In this paper, we propose the design of a low-power wireless sensor network architecture that enables robust communications inside offshore wind turbines. This research work is in the scope of the WATEREYE EU Project, where we have designed a corrosion monitoring solution to work unattended. The architecture is composed of several fixed sensor nodes, one mobile sensor node, several anchors and the WATEREYE Computer (WEC). Our approach is based on Impulse Radio Ultra wideband (IR-UWB) technology offering reliable and low-power communications in these harsh environments. On top of that, we propose a double star network using two UWB channels for the following purposes: one network for communications to send the sensor data and another one for ranging estimations to calculate the indoor positioning of the mobile sensor node. The power strategies applied to our system, at Hardware (HW) and Firmware (FW) levels, are described in detail. Furthermore, we present power consumption measurements obtaining the power profiles and the autonomy of the most important components of the proposed architecture supplied by battery. On the other hand, we describe the methodology to analyze the range, reliability and continuity of the two UWB links providing the packet loss and gaps as a function of distance. The proposed communications system has been validated in three different scenarios considering two of them very hostile environments. Furthermore, one of the scenarios is a real offshore wind turbine.
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New advances in biosensor and electronic technologies will merge in new health assistance paradigms strongly based on the remote biomonitoring. Biomedical circuit and systems have much to say on this, as for example the Central Venous Catheters (CVC). Central venous catheters are commonly used in clinical practice to improve a patient's quality of life. Nevertheless, there remains a large risk of infection associated with microbial biofilm (about 80% of all human bacterial infections). The standardization bodies, the radiofrequency devices and the biosensor technology are taking their positions, and the integration of all that effort is the work proposed in this paper. An ultra-low power active medical implant is presented for in-body monitoring of Electrical BioImpedance (EBI) based sensors with a new 3-D antenna. Transmission test and detailed evaluation have been done based on two typical monitoring parameters: the frequency of the internal sensor measuring and the frequency of external communication requests. The results show up to 20 months lifetime powered with a 50 mA coin-cell battery. (C) 2014 Elsevier Masson SAS. All rights reserved.
STUDIES IN HEALTH TECHNOLOGY AND INFORMATICS
Portable systems and global communications open a broad spectrum for new health applications. In the framework of electrophysiological applications, several challenges are faced when developing portable systems embedded in Cloud computing services. In order to facilitate new developers in this area based on our experience, five areas of interest are presented in this paper where strategies can be applied for improving the performance of portable systems: transducer and conditioning, processing, wireless communications, battery and power management. Likewise, for Cloud services, scalability, portability, privacy and security guidelines have been highlighted.