Luís Alexandre Rocha

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This paper presents LPRT, a new medium access control (MAC) protocol for wireless sensing and actuation systems. Some of the characteristics of the proposed protocol are low power consumption, support for real-time and loss intolerant traffic through contention-free operation and a retransmission scheme, flexibility, and high throughput efficiency. The LPRT(More)
BACKGROUND Postural stability analysis has shown that postural control is impaired in untreated idiopathic Parkinson's disease (IPD), even in the early stages of the disease. Vascular Parkinson's disease (VPD) lacks consensus clinical criteria or diagnostic tests. Moreover, the levodopa effect on postural balance remains undefined for IPD and even less so(More)
A test technique for capacitive MEMS accelerometers and electrostatic microactuators, based on the measurement of pull-in voltages and resonance frequency, is described. Using this combination of measurements, one can estimate process-induced variations in the device layout dimensions as well as deviations from nominal value in material properties, which(More)
The medical sector, similarly to other industries such as the aviation industry, has to comply with multiple regulations, guidelines and standards. In addition, there are multiple definitions for the expression 'medical device', and before entering the market, manufacturers must demonstrate their product's safety and effectiveness. In such a complex and(More)
BACKGROUND Postural stability requires the integration of multisensory input information and translation into appropriate motor responses. Surprisingly, few previous studies have addressed the role of auditory input on postural stability in healthy subjects, and none has investigated this in Alzheimer's disease (AD). OBJECTIVE To assess the influence of(More)
Models are abstract representations of reality that are built, analyzed and manipulated to augment the understanding of that reality. They can either be mental or codified but, in both cases, they contribute to good decision-making by ensuring that the right people use the right information at the right time. In order to reduce time to market, companies(More)
Postural control is a complex dynamic mechanism, which integrates information from visual, vestibular and somatosensory systems. Idiopathic Parkinson's disease (IPD) patients are unable to produce appropriate reflexive responses to changing environmental conditions. Still, it is controversial what is due to voluntary or involuntary postural control, even(More)
BACKGROUND The cause of frequent falls in patients with Alzheimer's disease (AD) is still not well understood. Nevertheless, balance control and sensory organization are known to be critical for moving safely and adapting to the environment. METHODS We evaluated postural stability in 20 AD patients (11 fallers and 9 nonfallers) and 16 healthy controls(More)
A wireless smart-suit network for monitoring body kinetics, heart and respiratory rate during hidrocinesiotherapy sessions is presented. Sensing modules composed by 3-axis accelerometers, 3-axis magnetometers and interface electronics are used to monitor the body kinetics. Heart rate is measured using an ear clip infrared sensor and respiratory frequency is(More)
The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and(More)