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- 2018
- Image processing
- Infrared camera
- Eye movement
- Non-contact switch
- Optoelectronic Information Science and Engineering
- Gunma University
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Two novel fluorescent probes based on phenothiazine: synthesis and “naked-eye” colorimetric recognition of Hg2+
摘要： Two novel colorimetric and fluorescent probes 2-(1,3-dithiolanes)-10-ethyl phenothiazine (PHE–Ed) and 2-(1,3-dithianes)-10-ethyl phenothiazine (PHE–Pd) based on phenothiazine were successfully synthesized, and their structure was confirmed by NMR and high resolution mass spectra. Fluorescence investigations revealed that the synthesized probes could be used for the selective detection of Hg2+, which was accompanied with an obvious color change from colorless to light yellow. The applicable ability of the two probes was investigated by a series of competitive experiments, solid colorimetric experiments, and applied experiments, which proved that these probes showed high sensitivity and great potential to detect Hg2+ in environmental analysis systems. Furthermore, the detection mechanism of the probes was investigated by FT-IR spectra and NMR spectra, and the results indicated that the detection of Hg2+ was accomplished through the Hg2+-promoted deprotection of thioacetal.
关键词： Phenothiazine,ICT fluorophore,1,3-propanedithiol,Naked-eye,1,2-ethanedithiol
更新于2025-09-23 15:22:29
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Use of DEMs Derived from TLS and HRSI Data for Landslide Feature Recognition
摘要： This paper addresses the problems arising from the use of data acquired with two different remote sensing techniques—high-resolution satellite imagery (HRSI) and terrestrial laser scanning (TLS)—for the extraction of digital elevation models (DEMs) used in the geomorphological analysis and recognition of landslides, taking into account the uncertainties associated with DEM production. In order to obtain a georeferenced and edited point cloud, the two data sets require quite different processes, which are more complex for satellite images than for TLS data. The differences between the two processes are highlighted. The point clouds are interpolated on a DEM with a 1 m grid size using kriging. Starting from these DEMs, a number of contour, slope, and aspect maps are extracted, together with their associated uncertainty maps. Comparative analysis of selected landslide features drawn from the two data sources allows recognition and classification of hierarchical and multiscale landslide components. Taking into account the uncertainty related to the map enables areas to be located for which one data source was able to give more reliable results than another. Our case study is located in Southern Italy, in an area known for active landslides.
关键词： kriging,Geo-Eye-1,TLS,morphometric feature,HRSI,uncertainty,DEM
更新于2025-09-23 15:22:29
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Employing Image Processing Techniques and Artificial Intelligence for Automated Eye Diagnosis Using Digital Eye Fundus Images
摘要： Blindness usually comes from two main causes, glaucoma and diabetes. Robust mass screening is performed for diagnosing, such as screening that requires a cost-effective method for glaucoma and diabetic retinopathy and integrates well with digital medical imaging, image processing, and administrative processes. For addressing all these issues, we propose a novel low-cost automated glaucoma and diabetic retinopathy diagnosis system, based on features extraction from digital eye fundus images. This paper proposes a diagnosis system for automated identification of healthy, glaucoma, and diabetic retinopathy. Using a combination of local binary pattern features, Gabor filter features, statistical features, and color features which are then fed to an artificial neural network and support vector machine classifiers. In this work, the classifier identifies healthy, glaucoma, and diabetic retinopathy images with an accuracy of 91.1%,92.9%, 92.9%, and 92.3% and sensitivity of 91.06%, 92.6%, 92.66%, and 91.73% and specificity of 89.83%, 91.26%, 91.96%, and 89.16% for ANN, and an accuracy of 90.0%,92.94%, 95.43%, and 97.92% and sensitivity of 89.34%, 93.26%, 95.72%, and 97.93% and specificity of 95.13%, 96.68%, 97.88%, and 99.05% for SVM, based on 5, 10, 15, and 31 number of selected features. The proposed system can detect glaucoma, diabetic retinopathy and normal cases with high accuracy and sensitivity using selected features, the performance of the system is high due to using of a huge fundus database.
