Biomechanical Engineering Commons^™

Solid Lubrication Bearing Design Through Analytical And Empirical Vibration Analysis Of Characteristic Frequencies, Christopher A. Schultz

Master's Theses (2009 -)

Ball bearings with solid lubrication lack the damping mechanisms of oil and produce well-defined vibration characteristics based upon given geometry and speed of operation. This work takes advantage of the high signal to noise ratio in x-ray bearings and develops an algorithm to statistically track bearing performance based upon fundamental bearing theory, Monte Carlo simulation, Order Analysis, and Weibull statistics. The technique gathers vibration data solely related to the theoretical operation of a bearing, negates the background noise, and provides descriptive vibration amplitude statistics of individual bearing components for evaluation. The practical implications of the thesis described herein allow the …

Validation Of Open Chain Model During Kinematic Analysis Of Joint Mobilization Of The Foot: An In Vitro Study, Anthony Ross Mcnally

Mechanical & Aerospace Engineering Theses & Dissertations

Joint mobilization techniques have been shown to improve dorsiflexion range of motion after ankle injury in multiple in vivo studies; however, the underlying arthrokinematic effects of this treatment still require clarification. Therefore, the purpose of this preliminary study was to determine the viability of an open kinetic chain in vitro model for applying Maitland Grade III anterior/posterior joint mobilizations to the talocrural joint while examining the osteokinematic and arthrokinematic changes at the talocrural, subtalar and hindfoot joints. Three fresh frozen cadaver lower legs had Maitland Grade III anterior-to-posterior joint mobilization applied to the talocrural joint in 2 sessions of 200 …

An Experimental Study On Passive Dynamic Walking, Philip Andrew Hatzitheodorou

USF Tampa Graduate Theses and Dissertations

In this study, a previously designed passive dynamic walker (PDW) is built out of aluminum and plastic. The aim of the study was to produce an asymmetrical PDW and to compare the results to a computer simulation to validate the mathematical model. It also aimed at identifying the limitations of using additive manufacturing to create components for a PDW as well as gain insights on asymmetric systems.

Beginning with a five mass kneed model, parameters were varied to produce up to a nine mass kneed model solution. The nine mass model allows more variability in added mass locations and separates …

Advantages Of A Finite Extensible Nonlinear Elastic Potential In Lattice Boltzmann Simulations, Tai-Hsien Wu, Dewei Qi

The Hilltop Review

A new structure, generalized lattice nonlinear spring model (GLNSM), which adopts non-linear FENE-LJ potential instead of harmonic potential, has been coupled with lattice Boltzmann simulation for solving fluid-solid interaction problem. In this article, a significant work is the relationship between the GLNSM (FENE-LJ potential) and Young’s modulus has been described in detail. A validation has also been presented to prove that GLNSM is reliable.

Inverse-Consistent Determination Of Young's Modulus Of Human Lung, Behnaz Seyfi Noferest

Electronic Theses and Dissertations

Human lung undergoes respiration-induced deformation due to sequential inhalation and exhalation. Accurate determination of lung deformation is crucial for tumor localization and targeted radiotherapy in patients with lung cancer. Numerical modeling of human lung dynamics based on underlying physics and physiology enables simulation and virtual visualization of lung deformation. Dynamical modeling is numerically complicated by the lack of information on lung elastic behavior, structural heterogeneity as well as boundary constrains. This study integrates physics-based modeling and image-based data acquisition to develop the patient-specific biomechanical model and consequently establish the first consistent Young's modulus (YM) of human lung. This dissertation has …

Computational Modeling Of Cardiac Biomechanics, Amir Nikou

Theses and Dissertations--Mechanical and Aerospace Engineering

The goal of this dissertation was to develop a realistic and patient-specific computational model of the heart that ultimately would help medical scientists to better diagnose and treat heart diseases. In order to achieve this goal, a three dimensional finite element model of the heart was created using magnetic resonance images of the beating pig heart. This model was loaded by the pressure of blood inside the left ventricle which was measured by synchronous catheterization. A recently developed structurally based constitutive model of the myocardium was incorporated in the finite element solver to model passive left ventricular myocardium. Additionally, an …

