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dos Santos M.P.S.,University of Aveiro | Ferreira J.A.F.,University of Aveiro | Ramos A.,University of Aveiro | Pascoal R.,University of Aveiro | And 7 more authors.
Communications in Computer and Information Science | Year: 2013

The development of smart orthopaedic implants is being considered as an effective solution to ensure their everlasting life span. The availability of electric power to supply active mechanisms of smart prostheses has remained a critical problem. This paper reports the first implementation of a new concept of energy harvesting systems applied to hip prostheses: the multi-source generation of electric energy. The reliability of the power supply mechanisms is strongly increased with the application of this new concept. Three vibration-based harvesters, operating in true parallel to harvest energy during human gait, were implemented on a Metabloc TM hip prosthesis to validate the concept. They were designed to use the angular movements on the flexion-extension, abduction-adduction and inward-outward rotation axes, over the femoral component, to generate electric power. The performance of each generator was tested for different amplitudes and frequencies of operation. Electric power up to 55 μJ/s was harvested. The overall function of smart hip prostheses can remain performing even if two of the generators get damaged. Furthermore, they are safe and autonomous throughout the life span of the implant. © Springer-Verlag Berlin Heidelberg 2013.


Lopes J.,Vodafone | Sargento S.,University of Aveiro | Sargento S.,Telecommunications Institute of Portugal | Zuquete A.,University of Aveiro | And 2 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The Spanning Tree Protocol (STP) is known to have stability problems and poor convergence intervals. Several protocols and variants exist targeting the replacement of STP variants, most of them proprietary and with limited scope of operation. The recent protocols, IETF TRILL and IEEE SPB, target mainly data center networks, are based on complex concepts, require great processing power from switches and huge investment in new gear. In this paper we propose Self-Configurable Switches Protocol (SCS) as an alternative to all these protocols. It has the following advantages: it is configuration-free, thus less vulnerable to human mistakes; it enhances the network stability and performance when comparing with STP; and it is suitable to the range of equipment and networks that typically run STP variants, minimizing the need for potential large investments required by TRILL and SPB. This paper describes the main characteristics, processes and mechanisms of SCS, presents some lab and simulation experiments with STP and SCS, and provides demonstrations that SCS provides a more reliable service than STP variants, and a more cost effective alternative to TRILL and SPB network dependability. © 2013 Springer-Verlag.


Ribeiro D.M.D.,Institute of Electronics and Telematics Engineering of Aveiro | Fu L.S.,University of Aveiro | Carlos L.A.D.,University of Aveiro | Cunha J.P.S.,University of Aveiro
IEEE Sensors Journal | Year: 2011

In this paper, we describe the design, implementation and testing of a dry active flexible electrode with a novel interface material for wearable biosignal recording. The new interface material takes the form of a gel and is highly bendable and comfortable on the wearer's skin. A comparison between common Ag/AgCl and our dry active electrode was performed on seven healthy volunteers. The presented prototype was designed for ECG signals but this technology can be modified for other biosignals. Our results show that the new dry active electrode presents better electrical characteristics than the common Ag/AgCl electrode, namely less power-line interference and better response in the signal band. We can conclude that our novel dry active flexible electrode outperforms the traditional Ag/AgCl wet electrode with the advantages of being dry and comfortable. Some future applications of this bio device are discussed. © 2011 IEEE.


Silva S.,University of Aveiro | Silva S.,Institute of Electronics and Telematics Engineering of Aveiro | Madeira J.,University of Aveiro | Madeira J.,Institute of Electronics and Telematics Engineering of Aveiro | And 3 more authors.
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS | Year: 2011

Multiple detector row computed tomography (MDCT) cardiac angiography provides a large amount of data concerning multiple cardiac phases which are not often considered. Segmentation is a first step towards exploring how this additional data can be used to perform left ventricle functional analysis or myocardial perfusion assessment. We present preliminary results regarding the assessment of inter-observer variability for a semi-automatic (multi-phase) segmentation tool for the left-ventricle. © 2011 IEEE.


Soares Dos Santos M.P.,University of Aveiro | Ferreira J.A.F.,University of Aveiro | Ramos A.,University of Aveiro | Simoes J.A.O.,University of Aveiro | And 8 more authors.
Expert Review of Medical Devices | Year: 2014

This paper reviews instrumented hip joint replacements, instrumented femoral replacements and instrumented femoral fracture stabilizers. Examination of the evolution of such implants was carried out, including the detailed analysis of 16 architectures, designed by 8 research teams and implanted in 32 patients. Their power supply, measurement, communication, processing and actuation systems were reviewed, as were the tests carried out to evaluate their performance and safety. These instrumented implants were only designed to measure biomechanical and thermodynamic quantities in vivo, in order to use such data to conduct research projects and optimize rehabilitation processes. The most promising trend is to minimize aseptic loosening and/or infection following hip or femoral replacements or femoral stabilization procedures by using therapeutic actuators inside instrumented implants to apply controlled stimuli in the bone-implant interface. © 2014 Informa UK Ltd.

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