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1.
Optom Vis Sci ; 101(6): 417-423, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38990240

RESUMO

SIGNIFICANCE: Individuals with reduced visual acuity (VA) may drive with bioptic telescopes in some jurisdictions. The effect of bioptic telescope use on on-road recognition distances is important for driving safety, as increased recognition distances increase the time available to react to road signs or driving events. PURPOSE: This study aimed to investigate the impact of bioptic telescope use on visual recognition of road signs, traffic lights, and hazards in an on-road driving environment in individuals with reduced VA. METHODS: Ten individuals (mean ± standard deviation age, 39.1 ± 19.1 years) with reduced VA (trained to use bioptic telescopes) participated in a repeated-measures on-road experiment for two viewing conditions, with and without a bioptic telescope (randomized order). Participants underwent a clinical low vision assessment, including high-contrast VA with and without the bioptic telescope aligned, visual fields, and contrast sensitivity testing. For the driving component, participants seated in the front passenger seat of a moving car reported all road signs, traffic lights, and hazards (unpredictable road events that represent a risk to driving safety including other vehicles, cyclists, pedestrians) seen along a route that included suburban roads and highways. Video cameras captured participants' viewing behavior, verbal commentary, and the distance at which three pre-selected road signs were reported. RESULTS: In the eye with the bioptic telescope, high-contrast VA improved from 0.75 ± 0.17 (without) to 0.25 ± 0.1 logMAR with the bioptic telescope. Bioptic telescope use did not affect the percentage of road signs, traffic lights, or hazards correctly recognized but did result in 2.6 times longer recognition distances (49 ± 23 vs. 19 ± 11 m, t9 = 5.02, p<0.001). CONCLUSIONS: Road signs were recognized at significantly longer distances when using a bioptic telescope, confirming their positive impact on timely visual recognition of objects within the driving scene. Future work should explore whether this effect generalizes to individuals using bioptic telescopes when driving a vehicle.


Assuntos
Condução de Veículo , Telescópios , Baixa Visão , Acuidade Visual , Humanos , Acuidade Visual/fisiologia , Adulto , Masculino , Feminino , Baixa Visão/fisiopatologia , Baixa Visão/reabilitação , Pessoa de Meia-Idade , Adulto Jovem , Desenho de Equipamento , Percepção Visual/fisiologia , Sensibilidades de Contraste/fisiologia , Campos Visuais/fisiologia
2.
Lasers Med Sci ; 39(1): 33, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38231430

RESUMO

As the demand for CO[Formula: see text] laser surgeries continues to grow, the quality of their main instrument, the laser micromanipulator, becomes increasingly important. However, in many surgery systems, a large ratio of the laser power is wasted due to the reflection from the mirror of a telescopic system, like a Cassegrain telescope, back to the laser side, which not only decreases the system's efficiency but can also damage the system itself. In this article, we introduce a new design of the micromanipulator telescope for CO[Formula: see text] laser surgery, which employs a Bessel beam to improve the system efficiency. As in the propagation of a Bessel beam, the power of the light beam can be transferred from the center to a ring shape, the whole power reflected from the first mirror can reach the second mirror and no power goes back to the second mirror hole. The micromanipulator telescope design and optimization are carried out using Zemax Optics Studio, and the integration of the Bessel beam into the system is implemented using MATLAB. Our simulation results show that by applying the appropriate Bessel beam, the system efficiency can reach more than 96%, and the normalized peak irradiance can increase by 40 to 73% for various working distances. In addition to increasing the system efficiency and normalized peak irradiance, resulting in a sharper surgical blade, the use of the Bessel beam enhances the depth of focus, making the system less sensitive to depth misalignment.


Assuntos
Telescópios , Simulação por Computador , Reprodução
3.
Phys Rev Lett ; 130(21): 211001, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37295105

RESUMO

We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical "drift model" of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.


