Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "optical coherence tomography" wg kryterium: Temat


Tytuł:
Readout System and Data Processing for OCT Pachymetry
Autorzy:
Dziewiecki, M.
Domański, G.
Frey, W.
Konarzewski, B.
Kurjata, R.
Marzec, J.
Smolnik, A.
Zaremba, K.
Ziembicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/226782.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical coherence tomography
pachymetry
optical signal detection
Opis:
A complete system for measurement control, signal acquisition and data processing for an OCT pachymeter is described. Moreover, dedicated data processing algorithm used for noise reduction is presented. A simple OCT scanner was built and some measurements were performed to examine the capabilities of the system.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 3; 223-230
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intraoperative imaging based on common-path time-domain reflectometry for brain tumor surgery
Autorzy:
Han, Jae-Ho
Cha, Jaepyeong
Powiązania:
https://bibliotekanauki.pl/articles/174648.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical coherence tomography
intraoperative imaging
reflectometry
endoscopy
Opis:
Minimally invasive intraoperative imaging plays a crucial role in delicate microsurgeries for precise operation monitoring in which fiber optic imaging can be considered as an endoscopy and surgical proximity guidance tool due to its compactness. This paper presents a near-infrared time-domain reflectometric common-path optical coherence tomography imaging technique using a bare-fiber probe mounted directly on a scanning galvanometer. The common-path setup allows the use of a freely adjustable optical path length and a disposable fiber probe, as well as eliminating the need for an additional dedicated reference optical path. Experimental results demonstrate clear discrimination between the brain tumor tissue and the normal tissue for mouse brains with the images acquired in real-time over a wide area. The proposed method enables real-time and in situ visualization of tumor resection for intraoperative imaging, and this study demonstrates the feasibility of its application to microsurgical interventions.
Źródło:
Optica Applicata; 2020, 50, 2; 223-227
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-destructive inspection of anti-corrosion protective coatings using optical coherent tomography
Autorzy:
Antoniuk, P.
Strąkowski, M. R.
Pluciński, J.
Kosmowski, B. B.
Powiązania:
https://bibliotekanauki.pl/articles/220649.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical coherence tomography
corrosion
anti-corrosion coatings inspection
Opis:
Optical Coherence Tomography (OCT) is one of the most rapidly advancing techniques. This method is capable of non-contact and non-destructive investigation of the inner structure of a broad range of materials. Compared with other methods which belong to the NDE/NDT group (Non-Destructive Evaluation/Non-Destructive Testing methods), OCT is capable of a broad range of scattering material structure visualization. Such a non-invasive and versatile method is very demanded by the industry. The authors applied the OCT method to examine the corrosion process in metal samples coated by polymer films. The main aim of the research was the evaluation of the anti-corrosion protective coatings using the OCT method. The tested samples were exposed to a harsh environment. The OCT measurements have been taken at different stages of the samples degradation. The research and tests results have been presented, as well as a brief discussion has been carried out.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 365-372
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of retina vessels by segmentation of images reconstructed from optical coherence tomography data
Autorzy:
Marciniak, Tomasz
Stankiewicz, Agnieszka
Dąbrowski, Adam
Stopa, Marcin
Rakowicz, Piotr
Marciniak, Elżbieta
Powiązania:
https://bibliotekanauki.pl/articles/220715.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical coherence tomography
image processing
mathematical morphology
vessel segmentation
Opis:
In this paper methods and their examination results for automatic segmentation and parameterization of vessels based on spectral domain optical coherence tomography (SD-OCT) of the retina are presented. We present three strategies for morphologic image processing of a fundus image reconstructed from OCT scans. A specificity of initial image processing for fundus reconstruction is analysed. Then, the parameterization step is performed based on the vessels segmented with the proposed algorithm. The influence of various methods on the vessel segmentation and fully automatic vessel measurement is analysed. Experiments were carried out with a set of 3D OCT scans obtained from 24 eyes (12 healthy volunteers) with the use of an Avanti RTvue OCT device. The results of automatic vessel segmentation were numerically compared with those prepared manually by the medical doctor experts.
