The Experts below are selected from a list of 4839 Experts worldwide ranked by ideXlab platform
Shizuo Mukai - One of the best experts on this subject based on the ideXlab platform.
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a portable inexpensive nonmydriatic Fundus Camera based on the raspberry pi computer
Journal of Ophthalmology, 2017Co-Authors: Bailey Y Shen, Shizuo MukaiAbstract:Purpose. Nonmydriatic Fundus Cameras allow retinal photography without pharmacologic dilation of the pupil. However, currently available nonmydriatic Fundus Cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a nonmydriatic Fundus Camera that was affordable and could be carried in a white coat pocket. Methods. We built a point-and-shoot prototype Camera using a Raspberry Pi computer, an infrared-sensitive Camera board, a dual infrared and white light light-emitting diode, a battery, a 5-inch touchscreen liquid crystal display, and a disposable 20-diopter condensing lens. Our prototype Camera was based on indirect ophthalmoscopy with both infrared and white lights. Results. The prototype Camera measured 133mm × 91mm × 45mm and weighed 386 grams. The total cost of the components, including the disposable lens, was $185.20. The Camera was able to obtain good-quality Fundus images without pharmacologic dilation of the pupils. Conclusion. A fully functional, inexpensive, handheld, nonmydriatic Fundus Camera can be easily assembled from a relatively small number of components. With modest improvements, such a Camera could be useful for a variety of healthcare professionals, particularly those who work in settings where a traditional table-mounted nonmydriatic Fundus Camera would be inconvenient.
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A Portable, Inexpensive, Nonmydriatic Fundus Camera Based on the Raspberry Pi® Computer
Hindawi Limited, 2017Co-Authors: Bailey Y Shen, Shizuo MukaiAbstract:Purpose. Nonmydriatic Fundus Cameras allow retinal photography without pharmacologic dilation of the pupil. However, currently available nonmydriatic Fundus Cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a nonmydriatic Fundus Camera that was affordable and could be carried in a white coat pocket. Methods. We built a point-and-shoot prototype Camera using a Raspberry Pi computer, an infrared-sensitive Camera board, a dual infrared and white light light-emitting diode, a battery, a 5-inch touchscreen liquid crystal display, and a disposable 20-diopter condensing lens. Our prototype Camera was based on indirect ophthalmoscopy with both infrared and white lights. Results. The prototype Camera measured 133mm×91mm×45mm and weighed 386 grams. The total cost of the components, including the disposable lens, was $185.20. The Camera was able to obtain good-quality Fundus images without pharmacologic dilation of the pupils. Conclusion. A fully functional, inexpensive, handheld, nonmydriatic Fundus Camera can be easily assembled from a relatively small number of components. With modest improvements, such a Camera could be useful for a variety of healthcare professionals, particularly those who work in settings where a traditional table-mounted nonmydriatic Fundus Camera would be inconvenient
Bailey Y Shen - One of the best experts on this subject based on the ideXlab platform.
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a portable inexpensive nonmydriatic Fundus Camera based on the raspberry pi computer
Journal of Ophthalmology, 2017Co-Authors: Bailey Y Shen, Shizuo MukaiAbstract:Purpose. Nonmydriatic Fundus Cameras allow retinal photography without pharmacologic dilation of the pupil. However, currently available nonmydriatic Fundus Cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a nonmydriatic Fundus Camera that was affordable and could be carried in a white coat pocket. Methods. We built a point-and-shoot prototype Camera using a Raspberry Pi computer, an infrared-sensitive Camera board, a dual infrared and white light light-emitting diode, a battery, a 5-inch touchscreen liquid crystal display, and a disposable 20-diopter condensing lens. Our prototype Camera was based on indirect ophthalmoscopy with both infrared and white lights. Results. The prototype Camera measured 133mm × 91mm × 45mm and weighed 386 grams. The total cost of the components, including the disposable lens, was $185.20. The Camera was able to obtain good-quality Fundus images without pharmacologic dilation of the pupils. Conclusion. A fully functional, inexpensive, handheld, nonmydriatic Fundus Camera can be easily assembled from a relatively small number of components. With modest improvements, such a Camera could be useful for a variety of healthcare professionals, particularly those who work in settings where a traditional table-mounted nonmydriatic Fundus Camera would be inconvenient.
