12 research outputs found
Energy-aware peering routing protocol for indoor hospital body area network communication
The recent research in Body Area Networks (BAN) is focused on making its communication more reliable, energy efficient, secure, and to better utilize system resources. In this paper we propose a novel BAN network architecture for indoor hospital environments, and a new mechanism of peer discovery with routing table construction that helps to reduce network traffic load, energy consumption, and improves BAN reliability. We have performed extensive simulations in the Castalia simulation environment to show that our proposed protocol has better performance in terms of reduced BAN traffic load, increased number of successful packets received by nodes, reduced number of packets forwarded by intermediate nodes, and overall lower energy consumption compared to other protocols
Algorithms for Transmission Power Control in Biomedical Wireless Sensor Networks
Abstract—Wireless sensor networks are increasingly being used for continuous monitoring of patients with chronic health conditions such as diabetes and heart problems. As biomedical sensor nodes become more wearable, their battery sizes dimin-ish, necessitating very careful energy management. This paper proposes feedback-based closed-loop algorithms for dynamically adjusting radio transmit power in body-worn devices, and evalu-ates their performance in terms of energy savings and reliability as the data periodicity and feedback time-scales vary. Using experimental trace data from body worn devices, we first show that the performance of dynamic power control is adversely affected at long data periods. Next for a given data period we show that modifying the transmit power at too long time-scales (around a minute) reduces the efficacy of dynamic power control, while too short a time-scale (few seconds or less) incurs a high feedback signaling overhead. We therefore advocate an intermediate range of time-scales (when permitted by the data periodicity), typically in the few tens of seconds, at which the control algorithms should adapt transmit power in order to achieve maximal energy savings in body-worn sensor devices used for medical monitoring. I
Smart system for children's chronic illness monitoring
[EN] Sick children need a continuous monitoring, but this involves high costs for the government and for the parents. The use of information and communication technologies (ICT) jointly with artificial intelligence and smart devices can reduce these costs, help the children and assist their parents. This paper presents a smart architecture for children's chronic illness monitoring that will let the caregivers (parents, teachers and doctors) to remotely monitor the health of the children based on the sensors embedded in the smartphones and smart wearable devices. The proposed architecture includes a smart algorithm developed to intelligently detect if a parameter has exceeded a threshold, thus it may imply an emergency or not. To check the correct operation of this system, we have developed a small wearable device that is able to measure the heart rate and the body temperature. We have designed a secure mechanism to stablish a Bluetooth connection with the smartphone. In addition, the system is able to perform the data fusion in both the information packetizing process, which contributes to improve the protocol performance, and in the measured values combination, where it is used a stochastic approach. As a result, our system can fusion data from different sensors in real-time and detect automatically strange situations for sending a warning to the caregivers. Finally, the consumed bandwidth and battery autonomy of the developed device have been measured.This work has been partially supported by the "Ministerio de EducaciOn, Cultura y Deporte", through the "Ayudas para contratos predoctorales de Formacion del Profesorado Universitario FPU (Convocatoria 2014)". Grant number FPU14/02953.Sendra, S.; Parra-Boronat, L.; Lloret, J.; Tomás Gironés, J. (2018). Smart system for children's chronic illness monitoring. Information Fusion. 40:76-86. https://doi.org/10.1016/j.inffus.2017.06.002S76864
Experiments in Adaptive Power Control for Truly Wearable Biomedical Sensor Devices
Emerging body-wearable devices for continuous health monitoring are severely energy constrained and yet re-quired to offer high communication reliability under fluctu-ating channel conditions. Such devices require very careful management of their energy resources in order to prolong their lifetime. In our earlier work we had proposed dynamic power control as a means of saving precious energy in off-the-shelf sensor devices. In this work we experiment with a real body-wearable device to assess the power savings pos-sible in a realistic setting. We quantify the power consump-tion against the packet loss and establish the feasibility of dynamic power control for saving energy in a truly-body-wearable setting. 1
Skip Trie Matching for Real-Time OCR Output Error Corrrection on Smartphones