Źródło:
Metrology and Measurement Systems; 2019, 26, 3; 449-461
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examination of Sol-Gel Derived Hydroxyapatite Enhanced with Silver Nanoparticles using OCT and Raman Spectroscopy
Autorzy:
Głowacki, M. J.
Gnyba, M.
Strąkowska, P.
Gardas, M.
Kraszewski, M.
Trojanowski, M.
Strąkowski, M. R.
Powiązania:
https://bibliotekanauki.pl/articles/221475.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hydroxyapatite
sol-gel
nanoparticles
Raman spectroscopy
optical coherence tomography (OCT)
Opis:
Hydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements of HAp molecular composition and solvent evaporation efficiency the Raman spectroscopy has been chosen. In order to evaluate dispersion and concentration of the silver nanoparticles inside the hydroxyapatite matrix, the optical coherence tomography (OCT) has been used. Five samples were developed and examined ‒ a reference sample of pure HAp sol and four samples of HAp colloids with different silver nanoparticle solution volume ratios. The Raman spectra for each solution have been obtained and analyzed. Furthermore, a transverse-sectional visualization of every sample has been created and examined by means of OCT.
Źródło:
Metrology and Measurement Systems; 2017, 24, 1; 153-160
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical coherence tomography image for automatic classification of diabetic macular edema
Autorzy:
Wang, Ping
Li, Jia-Li
Ding, Hao
Powiązania:
https://bibliotekanauki.pl/articles/1835815.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
diabetic macular edema
optical coherence tomography
transfer learning
fine-tuning
Opis:
Diabetic macular edema (DME) is the dominant reason of diabetic visual loss, so early detection and treatment of DME is of great significance for the treatment of diabetes. Based on transfer learning, an automatic classification method is proposed to distinguish DME images from normal images in optical coherence tomography (OCT) retinal fundus images. Features of the DME are automatically identified and extracted by the pre-trained convolutional neural network (CNN), which only involves fine-tuning the VGGNet-16 network without any user intervention. An accuracy of 97.9% and a sensitivity of 98.0% are acquired with the OCT images in the Duke data set from experimental results. The proposed method, a core part of an automated diagnosis system of the DME, revealed the ability of fine-tuning models to train non-medical images, allowing them can be classified with limited training data. Moreover, it can be developed to assist early diagnosis of the disease, effectively delaying (or avoiding) the progression of the disease, consequently.
Źródło:
Optica Applicata; 2020, 50, 4; 567-577
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graph-based segmentation with homogeneous hue and texture vertices
Autorzy:
Ngo, Lua
Han, Jae-Ho
Powiązania:
https://bibliotekanauki.pl/articles/2033896.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image segmentation
deep neural network
electron microscopy
optical coherence tomography
pattern recognition
Opis:
This work presents an automated segmentation method, based on graph theory, which processes superpixels that exhibit spatially similarities in hue and texture pixel groups, rather than individual pixels. The graph shortest path includes a chain of neighboring superpixels which have minimal intensity changes. This method reduces graphics computational complexity because it provides large decreases in the number of vertices as the superpixel size increases. For the starting vertex prediction, the boundary pixel in first column which is included in this starting vertex is predicted by a trained deep neural network formulated as a regression task. By formulating the problem as a regression scheme, the computational burden is decreased in comparison with classifying each pixel in the entire image. This feasibility approach, when applied as a preliminary study in electron microscopy and optical coherence tomography images, demonstrated high measures of accuracy: 0.9670 for the electron microscopy image and 0.9930 for vitreous/nerve-fiber and inner-segment/outer-segment layer segmentations in the optical coherence tomography image.
