2014
Authors
Oliveira, E; Goncalves, MM; Caridade, R; Rodrigues, N;
Publication
2014 IEEE 3RD INTERNATIONAL CONFERENCE ON SERIOUS GAMES AND APPLICATIONS FOR HEALTH (SEGAH)
Abstract
Rumination is a psychological process that is featured by a repetitive pattern of intrusive thoughts that, by focusing the person into painful cognitive contents, elicits suffering. Usually people try to deal with these ruminative thoughts by trying to avoid thinking, which paradoxically makes the thoughts even more intense. Several researchers proposed that ruminative thoughts are central in anxiety and depressive disorders and that the treatment of rumination is also pivotal in the treatment of these disorders. This study is a first attempt to construct a game that trains players in shifting the attention from ruminative thoughts to problem-solving tasks, illustrating the use of the game. We expect that training such an ability will reduce the intensity of that thoughts. It is our expectation that the continuous use of games with these kind of features will reduce the intensity of ruminative thoughts, improving the wellbeing and reducing the psychological suffering of players.
2014
Authors
Moreira, AHJ; Queirós, S; Fonseca, J; Rodrigues, PL; Rodrigues, NF; Vilaça, JL;
Publication
SeGAH 2014 - IEEE 3rd International Conference on Serious Games and Applications for Health, Books of Proceedings
Abstract
Hand and finger tracking has a major importance in healthcare, for rehabilitation of hand function required due to a neurological disorder, and in virtual environment applications, like characters animation for on-line games or movies. Current solutions consist mostly of motion tracking gloves with embedded resistive bend sensors that most often suffer from signal drift, sensor saturation, sensor displacement and complex calibration procedures. More advanced solutions provide better tracking stability, but at the expense of a higher cost. The proposed solution aims to provide the required precision, stability and feasibility through the combination of eleven inertial measurements units (IMUs). Each unit captures the spatial orientation of the attached body. To fully capture the hand movement, each finger encompasses two units (at the proximal and distal phalanges), plus one unit at the back of the hand. The proposed glove was validated in two distinct steps: a) evaluation of the sensors' accuracy and stability over time; b) evaluation of the bending trajectories during usual finger flexion tasks based on the intra-class correlation coefficient (ICC). Results revealed that the glove was sensitive mainly to magnetic field distortions and sensors tuning. The inclusion of a hard and soft iron correction algorithm and accelerometer and gyro drift and temperature compensation methods provided increased stability and precision. Finger trajectories evaluation yielded high ICC values with an overall reliability within application's satisfying limits. The developed low cost system provides a straightforward calibration and usability, qualifying the device for hand and finger tracking in healthcare and animation industries.
2014
Authors
Oliveira, E; Gonçalves, MM; Caridade, R; Rodrigues, N;
Publication
SeGAH 2014 - IEEE 3rd International Conference on Serious Games and Applications for Health, Books of Proceedings
Abstract
Rumination is a psychological process that is featured by a repetitive pattern of intrusive thoughts that, by focusing the person into painful cognitive contents, elicits suffering. Usually people try to deal with these ruminative thoughts by trying to avoid thinking, which paradoxically makes the thoughts even more intense. Several researchers proposed that ruminative thoughts are central in anxiety and depressive disorders and that the treatment of rumination is also pivotal in the treatment of these disorders. This study is a first attempt to construct a game that trains players in shifting the attention from ruminative thoughts to problem-solving tasks, illustrating the use of the game. We expect that training such an ability will reduce the intensity of that thoughts. It is our expectation that the continuous use of games with these kind of features will reduce the intensity of ruminative thoughts, improving the wellbeing and reducing the psychological suffering of players.
2014
Authors
Rodrigues, PL; Rodrigues, NF; Duque, D; Granja, S; Correia Pinto, J; Vilaca, JL;
Publication
COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE
Abstract
Background. Regulating mechanisms of branching morphogenesis of fetal lung rat explants have been an essential tool for molecular research. This work presents a new methodology to accurately quantify the epithelial, outer contour, and peripheral airway buds of lung explants during cellular development from microscopic images. Methods. The outer contour was defined using an adaptive and multiscale threshold algorithm whose level was automatically calculated based on an entropy maximization criterion. The inner lung epithelium was defined by a clustering procedure that groups small image regions according to the minimum description length principle and local statistical properties. Finally, the number of peripheral buds was counted as the skeleton branched ends from a skeletonized image of the lung inner epithelia. Results. The time for lung branching morphometric analysis was reduced in 98% in contrast to the manual method. Best results were obtained in the first two days of cellular development, with lesser standard deviations. Nonsignificant differences were found between the automatic and manual results in all culture days. Conclusions. The proposed method introduces a series of advantages related to its intuitive use and accuracy, making the technique suitable to images with different lighting characteristics and allowing a reliable comparison between different researchers.
2014
Authors
Rodrigues, PL; Rodrigues, NF; Pinho, ACM; Fonseca, JC; Correia Pinto, J; Vilaca, JL;
Publication
MEDICAL ENGINEERING & PHYSICS
Abstract
Pectus excavatum is the most common deformity of the thorax. Pre-operative diagnosis usually includes Computed Tomography (CT) to successfully employ a thoracic prosthesis for anterior chest wall remodeling. Aiming at the elimination of radiation exposure, this paper presents a novel methodology for the replacement of CT by a 3D laser scanner (radiation-free) for prosthesis modeling. The complete elimination of CT is based on an accurate determination of ribs position and prosthesis placement region through skin surface points. The developed solution resorts to a normalized and combined outcome of an artificial neural network (ANN) set. Each ANN model was trained with data vectors from 165 male patients and using soft tissue thicknesses (STT) comprising information from the skin and rib cage (automatically determined by image processing algorithms). Tests revealed that ribs position for prosthesis placement and modeling can be estimated with an average error of 5.0 +/- 3.6 mm. One also showed that the ANN performance can be improved by introducing a manually determined initial STT value in the ANN normalization procedure (average error of 2.82 +/- 0.76 mm). Such error range is well below current prosthesis manual modeling (approximately 11 mm), which can provide a valuable and radiation-free procedure for prosthesis personalization.
2014
Authors
Moreira, AHJ; Queiros, S; Rodrigues, NF; Pinho, ACM; Fonseca, JC; Vilaca, JL;
Publication
2014 IEEE INTERNATIONAL SYMPOSIUM ON MEDICAL MEASUREMENTS AND APPLICATIONS (MEMEA)
Abstract
The success of the osseointegration concept and the Branemark protocol is highly associated to the accuracy in the production of an implant-supported prosthesis. One of most critical steps for long-term success of these prosthesis is the accuracy obtained during the impression procedure, which is affected by factors such as the impression material, implant position, angulation and depth. This paper investigates the feasibility of 3D electromagnetic motion tracking systems as an acquisition method for modeling full-arch implant-supported prosthesis. To this extent, we propose an implant acquisition method at the patient mouth and a calibration procedure, based on a 3D electromagnetic tracker that obtains combined measurements of implant's position and angulation, eliminating the use of any impression material. Three calibration algorithms (namely linear interpolation, higher-order polynomial and Hardy multiquadric) were tested to compensate for the electromagnetic tracker distortions introduced by the presence of nearby metals. Moreover, implants from different suppliers were also tested to study its impact on tracking accuracy. The calibration methodology and the algorithms employed proved to implement a suitable strategy for the evaluation of novel dental impression techniques. However, in the particular case of the evaluated electromagnetic tracking system, the order of magnitude of the obtained errors invalidates its use for the full-arch modeling of implant-supported prosthesis.
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