Assuntos
Radiação Cósmica , Voo Espacial , Telescópios , Prótons , Elétrons
4.
Nature ; 612(7940): 381, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36517710
7.
Sensors (Basel) ; 23(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37447916

RESUMO

Linear active disturbance rejection control (LADRC) has been widely used to improve the tracking accuracy and anti-disturbance performance of telescope servo control under disturbances. However, the linear extended state observer (LESO) is sensitive to noise, and its bandwidth is limited by the resonant frequency of the telescope. To enhance the LARDC's ability to attenuate disturbances, a novel cascade anti-disturbance structure (NCADS) with LADRC on the outer speed loop and a nonlinear disturbance observer (NDOB) on the inner current loop is proposed. The NDOB compensates for the dominant disturbance through feedforwarding the q-axis current reference, and the LESO compensates for the residual disturbance on the outer speed loop. First, the NCADS is introduced in a three-closed-loop control framework of PMSM. Then, the design method of the controller for each loop and the NDOB are presented, the parameter-tuning method based on bandwidth is demonstrated, and the convergence of the NDOB is proved. Furthermore, to improve the searching and tracking efficiency of wide-field survey telescopes, the nonlinear tracking differentiator (NTD) was modified to plan the transition process of the position loop, which only needs to set the maximum speed and acceleration of the telescope. Finally, simulations and experiments were performed on a 2.5-m-wide field survey telescope. The experimental results verify that the proposed NCADS method has a better anti-disturbance performance and higher tracking precision than the conventional method, and the improved NTD method does not need to tune parameters and achieved a fast and smooth transition process of the position loop.


Assuntos
Telescópios , Projetos de Pesquisa , Aceleração
8.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-37830466

RESUMO

3D exoscopy based on Video Telescope Operating Monitor (VITOM) technology provides good visualization quality and portability. There are few data on comparison of extracorporeal telescoping with microsurgical techniques in spinal surgery. OBJECTIVE: To compare the effectiveness of VITOM 3D exoscopy and microsurgical techniques in spinal surgery. MATERIAL AND METHODS: A prospective study included 80 patients (54 men and 26 women). Two groups were distinguished: group 1 (ES, n=40) - VITOM 3D exoscopy, group 2 (SM, n=40) - Pentero 900 surgical microscope. We analyzed surgery time, postoperative rehabilitation, hospital-stay and complications. ES and microsurgical technique were compared using the questionnaire by Takahashi S. and rapid upper limb assessment (RULA). RESULTS: Conventional microsurgical technique was characterized by less surgery time (p<0.05) and morbidity (p=0.02). Postoperative rehabilitation and hospital-stay were similar (p=0.26 and p=0.39, respectively). Image quality in ES was comparable to microsurgical technique in shallow accesses and manipulations perpendicular to skin incision. Availability of neurosurgical instruments at different depths of the wound channel was comparable in both groups. The limitation of ES was length of skin incision, depth of the wound and its visualization at certain angle. These features required expansion of surgical approach or conversion of intervention. In general, surgeons rated intraoperative posture comfort as comparable in both groups that was consistent with the RULA scale. CONCLUSION: VITOM 3D exoscopy is an alternative to traditional microscopy and more ergonomically beneficial in spinal surgery in case of manipulations perpendicular to skin incision and shallow wide accesses. There are several important limitations of this device including difficult manipulations in narrow deep wounds and visualization under certain angle.


Assuntos
Telescópios , Masculino , Humanos , Feminino , Estudos Prospectivos , Procedimentos Neurocirúrgicos/métodos , Microcirurgia/métodos
9.
Nature ; 529(7584): 59-62, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26675732

RESUMO

Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet's formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3-5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.


Assuntos
Atmosfera/química , Meio Ambiente Extraterreno/química , Planetas , Água/análise , Júpiter , Pressão , Espectrofotometria Infravermelho , Telescópios , Temperatura
14.
Appl Opt ; 61(29): 8813-8818, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256016

RESUMO

The lobster eye telescope is promising for large-field x ray imaging in astronomy. The special structure of the lobster eye system makes the focal plane a sphere, resulting in detector defocus when the field is large. In this study, we established a model based on the principle of lobster eye imaging and simulated the imaging at different image distances. The results reveal the relationship between the defocus and position accuracy and angular resolution. To ensure the optical performance of the large field lobster eye telescope, we propose a detection system design method using multiple detectors stitched together to form a spherical-like surface and apply it to the development of the Einstein Probe/wide-field x ray telescope (EP/WXT) submodule. About 70% of the detection area is out of focus within 0.5 mm. The scanning image of the integrated WXT submodule shows good uniformity of the point spread function (PSF) for various incident angles, and the effect of defocus on imaging is acceptable.