Many Visually Impaired individuals are managing their daily activities with the help of smartphones. While there are many vision-based mobile applications to identify products, there is a relative dearth of applications for extracting useful nutrition information. In this report, we study the performance of existing OCR systems available for the Android platform, and choose the best to extract the nutrition facts information from U.S grocery store packages. We then provide approaches to improve the results of text strings produced by the Tesseract OCR engine on image segments of nutrition tables automatically extracted by an Android 2.3.6 smartphone application using real-time video streams of grocery products. We also present an algorithm, called Skip Trie Matching (STM), for real-time OCR output error correction on smartphones. The algorithm’s performance is compared with Apache Lucene’s spell checker. Our evaluation indicates that the average run time of the STM algorithm is lower than Lucene’s. (68 pages
Physical Context Detection using Wearable Wireless Sensor Networks
This paper presents the architecture of a wearable sensor network and a Hidden Markov Model (HMM) processingframework for stochastic identification of body postures andphysical contexts. The key idea is to collect multi-modal sensor data from strategically placed wireless sensors over a human subject’s body segments, and to process that using HMM in order to identify the subject’s instantaneous physical context. The key contribution of the proposed multi-modal approach is a significant extension of traditional uni-modal accelerometry in which only the individual body segment movements, without their relative proximities and orientation modalities, is used for physical context identification. Through real-life experiments with body mounted sensors it is demonstrated that while the unimodal accelerometry can be used for differentiating activityintensive postures such as walking and running, they are not effective for identification and differentiation between lowactivity postures such as sitting, standing, lying down, etc. In the proposed system, three sensor modalities namely acceleration, relative proximity and orientation are used for context identification through Hidden Markov Model (HMM) based stochastic processing. Controlled experiments using human subjects are carried out for evaluating the accuracy of the HMMidentified postures compared to a naïve threshold based mechanism over different human subjects
Systems and WBANs for Controlling Obesity
According to World Health Organization (WHO) estimations, one out of five adults worldwide will be obese by 2025. Worldwide obesity has doubled since 1980. In fact, more than 1.9 billion adults (39%) of 18 years and older were overweight and over 600 million (13%) of these were obese in 2014. 42 million children under the age of five were overweight or obese in 2014. Obesity is a top public health problem due to its associated morbidity and mortality. This paper reviews the main techniques to measure the level of obesity and body fat percentage, and explains the complications that can carry to the individual's quality of life, longevity and the significant cost of healthcare systems. Researchers and developers are adapting the existing technology, as intelligent phones or some wearable gadgets to be used for controlling obesity. They include the promoting of healthy eating culture and adopting the physical activity lifestyle. The paper also shows a comprehensive study of the most used mobile applications and Wireless Body Area Networks focused on controlling the obesity and overweight. Finally, this paper proposes an intelligent architecture that takes into account both, physiological and cognitive aspects to reduce the degree of obesity and overweight
Remote vital signs monitoring based on wireless sensor networks
Tese de doutoramento em Líderes para as Indústrias TecnológicasGovernmental and private institutions face a major challenge to provide quality
health care to a population consisting of a growing number of elderly and chronically ill
patients. According to the World Health Organization, in 2006, the total global health
expenditures exceeded US$ 4 trillion and are rising in the majority of countries
including Portugal which, during 2006, expended 9.9% of its gross domestic product in
health care.
The use of remote vital signs monitoring systems increases the probability of early
detection of risky situations, allows frequent monitoring of in-patients, elderly and
chronically ill patients, and streamlines the work of health professionals. However, at
present, these systems are expensive, complex and employ obtrusive sensors, which
limit their application to intensive care units and cardiac intermediate care units.
This work is part of a project that aims to design, prototype and evaluate a remote
vital signs monitoring system based on the IEEE 802.15.4 and ZigBee protocols, which
allow the development of small low-power sensors. The prototype system comprises
electrocardiogram/heart rate and axillary thermometer sensors, networking devices and
three informatics applications that collect, process, and exhibit medical data.
