A5070970801- Retinal Imaging and Analysis
- Optical Imaging and Spectroscopy Techniques
- Glaucoma and retinal disorders
- Retinal Diseases and Treatments
- Retinal and Optic Conditions
- Traumatic Brain Injury and Neurovascular Disturbances
- Non-Invasive Vital Sign Monitoring
- Cardiovascular Health and Disease Prevention
- Ocular and Laser Science Research
- Medical Image Segmentation Techniques
- Erythrocyte Function and Pathophysiology
- Retinal Development and Disorders
- Digital Imaging for Blood Diseases
- Hemodynamic Monitoring and Therapy
- Image Retrieval and Classification Techniques
- Temporomandibular Joint Disorders
- Advanced X-ray and CT Imaging
- Blood Pressure and Hypertension Studies
- Botulinum Toxin and Related Neurological Disorders
- Obstructive Sleep Apnea Research
- Laser Design and Applications
- CCD and CMOS Imaging Sensors
- Acute Ischemic Stroke Management
- EEG and Brain-Computer Interfaces
- Hydrogen's biological and therapeutic effects
University of Iceland
2004-2022
The Icelandic Physiotherapy Association
2009-2019
National University Hospital of Iceland
2018
To measure hemoglobin oxygen saturation (SO(2)) in retinal vessels and to test the reproducibility sensitivity of an automatic spectrophotometric oximeter.Specialized software automatically identifies blood on fundus images, which are obtained with four different wavelengths light. The calculates optical density ratios (ODRs) for each vessel. was evaluated by analyzing five repeated measurements same vessels. A linear relationship between SO(2) ODR assumed a model derived. After calibration,...
Animal studies have indicated that retinal oxygen consumption is greater in dark than light. In this study, saturation measured vessels of healthy humans during and light.The oximeter consists a fundus camera, beam splitter, digital camera software, which calculates hemoglobin the vessels. first experiment, 18 individuals underwent oximetry measurements after 30 minutes dark, followed by alternating 5-minute periods white light (80 cd/m(2)) dark. second 23 volunteers at 1, 10, 100 cd/m(2)....
We have previously reported that retinal vessel oxygen saturation is increased in mild-to-moderate dementia of Alzheimer's type when compared with healthy individuals. Mild cognitive impairment (MCI) the predementia stage disease. The main purpose was to investigate if these changes are seen MCI.Retinal measured 42 patients MCI and individuals a noninvasive oximeter, Oxymap T1. groups were paired according age.Arteriolar venular (arterioles: 93.1 ± 3.7% vs. 91.1 3.4%, P = .01; venules: 59.6...
Purpose.: Glaucoma may involve disturbances in retinal oxygenation and blood flow. The purpose of this study was to measure the effect glaucoma filtration surgery on vessel oxygen saturation. Methods.: A noninvasive spectrophotometric oximeter used hemoglobin saturation arterioles venules before after surgery. Twenty-five consecutive patients were recruited, 19 had adequate image quality. Fourteen underwent trabeculectomy five tube Twelve primary open-angle seven exfoliative glaucoma. IOP...
<h3>Aims:</h3> To examine whether the addition of dorzolamide to timolol monotherapy influences oxygen saturation in human retina. <h3>Methods:</h3> Non-invasive spectrophotometric retinal oximetry was used measure vessels. Twenty patients with open-angle glaucoma (11) and ocular hypertension (9) were recruited. The randomised into receiving or dorzolamide–timolol combination for an 8-month test period, followed by a second before which switched treatments. Oximetry measurements performed at...
The purpose of the study was to assess if a scanning laser ophthalmoscope (SLO), Optomap 200Tx, could be used for measurements hemoglobin oxygen saturation in retinal blood vessels.Optomap 200Tx uses two lasers image acquisition, 532 and 633 nm. Retinal images healthy individuals patients with vein occlusion were analyzed modified Oxymap Analyzer software, which tracks vessels calculates relative saturation.Oxygen measured as 92% ± 13% arterioles 57% 12% venules (mean SD, n = 11, P 0.0001)....
Purpose.: To assess the validity of spectrophotometric retinal oximetry by comparison to blood gas analysis and intravitreal measurements partial pressure oxygen (pO2). Methods.: Female domestic pigs were used for all experiments (n = 8). Oxygen fraction in inspired air was changed using a mixture room air, pure oxygen, nitrogen, ranging from 5% 100% oxygen. Femoral arterial performed at each level inspiratory fraction. Retinal commercial instrument, Oxymap Oximeter T1. The device...
The aim of this paper is to develop an automatic method for the registration multitemporal digital images fundus human retina. are acquired from same patient at different times by a color camera. proposed approach based on application global optimization techniques previously extracted maps curvilinear structures in be registered (such being represented vessels retina): particular, genetic algorithm used, order estimate optimum transformation between input and base image. tested two types...
This paper presents a method for automating the evaluation of hemoglobin oxygen saturation in retina. should prove useful monitoring ischemic retinal diseases and effect treatment. In order to obtain values automatically, spectral images must be registered pairs, vessels retina located measurement points selected. The registration algorithm is based on data driven approach that circumvents many problems have plagued previous methods. are extracted using an morphological profiles supervised...
Purpose Retinal oximetry is a technique based on spectrophotometry where images are analyzed with software capable of calculating vessel oxygen saturation and diameter. In this study, the effect automation measurements retinal diameter explored. Methods Until now, operators have had to choose each segment be measured explicitly. A new, automatic version automatically selects vessels once operator defines measurement area. Five image pairs from right eye 23 healthy subjects semiautomated...
The aim of this paper is to develop an automatic method for the detection changes that occurred in multitemporal digital images fundus human retina, terms white and red spots. are acquired from same patient at different times by a color camera. proposed approach unsupervised based on minimum-error thresholding technique. This technique applied both separate "change" "no-change" classes suitably defined difference image, distinguish among typologies change. algorithm tested 10 pairs images. A...
Purpose To develop and test an automatic method for analysing retinal oximetry images. Methods The dual‐wavelength Oxymap T1 oximeter captures images calculation of oxygen saturation in vessels. Images were taken healthy subjects testing repeatability sensitivity, the latter during 100% O2 breathing ( n = 21). also patients with diabetes no DR 16) non‐proliferative 24). diabetic groups compared 54 subjects. Semi‐automatic fully computer programs used analysis. main differences are: program...