Heart rate variability (HRV) and music have been demonstrated to have a relationship in previous literature. The primary objective of this study is to further investigate that relationship by observing HRV during periods of listening to relaxing and exciting music and comparing the results to a baseline as well as the other condition. The secondary objective of this study is to investigate the efficacy and potential usage of the Polar H10 chest strap monitor in measuring HRV parameters. The results of the Polar H10 will be compared to the iWorx TA-220 and iWorx-ECG12, the existing gold standard in HRV and ECG recording. The data will be exported to Matlab and Excel and analyzed to see if particular types of music display any trends for these HRV parameters, as well as heart rate (HR). Polar data will be gathered and analyzed using the EliteHRV app. Analysis included Fast Fourier Transform (FFT), Low Frequency/High Frequency Ratio (LF/HF), standard deviation of NN intervals (SDNN). Data was gathered in 10 minute intervals of No Music, Relaxing Music, Exciting Music. Results showed notable changes in LF/HF ratio in both directions. SDNN and Mean RR interval had moderate decreases in both relaxing and exciting music, with Total Power having a significant decrease in both. Comparison of Polar H10 and iWorx-ECG data showed strong agreement in heart rate and RR interval data, but significant differences in other data. This suggests differences in calculation by the software used.

A 2 cm ostectomy was performed on 10 pairs of canine cadaveric humeri proximal to the supratrochlear foramen. Stabilization was with a double plate construct (DB-PLATE) (n=10) or external skeletal fixator with intramedullary pin tie-in configuration (ESF-IMP) (n=10). Cyclic testing was performed. Axial compressive load to failure testing followed. Data analyzed included dynamic stiffness, stiffness and yield load. No constructs failed during cyclic testing or lost stiffness over time, although mean dynamic stiffness was greater for DB-PLATE compared to ESF-IMP. Mean stiffness of DB-PLATE in load-toailure testing was not significantly different than ESF-IMP. Yield force of DB-PLATE was significantly higher than ESF-IMP. These results suggest that both DB-PLATE and ESF-IMP would be appropriate fixation techniques for stabilization of comminuted supracondylar humeral fractures in dogs with appropriate exercise restriction. Double plate fixation may be preferable when prolonged healing or inadequate post-operative restraint was anticipated because it was stronger in destructive testing.

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found that most of these factors are directly or indirectly linked to subjects’ BMI (body mass index). Thus, from a statistical perspective, BMI could be an overall indicator of the probability of femur fracture from a sideways fall. Using a biomechanics approach coupled with statistical data we investigate this relationship with a large cohort of postmenopausal women aged 50-79 from WHI-OS (Women’s Health Initiative Observational Cohort). The cohort is divided into six sub-cohorts by BMI where each fall-related factor is examined and compared with each other. Significant differences are discovered among cohorts in terms of femur size, aBMD (areal bone mineral density), peak fall force based on kinematics, and maximum von Mises stresses induced in the proximal femur. Through a probabilistic margin of safety approach which has been recently applied to orthopedic application, we found the margin of safety predicted probability to be decreasing faster with increasing BMI and better v fitted with medical record of the identical cohort compared to that found using a deterministic risk factor approach. To promote the application in other situations, tumor damaged femur bones are examined and tested for possible stress concentration effect in terms of probability of failure. The influence of tumor lesion turned out to be size and location sensitive. The superior side of the femoral neck has the highest stress concentration effect from tumor lesion where a 4mm diameter lesion could result in a 1.7 times greater maximum von Mises stress and 2.95 times greater probability of failure.

<p> The present study develops a foot model to improve segment power estimates in the vertical jump. Modifications to the traditional foot model included the addition of a forefoot segment to allow for power flow across the metatarsal-phalangeal joint, and a re-definition of the ankle joint position to decrease foot segment length variability. The foot model was evaluated by comparison of the total segment power (TSP) with the rate of change of energy (RCE) of the foot segment. Pearson's correlation coefficients and percent root mean square (% RMS) error were used to compare curves. </p> <p> Power flow analysis was performed on a counter-movement jump (CMJ) and a squat jump (SQJ) for each of 8 male and 8 female subjects. Both a 4-Link and a 5-Link, sagittal plane, link-segment model were used to calculate the joint and muscle powers. </p> <p> The combination of both modifications to the traditional foot model (i.e. 5-Link(ankle) model), resulted in dramatic improvements for the match between the TSP and RCE. When comparing the traditional model with the 5-Link(ankle) model for the CMJ, correlation coefficients improved from -0.46 to 0.92 for the male group and from -0.50 to 0.77 for the female group. The %RMS error decreased from 380.5% to 35.4% for the male group and from 466.9% to 71.6% for the female group. SQJ improvements were similar. </p> <p> Ankle joint position re-definition succeeded in compensating for foot segment length changes in most cases, and indicates that a single point can be located to act as a hinge joint between the foot and leg segments throughout the vertical jump motion. Improvements associated with the addition of a forefoot segment to the traditional linksegment model indicate that substantial power flow occurs through the metatarsal-phalangeal joint during vertical jump motions. </p> / Thesis / Master of Science (MSc)