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A Portable, Inexpensive, Nonmydriatic Fundus Camera Based on the Raspberry Pi® Computer
Hindawi Limited, 2017Co-Authors: Bailey Y Shen, Shizuo MukaiAbstract:Purpose. Nonmydriatic Fundus Cameras allow retinal photography without pharmacologic dilation of the pupil. However, currently available nonmydriatic Fundus Cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a nonmydriatic Fundus Camera that was affordable and could be carried in a white coat pocket. Methods. We built a point-and-shoot prototype Camera using a Raspberry Pi computer, an infrared-sensitive Camera board, a dual infrared and white light light-emitting diode, a battery, a 5-inch touchscreen liquid crystal display, and a disposable 20-diopter condensing lens. Our prototype Camera was based on indirect ophthalmoscopy with both infrared and white lights. Results. The prototype Camera measured 133mm×91mm×45mm and weighed 386 grams. The total cost of the components, including the disposable lens, was $185.20. The Camera was able to obtain good-quality Fundus images without pharmacologic dilation of the pupils. Conclusion. A fully functional, inexpensive, handheld, nonmydriatic Fundus Camera can be easily assembled from a relatively small number of components. With modest improvements, such a Camera could be useful for a variety of healthcare professionals, particularly those who work in settings where a traditional table-mounted nonmydriatic Fundus Camera would be inconvenient
Paolo Lanzetta - One of the best experts on this subject based on the ideXlab platform.
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A comparison between a white LED confocal imaging system and a conventional flash Fundus Camera using chromaticity analysis
BMC ophthalmology, 2019Co-Authors: Valentina Sarao, Daniele Veritti, Enrico Borrelli, Srinivas R Sadda, Enea Poletti, Paolo LanzettaAbstract:Conventional flash Fundus Cameras capture color images that are oversaturated in the red channel and washed out in the green and blue channels, resulting in a retinal picture that often looks flat and reddish. A white LED confocal device was recently introduced to provide a high-quality retinal image with enhanced color fidelity. In this study, we aimed to evaluate the color rendering properties of the white LED confocal system and compare them to those of a conventional flash Fundus Camera through chromaticity analysis. A white LED confocal device (Eidon, Centervue, Padova, Italy) and a traditional flash Fundus Camera (TRC-NW8, Topcon Corporation, Tokyo, Japan) were used to capture Fundus images. Color images were evaluated with respect to chromaticity. Analysis was performed according to the image color signature. The color signature of an image was defined as the distribution of its pixels in the rgb chromaticity space. The descriptors used for the analysis are the average and variability of the barycenter positions, the average of the variability and the number of unique colors (NUC) of all signatures. Two hundred thirty-three color photographs were acquired with each retinal Camera. The images acquired by the confocal white LED device demonstrated an average barycenter position (rgb = [0.448, 0.328, 0.224]) closer to the center of the chromaticity space, while the conventional Fundus Camera provides images with a clear shift toward red at the expense of the blue and green channels (rgb = [0.574, 0.278, 0.148] (p
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A comparison between a white LED confocal imaging system and a conventional flash Fundus Camera using chromaticity analysis
2019Co-Authors: Valentina Sarao, Daniele Veritti, Enrico Borrelli, Srinivas R Sadda, Enea Poletti, Paolo LanzettaAbstract:Abstract BACKGROUND: Conventional flash Fundus Camera captures color images that are over-saturated in the red channel, producing a retinal picture that looks washed-out and uniform. A white LED confocal device was recently introduced to provide a neutral-looking retinal image. With this study we aimed to evaluate the color rendering properties of the white LED confocal system and to compare it to a conventional flash Fundus Camera through the use of chromaticity analysis. METHODS: A fully automated white LED confocal device (Eidon, Centervue, Padova, Italy) was used to capture Fundus images from healthy volunteers and patients with retinal diseases. The same pictures were acquired with a flash Fundus Camera (Triton, Topcon Corporation, Tokyo, Japan). All color images were evaluated with respect to the chromaticity. Color analysis was performed according to the image color signature. Color signature of an image was defined as the distribution of its pixels in the rgb chromaticity space. The descriptors used for the analysis are the average and variability of the barycenter positions, the average of the variability and the number of unique colors (NUC) of all signatures. RESULTS: Two hundred thirty-three color Fundus photographs were acquired with each retinal Camera. The images acquired by confocal white LED device demonstrated an average barycenter position (rgb = [0.448, 0.328, 0.224]) closer to the center of the chromaticity space, while conventional Fundus Camera provides images with a clear shift toward red at the expense of the blue and green (rgb = [0.574, 0.278, 0.148] (p<0.001). The variability of the barycenter positions was higher in white LED confocal system than in conventional flash Fundus Camera. The average variability of the distributions was higher (0.003 ± 0.007, p<0.001) in the Eidon images compared to Topcon Camera, indicating a greater richness of color. The NUC percentage was higher for white LED confocal device than for conventional flash Fundus Camera (0.071% versus 0.025%, p<0.001). CONCLUSIONS: Confocal white LED system provides well-balanced color images with a wider richness of color content compared to conventional flash Fundus Camera. The overall higher chromaticity of Eidon device may provide benefits in terms of discriminative power and diagnostic accuracy. KEYWORDS: Chromaticity; Confocal white LED system; conventional flash Fundus Camera; Eidon; Topcon.
