Measurement of the effect of physical exercise on the concentration of individuals with ADHD.

Attention Deficit Hyperactivity Disorder (ADHD) mainly affects the academic performance of children and adolescents. In addition to bringing physical and mental health benefits, physical activity has been used to prevent and improve ADHD comorbidities; however, its effectiveness has not been quantified. In this study, the effect of physical activity on children's attention was measured using a computer game. Intense physical activity was promoted by a relay race, which requires a 5-min run without a rest interval. The proposed physical stimulus was performed with 28 volunteers: 14 with ADHD (GE-EF) and 14 without ADHD symptoms (GC-EF). After 5 min of rest, these volunteers accessed the computer game to accomplish the tasks in the shortest time possible. The computer game was also accessed by another 28 volunteers: 14 with ADHD (GE) and 14 without these symptoms (GC). The response time to solve the tasks that require attention was recorded. The results of the four groups were analyzed using D'Agostino statistical tests of normality, Kruskal-Wallis analyses of variance and post-hoc Dunn tests. The groups of volunteers with ADHD who performed exercise (GE-EF) showed improved performance for the tasks that require attention with a difference of 30.52% compared with the volunteers with ADHD who did not perform the exercise (GE). The (GE-EF) group showed similar performance (2.5% difference) with the volunteers in the (GC) group who have no ADHD symptoms and did not exercise. This study shows that intense exercise can improve the attention of children with ADHD and may help their school performance.

Proposal of a magnetic resonance technique for the evaluation of the calcaneofibular ligament minimizing false positive results.

BACKGROUND: Magnetic resonance (MR) techniques used to detect lesions of the ligament complex for articulation of the ankle lack the desired accuracy for the study of the calcaneofibular ligament (CFL). The lack of sensitivity of the conventional techniques is due to variations in the dimensions of the CFL. The best results are obtained when the image plane is oriented parallel to the ligament. This study aims to develop a model that addresses the width, length and angle parameters of the CFL and the orientation of the MR image plane, and thus determine a technique in the oblique transversal plane with the foot in anatomical flexion, that is adequate for the majority of patients. METHOD: To determine this orientation and adapt it to the majority of people, images of the articulation of the ankle in the 3D isotropic, volumetric, sagittal plane of 100 volunteers were taken using the MR technique. None of the volunteers had a clinical history of ligament lesions, serious pathologies, or surgeries. A measurement of the length, width, and angle of the CFL relative to the sole of the foot was performed using the MR tools. A virtual model was developed that simulated the visualization of the CFL in the oblique transversal image plane from 35° to 45° using the CFL dimensions of 100 volunteers. The comparison of the simulations with the reconstructed images validated the model and permitted the calculation of the agreement and sensitivity of each technique in the detection of the complete CFL. RESULTS: Using the simulator, it was possible to obtain the limit angle for complete CFL visualization as a function of its dimensions for any angle of the oblique transversal image plane of the MR. CONCLUSION: The results suggest that a single image acquisition technique in the oblique transversal plane at 38° with the foot in anatomical flexion would serve the majority of patients.

Meniscal tears: comparison of the conventional spin-echo and fast spin-echo techniques through image processing.

BACKGROUND: Conventional spin-echo (PD-CSE) and fast spin-echo (PD-FSE) techniques are frequently used to detect meniscal tears. However, the time delay for imaging with PD-CSE has resulted in its replacement with faster techniques, such as proton density fast spin-echo (PD-FSE), which has become a frequent tool at most diagnostic centres.Qualitative analysis shows that the PD-CSE technique is more sensitive, but other authors have not found significant differences between the aforementioned techniques. Therefore, we performed a quantitative analysis in this study that aims to measure differences in the quality of the images obtained with both techniques. METHODS: We compared the PD-CSE and PD-FSE techniques by quantitatively analysing the obtained proton density images: the area shown, as well as the brightness and lesion contrast of the obtained image.A set of 100 images from 50 patients thought to contain meniscal tears of the knee were selected. These 100 images were obtained from all individuals using both the PD-CSE and PD-FSE techniques. The images were processed using software developed in Delphi. In addition to these quantifications, three physicians, who are specialists in radiology and capable of analysing magnetic resonance (MR) images of the musculoskeletal system, qualitatively analysed the diagnostic sensitivity of both techniques. RESULTS: On average, samples obtained via the PD-CSE technique contained 22% more pixels in the lesion area. The contrast differed by 28%, and the brightness differed by 31%. The two techniques were correlated using Student's t-test, which showed a statistically significant difference. The specialists detected meniscal tears in 30 of the images obtained via the PD-CSE technique, while only 72% of these cases were detected via the PD-FSE technique. CONCLUSIONS: The PD-CSE technique was shown to be superior to PD-FSE for all of the evaluated properties, making its selection preferable.

Grip and pinch capability assessment system for children.