关键词： and Classification,Diagnosis,Diabetic Retinopathy,Glaucoma,Eye Fundus
更新于2025-09-23 15:22:29
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New Parametric Imaging Method with Fluorescein Angiograms for Detecting Areas of Capillary Nonperfusion
摘要： Fluorescein angiography (FAG) is currently the most useful diagnostic modality for examining retinal circulation, and it is frequently used for the evaluation of patients with diabetic retinopathy, occlusive diseases, such as retinal venous and arterial occlusions, and wet macular degeneration. This paper presents a method for objectively evaluating retinal circulation by quantifying circulation-related parameters. Methods: This method allows the semiautomatic preprocessing and registering of FAG images. The arterial input function is estimated from the registered set of FAG images using gamma-variate fitting. Then, the parameters can be computed by deconvolution on the basis of truncated singular value decomposition, and they can finally be presented as parametric color images in a combination of three colors, red, green, and blue. Results: After the estimation of arterial input function, the parameters of relative blood flow and mean transit time were computed using deconvolution analysis based on truncated singular value decomposition. Conclusions: The parametric color image is helpful to interpret the status of retinal blood circulation and provides quantitative data on retina ischemia without interobserver variability. This system easily provides the status of retinal blood circulation both qualitatively and quantitatively. It also helps to standardize FAG interpretation and may contribute to network-based telemedicine systems in the future.
关键词： Fluorescein Angiography,Ophthalmology,Computer-Assisted Diagnosis,Eye Disease,Biomedical Engineering
更新于2025-09-23 15:22:29
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Paediatric Refractive Errors in an Eye Clinic in Osogbo, Nigeria
摘要： BACKGROUND: Paediatric ophthalmology is an emerging subspecialty in Nigeria and as such there is paucity of data on refractive errors in the country. This study set out to determine the pattern of refractive errors in children attending an eye clinic in South West Nigeria. METHODS: A descriptive study of 180 consecutive subjects seen over a 2-year period. Presenting complaints, presenting visual acuity (PVA), age and sex were recorded. Clinical examination of the anterior and posterior segments of the eyes, extraocular muscle assessment and refraction were done. The types of refractive errors and their grades were determined. Corrected VA was obtained. Data was analysed using descriptive statistics in proportions, chi square with p value <0.05. RESULTS: The age range of subjects was between 3 and 16 years with mean age = 11.7 and SD = 0.51; with males making up 33.9%.The commonest presenting complaint was blurring of distant vision (40%), presenting visual acuity 6/9 (33.9%), normal vision constituted >75.0%, visual impairment20% and low vision 23.3%. Low grade spherical and cylindrical errors occurred most frequently (35.6% and 59.9% respectively). Regular astigmatism was significantly more common, P <0.001. The commonest diagnosis was simple myopic astigmatism (41.1%). Four cases of strabismus were seen. CONCLUSION: Simple spherical and cylindrical errors were the commonest types of refractive errors seen. Visual impairment and low vision occurred and could be a cause of absenteeism from school. Low-cost spectacle production or dispensing unit and health education are advocated for the prevention of visual impairment in a hospital set-up.
关键词： Low-cost spectacle dispensing unit,Eye clinic,Child,Refractive error
更新于2025-09-23 15:22:29
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In vivo confocal microscopy morphometric analysis of corneal subbasal nerve plexus in dry eye disease using newly developed fully automated system
摘要： Purpose To evaluate in vivo confocal microscopy (IVCM) features of corneal subbasal nerve plexus (SNP) in the setting of dry eye disease (DED) using fully automated software BACCMetrics,^ and to further investigate its diagnostic performance in discriminating DED patients. Methods IVCM exams of SNP in DED patients and matched control subjects were performed using Heidelberg Retina Tomograph with the Rostock Cornea Module. The following parameters were obtained with ACCMetrics: corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fiber area (CNFA), corneal nerve fiber width (CNFW), and corneal nerve fractal dimension (CNFrD). The Mann–Whitney U test was used to compare variables. Receiver operating characteristic curves with calculations of the area under the curve (AUC) were used to describe the accuracy of IVCM parameters for discriminating DED patients from controls. Results Thirty-nine DED patients and 30 control subjects were included. Significantly, lower values of CNFD, CNBD, and CNFL and higher value of CNFW were found in DED patients compared to controls (respectively, 20.5 ± 8.7 vs 25.4 ± 6.7 n/ mm2; 25.6 ± 20.1 vs 37.6 ± 21.5 n/mm2; 12.6 ± 4.4 vs 14.5 ± 2.9 mm/mm2; 0.021 ± 0.001 vs 0.019 ± 0.001 mm/mm2; always p < 0.024). CNFW value had the highest diagnostic power in discriminating DED patients (AUC = 0.828). When the diagnosis of DED was made based on either CNFW or CNBD, the sensitivity was 97.4% and the specificity 46.7%. Conclusions The software ACCMetrics was able to rapidly detect SNP alterations occurring in the setting of DED and showed good diagnostic performance in discriminating DED patients.