Assuntos
Telescópios , Animais , Nephropidae , Raios X , Astronomia , Visão Ocular
15.
Optom Vis Sci ; 99(4): 417-421, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35149633

RESUMO

SIGNIFICANCE: Assisted and autonomous driving technologies may be a new paradigm shift for the driving rehabilitation field to enable less restricted driving, increase driving confidence, and maintain driving safety for drivers with vision impairment. PURPOSE: This study aimed to document how a driver with vision impairment uses assistance and automation systems in a Tesla car based on real-world experiences of using these technologies. METHODS: A 53-year-old man with Stargardt disease and 20/182 visual acuity self-explored the use of driver assistance technologies, which resulted in purchasing a Tesla Model Y with the full self-driving package in 2020. Two semistructured interviews were administered to quantify the driver's driving habits, adaptive strategies, use of the assisted and semiautonomous driving features in the Tesla car, and use of his bioptic telescope. RESULTS: When driving a Tesla car, the patient developed new driving strategies by codriving with different assisted and semiautonomous functions (e.g., Traffic-Aware Cruise Control, Traffic Light and Stop Sign Control, Autopilot) in different road environments. He shifted his main task from active driving to supervising the car automation systems in most driving situations. He also integrated a new use of his bioptic telescope to support him with monitoring the road environment before granting permission to the automated systems for car maneuver changes. The patient reported that driving confidence greatly increased and that he is able to drive more often and in situations that he would otherwise avoid because of difficulties related to his vision. CONCLUSIONS: This clinical report demonstrates how assisted and semiautonomous driving systems in a Tesla car were used to support daily driving by a driver with vision impairment. Codriving with these systems allows him to confidently drive more often and to avoid less situations than he used to.


Assuntos
Condução de Veículo , Telescópios , Acidentes de Trânsito , Automóveis , Óculos , Humanos , Masculino , Pessoa de Meia-Idade
16.
Optom Vis Sci ; 99(2): 121-126, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34889860

RESUMO

SIGNIFICANCE: Lack of knowledge regarding the mileage driven by drivers with low vision who use bioptic telescopes could obscure the relationship between vision and road safety. This study provides data suggesting that worse vision is correlated with less mileage driven but more collisions per mile in bioptic drivers. PURPOSE: The purpose of this study was to determine whether vision or demographic factors predict mileage driven in bioptic drivers and per-mile motor vehicle collision rate and also to compare the collision rate of bioptic drivers with previous estimates for the general population. METHODS: Driver data were collected retrospectively from clinic records. Collision data were collected from the Ohio Bureau of Motor Vehicles database. Subjects were also asked to estimate their yearly mileage. Regression models were used to investigate relationships between vision and collision rates. RESULTS: Seventy-three licensed Ohio bioptic drivers (36 male) were included. Mean ± standard deviation age was 51 ± 16 years. Mean logMAR visual acuity was 0.67 (approximately 20/100). Mean log contrast sensitivity was 1.57. Mean reported annual mileage was 9746. Age, sex, and previous (nonbioptic) driving experience were not associated with mileage. LogMAR visual acuity was inversely related to mileage (P = .02), and contrast sensitivity (P = .01) and horizontal visual field (P = .02) were directly associated with mileage. Visual acuity (P = .02) and visual field (P = .005), but not contrast sensitivity (P = .19), were associated with number of collisions. CONCLUSIONS: Visual acuity, visual field, and contrast sensitivity were associated with driving exposure in bioptic drivers (with drivers with poorer vision reporting lower annual mileage), and poorer visual acuity and visual field were associated with more collisions. The per-mile collision rate for bioptic drivers was within the range of that previously reported for fully sighted drivers, although higher than would be expected for fully sighted drivers of similar age distribution.