Morphology Of Brain Sulci Trabeculae And Its Effect On Brain During Impacts, Sharlin Anwar

Dissertations and Theses

Traumatic brain injury (TBI) is an intracranial injury caused by direct contact or non-contact head impacts to the brain. TBI is a major problem that accounts for high incidents of hospitalizations each year. Thus, it is important to understand and predict the occurrence of TBI in an impact. It has been shown that the subarachnoid space (SAS) trabeculae play an important role in damping the effect of an impact, thus reducing the injuries. However, the influence of sulci parameters and the sulci trabeculae in TBI due to impact is unexplored. Studies have shown that inclusion of sulci in brain models …

Anthropomorphic Robotic Ankle-Foot Prosthesis With Active Dorsiflexion- Plantarflexion And Inversion-Eversion, Evandro Ficanha

Dissertations, Master's Theses and Master's Reports

The main goal of the research presented in this paper is the development of a powered ankle-foot prosthesis with anthropomorphic characteristics to facilitate turning, walking on irregular grounds, and reducing secondary injuries on bellow knee amputees. The research includes the study of the gait in unimpaired human subjects that includes the kinetics and kinematics of the ankle during different types of gait, in different gait speeds at different turning maneuvers. The development of a robotic ankle-foot prosthesis with two active degrees of freedom (DOF) controlled using admittance and impedance controllers is presented. Also, a novel testing apparatus for estimation of …

Prosthetic Thermal Management Device, Garrett Dowd

Williams Honors College, Honors Research Projects

High temperatures in lower-limb prosthetics can lead to poor user skin conditions and mechanical slippage between the user’s limb and the prosthetic. This report presents an air-cooling device for a lower-limb prosthesis. This device’s purpose is to maintain a constant skin-prosthesis interface temperature. A compact heat sink and small fan were used to transfer the bio-heat to the ambient surroundings. By changing the power of the fan, the thermal resistance of the whole system can be adjusted to match various thermal loads and environmental temperatures. Heat pads were used to mimic the heat generation of a residual limb, and cooling …

2015 Afrl University Design Challenge, Daniel Slattery, Andrew P. Killmeyer, Brandon Null, Brendan Jones, Casey Hale, Jake Stein, Jeff Quartermaine, Kevin Rolik, Nick Tsangeos, Sam Moats, Marisa Seeley

Williams Honors College, Honors Research Projects

The University of Akron’s Air Force Research Laboratory’s Design Challenge Team has engineered a Heat Stress Prevention Kit that includes a facial mask in which the soldier will cool down from the inside out by breathing in the cool air circulating throughout the mask. This cool air is produced from a thermoelectric chip, which has a specific temperature difference on either side, one hot and one cold. Each of the sides is isolated from one another and with the combination of heat sinks, fans, and the simple process of breathing, a system is created by inhaling cool air. The entire …

Design And Implementation Of An Interactive Animatronic System For Guest Response Analysis, Brian Burns

College of Graduate Studies: Theses & Dissertations

In theme park based entertainment applications, there is a need for interactive, autonomous animatronic systems to create engaging and compelling experiences for the guests. The animatronic figures must identify the guests and recognize their status in dynamic interactions for enhanced acceptance and effectiveness as socially interactive agents, in the general framework of human-robot interactions. The design and implementation of an interactive, autonomous animatronic system in form of a tabletop dragon and the comparisons of guest responses in its passive and interactive modes are presented in this work. The dragon capabilities include a four degrees-of-freedom head, moving wings, tail, jaw, blinking …

Probabilistic Musculoskeletal Simulation Methods To Address Intersegmental Dependencies Of The Knee, Hip, And Spine, Casey A. Myers

