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1.
Artigo em Inglês | MEDLINE | ID: mdl-38083631

RESUMO

Training in surgery is essential for surgeons to develop skill and dexterity. Physical training phantoms provide excellent haptic feedback and tissue properties for stitching and operating with authentic instruments and are easily available. However, they lack realistic traits and fail to reflect the complex environment of a surgical scene. Generative Adversarial Networks can be used for image-to-image translation, addressing the lack of realism in physical phantoms, by mapping patterns from the intraoperative domain onto the video stream captured during training with these surgical simulators. This work aims to achieve a successful I2I translation, from intra-operatory mitral valve surgery images onto a surgical simulator, using the CycleGAN model. Different experiments are performed - comparing the Mean Square Error Loss with the Binary Cross Entropy Loss; validating the Fréchet Inception Distance as a training and image quality metric; and studying the impact of input variability on the model performance. Differences between MSE and BCE are modest, with MSE being marginally more robust. The FID score proves to be very useful in identifying the best training epochs for the CycleGAN I2I translation architecture. Carefully selecting the input images can have a great impact in the end results. Using less style variability and input images with good feature details and clearly defined characteristics enables the network to achieve better results.Clinical Relevance- This work further contributes for the domain of realistic surgical training, successfully generating fake intra operatory images from a surgical simulator of the cardiac mitral valve.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Retroalimentação , Imagens de Fantasmas
2.
J Mech Behav Biomed Mater ; 130: 105191, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35358940

RESUMO

Deformational plagiocephaly is a head deformity that occurs in newborns, treated in severe cases with helmets named cranial remodeling orthoses (CRO). Current CROs can fail to adapt to head growth, causing excessive pressure sores and other complications, and may lead to poor clinical results. In this work, we experimentally and numerically study the compressive behavior of a functionally graded lattice that may be used in future work as a potential inner lining for a CRO with a customized density distribution. This work is divided into five stages. First, we describe the design of all lattices involved in the study. Second, we measure the mechanical properties of the bulk material used in the manufacturing of the lattices. Third, we study the effect of unit cell size variation, testing three homogenous body-centered cubic (BCC) lattices, and creating a numerical model for the prediction of the compressive behavior of various lattices with different unit cell sizes. Fourth, we study the effects of truss diameter variation, designing and testing three homogenous lattices with different truss diameters. Finally, we design a BCC lattice with a truss diameter gradient and analyze compressive deformations in numerical and experimental compression studies. The numerical simulations of the compression of the homogenous and graded lattices agree with the experimental measurements, both in unit cell variation and in truss diameter variation. In the graded lattice, the compression displacements observed in each region are proportional to their density and agree with the numerical simulation. Truss diameter variation was found to have a wider range of compressive responses than unit cell size variation without major changes in the overall geometry of the lattice and found more suitable for the intended application. The studies showed the potential of the functionally graded lattice for use in the CRO.


Assuntos
Aparelhos Ortopédicos , Humanos , Recém-Nascido , Porosidade , Pressão
4.
Arch Gerontol Geriatr ; 74: 118-122, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29096225

RESUMO

The objective of this study was to determine the effect of 16 weeks of mat-based Pilates training on health perception and sleep quality among elderly women. A randomized and controlled trial was conducted in Caxias do Sul, Brazil, in 2015, in which 61 healthy older women were divided into two groups: experimental group (EG; n=31, average of 64.25 years old, SD 0.14) and control group (CG; n=30, average of 63.75 years old, SD 0.08). The EG participants performed mat-based Pilates exercises twice a week in 60-min sessions, whereas the CG did not train. All participants completed Brazilian-adapted and validated versions of the Pittsburgh Sleep Quality Index (PSQI-BR) and General Health Questionnaire (GHQ-12) at baseline and after 16 weeks. Significant time x group interaction effects were found for the GHQ-12 total score (p<0.001, η2=0.19), and the depression (p=0.002, η2=0.15) and social dysfunction subscales (p=0.001, η2=0.18), as well as the PSQI-BR total score (p=0.017, η2=0.09), and the sleep latency (p=0.023, η2=0.09) and use of sleeping medication subscales (p=0.019, η2=0.09), indicating better improvements (reductions) in these outcome variables for the Pilates EG when compared to the CG. All significant effects were classified as moderate to high. These results indicate that 16 weeks of mat-based Pilates training significantly improves the perceived health status and some sleep quality indices among elderly women. However, more studies are needed to assess the effectiveness of equipment-based Pilates exercises among this population.


Assuntos
Técnicas de Exercício e de Movimento , Nível de Saúde , Sono , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Percepção
5.
Porto Biomed J ; 2(1): 18-22, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-32258579

RESUMO

This work proposes a novel approach to assess spinal curvature, by using Microsoft's Kinect™ to obtain 3D reconstructed models of subject's dorsal skin surface in different postures. This method is non-invasive, radiation-free and low-cost. The trial tests here presented intended to evaluate the reliability of this approach, by assessing the tendency of 98 volunteers to present scoliosis. The shoulder height difference was calculated for each subject's scan, by quantifying the angular slope of a line crossing both scapulae. The volunteers' average age was 24.7 years. Results showed that 68.37% of the volunteers revealed differences higher than 1° between the shoulders, having that their record in what concerns to loads and lesions proved to increase the angular slope. This initial approach shall establish the grounds for assessing spinal posture in pre-clinical or industrial ergonomics scans. Further studies shall include comparison versus traditional imaging methods and experienced clinical evaluation.

