Global ETD Search

1	A Novel Technique for Creating Useful Estimates of Human Body Mechanics from Simple Digital Video Thompson, Craig M 09 April 2011 (has links) This document contains the results of an experiment conducted in the Biomechanics Research Laboratory at the University of Miami. Vicon motion capture data are used as a baseline for comparing values generated by an innovative motion capture technique using digital video analysis and other software packages. Marker locations, knee angle, ankle angle, knee moment and ankle moment values were produced by each system. The values show statistically significant differences, however if used as an estimator, digital analysis can be of great value. Possible applications for the use of the innovative video analysis technique are discussed. Methods for improving the accuracy and precision of the digital video motion analysis technique are outlined. video analysis Vicon Dartfish estimates body mechanics motion analysis
2	Saving Our Backs: Reducing Low Back Forces, Investigating Pain, and Observing Multifidus Larson, Robert Eugene 15 July 2020 (has links) BACKGROUND: Healthcare workers are among the most injured workers in the United States. This is due to the high rate of patient handling. The low back is the most injured in this population. This study observed biomechanical factors and how these factors affect low back and ground reaction forces. This study further investigated pain and its relationship to low back force, multifidus cross-sectional area, and multifidus activation in healthcare workers. METHODS: The 45 participants included 10 healthy subjects in the preliminary study and 35 active healthcare workers in the main study. Subjects filled out the VAS to determine current pain level. Ultrasound images of the multifidus muscles were taken. The participants were fitted with reflective markers and surface EMG sensors. A series of patient transfers at various bed heights using three different transfer devices was undertaken. The transfer devices included a Cotton sheet, a Skil-Care™ Transfer Sling, and an AirPal® device. RESULTS: There was a downward trend in resultant low back force when comparing lower bed heights to higher. Therefore, the highest bed position was determined to be optimal. There were significant differences in low back force between self-chosen and optimal bed heights among healthcare workers. There was no significant difference between peak low back or ground reaction forces between pain and nonpain groups. There was a significant difference in multifidus cross-sectional area between these groups at S1, a trend toward significance at L5, and no difference at L4. There was a trend toward significance when comparing multifidus activation between these groups as recorded by surface EMG. CONCLUSIONS: Healthcare workers should choose higher bed heights and appropriate equipment to reduce low back force and those who have smaller multifidus have more pain. sheets nurse posture body mechanics multifidus patient handling Life Sciences
3	ANALYSIS OF THE EFFECTS OF AN OCCUPATIONAL THERAPY BASED HEALTH PROMOTION AND INJURY PREVENTION PROGRAM FOR REGISTERED NURSES LAMBERS, STEPHANIE DALEY 11 October 2001 (has links) No description available. Education, Health body mechanics back discomfort stress management
4	Characterization of Quasi-Periodic Orbits for Applications in the Sun-Earth and Earth-Moon Systems Brian P. McCarthy (5930747) 17 January 2019 (has links) <div>As destinations of missions in both human and robotic spaceﬂight become more exotic, a foundational understanding the dynamical structures in the gravitational environments enable more informed mission trajectory designs. One particular type of structure, quasi-periodic orbits, are examined in this investigation. Speciﬁcally, eﬃcient computation of quasi-periodic orbits and leveraging quasi-periodic orbits as trajectory design alternatives in the Earth-Moon and Sun-Earth systems. First, periodic orbits and their associated center manifold are discussed to provide the background for the existence of quasi-periodic motion on n-dimensional invariant tori, where n corresponds to the number of fundamental frequencies that deﬁne the motion. Single and multiple shooting diﬀerential corrections strategies are summarized to compute families 2-dimensional tori in the Circular Restricted Three-Body Problem (CR3BP) using a stroboscopic mapping technique, originally developed by Howell and Olikara. Three types of quasi-periodic orbit families are presented: constant energy, constant frequency ratio, and constant mapping time families. Stability of quasi-periodic orbits is summarized and characterized with a single stability index quantity. For unstable quasi-periodic orbits, hyperbolic manifolds are computed from the diﬀerential of a discretized invariant curve. The use of quasi-periodic orbits is also demonstrated for destination orbits and transfer trajectories. Quasi-DROs are examined in the CR3BP and the Sun-Earth-Moon ephemeris model to achieve constant line of sight with Earth and avoid lunar eclipsing by exploiting orbital resonance. Arcs from quasi-periodic orbits are leveraged to provide an initial guess for transfer trajectory design between a planar Lyapunov orbit and an unstable halo orbit in the Earth-Moon system. Additionally, quasi-periodic trajectory arcs are exploited for transfer trajectory initial guesses between nearly stable periodic orbits in the Earth-Moon system. Lastly, stable hyperbolic manifolds from a Sun-Earth L<sub>1</sub> quasi-vertical orbit are employed to design maneuver-free transfer from the LEO vicinity to a quasi-vertical orbit.</div> Aerospace Engineering aerospace engineering trajectory trajectory design astrodynamics three body three body mechanics circular restricted three body problem CR3BP quasi-periodic orbits periodic orbits orbit mechanics celestial mechanics dynamical systems dynamical systems theory dynamics applications orbits astronautics differential corrections invariance invariant circle invariant torus torus invariant tori stroboscopic mapping manifolds Sun-Earth system Earth-Moon system stability multiple shooting stroboscopic map eclipse avoidance vertical orbit halo orbit distant retrograde orbit quasi-halo quasi-vertical lissajous quasi-DRO DRO NRHO quasi-NRHO synodic resonance trajectory arcs mission design astromechanics spaceflight mechanics dynamical structures

1

Page generated in 0.0892 seconds