Electronic Theses and Dissertations

Orthropaedic clinical practice in the area of the knee, hip, and spine has benefited from the concept of regional interdependence, where interventions applied to one region can influence the outcome and function of other regions of the body that may be seemingly unrelated to the applied intervention. An understanding of the biomechanical mechanisms that describe clinical practice involving knee, hip, and spine regional interdependence can improve treatment of a wide range of pathological conditions. Improvement in this area can be particularly impactful on the outcomes of patients with total joint replacement, where pathology and compensatory strategies develop during multi-joint interactions. …

Computational Modeling To Assess Surgical Procedures For The Treatment Of Adult Acquired Flatfoot Deformity, Brian A. Smith

Theses and Dissertations

Several surgically corrective procedures are considered to treat Adult Acquired Flatfoot Deformity (AAFD) patients, relieve pain, and restore function. Procedure selection is based on best practices and surgeon preference. Recent research created patient specific models of Adult Acquired Flatfoot Deformity (AAFD) to explore their predictive capabilities and examine effectiveness of the surgical procedure used to treat the deformity. The models’ behavior was governed solely by patient bodyweight, soft tissue constraints, and joint contact without the assumption of idealized joints. The current work expanded those models to determine if an alternate procedure would be more effective for the individual. These procedures …

A Microstructural Constitutive Framework For Injured Ligament, Christina J. Stender, Evan Rust, Raquel J. Brown, Trevor J. Lujan

Biomedical Research Institute Student Presentations

No abstract provided.

Evaluation Of The Mass Transfer Effect Of The Stalk Contraction–Relaxation Cycle Of Vorticella Convallaria, Jiazhong Zhou

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Vorticella convallaria is a genus of protozoa living in fresh water. It has a bell-shaped zooid equipped with adoral ciliary bands and a contractile stalk tethering the zooid to a substrate. Vorticella is regarded as a biological spring because its contractile stalk can pull the zooid towards the substrate at a remarkably high speed and then relaxes to its extended state much more slowly. However, reasons for Vorticella’s stalk contraction are still unknown. It is presumed that the flow field induced by the contraction-relaxation cycle of Vorticella would augment mass transfer effect near the substrate. We investigated this hypothesis …

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

Team Nathan Suspension, Frankie J. Wiggins, Alex D. Seitz, Justin P. Bautista

Mechanical Engineering

Nathan Cooper is an 8-year old boy with Spinal Muscular Atrophy (SMA). SMA has affected Nathan’s muscle development and requires him to use the Standing Dani™ mobility device. The Standing Dani is a motorized standing wheelchair, or Wheelstand. Nathan controls and uses it to get around. Though the Standing Dani performs well for most functions, it has some distinct issues. The primary issue that this project addresses is its lack of suspension and the discomfort that Nathan feels as a result. After talking with our client, we developed several specifications generally related to geometry, safety, vehicle dynamics, and reliability. Many …

Within-Socket Myoelectric Prediction Of Continuous Ankle Kinematics For Control Of A Powered Transtibial Prosthesis, Samuel Farmer, M. Barbara Silver-Thorn, Philip A. Voglewede, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Objective. Powered robotic prostheses create a need for natural-feeling user interfaces and robust control schemes. Here, we examined the ability of a nonlinear autoregressive model to continuously map the kinematics of a transtibial prosthesis and electromyographic (EMG) activity recorded within socket to the future estimates of the prosthetic ankle angle in three transtibial amputees. Approach. Model performance was examined across subjects during level treadmill ambulation as a function of the size of the EMG sampling window and the temporal 'prediction' interval between the EMG/kinematic input and the model's estimate of future ankle angle to characterize the trade-off between model error, …

A Collagen‐Glycosaminoglycan‐Fibrin Scaffold For Heart Valve Tissue Engineering Applications, Claire Brougham, Stefan Jockenhoevel, Thomas Flanagan, Fergal O'Brien

Conference Papers

The field of heart valve biology and tissue engineering a heart valve continue to expand. The presentatio ns at this meeting reflect the advances made in both areas due to the multi-disciplinary approach taken by many laboratories.