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1.
Comput Math Methods Med ; 2022: 3545712, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36388160

RESUMO

Tongue diagnosis, a noninvasive examination, is an essential step for syndrome differentiation and treatment in traditional Chinese medicine (TCM). Sublingual vein (SV) is examined to determine the presence of blood stasis and blood stasis syndrome. Many studies have shown that the degree of SV stasis positively correlates with disease severity. However, the diagnoses of SV examination are often subjective because they are influenced by factors such as physicians' experience and color perception, resulting in different interpretations. Therefore, objective and scientific diagnostic approaches are required to determine the severity of sublingual varices. This study aims at developing a computer-assisted system based on machine learning (ML) techniques for diagnosing the severity of sublingual varicose veins. We conducted a comparative study of the performance of several supervised ML models, including the support vendor machine, K-neighbor, decision tree, linear regression, and Ridge classifier and their variants. The main task was to differentiate sublingual varices into mild and severe by using images of patients' SVs. To improve diagnostic accuracy and to accelerate the training process, we proposed using two model reduction techniques, namely, the principal component analysis in conjunction with the slice inverse regression and the convolution neural network (CNN), to extract valuable features during the preprocessing of data. Our results showed that these two extraction methods can reduce the training time for the ML methods, and the Ridge-CNN method can achieve an accuracy rate as high as 87.5%, which is similar to that of experienced TCM physicians. This computer-aided tool can be used for reference clinical diagnosis. Furthermore, it can be employed by junior physicians to learn and to use in clinical settings.


Assuntos
Medicina Tradicional Chinesa , Varizes , Humanos , Medicina Tradicional Chinesa/métodos , Aprendizado de Máquina , Redes Neurais de Computação , Língua , Varizes/diagnóstico por imagem
2.
Tomography ; 7(4): 555-572, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34698286

RESUMO

In order to improve the image quality of BLADE magnetic resonance imaging (MRI) using the index tensor solvers and to evaluate MRI image quality in a clinical setting, we implemented BLADE MRI reconstructions using two tensor solvers (the least-squares solver and the L1 total-variation regularized least absolute deviation (L1TV-LAD) solver) on a graphics processing unit (GPU). The BLADE raw data were prospectively acquired and presented in random order before being assessed by two independent radiologists. Evaluation scores were examined for consistency and then by repeated measures analysis of variance (ANOVA) to identify the superior algorithm. The simulation showed the structural similarity index (SSIM) of various tensor solvers ranged between 0.995 and 0.999. Inter-reader reliability was high (Intraclass correlation coefficient (ICC) = 0.845, 95% confidence interval: 0.817, 0.87). The image score of L1TV-LAD was significantly higher than that of vendor-provided image and the least-squares method. The image score of the least-squares method was significantly lower than that of the vendor-provided image. No significance was identified in L1TV-LAD with a regularization strength of λ= 0.4-1.0. The L1TV-LAD with a regularization strength of λ= 0.4-0.7 was found consistently better than least-squares and vendor-provided reconstruction in BLADE MRI with a SENSitivity Encoding (SENSE) factor of 2. This warrants further development of the integrated computing system with the scanner.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Simulação por Computador , Análise dos Mínimos Quadrados , Imageamento por Ressonância Magnética/métodos , Reprodutibilidade dos Testes
3.
Biomed Sci Instrum ; 40: 325-30, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15133979

RESUMO

We present a fully parallel nonlinearly implicit algorithm for the numerical simulation of some branching blood flow problems, which require efficient and robust solver technologies in order to handle the high nonlinearity and the complex geometry. Parallel processing is necessary because of the large number of mesh points needed to accurately discretize the system of differential equations. In this paper we introduce a parallel Newton-Krylov-Schwarz based implicit method, and software for distributed memory parallel computers, for solving the nonlinear algebraic systems arising from a Q2-Q1 finite element discretization of the incompressible Navier-Stokes equations that we use to model the blood flow in the left anterior descending coronary artery.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Metodologias Computacionais , Vasos Coronários/fisiologia , Modelos Cardiovasculares , Análise Numérica Assistida por Computador , Artérias/fisiologia , Pressão Sanguínea/fisiologia , Simulação por Computador , Análise de Elementos Finitos , Fluxo Sanguíneo Regional/fisiologia
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