Biomedical Engineering and Bioengineering Commons^™

Locating And Extracting Acoustic And Neural Signals, Na Zhu

Wayne State University Dissertations

This dissertation presents innovate methodologies for locating, extracting, and separating multiple incoherent sound sources in three-dimensional (3D) space; and applications of the time reversal (TR) algorithm to pinpoint the hyper active neural activities inside the brain auditory structure that are correlated to the tinnitus pathology. Specifically, an acoustic modeling based method is developed for locating arbitrary and incoherent sound sources in 3D space in real time by using a minimal number of microphones, and the Point Source Separation (PSS) method is developed for extracting target signals from directly measured mixed signals. Combining these two approaches leads to a novel technology …

Comparison Of Progression Of Diffuse Axonal Injury With Histology And Diffusion Tensor Imaging, Nisrine Zakaria

Wayne State University Dissertations

Diffuse axonal injury, also known as traumatic axonal injury (TAI), is a major contributor to the pathology of traumatic brain injury. However, TAI is undetectable to conventional clinical magnetic resonance (MR) imaging techniques. Histologically, TAI is characterized by swollen axons that eventually disconnect and form axonal retraction balls (RB) in various white matter tracts. MR-diffusion tensor imaging (MR-DTI) has been reported to be sensitive to TAI in human TBI patients by measuring water molecular diffusion motion in white matter fiber tracts. To date, only one correlative animal study has been carried out to investigate the DTI relationship to TAI, and …

Development Of A Biomechanical Surrogate For The Evaluation Of Commotio Cordis Protection, Nathan Dau

Wayne State University Dissertations

Commotio Cordis (CC) has proven to be life threatening for young athletes as it is the second leading cause of mortality in youth sports. In the past 15 years, researchers have been working to understand the pathophysiology of this event. It has been proven that impacts directly over the cardiac silhouette during a vulnerable period of the cardiac cycle can cause CC. In order to reduce the occurrence of CC in sports, chest protectors need to be tested for efficacy. Currently there is no biofidelic surrogate to serve this purpose. In order to test equipment to a given standard of …

Computational Simulation Of Skull Fracture Patterns In Pediatric Subjects Using A Porcine Model, Christina Devito Wagner

Wayne State University Dissertations

In cases of suspected child abuse with skeletal trauma, it is often the role of the injury biomechanist, forensic pathologist, clinical radiologist, and forensic anthropologist to determine the mechanism of injury when the child victims cannot speak for themselves. This is a challenging task, especially for the head, as comprehensive biomechanical data on skull fracture in infants and children do not currently exist, and frequently the determination regarding cause of injury is based on anecdotal evidence from the medical literature and unsubstantiated eyewitness accounts. The current process may result in unreliable autopsy interpretation and miscarriages of justice due to a …

Differences Between Adult And Pediatric Neck Muscle Stress Due Muscle Recruitment Patterns, Renee Dawson

Wayne State University Dissertations

In 2000 and 2001 an estimated 150,000 children between the ages of 0 and 8 years old were injured or killed in a motor vehicle accident. Despite advances in child safety restraints and vehicle restraints, automobile accidents remain the primary cause of death for children in the 0-8 year old age group. In 1982, in an attempt to reduce the number of deaths and injuries of children, the first child crash test dummy was developed. The responses of this dummy were scaled from the adult response data based on the assumption that children were similar to adults both anatomically and …

Reinforced Chitosan-Based Heart Valve Scaffold And Utility Of Bone Marrow-Derived Mesenchymal Stem Cells For Cardiovascular Tissue Engineering, Mohammad Z. Albanna

Wayne State University Dissertations

Recent research has demonstrated a strong correlation between the differentiation profile of mesenchymal stem cells (MSCs) and scaffold stiffness. Chitosan is being widely studied for tissue engineering applications due to its biocompatibility and biodegradability. However, its use in load-bearing applications is limited due to moderate to low mechanical properties. In this study, we investigated the effectiveness of a fiber reinforcement method for enhancing the mechanical properties of chitosan scaffolds. Chitosan fibers were fabricated using a solution extrusion and neutralization method and incorporated into porous chitosan scaffolds. The effects of different fiber/scaffold mass ratios, fiber mechanical properties and fiber lengths on …

Supercritical Carbon Dioxide-Processed Resorbable Polymer Nanocomposites For Bone Graft Substitute Applications, Kevin Baker