Źródło:
Optica Applicata; 2021, 51, 4; 541-549
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Advances in the diagnostics of eye diseases
Postępy w diagnostyce chorób oczu
Autorzy:
Romańczuk, Helena
Mazur, Artur
Powiązania:
https://bibliotekanauki.pl/articles/437887.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
ophthalmology
diagnostics
optical coherence tomography, perimetry
okulistyka
diagnostyka optyczna koherentna
tomografia
perymetria
Opis:
The advances in the diagnostics of eye diseases have been presented in the work including the optic coherence tomography, confocal microscopy, ultrabiomicroscopy and perimetry. Introduction: The advances in the diagnostics of eye diseases during the last decade of the 20th century and in 21st century is incomparable with the corresponding, earlier periods of development of that discipline. This can be attributed, inter alia, to the pace of the development of imaging techniquesat present at the level close to the histological picture. Objective: The latest methods of diagnosis of changes of the front and back of the eye have been presented in the paper. Material and method: The overview of the current national and foreign literature has been done, mainly for over 10 last years. The following databases have been searched: PubMed and Polska Bibliografia Lekarska.
W pracy przedstawiono postępy w diagnostyce chorób oczu, uwzględniając optyczną koherentną tomografię, mikroskopię konfokalną, ultrabiomikroskopię oraz perymetrię. Wstęp: Postęp w dziedzinie diagnostyki okulistycznej w ostatniej dekadzie XX wieku oraz w XXI wieku jest nieporównywalny z analogicznymi, wcześniejszymi okresami rozwoju tej dyscypliny. Wynika on między innymi z tempa rozwoju technik obrazowania – obecnie już na poziomie zbliżonym do obrazu histologicznego. Cel: W pracy przedstawiono najnowsze metody diagnozowania zmian przedniego i tylnego odcinka oka. Materiał i metoda: Dokonano przeglądu aktualnego piśmiennictwa krajowego i zagranicznego, głównie z ostatnich 10 lat. Przeszukano następujące bazy danych: PubMed i Polska Bibliografia Lekarska.
Źródło:
Medical Review; 2016, 4; 473-482
2450-6761
Pojawia się w:
Medical Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hyperreflective dots in optical coherence tomography
Autorzy:
Paczwa, Katarzyna
Szabelska, Paulina
Rerych, Magdalena
Różycki, Radosław
Gołębiewska, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/2159017.pdf
Data publikacji:
2022-09-30
Wydawca:
Medical Education
Tematy:
hyperreflective dots
HRDs
optical coherence tomography
AMD
diabetic retinopathy
retinal vein occlusion
Opis:
Optical coherence tomography is a non-invasive and repeatable imaging method of posterior segment of the eye used in medical practice. Hyperreflective dots visible in OCT scans have been reported in various retinal diseases such as age-related macular degeneration, diabetic macular edema, retinal vein occlusion and central serous chorioretinopathy. In the future, HRDs may become a useful biomarker in making treatment decision and monitoring ocular conditions among the patients with mentioned diseases.
Źródło:
OphthaTherapy; 2022, 9, 3; 175-179
2353-7175
2543-9987
Pojawia się w:
OphthaTherapy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Retained subretinal perfluorocarbon in multimodal image
Autorzy:
Guzmán Almagro, Elena
Cobo Soriano, Rosario
Fuentes-Vega, Irene
Fernández Hortelano, Ana
González Martin-Moro, Julio
Powiązania:
https://bibliotekanauki.pl/articles/2040460.pdf
Data publikacji:
2021-04-08
Wydawca:
Medical Education
Tematy:
vitreo-retinal surgery
surgical complication
optical coherence tomography
multimodal image
subretinal perfluorocarbon
Opis:
Introduction: Retained subretinal perfluoro-n-octane droplets occur in nearly 1% of the procedures. When subretinal cystoid cavities are registered, differential diagnosis including this condition is needed. Clinical case: A 77-year-old male presented three small bubbles of perfluoro-n-octane under the papillomacular bundle after vitrectomy due to a retina redetachment, evidenced by multimodal image. Conclusions: Multimodal image can help to diagnose this condition. There are several signs that can support this diagnosis. If visual acuity is threatened, removing the bubbles is mandatory, accepting risks.