Assuntos
Condução de Veículo , Telescópios , Baixa Visão , Acidentes de Trânsito , Adulto , Idoso , Óculos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Baixa Visão/epidemiologia
17.
Childs Nerv Syst ; 38(11): 2171-2177, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35943568

RESUMO

PURPOSE: Vision and ergonomics are crucial variables for successful outcomes during neurosurgery procedures. Two-dimension video telescope operating monitor (VITOM) exoscope has emerged as an alternative, which is cheaper than microscope. The aim of this study is to evaluate the clinical utility of 2D VITOM and to compare its merits and demerits with respect to microscope. METHODS: VITOM 2D (Karl Storz, Germany) was used in 9 cranial and 5 spinal pediatric cases. While KINEVO operative microscope (Carl Zeiss, Germany) was used in 12 cranial and 6 spinal pediatric patients. All surgeries were performed by single senior neurosurgeon. The author's experience and opinions, as well as qualitative data, were analyzed. A comparison was made on image quality, illumination, field of view, and magnification of the operative field and ergonomics. RESULTS: Seven out of 9 cranial pediatric cases were switched from VITOM 2D to operative microscope due to low-image definition in depth of cranial cavity. Poor visualization of bleeding source in surgical field was another major drawback. Two cranial cases in which exoscope were used exclusively, included superficial tumors. In all 5 spinal cases, VITOM 2D was successfully used without any major difficulty. The exoscope's advantages were observed in ergonomics and ease in switching to naked eyes, but the microscope's field of view, illumination, magnification, and user-friendliness was considered superior. CONCLUSION: 2D-VITOM is best suited for spinal and superficial cranial tumors. However, a lot of modifications are to be done especially in optics to become a substitute for operative microscope.


Assuntos
Pediatria , Telescópios , Humanos , Criança , Procedimentos Neurocirúrgicos/métodos , Coluna Vertebral , Encéfalo , Microcirurgia/métodos
18.
Proc Jpn Acad Ser B Phys Biol Sci ; 98(8): 439-469, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36216535

RESUMO

The establishment of the Nobeyama Radio Observatory (NRO) in 1982 was an important event that greatly influenced the subsequent development of Japanese astronomy. The 45 m radio telescope and the Nobeyama Millimeter Array (NMA) pushed Japanese radio astronomy to the forefront of the world. As a plan beyond the Nobeyama telescopes, the Japanese radio astronomy community considered a large array to achieve unprecedented resolution at millimeter and submillimeter wavelengths under the project name of the Large Millimeter and Submillimeter Array (LMSA). After long and patient discussions and negotiations with the United States and Europe, the LMSA plan eventually led to the ALMA (Atacama Large Millimeter/submillimeter Array) as an international joint project, and the ALMA was inaugurated in 2013. This paper reviews the process from the establishment of the NRO to the realization of the ALMA, including planning of the LMSA, international negotiations, site survey, instrumental developments, and initial science results.


Assuntos
Astronomia , Telescópios , Astronomia/métodos , Meio Ambiente Extraterreno , Humanos , Japão
19.
Acta Oncol ; 60(11): 1413-1418, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34259117

RESUMO

BACKGROUND: Proton computed tomography (pCT) and radiography (pRad) are proposed modalities for improved treatment plan accuracy and in situ treatment validation in proton therapy. The pCT system of the Bergen pCT collaboration is able to handle very high particle intensities by means of track reconstruction. However, incorrectly reconstructed and secondary tracks degrade the image quality. We have investigated whether a convolutional neural network (CNN)-based filter is able to improve the image quality. MATERIAL AND METHODS: The CNN was trained by simulation and reconstruction of tens of millions of proton and helium tracks. The CNN filter was then compared to simple energy loss threshold methods using the Area Under the Receiver Operating Characteristics curve (AUROC), and by comparing the image quality and Water Equivalent Path Length (WEPL) error of proton and helium radiographs filtered with the same methods. RESULTS: The CNN method led to a considerable improvement of the AUROC, from 74.3% to 97.5% with protons and from 94.2% to 99.5% with helium. The CNN filtering reduced the WEPL error in the helium radiograph from 1.03 mm to 0.93 mm while no improvement was seen in the CNN filtered pRads. CONCLUSION: The CNN improved the filtering of proton and helium tracks. Only in the helium radiograph did this lead to improved image quality.


Assuntos
Telescópios , Humanos , Processamento de Imagem Assistida por Computador , Método de Monte Carlo , Redes Neurais de Computação , Imagens de Fantasmas , Radiografia
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