Wayne State University Dissertations

Numerous clinical situations necessitate the use of bone graft materials to enhance bone formation. While autologous and allogenic materials are considered the gold standards in the setting of fracture healing and spine fusion, their disadvantages, which include donor site morbidity and finite supply have stimulated research and development of novel bone graft substitute materials. Among the most promising candidate materials are resorbable polymers, composed of lactic and/or glycolic acid. While the characteristics of these materials, such as predictable degradation kinetics and biocompatibility, make them an excellent choice for bone graft substitute applications, they lack mechanical strength when synthesized with the …

Monitoring, Diagnosis, And Control For Advanced Anesthesia Management, Zhibin Tan

Wayne State University Dissertations

Modern anesthesia management is a comprehensive and the most critical issue in medical care. During the past dacades, a large amount of research works have been focused on the problems of monitoring anesthesia depth, modeling the dynamics of anesthesia patient for the purpose of control, prediction, and diagnosis.

Monitoring the anesthesia depth is not only for keeping the patient in adquate anesthesia level but also for preventing the patient from overdosing. Several EEG based indexes have been developed such as the BIS, and Entropy etc. for measuring depth. However, reports mentioned that those indexes in some cases fail in detecting …

Finite Element Reconstruction Of Real World Aortic Injury In Near-Side Lateral Automotive Crashes With Conceptual Countermeasures, Aditya Neelakanta Belwadi

Wayne State University Dissertations

Traumatic rupture of the aorta (TRA) remains the second most common cause of death associated with motor vehicle crashes after brain injury. On an average, nearly 8,000 people die annually in the United States due to blunt injury to the aorta. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest. With the advent of more accurate and established human body finite element (FE) models, FE crash reconstruction methods may become a valuable tool when assessing crash scenarios and occupant injury mechanisms.

The current study is …

An Investigation Of The Biomechanical Response From Shock Wave Loading To The Head, Alessandra Dal Cengio Leonardi

Wayne State University Dissertations

There is a pressing need for a comprehensive explanation of the mechanism of brain injury after exposure to blast and several hypotheses have been suggested. The focus of this research was to investigate one of the hypotheses for primary brain injury due to blast: multimodal skull flexure. The significance of this research is twofold. First, resolution of the mode of energy transfer and of the induced stresses within the skull-brain system will allow for creations of mitigation/protective techniques/equipment, as well as design of experiments investigating live-cell response using more reliable physical models. Second, the data obtained experimentally will be available …

Longissimus Muscle Fatigue And Injury Response Due To Electrical Stimulation With Varied Work/Rest Ratios, Peter Wawrow

Wayne State University Dissertations

LONGISSIMUS MUSCLE FATIGUE AND INJURY RESPONSE DUE TO ELECTRICAL STIMULATION WITH VARIED WORK/REST RATIOS

BY

PETER WAWROW

May 2011

Advisor: John Cavanaugh, MD

Major: Biomedical Engineering

Degree: Doctor of Philosophy

The estimated yearly cost of lost-time work injuries and illnesses is $140 billion. The average cost of musculoskeletal disorders (MSDs) exceeds all other claims. These injuries persist in spite of ergonomic interventions addressing known risk factors. Work/rest ratios have not received a significant amount of attention, particularly in low back disorders, and it is hypothesized that the lack of adequate rest within a work cycle may contribute to muscle fatigue …

A Multi-Species Analysis Of Biomechanical Responses Of The Head To A Shock Wave, Richard Bolander

Wayne State University Dissertations

Shock wave induced brain injury remains a field of research that has great consequences for the rehabilitation of soldiers and civilians that are exposed to an explosion. As such, for the research to be successful in developing strategies to mitigate the effects of these injuries, appropriate research methods need to be developed. Animal models are currently employed to understand the brain's response to a shock wave exposure. Unfortunately no criteria have been established that indicates in what way the mechanical inputs that the cells in an animal's brain are subjected to are similar to a human. The purpose of this …

Processing Random Signals In Neuroscience, Electrical Engineering And Operations Research, Kalyan Raman

Wayne State University Dissertations

The topic of this dissertation is the study of noise in electrical engineering, neuroscience, biomedical engineering, and operations research through mathematical models that describe, explain, predict and control dynamic phenomena. Noise is modeled through Brownian Motion and the research problems are mathematically addressed by different versions of a generalized Langevin equation. Our mathematical models utilize stochastic differential equations (SDEs) and stochastic optimal control, both of which were born in the soil of electrical engineering. Central to this dissertation is a brain-physics based model of cerebrospinal fluid (CSF) dynamics, whose structure is fundamentally determined by an electrical circuit analogy. Our general …