Źródło:
OphthaTherapy; 2021, 8, 2; 87-91
2353-7175
2543-9987
Pojawia się w:
OphthaTherapy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Choroidal neovascularization related to melanocytic naevus - a single centre study
Autorzy:
Zwolińska, Emilia
Rospond-Kubiak, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/2232254.pdf
Data publikacji:
2022-12-31
Wydawca:
Medical Education
Tematy:
choroidal naevus
choroidal neovascularization
subretinal uflid
optical coherence tomography angiography
CNV
OCTA
Opis:
Purpose: To assess the angiographic and optical coherence tomography angiography (OCTA) features as well as the natural course of the choroidal neovascularization (CNV) associated with choroidal naevi. Setting/venue: Ocular Oncology Service, Department of Ophthalmology, Poznan University of Medical Sciences. Material and methods: Retrospective chart analysis of the patients who presented to the Ocular Oncology Service in Poznan, Poland between 2011–2021 with the diagnosis of suspicious choroidal naevus. In all patients full ophthalmic examination and multimodal imaging, including fundus photography, autofluorescence, B-ultrasound, optical coherence tomography (OCT), OCT angiography (OCTA) and fluorescein angiography (FAF), were performed. Results: There were 9 lesions in 9 patients, 9 women aged 14–79 years (mean age: 58.2 years). All the lesions were located in the posterior pole and most of them were pigmented (88.9%). CNVs associated with choroidal naevi were type I in 66.7% and type II in 33.3% of cases. 5 patients required treatment: anti-VEGF injection (alone or with transpupillary thermotherapy) was administered. The median follow-up was 24 months (range: 2–145). In two of all treated patients (40%), we observed BCVA gain (2–4 lines), in one patient (20%) it remained stable and in two (40%) it deteriorated. The final visual acuity was below 0.1 only in 1 patient. During the period of observation none of the lesions progressed to uveal melanoma. Conclusions: CNV associated with choroidal naevus could be the reason for subretinal fluid (SRF) leakage and visual loss. The response to anti-VEGF treatment is satisfactory in the majority of patients. Choroidal naevi with accompanying CNV have none or very low malignant transformation potential.
Źródło:
OphthaTherapy; 2022, 9, 4; 243-248
2353-7175
2543-9987
Pojawia się w:
OphthaTherapy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving Segmentation of 3D Retina Layers Based on Graph Theory Approach for Low Quality OCT Images
Autorzy:
Stankiewicz, A.
Marciniak, T.
Dąbrowski, A.
Stopa, M.
Rakowicz, P.
Marciniak, E.
Powiązania:
https://bibliotekanauki.pl/articles/221548.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Optical Coherence Tomography (OCT)
segmentation of retinal layers
image segmentation
graph theory
Opis:
This paper presents signal processing aspects for automatic segmentation of retinal layers of the human eye. The paper draws attention to the problems that occur during the computer image processing of images obtained with the use of the Spectral Domain Optical Coherence Tomography (SD OCT). Accuracy of the retinal layer segmentation for a set of typical 3D scans with a rather low quality was shown. Some possible ways to improve quality of the final results are pointed out. The experimental studies were performed using the so-called B-scans obtained with the OCT Copernicus HR device.
