The purpose of this study was to investigate empirically how lever length and its axis of rotation position influences human performance during lever wheelchair propulsion. In order to fulfill this goal, a dedicated test stand allowing easy implementation of various lever positions was created. In the experiment, 10 young, healthy, male subjects performed 8 tests consisting of propulsion work with levers of different lengths and lever axis of rotation positions. During tests heart rate, oxygen consumption and EMG assessment of 6 muscles was carried out. Measurements of power output on the test stand were done as well. Together with oxygen consumption analysis, this allowed calculation of human work efficiency. The results show significant (p<0.05 and p<0.001) differences between lever configurations when comparing various parameters values. From the carried out experiments, the authors conclude that levers' length and their axis of rotation position significantly influence human performance during lever wheelchair propulsion. For the examined subjects, placing the levers' axis of rotation close behind the back wheels axis of rotation offered advantageous work conditions.
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http://dx.doi.org/10.1016/j.jelekin.2015.06.007 | DOI Listing |
Am J Orthod Dentofacial Orthop
January 2025
Department of Orthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. Electronic address:
Introduction: The objective of this study was to evaluate the effects of the miniplate application sites in the maxilla and the applied force vector changes during skeletally supported facemask application in adolescent patients with unilateral cleft lip and palate (UCLP) using finite element model (FEM) analysis.
Methods: A FEM was obtained from a cone-beam computed tomography image of a 12-year-old female patient with UCLP. Miniplates were placed on 3 different sites of the maxilla; 500 g of advancement force was applied bilaterally, parallel (0°), and downward (-30°) to the occlusal plane.
Artif Organs
January 2025
BioCirc Research Laboratory, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA.
Background: Safe and effective pediatric blood pumps continue to lag far behind those developed for adults. To address this growing unmet clinical need, we are developing a hybrid, continuous-flow, magnetically levitated, pediatric total artificial heart (TAH). Our hybrid TAH design, the Dragon Heart (DH), integrates both an axial flow and centrifugal flow blood pump within a single, compact housing.
View Article and Find Full Text PDFSensors (Basel)
December 2024
College of Aerospace and Engineering, National University of Defense Technology, Changsha 410073, China.
Due to a short flight time, the dual-axis rotational inertial navigation system carried by some launch vehicles or missiles is often only used for self-calibration and self-alignment. It is generally in the strap-down state rather than the rotation modulation state during flight. This wastes the precision potential of the navigation system.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Guangxi Key Laboratory of Machine Vision and Intelligent Control, Wuzhou University, Wuzhou 543000, China.
A high-quality optical path alignment is essential for achieving superior image quality in optical biological microscope (OBM) systems. The traditional automatic alignment methods for OBMs rely heavily on complex masker-detection techniques. This paper introduces an innovative, image-sensor-based optical path alignment approach designed for low-power objective (specifically 4×) automatic OBMs.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Fraunhofer Institute for Machine Tools and Forming Technology IWU, Nöthnitzer Straße 44, 01187 Dresden, Germany.
Using a newly developed tool head with an additional rotational axis and a wire feed, wires can be directly processed in the fused filament fabrication (FFF) process. Thus, electrical structures such as conductive paths, coils, heating elements, or sensors can be integrated into polymer parts. However, the accuracy of the wire deposition in curved sections of the print track is insufficient.
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