Biomechanics and Biotransport Commons^™

Measurement, Characterization, And Effects Of Head Impacts In Women's Soccer, Emily C. Mccuen

Open Access Theses

The potential for long term neurological deficits resulting from repetitive head trauma is a major concern for collision sport athletes. Research conducted on football played has found neurophysiologic changes in the absence of concussion in athletes as early as high school age. Given that female soccer players show the highest rate of concussion for female athletes and a higher rate of concussion than their male counterparts, it is important to characterize the types of impacts female soccer athletes receive and assess female soccer athletes for neurophysiologic changes due to these impacts. This work paired head impact sensors with functional MRI …

A Three Constituent Mixture Theory Model Of Cutaneous And Subcutaneous Tissue In The Context Of Neonatal Pressure Ulcer Etiology And Prevention, Anne Dye Zakrajsek

Open Access Dissertations

Localized ischemia, impaired interstitial fluid flow, and sustained mechanical loading of cells have all been hypothesized as mechanisms of pressure ulcer (PrU) etiology. Time-varying loading has experimentally been shown to increase fluid flow in human skin in vivo. Towards the design of prophylactic protocols and treatment modalities for PrU management there is a need for an analytical model to investigate the local fluid flow characteristics of skin tissue under time-varying loading. In this study, a triphasic mixture theory model with constituents of extracellular matrix, interstitial fluid, and blood was calibrated and validated and used to investigate stress and fluid velocity …

Unveiling The Mechanical Behavior Of The Rod-Like Microstructure In The Radular Teeth Of Cryptochiton Stelleri, Enrique Escobar De Obaldia

Open Access Dissertations

Natural ceramics provided with high volume fractions of mineralized materials that are surrounded by a weak organic interface combine the stiff mechanical behavior of building blocks, like hydroxyapatite or aragonite, and the compliance of the organic surroundings. Unique mechanical properties (e.g. light density and toughness) distinguish bio-composites from common engineering materials. A key example is the highly mineralized shell of the radular teeth of the Crypochiton stelleri. Nature has provided the radular teeth with a highly oriented rod-like microstructure of nano-scale dimensions embedded in a matrix of chitin sheaths. Compared to other biological materials, the external iron oxide layer of …

Collagen Crosslinking Reagent Utilized To Modify The Mechanical Properties Of The Soft Palate In Equine Snoring And Apnea Applications, Stephanie L. Hunt

Theses and Dissertations--Biomedical Engineering

Snoring is a sleep disruption that can lead to obstructive sleep apnea (OSA), which interrupts breathing by obstructing the airway. Injecting a protein crosslinker, such as genipin, into the soft palate could decrease the severity of snoring and OSA by stiffening the soft palate. Equine soft palates modeled human palates due to a high incidence of awake snoring and apnea.

The pilot in vivo study treated six horses with two 100 mM injections of the buffered genipin reagent. The efficacy phase horses underwent respiratory audio recordings to document snoring changes using Matlab and ImageJ in the time and frequency domains. …

Emg And Kinematic Responses To Unexpected Slips After Slip Training In Virtual Reality, Prakriti Parijat, Thurmon E. Lockhart, Jian Liu

Computer Sciences and Electrical Engineering Faculty Research

The objective of the study was to design a virtual reality (VR) training to induce perturbation in older adults similar to a slip and examine the effect of the training on kinematic and muscular responses in older adults. Twenty-four older adults were involved in a laboratory study and randomly assigned to two groups (VR training and control). Both groups went through three sessions including baseline slip, training, and transfer of training on slippery surface. The training group experienced 12 simulated slips using a visual perturbation induced by tilting a VR scene while walking on the treadmill and the control group …

Du02, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Du06, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Blast-Induced Mild Traumatic Brain Injury Through Ear Canal: A Finite Element Study, Praveen Akula, Yi Hua, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Purpose The role of ear canal in transmitting blast waves to the brain is not clear. The goal of this work is to characterize the influence of ear canal on blast-induced mild traumatic brain injury through a computational approach.

Methods A three-dimensional human head model with single-side ear canal details was reconstructed from computed tomography images. The ear canal was positioned either facing the incident blast wave or facing away from the blast wave.

