Results 41 to 50 of about 415,852 (378)

A geometric model of ocular accommodation

open access: yesVision Research, 2010
An exoteric geometric mechanics model of ocular accommodation is detailed to elucidate the main ideas of various ongoing modeling efforts. The present study derives solutions for the stretched state of the ocular lens as it might appear during accommodation by using simple geometric arguments and a volume constraint, rather than the more mathematically
Matthew Aaron Reilly   +2 more
openaire   +3 more sources

Real-time measurement of ocular wavefront aberrations in symptomatic subjects [PDF]

open access: yes, 2018
Te purpose of this work was to study the real-time changes of the optical properties of the eye with accommodation in subjects with symptoms of accommodative disorders.
Franco, Sandra, Gomes, Jessica
core   +2 more sources

Axial length changes during accommodation in myopes and emmetropes [PDF]

open access: yes, 2010
Purpose: To investigate the influence of accommodation upon axial length (and a comprehensive range of ocular biometric parameters), in populations of young adult myopic and emmetropic subjects.
Cheong, Shiow Huoy   +3 more
core   +1 more source

Mechanism of accommodation: A review of theoretical propositions

open access: yesAfrican Vision and Eye Health, 2015
Accommodation is the process by which the human eye changes its focus to see objects at varying distances from the eye. For nearly 300 years, scientists have investigated and presented various views on the mechanism of accommodation.
Godwin O. Ovenseri-Ogbomo   +1 more
doaj   +1 more source

Semi‐supervised classification of fundus images combined with CNN and GCN

open access: yesJournal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose Diabetic retinopathy (DR) is one of the most serious complications of diabetes, which is a kind of fundus lesion with specific changes. Early diagnosis of DR can effectively reduce the visual damage caused by DR. Due to the variety and different morphology of DR lesions, automatic classification of fundus images in mass screening can ...
Sixu Duan   +8 more
wiley   +1 more source

Gullstrand Intracapsular Accommodation Mechanism Revised

open access: yesPhotonics, 2022
More than a century has passed since Allvar Gullstrand proposed his so called “mechanism of intracapsular accommodation” based on the concept that the change in lens power during accommodation can be larger if the lens is modeled by two different ...
Norberto López-Gil
doaj   +1 more source

COMP Report: CPQR technical quality control guidelines for use of positron emission tomography/computed tomography in radiation treatment planning

open access: yesJournal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Positron emission tomography with x‐ray computed tomography (PET/CT) is increasingly being utilized for radiation treatment planning (RTP). Accurate delivery of RT therefore depends on quality PET/CT data. This study covers quality control (QC) procedures required for PET/CT for diagnostic imaging and incremental QC required for RTP.
Ran Klein   +7 more
wiley   +1 more source

Uniqueness of radiomic features in non‐small cell lung cancer

open access: yesJournal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose The uniqueness of radiomic features, combined with their reproducibility, determines the reliability of radiomic studies. This study is to test the hypothesis that radiomic features extracted from a defined region of interest (ROI) are unique to the underlying structure (e.g., tumor). Approach Two cohorts of non‐small cell lung cancer (
Gary Ge, Jie Zhang
wiley   +1 more source

Uncertainty propagation and sensitivity analysis: results from the Ocular Mathematical Virtual Simulator [PDF]

open access: yes, 2021
We propose an uncertainty propagation study and a sensitivity analysis with the Ocular Mathematical Virtual Simulator, a computational and mathematical model that predicts the hemodynamics and biomechanics within the human eye. In this contribution, we focus on the effect of intraocular pressure, retrolaminar tissue pressure and systemic blood pressure
arxiv   +1 more source

Evaluation of intrafraction couch shifts for proton treatment delivery in head‐and‐neck cancer patients: Toward optimal imaging frequency

open access: yesJournal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Purpose Treatment planning for head‐and‐neck (H&N) cancer, in particular oropharynx, nasopharynx, and paranasal sinus cases, at our center requires noncoplanar proton beams due to the complexity of the anatomy and target location. Targeting accuracy for all beams is carefully evaluated by using image guidance before delivering proton beam ...
Nrusingh C. Biswal   +5 more
wiley   +1 more source

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