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Publications

Publications by BIO

2013

Robust Iris Localisation in Challenging Scenarios

Authors
Monteiro, JC; Sequeira, AF; Oliveira, HP; Cardoso, JS;

Publication
Computer Vision, Imaging and Computer Graphics - Theory and Applications - International Joint Conference, VISIGRAPP 2013, Barcelona, Spain, February 21-24, 2013, Revised Selected Papers

Abstract
The use of images acquired in unconstrained scenarios is giving rise to new challenges in the field of iris recognition. Many works in literature reported excellent results in both iris segmentation and recognition but mostly with images acquired in controlled conditions. The intention to broaden the field of application of iris recognition, such as airport security or personal identification in mobile devices, is therefore hindered by the inherent unconstrained nature under which images are to be acquired. The proposed work focuses on mutual context information from iris centre and iris limbic and pupillary contours to perform robust and accurate iris segmentation in noisy images. The developed algorithm was tested on the MobBIO database with a promising 96% segmentation accuracy for the limbic contour.

2013

Biomechanical Modeling and Simulation of the Spider Crab (Maja brachydactyla)

Authors
Rynkevic, R; Silva, MF; Marques, MA;

Publication
2013 IEEE 3RD PORTUGUESE MEETING IN BIOENGINEERING (ENBENG)

Abstract
One line of research and development in robotics receiving increasing attention in recent years is the development of biologically inspired walking robots. The purpose is to gain knowledge of biological beings and apply that knowledge to implement the same methods of locomotion ( or at least use the biological inspiration) on the machines we build. It is believed that this way it is possible to develop machines with capabilities similar to those of biological beings in terms of locomotion skills and energy efficiency. One way to better understand the functioning of these systems, without the need to develop prototypes with long and costly development, is to use simulation models. Based on these ideas, this work concerns the biomechanical study of the spider crab, using the SimMechanics toolbox of Matlab/Simulink. This paper describes the anatomy and locomotion of the spider crab, its modeling and control and the locomotion simulation of a crab within the SimMechanics environment.

2013

Innovations in health care services: The CAALYX system

Authors
Rocha, A; Martins, A; Freire Junior, JC; Boulos, MNK; Escriche Vicente, ME; Feld, R; van de Ven, P; Nelson, J; Bourke, A; OLaighin, G; Sdogati, C; Jobes, A; Narvaiza, L; Rodriguez Molinero, A;

Publication
INTERNATIONAL JOURNAL OF MEDICAL INFORMATICS

Abstract
Purpose: This paper describes proposed health care services innovations, provided by a system called CAALYX (Complete Ambient Assisted Living eXperiment). CAALYX aimed to provide healthcare innovation by extending the state-of-the-art in tele-healthcare, by focusing on increasing the confidence of elderly people living autonomously, by building on the knowledge base of the most common disorders and respective characteristic vital sign changes for this age group. Methods: A review of the state-of-the-art on health care services was carried out. Then, extensive research was conducted on the particular needs of the elderly in relation to home health services that, if offered to them, could improve their day life by giving them greater confidence and autonomy. To achieve this, we addressed issues associated with the gathering of clinical data and interpretation of these data, as well as possibilities of automatically triggering appropriate clinical measures. Considering this initial work we started the identification of initiatives, ongoing works and technologies that could be used for the development of the system. After that, the implementation of CAALYX was done. Findings: The innovation in CAALYX system considers three main areas of contribution: (i) The Roaming Monitoring System that is used to collect information on the well-being of the elderly users; (ii) The Home Monitoring System that is aimed at helping the elders independently living at home being implemented by a device (a personal computer or a set top box) that supports the connection of sensors and video cameras that may be used for monitoring and for interaction with the elder; (iii) The Central Care Service and Monitoring System that is implemented by a Caretaker System where attention and care services are provided to elders, where actors as Caretakers, Doctors and Relatives are logically linked to elders. Innovations in each of these areas are presented here. Conclusions: The ageing European society is placing an added burden on future generations, as the 'elderly-to-working-age-people' ratio is set to steadily increase in the future. Nowadays, quality of life and fitness allows for most older persons to have an active life well into their eighties. Furthermore, many older persons prefer to live in their own house and choose their own lifestyle. The CAALYX system can have a clear impact in increasing older persons' autonomy, by ensuring that they do not need to leave their preferred environment in order to be properly monitored and taken care of.

2013

Empirical mode decomposition for self-mixing Doppler signals of hemodynamic optical probes

Authors
Pereira, T; Vaz, P; Oliveira, T; Santos, I; Pereira, HC; Almeida, V; Correia, C; Cardoso, J;

Publication
PHYSIOLOGICAL MEASUREMENT

Abstract
A new type of optical probe based on laser Doppler self-mixing technology, for a truly non-contact measurement in a single location, and extraction of the temporal features of the distension wave in the arterial wall, was developed. The monitoring of temporal features allows the assessment of cardiovascular function when measurement is carried out at the carotid artery. An algorithm based on the short-time Fourier transform and empirical mode decomposition was applied to the test setup self-mixing signals for the determination of waveform features, with an accuracy of a few milliseconds and a root mean square error less than 3 ms. In vivo testing signals show great consistency in the measured pulse pressure waveform.

2013

IntellWheels: Intelligent wheelchair with user-centered design

Authors
Petry, MR; Moreira, AP; Faria, BM; Reis, LP;

Publication
2013 IEEE 15th International Conference on e-Health Networking, Applications and Services, Healthcom 2013

Abstract
Intelligent wheelchairs can become an important solution to assist physically impaired individuals who find it difficult or impossible to drive regular powered wheelchairs. However, when designing the hardware architecture several projects compromise the user comfort and the wheelchair normal usability in order to solve robotic problems. In this paper we describe the main concepts regarding the design of the IntellWheels intelligent wheelchair. Our approach has a user-centered perspective, in which the needs and limitations of physically impaired users are given extensive attention at each stage of the design process. Finally, our design was evaluated through a public opinion assessment. A statistical analysis suggested that the design was effective to mitigate the visual and ergonomic impacts caused by the addition of sensorial and processing capabilities on the wheelchair. © 2013 IEEE.

2013

Upper limb automatisms differ quantitatively in temporal and frontal lobe epilepsies

Authors
Silva Cunha, JPS; Remi, J; Vollmar, C; Fernandes, JM; Gonzalez Victores, JA; Noachtar, S;

Publication
EPILEPSY & BEHAVIOR

Abstract
We quantitatively evaluated the localizing and lateralizing characteristics of ictal upper limb automatisms (ULAs) in patients with temporal lobe epilepsy (TLE; n = 38) and frontal lobe epilepsy (FLE; n = 20). Movement speed, extent, length, and duration of ULAs were quantitatively analyzed with motion capturing techniques. Upper limb automatisms had a larger extent (p < 0.001), covered more distance (p < 0.05), and were faster (p < 0.001) in FLE than in TLE. In TLE, the maximum speed of ULAs was higher ipsilaterally than contralaterally (173 vs. 84 pixels/s; p = 0.02), with no significant difference in FLE (511 vs. 428). The duration of ictal automatisms in relation to the total seizure duration was shorter in TLE than in FLE (median 36% vs. 63%; p < 0.001), with no difference in the absolute duration (26 s vs. 27 s). These results demonstrate that quantitative movement analysis of ULAs differentiates FLE from TLE, which may aid in the localization of the epileptogenic zone.

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