The goal of this thesis is to use biomechanical data describing shoulder motion to determine optimal parameters to assist in the design of a 5 DOF active shoulder exoskeleton. This thesis will provide a proof of concept on optimization techniques using motion data using a simplified 3 DOF model to facilitate future work implementing a full 5 DOF model. Optimization will be performed to determine the link lengths and, consequently, the locations of the joints of the exoskeleton by considering the human's workspace to maximize range of motion and promote user safety by minimizing collisions of the exoskeleton with the user and with the exoskeleton itself. The thesis will detail the development of computational models of the human and proposed exoskeleton, the processing of experimental data used to estimate the human's capabilities, optimization, and future work. This work will contribute to a large-scale NSF-funded project of building an upper body exoskeleton emulator. The emulator will promote the widespread adoption of exoskeletons in industry by providing a test-bed to streamline the rapid design of various assistance profiles for various users and tasks. / Master of Science / An exoskeleton is a robotic assistive device used in industrial and rehabilitative settings. This thesis will use data describing how the human shoulder moves during certain tasks to help design an exoskeleton to assist with theses tasks. A model of the human shoulder and a model of the exoskeleton will be developed and used in an optimization to figure out the best dimensions of the exoskeleton links to support the human's movements.

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<div>As aging proceeds, the occurrence of cardiovascular diseases increases independent of other risk factors. At atherosclerotic sites, the rise in the senescent cell population was also observed. Patients with Hutchinson Gilford Progeria Syndrome (HGPS) also showed accelerated aging syndromes and extensive atherosclerosis progression, which was due to missense mutations on the LMNA gene that led to the production of progerin, an aberrant lamin A isoform instead of regular lamin A protein. Lamins act as structural and functional components in nuclear lamina, and recent findings suggested that the ectopic expression of mutant lamin A or lamin A precursor (prelamin A) not only caused defects in cell mechanics but also disturbed mechanotransduction pathways involving lamin A, both of which may contribute to vascular dysregulation. Moreover, the observation of the accumulation of prelamin A in normal aged vascular cells further suggests shared dysregulations involving lamin A in the vascular system between aged people and HGPS patients.</div><div>In the vascular system, endothelial cells were well regulated by hemodynamic forces in vivo to maintain vascular homeostasis. Endothelial dysfunction, including impaired vasodilation and increased permeability, was regarded as the initial marker of atherosclerosis. Despite recent advancements and discussions about the potential mechanisms of progerin-induced vascular disorders, how progerin triggers endothelial dysfunction in a mechanical environment as an early event during atherosclerotic lesion formation has not been studied intensively.</div><div>To help answer the gap question, we first set our goal to understand the effect of laminar flow at arterial levels on endothelial lamins as part of the aging process. Spatial and temporal changes in lamin A/C expression were observed as cell passage went up without flow present. As shear stress was applied, lamin A/C expressions were modulated on both transcriptional and translational levels, which were also dependent on PDL. To further examine how progerin was involved in EC functions with a particular focus on the flow effects, we next generated a stable endothelial cell line that expressed progerin as our EC aging model. Endothelial wound repair under laminar flow at different rates was characterized, and differential cell proliferation activities, as well as migration deficiencies in progerin-expressing ECs during the process, were also recognized. Furthermore, we also showed the overactivated mTORC2 pathway and unusual actin polymerization activities in these cells after flow application. Our results reported changes in cell migration by progerin with flow application for the first time and provided potential candidate pathways that were disturbed by progerin under arterial flow, which may help explain the high occurrence of atherosclerotic lesions in HGPS vasculature, even at straight portion. The reported progerin-induced wound recovery defects in endothelial cells in the presence of physiological flow may also suggest a mechanism of how progerin disturbs endothelial integrity and functions under mechanical stimuli in the development of vascular pathologies.</div><div>Further extended studies may help to understand the roles of progerin in initiating atherosclerosis, which will aid in the development of potential therapies for those suffering from prelamin A-associated accelerated aging syndromes.</div>