.

Simultaneous three-wavelength unwrapping using external digital holographic multiplexing module.

We present an external interferometric setup that is able to simultaneously acquire three wavelengths of the same sample instance without scanning or multiple exposures. This setup projects onto the monochrome digital camera three off-axis holograms with rotated fringe orientations, each from a different wavelength channel, without overlap in the spatial-frequency domain, and thus allows the full reconstruction of the three complex wavefronts from the three wavelength channels. We use this new setup for three-wavelength phase unwrapping, allowing phase imaging of thicker objects than possible with a single wavelength, but without the increased level of noise. We demonstrate the proposed technique for micro-channel profiling and label-free cell imaging.

Calibration Method for the Wavelength and Uniformity of Pixel Response in Photodetector Arrays

Abstract Digital cameras are photodetector arrays that respond to particular bands of the electromagnetic spectrum, and specifically those in the visible spectrum between 380 and 780 nm are the most commonly used. The main cameras function is store the image from an aesthetic point of view, when these are used in home applications. For this reason, several processes are used in image reconstruction to improve the visual appearance, even from the manufacturing process of sensor decreasing the possibility to obtain optical measurements with this cameras. However, digital cameras can also be used as optical measuring instruments knowing their features in depth. Therefore, in this paper is proposed a calibration method for monochrome digital camera using a monochromator and an automatic rotation system. In this way, the uniformity of the pixels response is verified, bad pixels are detected, and the sensitivity curve is obtained. The results show the advantages of the method to find regions of pixels turned off. Also, the value of sensitivity as a function of wavelength is obtained to verify the regions with significant changes of uniformity. This work aims to the prototyping of a color measurement system and it is very important a comprehensive understanding of the camera.

Issue Cover (May 2015)

Front cover: Immature oligodendrocytes show complex morphology as revealed by Rip immunostaining. Oligodendrocyte progenitor cells were prepared from P1 rat forebrain and were differentiated into immature oligodendrocytes under defined medium condition. Cells were immunostained with anti-oligodendrocyte (Rip) antibody (green), nuclei were counter-stained with propidium iodide (red) (original micrograph G of the lower panel in Figure 3). Images were acquired by a QICLICK monochrome digital camera attached to an Olympus BX60 fluorescence microscope with 40x objective lens. J. Neurochem. 2015, vol. 133 (4), pp. 532–543. Read the full article on doi: 10.1111/jnc.12988

Recovering the Colors of Objects from Multiple Near-IR Images

This paper proposes an algorithm for recovering the colors of objects from multiple near-infrared (near-IR) images. The International Commission on Illumination (CIE) color coordinates of objects are recovered from a series of gray images captured under multiple spectral near-IR illuminations using polynomial regression. The feasibility of the proposed algorithm is tested experimentally by using 24 color patches of the Color Rendition Chart. The experimental apparatus is composed of a monochrome digital camera without an IR cut-off filter and a custom-designed LED illuminator emitting multiple spectral near-IR illuminations, with peak wavelengths near the red edge of the visible band, namely at 700, 740, 780, and 860 nm. The average color difference between the original and the recovered colors for all 24 patches was found to be 11.1. However, if some particular patches with high value are disregarded, the average color difference is reduced to 4.2, and this value is within the acceptability tolerance for complex image on the display.

Aerial Radiometric and Video Measurements of Whitecap Coverage

This paper presents the results of high-altitude microwave radiometric and video measurements in the presence of breaking waves made during the passage of Hurricane Dean on August 21, 2007, over the Gulf of Mexico. Previous measurements of foam fraction and radiometric brightness temperature have focused on the small scale, in which individual foam patches were of the same scale as the radiometer footprint. To work with data from spaceborne microwave radiometers, which have footprints on the scale of tens of kilometers, the knowledge of how the foam fraction sensitivity of brightness temperature scales when footprints increase from meters to kilometers is necessary. Video images of the sea surface recorded with a high-resolution monochrome digital camera were used to determine the foam fraction. Ocean-surface brightness temperature was measured with the Airborne Polarimetric Microwave Imaging Radiometer (APMIR) of the Naval Research Laboratory at frequencies of 6.6 [vertical and horizontal (VH) polarizations], 6.8 (VH), 7.2 (VH), and 10.7 GHz (V), with full polarimetric brightness temperatures measured at 19.35 and 37.0 GHz. Collocated nearly contemporaneous brightness temperatures were available from WindSat, Special Sensor Microwave Imager/Sounder, and Special Sensor Microwave/Imager satellite radiometer overpasses. Oceanographic and meteorological data were taken from buoys located along the flight track. There was good correlation between brightness temperatures measured with APMIR and satellite-borne radiometers with absolute differences largely within the expected uncertainty of the data. An analysis of the video imagery provided the fractional area coverage of the actively breaking waves on the ocean surface. The increase in brightness temperature from each of the microwave sensors was correlated with the whitecap coverage measured by the camera. The experiment not only serves as an important bridge between measurements made with spatial scales on the order of tens of meters and data collected from satellites with spatial scales of tens of kilometers but also provides guidance for improving future field measurements on this topic.