Źródło:
Metrology and Measurement Systems; 2016, 23, 2; 269-280
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Common path optical coherence tomography with electronic feedback for improved sensitivity
Autorzy:
Alsnaie, Khalid
Powiązania:
https://bibliotekanauki.pl/articles/27310102.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical coherence tomography
frequency domain
OCT
medical imaging
partially coherent interferometers
B-scan
Opis:
Optical coherence tomography (OCT) imaging has become a useful tool in medical diagnosis over the past 25 years, because of its ability to visualize intracellular structures at high resolution. The main objective of this work is to add electronic feedback to the optical coherence tomography setup to increase its sensitivity. Noise added to the measured interferogram obscures some details of examined tissue layered structure. Adjusting signal power level in such a way to improve signal-to-noise ratio can help to enhance image quality. Electronic feedback is added to enhance system sensitivity. A logarithmic amplifier is included in the OCT setup to automatically adapt signal level. Moreover, the resolution of the optical spectrum analyzer is controlled according to the farthest layer detected in the A-scan. These techniques are tested showing an improvement in obtained image of a human nail.
Źródło:
Optica Applicata; 2023, 53, 3; 495--504
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of epithelial thickness mapping in corneal refractive surgery
Autorzy:
Wlaź, Aleksandra
Czarnota-Nowakowska, Barbara
Wierzbowska, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/2042902.pdf
Data publikacji:
2021-09-30
Wydawca:
Medical Education
Tematy:
epithelial thickness mapping
cornea
refractive surgery
optical coherence tomography
laser in situ keratomileusis
Opis:
Refractive surgery has stimulated significant progress in anterior segment imaging. Knowledge of epithelial thickness profile considerably increases the efficacy and safety of refractive procedures. This review aims to present new technologies evaluating corneal epithelial thickness and the most important clinical applications in the field of corneal refractive surgery.
Źródło:
OphthaTherapy; 2021, 8, 3; 196-201
2353-7175
2543-9987
Pojawia się w:
OphthaTherapy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of petroleum products using optical coherence tomography
Wykrywanie produktów naftowych za pomocą optycznej tomografii koherencji
Autorzy:
Kamińska, Aleksandra M.
Pluciński, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/2031380.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
pollutions
petroleum products
detection
optical coherence tomography
zanieczyszczenia
produkty ropopochodne
detekcja
optyczna tomografia koherentna
Opis:
In this work, we present a novel method developed for the analysis of the properties of thin layers for detecting petroleum products on a water surface using a commercially available optical coherence tomography (OCT) system. The spectral density analysis of the signal from a spectroscopic OCT (S-OCT) enables us to perform the precision calculation of the thin layer thickness and other properties like homogeneity, and dispersion, even if layer thickness is smaller than the coherence length of light from the used broadband light source. Mathematical modeling has been confirmed by measurements. The experiment with thin oil films on the surface of the water was conducted. The obtained results indicate that it is possible to measure the thickness of the petroleum product layers on the surface of the water smaller than 1 μm with 10 nm resolution.
W pracy przedstawiono nowatorską metodę analizy właściwości cienkich warstw przy użyciu standardowych dostępnych na rynku systemów optycznej tomografii koherentnej (ang. optical coherence tomography – OCT) na potrzeby wykrywania produktów naftowych na powierzchni wody. Analiza gęstości widmowej mocy sygnału pochodzącego z systemu OCT z detekcją spektroskopową (ang. spectroscopic OCT – S-OCT) pozwala na dokładne obliczenie grubości cienkiej warstwy i innych jej właściwości, takich jak jednorodność i dyspersja, nawet jeśli grubość warstwy jest mniejsza niż długość drogi koherencji stosowanego szerokopasmowego źródła światła. Wyniki działania systemu uzyskane metodą modelowania matematycznego zostały potwierdzone pomiarami uzyskanymi z komercyjnego systemu, wykorzystując zaawansowane metody przetwarzania sygnałów. Przeprowadzono eksperyment z cienkimi warstwami olejowymi na powierzchni wody. Na podstawie uzyskanych wyników można stwierdzić, że możliwy jest pomiar grubości warstwy produktu ropopochodnego na powierzchni wody cieńszej niż 1 μm przy rozdzielczości pomiarów 10 nm.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2021, 73; 27-30
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies