71,757 research outputs found

    Effect of Tilt Sensor versus Heel Loading on Neuroprosthesis Stimulation Reliability and Timing for Individuals Post-Stroke during Level and Non- Level Treadmill Walking

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    Study background: Non-level walking may adversely affect stimulation of neuroprostheses as initial programming is performed during level walking. The objectives of this study were to assess stimulation reliability of tilt and heel sensor-based neuroprosthesis stimulation during level and non-level walking, examine stimulation initiation and termination timing during level and non-level walking, and determine whether heel or tilt sensor-based stimulation control is more robust for non-level ambulation. Methods: Eight post-stroke individuals with drop foot who were able to actively ambulate within the community were selected for participation. Each subject acclimated to the neuroprosthesis and walked on a treadmill randomly positioned in inclined, level and declined orientations. The primary measures of interest were stimulation reliability and timing. Results: Statistically significant differences in tilt, but not heel, sensor-based stimulation reliability were observed between level and non-level walking trials. Tilt sensor-based stimulation initiation occurred significantly closer to swing as the treadmill processed from declined to inclined orientations. No statistically significant differences in stimulation reliability or timing were observed between theoretical heel versus clinical tilt sensor-based stimulation control. Discussion and conclusions: Tilt sensor-based stimulation reliability may be adversely affected by non-level walking. Differences in stimulation initiation timing with tilt sensor-based control during non-level walking may be advantageous as stimulation initiation closer to swing during inclined ambulation may allow for greater ankle plantar flexion to assist with forward progression. Despite a lack of significant differences in stimulation reliability or timing between sensors, theoretical heel sensor-based stimulation control exhibited more consistent stimulation timing with less variability than for tilt sensor-based stimulation during non-level ambulation

    Light-direction sensor based on birefringency

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    Optical system consisting of polarizer, analyzer, quarterwave retarder converts incident light beam to one which has an intensity related to the extent the incident beam is off axis

    A Comparison of Video and Accelerometer Based Approaches Applied to Performance Monitoring in Swimming.

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    The aim of this paper is to present a comparison of video- and sensor based studies of swimming performance. The video-based approach is reviewed and contrasted to the newer sensor-based technology, specifically accelerometers based upon Micro-Electro-Mechanical Systems (MEMS) technology. Results from previously published swim performance studies using both the video and sensor technologies are summarised and evaluated against the conventional theory that upper arm movements are of primary interest when quantifying free-style technique. The authors conclude that multiple sensor-based measurements of swimmers’ acceleration profiles have the potential to offer significant advances in coaching technique over the traditional video based approach

    Glucose sensor based on the LUQUEN-principle

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    A new type of glucose sensor based on luminescence quenching (LUQUEN) is proposed. In this LUQUEN principle the concentration induced quenching is enlarged by radiationless (excited-state) energy transfer within the luminescent material. We describe the integrated optical detection part and the chemo-optical interface, in which the concentration induced optical changes are based on the binding of glucose. Some experiments on the internal energy transfer are reported, and the results are discussed

    Anti Collision Sensor Based Blind Stick

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    Visually impaired people find difficulties detecting obstacles in front of them, during walking in the street, which makes it dangerous. The smart stick comes as a proposed solution to enable them to identify the world around. In this paper we propose a solution, represented in a smart stick with ultrasonic sensor to detect any other obstacles in front, left and right of the user, within a range of four meters. Moreover, another sensor is placed at the bottom of the stick for the sake of avoiding puddles. The vibration of motor is activated when any obstacle is detected. The blind stick is integrated with ultrasonic sensor along with GPS ampGSM based Navigation/Tracking system. This proposed system uses the microcontroller ATmega 328 embedded system. The stick is capable of detecting all obstacles in the range 4 meter during 39 ms and gives a suitable respect message empowering blind to move twice his normal speed because she/he feels safe. The smart stick is of low cost, fast response, low power consumption, light weight

    Testing of hydrogen sensor based on organic materials

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    Práce je zaměřena na problematiku bezpečnostních vodíkových senzorů. Základní principy a teorie vodíkových senzorů je rozebrána v první části práce. Je navržena metodologie testování organických vodíkových senzorů vyvinutých a vyrobených na Fakultě Chemické Vysokého Učení Technického v Brně. Nejslibnější organický material byl testován. V závěrečné části byl navržen teplotní regulátor pro použití s keramickou senzorovou platformou.This thesis is focused on topic of safety hydrogen sensors. Theory of hydrogen sensors and main sensor principles are discussed. Methodology for testing of organic hydrogen sensors developed and fabricated at the Faculty of Chemistry of Brno University of Technology is outlined. A set of tests is done for the most promising organic material. Also, temperature regulator for ceramic sensor platform is designed.
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