Integrating sensor streams in pHealth networks

Personal Health (pHealth) sensor networks are generally used to monitor the wellbeing of both athletes and the general public to inform health specialists of future and often serious ailments. The problem facing these domain experts is the scale and quality of data they must search in order to extract meaningful results. By using peer-to-peer sensor architectures and a mechanism for reducing the search space, we can, to some extent, address the scalability issue. However, synchronisation and normalisation of distributed sensor streams remains a problem in many networks. In the case of pHealth sensor networks, it is crucial for experts to align multiple sensor readings before query or data mining activities can take place. This paper presents a system for clustering and synchronising sensor streams in preparation for user queries

Association of objectively measured physical activity with vascular endothelial function in male adolescents

Purpose: Cardiovascular disease (CVD) begins in childhood primarily due to exposure to lifestyle-mediated risk factors such as inactivity and low cardiorespiratory fitness (CRF). Endothelial dysfunction is one of the earliest events in the development of CVD. Self-reported light intensity physical activity (LIPA) is positively associated with endothelial function (EF) in adolescents. The purpose of this study was to examine the relation between objectively measured physical activity (PA) and EF in healthy male adolescents. Methods: Low (n=8, VO2max = 40.4 ± 2.3 mL.kg1.min-1), moderate CRF (n=12,VO2max = 54.6 ± 3.9 mL.kg1.min-1) and high CRF (n=15, VO2max = 63.7 ± 4.0 mL.kg1.min-1) healthy males (mean age 15.77 ± 0.4; yr) participated in the study. High-resolution ultrasonography was used to assess endothelial dependent (EDD) in response to brachial artery flow mediated dilation. Participants wore a tri-axial ActivPAL accelerometer for 6 days. Total time spent in sitting, standing, LIPA, moderate-vigorous PA (MVPA) and steps per day was calculated using previously published methodology (Dowd et al., 2012). Results: EDD was significantly lower in low CRF than the high CRF group. Steps per day were significantly lower in low CRF (9251 ± 4113) than high CRF group (14007 ± 3176) (p<0.005). Time in sitting was significantly higher in low CRF than high CRF group (p<0.028). MVPA was significantly lower in low CRF than high CRF group (p<0.01). There was no significant difference in standing and LIPA between the groups. There was a significant positive relation between steps per day and % change (r=0.54, p<0.001) and absolute change in EDD (r= 0.60, p<0.001). Sitting was inversely related to % change (r=-0.497, p< 0.002) and absolute change in EDD (r=-0.49, p<0.003). There was a significant positive relation between MVPA and % change (r=0.47, p<0.005) and absolute change in EDD (r=0.57 p<0.000). Conclusion: There was a significant difference in steps per day, time spent sitting and in MVPA between low CRF and high CRF. MVPA was positively associated with EF in healthy adolescent males

Textile-based wearable sensors for assisting sports performance

There is a need for wearable sensors to assess physiological signals and body kinematics during exercise. Such sensors need to be straightforward to use, and ideally the complete system integrated fully within a garment. This would allow wearers to monitor their progress as they undergo an exercise training programme without the need to attach external devices. This takes physiological monitoring into a more natural setting. By developing textile sensors the intelligence is integrated into a sports garment in an innocuous manner. A number of textile based sensors are presented here that have been integrated into garments for various sports applications

Cardiorespiratory fitness and vascular health in youth

CVD refers to disease of the heart and blood vessels and is the leading cause of mortality in Ireland. CVD Begins in childhood and adolescence due primarily to exposure to lifestyle mediated risk factors . Endothelail dysfunction, induced by CVD risk factors, is one of the earliest events in the development of CVD and precedes structural changes in the artery walll such as intima media thickness. Exercise training has been shown to restrore endothelial function (EF), decrease carotid intima media thickness (cIMT) and improve CV risk profile in obese children. There is currently no research that has examined subclinical atherosclerotic CVD in asympomatic adolescents with low and high cardiorepsiratory fitness (CRF). This study compared CVD risk factors, cIMT and EF in adolescent boys with low and high CRF and examined the relation between CRF and cIMT and CRF and FMD in asympomatic adolescent boys. It was hypothesised that boys with a high CRF would have a healthier CV profile and that there would be an inverse relation between CRF and cIMT and CRF and EF