6.
Reumatismo ; 67(1): 21-5, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26150271

RESUMO

Systemic sclerosis (SSc) sine scleroderma (ssSSc) is characterized by the absence of skin involvement, despite other manifestations of systemic sclerosis are present. It is not known whether sSSc represents a forme fruste of limited cutaneous SSc or a distinct entity, but the 2013 American College of Rheumatology/European League Against Rheumatism criteria for the classification of SSc have considered SSc without skin involvement to be a distinct subset. The authors present the case of a 70-year old female that was referred for a consultation for Raynaud's phenomenon and a chronic anterior uveitis (CAU). She had a history of dysphagia, diffuse pulmonary emphysema and a biopsy-documented fibrosis of the upper lobes, and an idiopathic non-ischemic dilated cardiomyopathy with severe left ventricle systolic dysfunction and left bundle branch block. Anti-nuclear and anti-centromere antibodies were positive, while manometry revealed distal esophageal hypomotility. After establishing the diagnosis of ssSSc and starting immunosuppression, the ocular disease improved, while the lung and heart diseases remained stable. This case underlines that it is very important to suspect SSc when CAU is present and/or skin thickening is absent. To our knowledge, this is the first report of CAU in a patient with ssSSc.


Assuntos
Anticorpos Antinucleares/sangue , Escleroderma Sistêmico/imunologia , Uveíte Anterior/imunologia , Idoso , Biomarcadores/sangue , Feminino , Humanos , Imunossupressores/uso terapêutico , Fatores de Risco , Esclerodermia Difusa/imunologia , Esclerodermia Limitada/imunologia , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/tratamento farmacológico , Resultado do Tratamento , Uveíte Anterior/sangue , Uveíte Anterior/tratamento farmacológico , Uveíte Anterior/etiologia
7.
Pathol Res Pract ; 211(1): 71-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25446246

RESUMO

PURPOSE: Angiogenesis and tumor invasion are complex processes that are mediated by various proteins, such as vascular endothelial growth factor (VEGF-α) and the matrix-degrading enzymes metalloproteinase-2 and -9 (MMP-2, MMP-9). The aim of this study was to determine what roles MMP-2, MMP-9, and VEGF-α play in colorectal cancer (CRC) by correlating their expression levels with the cancer TNM stage, modified Dukes criteria, degree of cell differentiation, and long-term patient survival. METHODS: The present series consisted of tissue samples obtained from 180 patients who had undergone large bowel resection during 1995 and 2005 at the Luis Antonio Hospital. Archival paraffin-embedded CRC tissue samples were used to generate tissue microarray blocks, which were immunohistochemically stained for MMP-2, MMP-9, and VEGF-α. Three different grading systems were applied to evaluate staining intensity. Chi-squared Person test and Kaplan-Meier survival curves were used, and values of p<0.05 were considered statistically significant. RESULTS: MMP-2 expression showed a significant association with more invasive cancer stages (p<0.001) and death (p<0.041). VEGF-α expression correlated with a high TNM stage (p<0.009), the degree of cell differentiation (p<0.025) and patient death as a result of disease (p<0.035). The Kaplan-Meier survival estimated that patients with strong staining for MMP-2 (log-rank x(2)=34.09; p<0.0001), MMP-9 (log-rank x(2)=12.83; p<0.0003) and VEGF (log-rank x(2)=33.9; p<0.0001) showed a greater tendency towards death during 60 months of follow up. CONCLUSIONS: The quantification of VEGF-α, MMP-2 and MMP-9 expression in colorectal cancer may be related to survival. These data add to the growing epidemiological and experimental evidence that VEGF-α, MMP-2 and MMP-9 may play a role in colorectal tumorigenesis.


Assuntos
Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Neovascularização Patológica/diagnóstico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/mortalidade , Feminino , Humanos , Imuno-Histoquímica/métodos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/métodos , Neovascularização Patológica/patologia , Prognóstico
8.
Rev. bras. oftalmol ; 50(4): 11-4, ago. 1991. tab
Artigo em Português | LILACS | ID: lil-99993

RESUMO

A hipertensäo arterial foi a causa mais importante de trombose da veia central da retina nos pacientes acima dos 40 anos de idade. O diabete näo foi täo comum quanto se esperava. Nos poucos casos estudados, a hipertensäo arterial ou a hipercolesterolemia estavam quase sempre presentes. A incidência de trombose da veia central da retina na populaçäo feminina se iguala ao contingente masculino afetado após os 60 anos de idade. Até esta faixa etária as mulheres contam com uma proteçäo hormonal


Assuntos
Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Hipercolesterolemia/etiologia , Oclusão da Veia Retiniana/etiologia , Brasil
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