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a comparison between a white led confocal imaging system and a conventional flash Fundus Camera using chromaticity analysis
BMC Ophthalmology, 2019Co-Authors: Valentina Sarao, Daniele Veritti, Enrico Borrelli, Srinivas R Sadda, Enea Poletti, Paolo LanzettaAbstract:Conventional flash Fundus Cameras capture color images that are oversaturated in the red channel and washed out in the green and blue channels, resulting in a retinal picture that often looks flat and reddish. A white LED confocal device was recently introduced to provide a high-quality retinal image with enhanced color fidelity. In this study, we aimed to evaluate the color rendering properties of the white LED confocal system and compare them to those of a conventional flash Fundus Camera through chromaticity analysis. A white LED confocal device (Eidon, Centervue, Padova, Italy) and a traditional flash Fundus Camera (TRC-NW8, Topcon Corporation, Tokyo, Japan) were used to capture Fundus images. Color images were evaluated with respect to chromaticity. Analysis was performed according to the image color signature. The color signature of an image was defined as the distribution of its pixels in the rgb chromaticity space. The descriptors used for the analysis are the average and variability of the barycenter positions, the average of the variability and the number of unique colors (NUC) of all signatures. Two hundred thirty-three color photographs were acquired with each retinal Camera. The images acquired by the confocal white LED device demonstrated an average barycenter position (rgb = [0.448, 0.328, 0.224]) closer to the center of the chromaticity space, while the conventional Fundus Camera provides images with a clear shift toward red at the expense of the blue and green channels (rgb = [0.574, 0.278, 0.148] (p < 0.001). The variability of the barycenter positions was higher in the white LED confocal system than in the conventional Fundus Camera. The average variability of the distributions was higher (0.003 ± 0.007, p < 0.001) in the Eidon images compared to the Topcon Camera, indicating a greater richness of color. The NUC percentage was higher for the white LED confocal device than for the conventional flash Fundus Camera (0.071% versus 0.025%, p < 0.001). Eidon provides more-balanced color images, with a wider richness of color content, compared to a conventional flash Fundus Camera. The overall higher chromaticity of Eidon may provide benefits in terms of discriminative power and diagnostic accuracy.
Paula Anne Newmancasey - One of the best experts on this subject based on the ideXlab platform.
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glaucoma screening in nepal cup to disc estimate with standard mydriatic Fundus Camera compared to portable nonmydriatic Camera
American Journal of Ophthalmology, 2017Co-Authors: Sarah E Miller, Leslie M. Niziol, Maria A. Woodward, Alan L. Robin, Suman S Thapa, Pradeep Y Ramulu, Indira Paudyal, Ian Pitha, Tyson N Kim, Paula Anne NewmancaseyAbstract:Purpose To compare cup-to-disc ratio (CDR) measurements from images taken with a portable, 45-degree nonmydriatic Fundus Camera to images from a traditional tabletop mydriatic Fundus Camera. Design Prospective, cross-sectional, comparative instrument validation study. Methods Setting: Clinic-based. Study Population: A total of 422 eyes of 211 subjects were recruited from the Tilganga Institute of Ophthalmology (Kathmandu, Nepal). Two masked readers measured CDR and noted possible evidence of glaucoma (CDR ≥ 0.7 or the presence of a notch or disc hemorrhage) from Fundus photographs taken with a nonmydriatic portable Camera and a mydriatic standard Camera. Each image was graded twice. Main Outcome Measures: Effect of Camera modality on CDR measurement; inter- and intraobserver agreement for each Camera for the diagnosis of glaucoma. Results A total of 196 eyes (46.5%) were diagnosed with glaucoma by chart review; 41.2%–59.0% of eyes were remotely diagnosed with glaucoma over grader, repeat measurement, and Camera modality. There was no significant difference in CDR measurement between Cameras after adjusting for grader and measurement order (estimate = 0.004, 95% confidence interval [CI], 0.003–0.011, P = .24). There was moderate interobserver reliability for the diagnosis of glaucoma (Pictor: κ = 0.54, CI, 0.46–0.61; Topcon: κ = 0.63, CI, 0.55–0.70) and moderate intraobserver agreement upon repeat grading (Pictor: κ = 0.63 and 0.64, for graders 1 and 2, respectively; Topcon: κ = 0.72 and 0.80, for graders 1 and 2, respectively). Conclusions A portable, nonmydriatic, Fundus Camera can facilitate remote evaluation of disc images on par with standard mydriatic Fundus photography.
Deanna Vecchi - One of the best experts on this subject based on the ideXlab platform.
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Reliability of photometric measurements in the Zeiss Fundus Camera.
Acta ophthalmologica, 2009Co-Authors: Sergio Fonda, Antonietta M. Gatti, Deanna VecchiAbstract:The authors test the hypothesis of systematic errors in photometric and/or densitometric measurements performed by Fundus Camera equipment. By means of 2 different methods (reflection and transmission) the non-uniformity of light-distribution on sample surfaces placed in front of the Fundus Camera is shown. The consequent point by point variability in retinal illumination can be defined as the 'retinal shading problem'. This conclusion must be taken into account when equidensitometric measurements are carried out on eye Fundus images with Fundus Camera, by photographic, cinematographic or TV techniques.