关键词： Dry eye,Sub-basal nerve plexus,Automated analysis,ACCMetrics,In vivo confocal microscopy
更新于2025-09-23 15:22:29
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Assessment of diabetic teleretinal imaging program at the Portland Department of Veterans Affairs Medical Center
摘要： We conducted a retrospective chart review of 200 diabetic patients who had teleretinal imaging performed between January 1, 2010, and January 1, 2011, at Portland Department of Veterans Affairs (VA) Medical Center outpatient clinics to assess the effectiveness of the diabetic teleretinal imaging program. Twenty patients (10%) had diabetic retinopathy. Ninety percent of the available teleretinal imaging studies were of adequate quality for interpretation. In accordance with local VA policy at that time, all teleretinal imaging patients should have been referred for a dilated retinal examination the following year. Image readers referred 97.5% of the patients to eye clinics for subsequent eye examinations, but the imagers scheduled appointments for only 80% of these patients. The redundancy rate, i.e., patients who had an eye examination within the past 6 mo, was 11%; the duplicate recall rate, i.e., patients who had a second teleretinal imaging performed within 1 yr of the eye examination, was 37%. Rates of timely diabetic eye examinations at clinics with teleretinal imaging programs, particularly when teleretinal imaging and eye clinics were colocated at the same community-based outpatient clinic, were higher than at those without a teleretinal imaging program. We concluded that the Portland VA Medical Center's teleretinal imaging program was successful in increasing the screening rate for diabetic retinopathy.
关键词： teleretinal imaging program,diabetes mellitus,dilated eye examination,diabetic retinal examination,primary care,diabetic retinopathy,outpatient clinic,screening,teleretinal imaging,telehealth
更新于2025-09-23 15:22:29
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Two novel rhodamine-based fluorescent probes for the rapid and sensitive detection of Fe3+: Experimental and DFT calculations
摘要： Fe3+ ions play an important role in both biological and environmental field. In this work, two novel rhodamine-based colorimetric and fluorescent probes (RBA2 and RBA3) were designed and synthesized for the efficient detection of Fe3+. Upon the addition of Fe3+, the fluorescence intensity of RBA2 and RBA3 enhanced 108-fold and 222-fold, respectively. RBA2 and RBA3 exhibited a low detection limit which could achieve 12.8 nM and 11.0 nM. In addition, the binding modes of RBA2 and RBA3 with Fe3+ were proved to be 1:1 stoichiometry in the complexes by Job’s plot, ESI-MS and 1H NMR results. The complexing ability of RBA3 with Fe3+ excessed to that of RBA2 that was determined by the binding association constants, and highly consistent with DFT calculations results. Furthermore, RBA2 and RBA3 were further utilized to detect Fe3+ in living cells and real water samples, indicating their promising prospects in biological and environmental field.
关键词： Cell imaging,DFT calculation,Binding ability,Naked eye,Fe3+
更新于2025-09-23 15:22:29
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Real-time motorized electrical hospital bed control with eye-gaze tracking
摘要： Patients with motor neuron disease and most terminal patients cannot use their hands or arms, and so they need another person for their all needs. However, the mental functions and memories of such patients are generally sound, and they can control their eyes. Using an eye-gaze tracking technique, we have realized a real-time system for such patients. The system controls a motorized electrical hospital bed (EHB) by eye gaze with 4 degrees of freedom, using a low-cost webcam. Contactless systems that require calibration cannot be used for EHB control. The system developed in this work does not require any calibration process and it is contactless. These properties are the most innovative part of the proposed approach. To begin, the system detects the eye region and computes the iris centers. It then tracks the centers and moves a mouse pointer on a screen with the eye gaze. The speci(cid:12)c movements of the mouse pointer are evaluated as position changing requests and the completed movements of the mouse pointer change the EHB position electrically. The communication between the computer and the EHB is provided by a relay control card driven by Arduino Mega. The system works under day/arti(cid:12)cial lighting conditions successfully with or without eyeglasses. The system was tested with 30 volunteers on the EHB safely and was completed with 90% success (the exceptions being people with slanted eyes).
关键词： electrical hospital bed,Calibration-free eye tracking,real-time eye-gaze tracking,eye-based mouse control
更新于2025-09-23 15:21:21
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Optical wonderlands: vision science from photons to philosophy
摘要： The many eyes of scallops use reflecting mirrors, something like telescopes. Mantis shrimp have 12 classes of colour receptor to our 3. These findings in vision science are just two of many milestones in neurobiologist Michael Land’s meander through topics in the field — from the optical physics of eye function to the neurobiology of how brains interpret optical phenomena. Eyes to See is the journey of a scientist who followed his nose (and eyes) towards what fascinated him.
关键词： vision science,neurobiology,eye function,evolution of eyes,optical physics
更新于2025-09-23 15:21:21