Recognition of lipid-protein rafts in vacuolar membrane

120 The well known Singer–Nicholson model, according to which proteins “float” in a homogeneous lipid sea, has undergone significant changes. Today it is generally accepted that cell membranes are highly heterogeneous: they contain various lipid–protein structures that are involved in many metabolic pro cesses occurring in living cells [1]. According to the model of lipid–protein microdomains (rafts), which is currently most widespread, areas enriched in gly cosphingolipids, sterols, and lipids with saturated fatty acids occur around certain proteins; lipids in these areas are characterized by a denser packing of mole cules compared to the surrounding areas of mem branes [2]. The interest to rafts is determined by the increasing number of experimental data that confirm their involvement in vital cellular processes, such as intrac ellular signaling, endocytosis, apoptosis, sorting of proteins, as well as internalization of toxins, bacteria, viruses, etc. [3, 4]. In addition to specific lipid compo sition, these membrane domains are characterized by specific protein profiles. In plant plasma membrane rafts, P and V type ATPases, protein kinases, mono meric and heteromeric G proteins, 14 3 3 family proteins, aquaporins, etc. were identified [5]. Rafts have been found in the plasma membrane and in endoplasmic reticulum and Golgi membranes. Mitochondrial membranes do not contain rafts [6]. Data on the lipid composition of tonoplasts [7] suggest that plant vacuolar membranes may also contain pro tein–lipid rafts. In this study, we found lipid protein domains (rafts) in the vacuolar membrane. Experiments were performed with isolated vacu oles and membrane vesicles of dormant storage roots of the red beet (Beta vulgaris L.) variety Bordeaux. Vacuoles and tonoplast vesicles from the storage root tissue were isolated and purified as described in [8]. Sterol enriched microdomains (rafts) were detected by fluorescent microscopy using the sterol binding antibiotic filipin [9]. To ensure the binding of filipin to the vacuolar membrane, a suspension of isolated vac uoles in the isolation medium (0.8 M KCl, 20 mM EDTA, and 50 mM Na2HPO4 (pH 8.0)) was supple mented with filipin (0.2% solution in DMSO) to a final concentration of 5 μM. The suspension was incu bated at 20 ± 2°С for 30 min, washed in the same buffer, and analyzed under an Axio observer Z1 fluo rescence microscope (Carl Zeiss, Germany) equipped with an Axio Cam MRm monochrome digital camera and Axio Vision Rel.4.8 software package for captur Recognition of Lipid–Protein Rafts in Vacuolar Membrane

Recovery of reflection spectra in a multispectral imaging system with light emitting diodes

Performance of recently proposed multispectral imaging system for fast acquisition of two dimensional distribution of reflectance spectrum is experimentally studied. The system operation is based on a subspace vector model in which any reflectance spectrum is described in the compressed form as a linear combination of few spectral functions. A key element of the proposed system is a light source which includes a set of light-emitting diodes with different central wavelengths. The light source provides illumination of the object by fast-switchable sequences of spectral bands whose energy distributions are proportional to mutually orthogonal spectral functions (calculated in-advance). Object illumination is synchronized with a monochrome digital camera. The system allows us fast acquisition of reflectance spectra in a compressed form with high spatial resolution. A model of the system calibration by using standard white matte sample is proposed. Reconstruction of the reflectance spectrum from the compressed data collected after illumination of selected color samples from the Munsell book by 7 mutually orthogonal spectral functions is demonstrated. Parameters of the system, which affect the accuracy of the spectrum reconstruction, are analyzed and discussed.

컴퓨터 영상을 이용한 오염방지 친수성능 측정 시스템 개발

Surface energy is the principal factor of anti-condensation. High surface energy appears hydrophilic itself and low surface energy represents hydrophobic itself. The contact angle is widely being used for measurement of surface energy of materials, evaluation of coating performances, measurement of wettability, and so on. However, the existing contact angle measuring system is so expensive for purchasing and complicated, so it takes a lot of time and money to use. This study was conducted to develop the algorithm for evaluating hydrophilic performance through measuring the contact angle of water droplet automatically, and fabricate relatively simple measuring system using a low-cost monochrome camera and image processing. A constant amount of water was firstly allocated on a slide by a micropipette, and then the image of water droplet was captured by monochrome digital camera and sent to a computer. The image was binarized and then reduced noises by labeling. Finally, the contact angle of water droplet was computed by using three points (left, right, and top coordinates), simple linear mathematics, and trigonometric function. The experimental results demonstrated the accuracy and reproducibility of the developed system showing less deviations and deviation ratio.