The grip movement is essential for performing daily activities. However, the assessment of this movement is currently made subjectively, due to the lack of appropriate quantification equipment. The objective of this study was to develop, validate and test a virtual environment controlled by five trigger devices used to analyse cylindrical, spherical and hook grips as well as tip-to-tip pinch and pulp-to-side movements. Sensors and electronic circuits that detect the correct grip, the threshold of grip strength and the range of motion were inserted into the devices. To validate this system, tests were conducted with 20 children while being evaluated by three physical therapists, all specialists in neurology. The results from the evaluators and the system agreed to an extent of 86.6%. Following validation, the system was used by 35 children with no motor impairment and by 10 children with mild motor abnormalities in an upper limb; these assessments provided efficient and reliable results. The developments presented in this study may help to assess grip and pinch movements and facilitate the choice of strategies in therapeutic processes.

Virtual environment to quantify the influence of colour stimuli on the performance of tasks requiring attention.

BACKGROUND: Recent studies indicate that the blue-yellow colour discrimination is impaired in ADHD individuals. However, the relationship between colour and performance has not been investigated. This paper describes the development and the testing of a virtual environment that is capable to quantify the influence of red-green versus blue-yellow colour stimuli on the performance of people in a fun and interactive way, being appropriate for the target audience. METHODS: An interactive computer game based on virtual reality was developed to evaluate the performance of the players.The game's storyline was based on the story of an old pirate who runs across islands and dangerous seas in search of a lost treasure. Within the game, the player must find and interpret the hints scattered in different scenarios. Two versions of this game were implemented. In the first, hints and information boards were painted using red and green colours. In the second version, these objects were painted using blue and yellow colours. For modelling, texturing, and animating virtual characters and objects the three-dimensional computer graphics tool Blender 3D was used. The textures were created with the GIMP editor to provide visual effects increasing the realism and immersion of the players. The games were tested on 20 non-ADHD volunteers who were divided into two subgroups (A1 and A2) and 20 volunteers with ADHD who were divided into subgroups B1 and B2. Subgroups A1 and B1 used the first version of the game with the hints painted in green-red colors, and subgroups A2 and B2 the second version using the same hints now painted in blue-yellow. The time spent to complete each task of the game was measured. RESULTS: Data analyzed with ANOVA two-way and posthoc TUKEY LSD showed that the use of blue/yellow instead of green/red colors decreased the game performance of all participants. However, a greater decrease in performance could be observed with ADHD participants where tasks, that require attention, were most affected. CONCLUSIONS: The game proved to be a user-friendly tool capable to detect and quantify the influence of color on the performance of people executing tasks that require attention and showed to be attractive for people with ADHD.

Novo dispositivo para aferição de KVp e dose em equipamentos de radiodiagnóstico / New device for kVp and dose measurements of diagnostic X-ray tubes

Neste artigo é apresentado um novo dispositivo para aferição do pontecial aplicado entre os eletrodos de um tubo radiográfico. Ele opera utilizando um sensor de raios-X à base de silício e o sistema eletrônico empregado deriva de um instrumento detector de cintilação desenvolvido anteriormente. No trabalho são apresentados, também, os resultados da calibração e dos testes realizados com um equipamento convencional de radiodiagnóstico, com um mamógrafo e com um aparelho de raios-X odontológico. Além disso, uma ampliação do circuito eletrônico tambem permite que o dispositivo possa atuar como dosímetro. São discutidas as vantagens desse novo dispositivo numa comparação com outros instrumentos de aferição de kVp, incluindo o detector de cintilaçao proposto anteriormente.

Determinaçäo da regiäo ótima de sistemas mamográficos com base em simulaçöes computacionais da FTM / Determination of optimum region of mammographic sysytems on basis in FTM computer simulation

Este trabalho consiste numa investigação da "Região Ótima' do campo de radiação, particularmente voltada a sistemas mamográficos. Esta região foi definida em pesquisas anteriores como a faixa do campo onde o sistema apresenta sua melhor performance, produzindo, portanto, imagens mais nítidas. A investigação aqui proposta toma por base a associação de dois métodos de avaliação de sistemas de imagem radiológica que empregam simulação computacional para determinar as Funções de Transferência de Modulação (FTMs) associadas ao ponto focal em diversas orientações e posições do campo.

This work reports an investigation of the "Optimum Region" of the radiation field, directed to mammographic systems. Such a region was defined in previous works as the field range where the system has its best performance and where it yelds sharpest images. This study is based on a correlation of two methods for evaluating radiologié imaging systems, both using computer simulation in order to determine modulation transfer functions (MTFs) dueto the X-ray tube focal spot in severa! field orientations and locations.

Método computadorizado para simulaçäo da distribuiçäo angular dos raios X em sistemas radiológicos / Computerized method for simulation of angular distribuition of the X-rays in radiological systems

O presente trabalho apresenta uma técnica para simular, em sistemas de imagens radiológicas, a variação da distribuição angular dos raios X (Efeito "Heel"), que é responsável pela variação de intensidade ao longo do campo de radiação. Com esta simulação pode ser previsto o contraste das imagens para qualquer técnica de exposição.

Técnica computacional para correçäo da näo-homogeneidade da distribuiçäo de intensidade em imagens radiológicas / Computational technique for non-homogeneity correction of intensity distribuition in radiological images

Este trabalho propõe uma técnica de processamento de imagens para a compensação do efeito "Heel" em imagens médicas, permitindo melhorar a detecção das estruturas através da homogeneização do fundo. Tal técnica pode ser utilizada para qualquer sistema radiológico.