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1.
Med Biol Eng Comput ; 61(11): 2921-2938, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37530886

RESUMO

In this paper, a multi-level algorithm for pre-processing of dermoscopy images is proposed, which helps in improving the quality of the raw images, making it suitable for skin lesion detection. This multi-level pre-processing method has a positive impact on automated skin lesion segmentation using Regularized Extreme Learning Machine. Raw images are subjected to de-noising, illumination correction, contrast enhancement, sharpening, reflection removal, and virtual shaving before the skin lesion segmentation. The Non-Local Means (NLM) filter with lowest Blind Reference less Image Spatial Quality Evaluator (BRISQUE) score exhibits better de-noising of dermoscopy images. To suppress uneven illumination, gamma correction is subjected to the denoised image. The Robust Image Contrast Enhancement (RICE) algorithm is used for contrast enhancement, and produces enhanced images with better structural preservation and negligible loss of information. Unsharp masking for sharpening exhibits low BRISQUE scores for better sharpening of fine details in an image. Output images produced by the phase congruency-based method in virtual shaving show high similarity with ground truth images as the hair is removed completely from the input images. Obtained scores at each stage of pre-processing framework show that the performance is superior compared to all the existing methods, both qualitatively and quantitatively, in terms of uniform contrast, preservation of information content, removal of undesired information, and elimination of artifacts in melanoma images. The output of the proposed system is assessed qualitatively and quantitatively with and without pre-processing of dermoscopy images. From the overall evaluation results, it is found that the segmentation of skin lesion is more efficient using Regularized Extreme Learning Machine if the multi-level pre-processing steps are used in proper sequence.


Assuntos
Melanoma , Dermatopatias , Neoplasias Cutâneas , Humanos , Neoplasias Cutâneas/diagnóstico , Dermoscopia/métodos , Reconhecimento Automatizado de Padrão/métodos , Reprodutibilidade dos Testes , Melanoma/diagnóstico , Algoritmos
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 870-873, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34891428

RESUMO

Asthma is an inflammatory disease of the airways which causes cough, chest tightness, wheezing and other distinct sounds during breathing. Spirometry is a golden standard lung function test, is used to monitor and diagnose asthma. Spirometry is very time-consuming and requires a lot of patient's efforts. Therefore, an alternate method which can overcome spirometry limitations is required. Sound based method can be one such alternative as it is less tedious, less time consuming and suitable for patients of all ages. It has been shown in the past that breath, among other vocal sounds, performs the best for an asthma vs healthy subject classification task. Breath consists of two phases, namely, inhale and exhale. Experiments in this work show, exhale performs better for classification task compared to the entire breath cycle as well as the inhale. However, this requires manual marking of the breath boundaries, which is a very time-consuming task. We, in this work, investigate how critical are the breath cycle and breath phase boundaries for the classification task. Experiments with chunks of random duration shows that they perform on par or better than the exhale. However, a segment comprising the second and third quarters of a breath cycle results in the highest classification accuracy of 80.64%. This suggests that, while breath phase boundaries may not be important, breath cycle boundaries could benefit in the classification task.


Assuntos
Asma , Sons Respiratórios , Asma/diagnóstico , Voluntários Saudáveis , Humanos , Testes de Função Respiratória , Espirometria
3.
J Environ Biol ; 27(1): 93-5, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16850883

RESUMO

In vivo cytogenetic assay in Allium cepa root tip cells has been carried out to detect the modifying effect of Ocimum sanctum aqueous leaf extract against chromium (Cr) and mercury (Hg) induced genotoxicity. It was observed that the roots post-treated with the leaf extract showed highly significant (p < 0.001) recovery in mitotic index (MI) and chromosomal aberrations (CA) when compared to pre-treated (Cr/Hg) samples and the lower doses of the leaf extract were found to be more effective than higher doses. The present study reveals that the Ocimum sanctum leaf extract possesses the protective effect against Cr/Hg induced genetic damage.


Assuntos
Allium/efeitos dos fármacos , Cromo/toxicidade , Mercúrio/toxicidade , Meristema/efeitos dos fármacos , Ocimum/química , Extratos Vegetais/farmacologia , Allium/genética , Aberrações Cromossômicas/efeitos dos fármacos , Meristema/genética , Índice Mitótico , Folhas de Planta/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética
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