High precision measurement of surface cracks using an optical system

In this contribution an advanced technique to measure the width of surface cracks in concrete is presented. The goal is to provide a system for laboratory applications with a high resolution in order to be able to estimate the stabilization of surface cracks in the range of 0–250 µm during laboratory loading tests. Using digital imaging and suitable image processing algorithms, an automated system for the determination of crack widths was developed. A 4 megapixel monochrome digital camera was used in combination with a special telecentric lens, in order to achieve a resolution of 1 µm per pixel. The main challenge in this work was to develop a robust image processing algorithm, which determines the surface crack width under changing environmental conditions, especially in terms of ambient light.

Development and Calibration of a Gonio-Spectral Imaging System for Measuring Surface Reflection

This paper proposes a gonio-spectral imaging system for measuring light reflection on an object surface by using two robot arms, a multi-band lighting system, and a monochrome digital camera. It allows four degrees of freedom in incident and viewing angles necessary for full parametrization of a reflection model function. Spectral images captured for various incident and viewing angles are warped as if they were all captured from the same viewing direction. The intensity of reflected light is thus recorded in a normalized image form for any incident and viewing directions. The normalized images are used to estimate reflection model parameters at each surface point. To ensure point-wise reflection modeling, a calibration method is also proposed based on a geometrical model of the robot arms and camera. The proposed system can deal with objects with surface texture. Experiments are done on system calibration, reflection model, and spectral estimation. The results using colored objects show the feasibility of the proposed imaging system.

Differential Regulation of Pulmonary Endothelial Monolayer Integrity by Varying Degrees of Cyclic Stretch

Ventilator-induced lung injury is a life-threatening complication of mechanical ventilation at high-tidal volumes. Besides activation of proinflammatory cytokine production, excessive lung distension directly affects blood-gas barrier and lung vascular permeability. To investigate whether restoration of pulmonary endothelial cell (EC) monolayer integrity after agonist challenge is dependent on the magnitude of applied cyclic stretch (CS) and how these effects are linked to differential activation of small GTPases Rac and Rho, pulmonary ECs were subjected to physiologically (5% elongation) or pathologically (18% elongation) relevant levels of CS. Pathological CS enhanced thrombin-induced gap formation and delayed monolayer recovery, whereas physiological CS induced nearly complete EC recovery accompanied by peripheral redistribution of focal adhesions and cortactin after 50 minutes of thrombin. Consistent with differential effects on monolayer integrity, 18% CS enhanced thrombin-induced Rho activation, whereas 5% CS promoted Rac activation during the EC recovery phase. Rac inhibition dramatically attenuated restoration of monolayer integrity after thrombin challenge. Physiological CS preconditioning (5% CS, 24 hours) enhanced EC paracellular gap resolution after step-wise increase to 18% CS (30 minutes) and thrombin challenge. These results suggest a critical role for the CS amplitude and the balance between Rac and Rho in mechanochemical regulation of lung EC barrier.

Low Conductance Gap Junctions Mediate Specific Electrical Coupling in Body-wall Muscle Cells of Caenorhabditis elegans

Invertebrate innexins and their mammalian homologues, the pannexins, are gap junction proteins. Although a large number of such proteins have been identified, few of the gap junctions that they form have been characterized to provide combined information of biophysical properties, coupling pattern, and molecular compositions. We adapted the dual whole cell voltage clamp technique to in situ analysis of electrical coupling in Caenorhabditis elegans body-wall muscle. We found that body-wall muscle cells were electrically coupled in a highly organized and specific pattern. The coupling was characterized by small (350 pS or less) junctional conductance (G(j)), which showed a bell-shaped relationship with junctional potential (V(j)) but was independent of membrane potential (V(m)). Injection of currents comparable to the junctional current (I(j)) into body-wall muscle cells caused significant depolarization, suggesting important functional relevance. The innexin UNC-9 appeared to be a key component of the gap junctions. Both Myc- and green fluorescent protein-tagged UNC-9 was localized to muscle intercellular junctions. G(j) was greatly inhibited in unc-9(fc16), a putative null mutant. Specific inhibition of UNC-9 function in muscle cells reduced locomotion velocity. Despite UNC-9 expression in both motor neurons and body-wall muscle cells, analyses of miniature and evoked postsynaptic currents in the unc-9 mutant showed normal neuromuscular transmission. These analyses provide a relatively detailed description of innexin-based gap junctions in a native tissue and suggest that innexin-based small conductance gap junctions can play an important role in processes such as locomotion.

Measurement of Mechanical and Optical Dot Gain of Ink Jet Printing and Its Application to Estimate the Reflectances of the Images

In this paper, we propose a method to separately measure the ink dot transmittance on paper without the effect of optical dot gain. The single dot profiles on paper are measured by a monochrome digital camera attached on a microscope using underneath illumination in order to capture only ink dot distribution (mechanical dot gain). From single dot profile on glossy, matt and uncoated paper, the transmittances of the ink image are simulated using dot overlap model in the high resolution grid. The reflectance of ink jet images are estimated from the simulated ink image transmittance and the optical point spread function of paper using the image reflectance model. The result shows that the image transmittance and reflectance are well estimated if the paper behaves as a perfect diffuser.