The wireless sensors, the networking devices and one of the applications were
developed under this work. Additionally, the wireless sensor network was evaluated
through simulations at the MAC level and experimental and field tests. Field tests were
performed at an in-patient floor of Hospital Privado de Guimarães, a Portuguese
hospital. Finally, questionnaires were used to measure the satisfaction of users and
catalog their critics and suggestions for improvement. Simulations considered different topologies, operation modes and a crescent
number of sensors and hops. Experimental and field tests confirmed most of the results
obtained by simulations, but revealed that networks which did not assign transmission
time slots to electrocardiogram sensors were unable to maintain a high delivery ratio.
Contention between devices, aggravated by the inability of routers in receiving
incoming packets during backoff, and collisions between packets generated by hiddennodes
were responsible for most message losses. On the other hand, beacon-enabled star
IEEE 802.15.4 networks that assigned a guaranteed time slot to sensors were able to
maintain a very high delivery ratio. In contrast, these networks are restricted in terms of
the coverage area and the number of sensors. Also, field tests showed that under low
traffic scenarios ZigBee nonbeacon-enabled networks can achieve a high delivery ratio
even in presence of a high percentage of hidden-nodes.Instituições governamentais e privadas enfrentam um grande desafio para prestar
cuidados de saúde de qualidade a uma população constituída por um número crescente
de idosos e doentes crónicos. Segundo a Organização Mundial de Saúde, em 2006, a
despesa mundial em saúde ultrapassou a quantia de 4 bilhões de dólares americanos e
cresce anualmente na maioria dos países, incluindo Portugal, o qual, em 2006, gastou
9,9% do seu produto interno bruto em cuidados de saúde.
O uso de sistemas de monitorização remota de sinais vitais aumenta a probabilidade
de deteção precoce de situações de risco, permite que doentes internados, idosos ou
doentes crónicos sejam frequentemente monitorizados e agiliza o trabalho dos
profissionais de saúde. No entanto, atualmente, estes sistemas são caros e complexos, o
que limita a sua aplicação a alguns setores dos hospitais, tais como as unidades de
cuidados intensivos e as unidades de cuidados intermédios na área da cardiologia.
O projeto no qual insere-se este trabalho visa a conceção, a prototipagem e a
avaliação de um sistema de monitorização remota de sinais vitais com base nos
protocolos IEEE 802.15.4 e ZigBee, os quais oferecem a possibilidade de construção de
sensores com consumos energéticos muito baixos e reduzidas dimensões. O sistema
consiste em sensores de eletrocardiograma/frequência cardíaca e temperatura axilar,
dispositivos de rede e três aplicações que coletam, processam e apresentam o
eletrocardiograma e os sinais vitais.
No âmbito deste trabalho foram desenvolvidos os sensores sem fios, os dispositivos
de rede e uma das aplicações informáticas. Além disso, foi feita a avaliação do
desempenho da rede de sensores sem fios através da análise de simulações a nível da
camada de acesso ao meio (MAC) e de testes de laboratório e de campo. Os testes de campo da rede de sensores sem fios foram executados em um dos pisos de internamento
do Hospital Privado de Guimarães. Finalmente, foram usados questionários para medir
a satisfação dos utilizadores e recolher críticas e sugestões de melhoria.
As simulações consideraram diferentes topologias e modos de operação, além de
um número crescente de sensores e saltos. Testes experimentais e de campo
confirmaram grande parte dos resultados obtidos por simulação mas, adicionalmente,
revelaram que as redes constituídas por vários sensores de eletrocardiograma e que não
reservaram um intervalo de tempo de transmissão aos sensores não foram capazes de
manter uma elevada taxa de entrega de mensagens. Perdas de mensagens ocorreram
devido a disputas entre sensores pelo acesso ao canal sem fios e devido a ocorrência de
colisões de pacotes transmitidos por nós escondidos. Por outro lado, as redes baseadas
no protocolo IEEE 802.15.4 que atribuíram um intervalo de tempo de transmissão a
cada sensor conseguiram manter uma elevada taxa de entrega. Entretanto, essas redes
são limitadas em termos da área de cobertura e do número de sensores. Adicionalmente,
durante os testes de campo em cenários de tráfego reduzido, as redes ZigBee que não
empregaram beacons atingiram uma elevada taxa de entrega mesmo na presença de uma
grande percentagem de nós escondidos