1,720,969 research outputs found
Real time Reader Device for Blind People
No full text[110316.EG Anno 2007 (non 2010): Lecture Notes in Computer Science, 2007, Volume 4694/2007, 292-299, DOI: 10.1007/978-3-540-74829-8_36
In-vivo monitoring for electrical expression of plant living parameters by an impedance lab system
Full text linkWe present a complete in-lab system to monitor the plant and its surrounding environment. The plant impedance is directly measured in a continuous manner, while, simultaneously surrounding environment parameters known to affect plant status, are monitored. This is done combining a new in-vivo direct measurement of the plant together with an embedded system using available sensor technology and a designated interface for continuous data acquisition. Furthermore, the next versions this system can be deployed as a field monitoring device, with simple adaptations
Miniaturised Wireless Power Transfer Systems for Neurostimulation: A Review
Full text linkIn neurostimulation, wireless power transfer is an efficient technology to overcome several limitations affecting medical devices currently used in clinical practice. Several methods were developed over the years for wireless power transfer. In this review article, we report and discuss the three most relevant methodologies for extremely miniaturised implantable neurostimulator: ultrasound coupling, inductive coupling and capacitive coupling. For each powering method, the discussion starts describing the physical working principle. In particular, we focus on the challenges given by the miniaturisation of the implanted integrated circuits and the related ad-hoc solutions for wireless power transfer. Then, we present recent developments and progresses in wireless power transfer for biomedical applications. Last, we compare each technique based on key performance indicators to highlight the most relevant and innovative solutions suitable for neurostimulation, with the gaze turned towards miniaturisation
Assessing the feasibility of augmenting fall detection systems by relying on UWB-based position tracking and a home robot
Full text linkFalls in the home environment are a primary cause of injury in older adults. According to the U.S. Centers for Disease Control and Prevention, every year, one in four adults 65 years of age and older reports experiencing a fall. A variety of different technologies have been proposed to detect fall events. However, the need to detect all fall instances (i.e., to avoid false negatives) has led to the development of systems marked by high sensitivity and hence a significant number of false alarms. The occurrence of false alarms causes frequent and unnecessary calls to emergency response centers, which are critical resources that should be utilized only when necessary. Besides, false alarms decrease the level of confidence of end-users in the fall detection system with a negative impact on their compliance with using the system (e.g., wearing the sensor enabling the detection of fall events). Herein, we present a novel approach aimed to augment traditional fall detection systems that rely on wearable sensors and fall detection algorithms. The proposed approach utilizes a UWB-based tracking system and a home robot. When the fall detection system generates an alarm, the alarm is relayed to a base station that utilizes a UWB-based tracking system to identify where the older adult and the robot are so as to enable navigating the environment using the robot and reaching the older adult to check if he/she experienced a fall. This approach prevents unnecessary calls to emergency response centers while enabling a tele-presence using the robot when appropriate. In this paper, we report the results of a novel fall detection algorithm, the characteristics of the alarm notification system, and the accuracy of the UWB-based tracking system that we implemented. The fall detection algorithm displayed a sensitivity of 99.0% and a specificity of 97.8%. The alarm notification system relayed all simulated alarm notification instances with a maximum delay of 106 ms. The UWB-based tracking system was found to be suitable to locate radio tags both in line-of-sight and in no-line-of-sight conditions. This result was obtained by using a machine learning-based algorithm that we developed to detect and compensate for the multipath effect in no-line-of-sight conditions. When using this algorithm, the error affecting the estimated position of the radio tags was smaller than 0.2 m, which is satisfactory for the application at hand
Live Wire - A Low-Complexity Body Channel Communication System for Landmark Identification
Full text linkThis paper presents a robust simplex Body Channel Communication (BCC) system aimed at providing an interactive infrastructure solution for visually impaired people. Compared to existing BCC solutions, it provides high versatility, weara- bility and installability in an environment in a low complexity hardware-software solution. It operates with a ground referred transmitter (TX) and it is based on an asynchronous thresh- old receiver (RX) architecture. Synchronization, demodulation and packetizing and threshold control are completely software defined and implemented using MicroPython. The RX includes Bluetooth® (BT) radio connectivity and a cell-phone application provides push text-to-speech notifications to a smartphone. The hardware achieves a Packet Error Rate (PER) of ∼0.1 at 550 kHz pulse center frequency, Synchronized-On Off Keying (S- OOK) modulation and 1 kbps data rate, for an average current consumption of 44mA
Development of a Partial Power DC/DC Converter Based on Buck-Boost Topology for Battery Parallelization Systems
No full textBattery parallelization enables the use of second-life electric vehicle batteries and low-cost battery technology in energy storage systems for smart grid applications. Partial power DC/DC converters can connect batteries in parallel with higher efficiency compared to traditional AC/DC and DC/DC converters thanks to their reduced power requirements. This work presents the design and the implementation of a scaled prototype of a partial power DC/DC converter based on the buck-boost topology. The prototype was characterized achieving efficiencies from 84.1% to 93.2% for different output power levels. The characterization of the implemented DC/DC converter allowed us to develop an accurate model. This model will enable us to gain a deeper understanding of battery parallelization in stationary energy storage applications
Optimal Sizing of PCB Coils for Lithium-Ion Cell Dilation Measurement
No full textLithium-ion batteries are widely used, but accurate estimation of their state of charge and state of health is still an open issue. Integrating chemical and physical sensor data with electrical measurements can improve the estimation algorithms and foster the early detection of destructive failures. One-dimensional dilatometry systems based on the eddy currents principle represent low-cost and promising solutions to measure the dilation of the cells caused by charging operations and health degradation phenomena. These systems are based on a simple inductance-to-digital converter that measures the inductance of a PCB coil to evaluate the distance between the coil and a target. These devices require an accurate design since the coil sizing strongly influences the measurement accuracy. This work aims to optimize the design of the coil considering different parameters, notably the shape, the trace width, and the internal filling of the spiral
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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