Search results for " wireless"
showing 10 items of 200 documents
Design of a Programmable and Modular Neuromuscular Electrical Stimulator Integrated Into a Wireless Body Sensor Network
2021
Neuromuscular electrical stimulation finds application in several fields, from basic neurophysiology, to motor rehabilitation and cardiovascular conditioning. Despite the progressively increasing interest in this technique, its State-of-the-Art technology is mainly based on monolithic, mostly wired devices, leading to two main issues. First, these devices are often bulky, limiting their usability in applied contexts. Second, the possibility of interfacing these stimulation devices with external systems for the acquisition of electrophysiological and biomechanical variables to control the stimulation output is often limited. The aim of this work is to describe the design and development of a…
The effect of body shape and gender on wireless Body Area Network on-body channels
2010
Technological advancements have made possible the emergence of Body Area Networks (BANs). There are numerous on-body channel characterizations in the literature performed on a phantom or a single human subject. In this paper, using multiple subjects, we consider the effect of body shape and gender on the on-body channel. A characterization of a narrowband on-body to on-body channel among different subjects is presented. The paper investigates the relationship between the propagation and the subject's physical characteristics. The investigation is performed at 2360 MHz; the new medical band undergoing FCC approval. Our results show that the path loss in women is less than that in men and the…
Demystifying the Possibilities of ICT4D in the Mountain Regions of Nepal
2011
Author's version of a chapter in the book: Proceedings of the 44th Hawaii International Conference on System Sciences. Also available from the publisher at: http://dx.doi.org/10.1109/HICSS.2011.142 Despite the substantial investments in ICT4D projects in developing countries, the benefits are yet to be realised by the majority of remote communities. Inaccessibility to ICT has widened educational, healthcare, information, and communication gaps between urban and remote communities. This paper focuses on an interpretive case study in Nepal to widen our understanding of how locally-initiated ICT4D projects may help to narrow these gaps. The study utilises the Assets Pentagon Model to identify …
Novel Wireless Sensor System for Dynamic Characterization of Borehole Heat Exchangers
2011
The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE) is presented. The system, by means of two specials valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the…
Adaptive Collision Avoidance through Implicit Acknowledgments in WSNs
2008
The large number of nodes, typical of many sensor network deployments, and the well-known hidden terminal problem make collision avoidance an essential goal for the actual employment of WSN technology. Collision avoidance is traditionally dealt with at the MAC Layer and plenty of different solutions have been proposed, which however have encountered limited diffusion because of their incompatibility with commonly available devices.In this paper we propose an approach to collision avoidance which is designed to work over a standard MAC Layer, namely the IEEE 802.15.4 MAC, and is based on application-controlled delays of packet transmission times. The proposed scheme is simple, decentralized …
Cooperative RTS/CTS MAC with relay selection in distributed wireless networks
2009
This paper proposes a cooperative multiple access protocol based on the Distributed Coordination Function (DCF) Request-To-Send/Clear-To-Send (RTS/CTS) scheme for distributed wireless networks. It answers three key questions concerning cooperation from the network perspective, namely when to cooperate, whom to cooperate with and how to protect cooperative transmissions. According to our protocol, the cooperation is initiated only if the direct transmission fails. An optimal relay node is selected in a distributed manner according to instantaneous relay channel conditions without prior information or extra signaling among relay candidates in the network. An additional three-way handshake is …
Revisit of RTS/CTS Exchange in High-Speed IEEE 802.11 Networks
2005
IEEE 802.11 medium access control (MAC), called distributed coordination function (DCF), provides two different access modes, namely, 2-way (basic access) and 4-way (RTS/CTS) handshaking. The 4-way handshaking has been introduced in order to combat the hidden terminal phenomenon. It has been also proved that such a mechanism can be beneficial even in the absence of hidden terminals, because of the collision time reduction. We analyze the effectiveness of the RTS/CTS access mode, in current 802.11b and 802.11a networks. Since the rates employed for control frame transmissions can be much lower than the rate employed for data frames, the assumption on the basis of the 4-way handshaking introd…
A circularly polarized wideband high gain patch antenna for wireless power transfer
2018
This article deals with a microstrip patch antenna working at 868 MHz, suitable for the radio frequency wireless power transfer and energy harvesting applications. The proposed monolithic antenna is compact, lightweight and it is printed on a thick substrate in order to maximize the total gain in the broadside direction. The antenna radiates at 868 MHz with a fractional impedance bandwidth of 5% and it shows a gain of 4.14 dB.
HLPV Identication in wireless ad hoc networks
2013
Hybrid systems are dynamical systems consisting of components with con- tinuous and discrete behavior and thus they have required a new hybrid systems and control theory that has been developed in the past years and is still an active research topic. Motivated by a practical example, the tra c ow in wireless ad hoc network model, we derive Hybrid LPV modeling and identi cation techniques. Finally we show simulation results of o line identi cation and possible future algorithms.
Development and characterization of xyloglucan-poly(vinyl alcohol) hydrogel membrane for wireless smart wound dressings
2018
Research which addresses advanced wound management can contribute to the needs of modern healthcare, especially in situations that require continuous monitoring, analysis, responsive therapeutic treatments and data recording. The development of “smart” bandages and dressings that can remotely monitor relevant parameters for the wound healing process without a hospital intervention can be very useful tools for patients and physicians and for advancing the understanding of the healing process. In the present work, biocompatible xyloglucan/poly(vinyl alcohol) hydrogels are being developed as smart wound dressings that, in addition to the traditional favorable properties of hydrogels as skin ca…