8 research outputs found
Fully printed, stretchable and wearable bioimpedance sensor on textiles for tomography
No full textElectrical impedance tomography (EIT) is a non-invasive, real-time, continuous imaging technique that has multiple applications in health care. EIT is a realizable technique for radiation-free medical imaging ranging from real-time monitoring of bone fracture repair to lung functioning. This work explores the prospect of printing a wearable bioimpedance sensor on textiles for EIT imaging. Screen printing and stencil printing were applied to fabricate the sensor on the textile substrate and the imaging was carried out with the worn sensor on the human body. The first part of this work focuses on developing a flexible textile sensor in the form of a bracelet to obtain cross-sectional images of the forearm that unravel bone features like shape, size and position. However, body parts such as the thorax have added complexities due to their constantly varying perimeter and uneven shape. It is a significant prerequisite for the wearable sensors to apply to dynamic body parts where irregular shape and continuous volume variations occur. The second part of the paper therefore addresses the fabrication and testing of a stretchable textile-based sensor to address such instances of body dynamicity. The proposed stretchable sensor, worn on the thorax, demonstrates the feasibility of imaging such an uneven and dynamic body part. Although the EIT images are inherently attributed to low resolution, this work shows the prospect of wearable imaging applications in health monitoring. Apart from demonstrating the printed sensor for EIT imaging, this paper shows the image rendering quality dependency over the frequency of the signal and the number of electrodes. This work could initiate further research on wearable EIT based health monitoring devices for real-life scenarios.This work is funded by the BIOMAT project which is carried out under Interreg V-A grensregio Vlaanderen - Nederland and is supported by the European Union and The European Regional Development Fund and with financial support of province of Limburg - Belgium. The authors would like to thank Professor Jan D'Haen from Hasselt University for providing SEM images.Deferme, W (corresponding author), Hasselt Univ, Inst Mat Res IMO IMOMEC 1, B-3590 Diepenbeek, Belgium ; IMEC VZW, Div IMOMEC, Wetenschapspk 1, B-3590 Diepenbeek, Belgium.
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Contributing WPs: WP1 Author(s) : H. de Groot, M. van Hartskamp, P. van der Stok (Philips)
No full textThis document describes the main scenarios for the BETSY project divided over the home environment and a hot spot. Afterwards the technical requirements are derived in chapter 5, limiting the scope of the project, but still including the important aspects for our research. We have written down detailed requirements for the network, the mobile devices involved and the coding characteristics of the content in our scenarios. Main conclusions are that the BETSY focus will be on 802.11a/b/g networks, point-topoint and multicast communication, including handovers. A maximum number of three video streams at the same time within one AP are considered. Special attention will be paid to the timing requirements in the case of user input that leads to changes in the number of streams or reconfiguration of existing streams. For the video coding format certain specific types of MPEG-4 scalable coding, sometimes compared with the currently popular MPEG-2 format, will be taken into account. For the mobile devices we will only take into account devices, which have the possibility of doing power management, as energy reduction is one of the project goals. Several possible hardware/software platforms to do the verification of the theoretical results were investigated, but the actual decision which platform to use will only be made at the start of WP4, in order to take the latest developments into account. The requirements derived, will be used as input to WP2 and WP3, defining their playground, while we will iterate and finally implement (a part of) the scenarios defined in this document in WP4. The scenarios will also be used to validate the found proposed solutions later
Monitoring Body Fluids in Textiles: Combining Impedance and Thermal Principles in a Printed, Wearable, and Washable Sensor
No full textThis work explores the feasibility of coupling two different techniques, the impedance and the transient plane source (TPS) principle, to quantify the moisture content and its compositional parameters simultaneously. The sensor is realized directly on textiles with the use of printing and coating technology. Impedance measurements use the fluid's electrical properties, while the TPS measurements are based on the thermal effusivity of the liquid. Impedance and TPS measurements show equal competency in measuring the fluid volume with a lowest measurable quantity of 0.5 mu L, enabling ultralow volume passive measurements for sweat analysis. Both sensor principles were tested by monitoring the drying of a wet cloth and the measurements show perfect repeatability and accuracy. Nevertheless, when the biofluid property changes, the TPS sensor does not reflect this information on its readings, whereas, on the other hand, impedance can provide information on compositional changes. However, since the volume of the fluid changes simultaneously, one cannot differentiate between a volume change and a compositional change from impedance measurements alone. Therefore, we show in this work that we can apply impedance to measure the compositional properties; meanwhile, the TPS measurements accurately carry out volume measurements irrespective of the interferences from its compositional variations. To prove this, both of these techniques are applied for the quantification and composition monitoring of sweat, showing the capability to measure moisture content and compositional parameters simultaneously. TPS measurements can also be an indicator of the local temperature of the medium confined by the sensor, and it does not influence the fluid parameters. Compiling both impedance and thermal sensors in a single platform triggers smart wearable prospects of metering the liquid volume and simultaneously analyzing other compositional changes and body temperature. Finally, the repeatability and stability of the sensor readings and the washability of the device are tested. This device could be a potential sensing tool in real-life applications, such as wound monitoring and sweat analysis, and could be a promising addition toward future smart wearable sensors.Deferme, W (corresponding author), Hasselt Univ, Inst Mat Res IMO IMOMEC 1, B-3590 Diepenbeek, Belgium ; IMEC, Div IMOMEC, B-3590 Diepenbeek, Belgium.
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The BETSY project on timeliness and energy aspects of wireless video streaming M. Sénéclauze, J-D Decotignie (CSEM), P. van der Stok, H. de Groot, M. van Hartskamp, G. van
No full textThe BETSY project focuses on the seamless adaptation of multimedia streams on wireless hand-held devices to fluctuating network conditions and available terminal resources. Consequently, the user can enjoy true multimedia experiences with freedom of movement in a networked home or at any hot-spot. A stream model is developed during the project to optimize the energy consumption and satisfy the timeliness constraints and optimize the energy consumption. The project is in its first 8 months. The initial stream model that is the basis of further work is described and motivated