Results The blast wave-head interaction has demonstrated that the overpressure within the ear canal was substantially amplified when the ear directly faced the blast wave. When …

The Effect Of Cholesterol On The Osteoblast Responsiveness To Hydrodynamic Pressure Stimulation, Kristen Lough

Theses and Dissertations--Biomedical Engineering

Hypercholesterolemia is a risk factor for osteoporosis but the underlying mechanism is unknown. Previous evidence suggests that osteoporosis results from an impaired regulation of osteoblasts by fluid pressure fluctuations in the bone matrix. Recently, our laboratory showed that enhanced cholesterol in the cell membrane, due to hypercholesterolemia, alters leukocyte mechanosensitivity. We predict a similar link between osteoblasts and hypercholesterolemia leading to osteoporosis. Specifically, we hypothesize that extracellular cholesterol modifies the osteoblast sensitivity to pressure. MC3T3-E1 cells were exposed to hydrodynamic pressures regimes (mean=40mmHg, amplitude=0-20mmHg, frequency=1Hz) for 1-12 hours. To assess the impact of membrane cholesterol enrichment, cells were pre-treated with …

Long Term Blood Oxygenation Membranes, Joseph V. Alexander

Theses and Dissertations--Biomedical Engineering

Hollow fiber membranes are widely used in blood oxygenators to remove carbon dioxide and add oxygen during cardiopulmonary bypass operations. These devices are now widely used off-label by physicians to perform extracorporeal blood oxygenation for patients with lung failure. Unfortunately, the hollow fiber membranes used in these devices fail prematurely due to blood plasma leakage and gas emboli formation.

This project formed ultrathin (~100nm) polymer coatings on polymer hollow fiber membranes. The coatings were intended to “block” existing pores on the exterior surfaces while permitting high gas fluxes. This coating is synthesized using surface imitated control radical polymerization.

The coating …

Body Armor Induced Changes In The Trunk Mechancial And Neuromuscular Behavior, Rebecca Leigh Tromp

Theses and Dissertations--Biomedical Engineering

While military body armor is used among warfighters for protection on and off the battlefield, it has been suggested to impede performance and act as a risk factor for the development of musculoskeletal disorders, especially low back pain. Apart from personal suffering, low back pain in soldiers is a great economic burden on the US economy. The objective of this study was to quantify the changes in trunk mechanical and neuromuscular behavior following prolonged exposure to body armor compared to exposure without. A crossover study design was used where 12 sex-balanced participants completed a series of tests before and after …

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 …

Mechanical Impedance Of Ankle As A Function Of Electromyography Signals Of Lower Leg Muscles Using Artificial Neural Network, Chen Jia

Dissertations, Master's Theses and Master's Reports - Open

This paper reports on the feasibility of developing a model to describe the nonlinear relationship between the mechanical impedance of the human ankle within a specified range of frequency and the root mean square (RMS) value of the Electromyography (EMG) signals of the muscles of human ankle using Artificial Neural Network (ANN). A lower extremity rehabilitation robot — Anklebot was used to apply pseudo-random mechanical perturbations to the ankle and measure the angular displacement of the ankle to estimate the data of ankle mechanical impedance. Meanwhile, the surface EMG signals from the selected muscles were monitored and recorded using a …

The Influence Of Passive Ankle Joint Power On Balance Recovery, Stephanie E. Hamilton

Dissertations, Master's Theses and Master's Reports - Open

Over one–third of Americans over the age of 65 fall each year, costing more than $19 billion in health care costs in 2000. Many adults 65+ who have not experienced a fall still fear falling, and fear can decrease quality of life and increase the likelihood of falls. Several factors such as muscle strength, power, stiffness and tendon properties change in the human body with age affecting balance, which has been tagged as a fall risk predictor. Additionally, balance recovery strategies also differ between young and older adults, with young adults primarily utilizing their ankle joint and older adults utilizing …

Brainstorm Radiation Systems Inc, Calia Battista, Leah Krichbaum, Lauren Wickert, Cody George, Ryan Manges

Williams Honors College, Honors Research Projects

Many different designs have been created to immobilize patients for radiation therapy of the head and neck. Options exist which result in varying degrees of patient comfort, radiation attenuation, and limitation of movement. While one requirement can be met effectively, it is difficult to design a system which adequately meets all requirements for radiation therapy. Brainstorm Radiation Systems aims to address all of these variables and transform the patient and technician experience during radiation treatment. The requirements for our head and neck immobilization design were to immobilize the patient within 3mm of movement for at least 30 minutes, and must …

Mangled Extremity Simulator, Abigail Miller, Jonathan Clevenger, Nadia Gaskins

Williams Honors College, Honors Research Projects

No abstract provided.

Du05, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Du04, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Du03, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.