Querying XML data streams from wireless sensor networks: an evaluation of query engines

As the deployment of wireless sensor networks increase and their application domain widens, the opportunity for effective use of XML filtering and streaming query engines is ever more present. XML filtering engines aim to provide efficient real-time querying of streaming XML encoded data. This paper provides a detailed analysis of several such engines, focusing on the technology involved, their capabilities, their support for XPath and their performance. Our experimental evaluation identifies which filtering engine is best suited to process a given query based on its properties. Such metrics are important in establishing the best approach to filtering XML streams on-the-fly

Synchronizing sensed data in team sports

In this article we will be discussing the synchronization of sensor data in team sports. Synchronization allows us to use more expressive queries, to query across all participants in a given activity and to potentially discover new knowledge from the semantically enriched data. A collaborative research effort between groups working on data management and on health and human performance (both at Dublin City University) involved a series of experiments using wearable sensors during team games and the capture and querying of sensed dat

Using sensor networks to measure intensity in sporting activities

The deployment of sensor networks is both widespread and varied with more niche applications based on these networks. In the case study provided in this work, the network is provided by two football teams with sensors generating continuous heart rate values for the duration of the activity. In wireless networks such as these, the requirement is for complex methods of data management in order to deliver more and more powerful query results. In effect, what is required is a traditional database-style query interface where domain experts can continue to probe for the answers required in more specialised environments. This paper describes a system and series of experiments that requires powerful data management capabilities to meet the requirements of sports scientists

Cardiorespiratory fitness, oxygen uptake efficency slope and endothelial function in male adolescents

Cardiorespiratory fitness (CRF) is a independent risk factor for CVD and all-cause mortality. Maximal oxygen uptake (VO2max), is considered the gold standard measurement of CRF. Due to its effort dependency, a true plateau in VO2 during incremental exercise is often not attained, particularly in overweight and obese pediatric populations 1. The oxygen uptake efficiency slope (OUES) has been proposed as an objective and effort independent submaximal measure of cardiopulmonary reserve. Studies in healthy and obese children have reported a strong positive relation between OUES and VO2max. Children with high CRF have higher OUES values than those with low CRF 2. Furthermore, improvements in CRF following exercise training, are associated with restoration of endothelial function (EF) in obese children 3. The purpose of this study was to examine the relation between OUES, VO2max and EF in healthy male adolescents. ad

Effect of lower body negative pressure on physiological, perceptual and affective responses during self regulated exercise

Purpose: Lower body negative pressure (LBNP) treadmill exercise was developed for health maintenance during periods of microgravity. It involves exercising on a treadmill within a waist-high pressure chamber connected to a pump. LBNP treadmill exercise generates a pressure differential between the upper and lower body increasing ground reaction forces (GRFs). This study compared the physiological, perceptual and affective responses in women during 30 min of self-regulated treadmill walking with and without LBNP

A wearable electrochemical sensor for the real-time measurement of sweat sodium concentration

We report a new method for the real-time quantitative analysis of sodium in human sweat, consolidating sweat collection and analysis in a single, integrated, wearable platform. This temporal data opens up new possibilities in the study of human physiology, broadly applicable from assessing high performance athletes to monitoring Cystic Fibrosis (CF) sufferers. Our compact Sodium Sensor Belt (SSB) consists of a sodium selective Ion Selective Electrode (ISE) integrated into a platform that can be interfaced with the human body during exercise. No skin cleaning regime or sweat storage technology is required as the sweat is continually wicked from the skin to a sensing surface and from there to a storage area via a fabric pump. Our results suggest that after an initial equilibration period, a steady-state sodium plateau concentration was reached. Atomic Absorption Spectroscopy (AAS) was used as a reference method, and this has confirmed the accuracy of the new continuous monitoring approach. The steady-state concentrations observed were found to fall within ranges previously found in the literature, which further validates the approach. Daily calibration repeatability (n 1⁄4 4) was +/- 3.0% RSD and over a three month period reproducibility was +/- 12.1% RSD (n 1⁄4 56). As a further application, we attempted to monitor the sweat of Cystic Fibrosis (CF) sufferers using the same device. We observed high sodium concentrations symptomatic of CF ($60 mM Na+) for two CF patients, with no conclusive results for the remaining patients due to their limited exercising capability, and high viscosity/low volume of sweat produced