Biomedical Engineering and Bioengineering Commons^™

Response Of Stretch-Injured Schwann Cells, Stephanie Iring

Theses

Axon fibers are covered by myelin sheath. After axonal damage, demyelination follows with the production of debris. In the Central Nervous System many studies have been performed to observe and analyze stretch injured axons, but very little has been done to study the white matter axonal tracts, oligodendrocytes. Schwann cells can help take a first look into stretch injured glia cells from the Peripheral nervous system. In order to observe changes in Schwann Cells a stretch injury device is used to produce the effects of severe and moderate injuries. Schwann Cells are stretch injured in both their undifferentiated and differentiated …

An Electromechanical System For Characterization Of Piezoelectric Materials, Ahmet Sait Asan

Theses

Piezoelectric materials have been used in medical applications for a long time due to their unique characteristics, which is to respond to mechanical stimulation by producing an electrical current and vice versa. They perform a pivotal role in medical applications both for diagnostic and therapeutic purposes. In this regard, characterizing the piezoelectric properties of these materials is crucial for their usage. In this particular study, an electromechanical system for measurement of piezoelectric output signals is designed and tested. The project is motivated by the question: can the piezoelectric properties be characterized by applying different mechanical stimulation waveforms and frequencies. Two …

Continuum Mechanical Analysis Of Space And Time Dependent Deformation Pattern Of Brain With Blunt Injury, Chen Miao

Theses

Deformation of human brain due to acceleration impact has been widely accepted as the direct connection to the Trauma Brain Injury (TBI). However, the limitation of obtaining deformation data of TBI is a major obstacle to understanding TBI mechanism. This experiment mainly focuses on developing a method to measure deformation pattern of brain with blunt injury. First of all, displacement data of markers on sagittal plane of an injury head model was collected using 3D reconstruction software after an impact test. Second, the displacement data was used to calculate 2D Lagrangian strain tensor and the principal strain. The temporal and …

Antibacterial Efficacy Of Nanometals In Conjunction With Electrical Stimulus, Syed A. Hussain

Theses

Hospital related infections generally result from the combined effect of preexisting bacteria on the patient and invasive devices. This demonstrates the significance in improving these medical devices to increase the quality of life of the patients that require them. This study will attempt to evaluate the antibacterial efficacy of nanocopper particles and an electrical stimulus for the usage in medical device development and the hospital environment.

For devices such as catheters, infections typically result from bacteria entering the body from the outside. This is accomplished by bacteria attaching themselves to the exterior of the device and producing biofilm which allows …

Effect Of Melt Method On Thoracolumbar Connective Tissue, Faria Sanjana

Theses

Approximately, 31 million adults in the United States suffer from low back pain (LBP). Altered connective tissue structure has been identified in adults with chronic LBP. Numerous novel treatments are being developed targeting the connective tissue and nervous system to relieve people from LBP. One such self-care treatment is the MELT method. The objective of this study was to determine whether thickness of thoracolumbar connective tissue and other biomechanical and viscoelastic properties of myofascial tissue in the low back region change in subjects with chronic LBP as a result of MELT.

Using ultrasound imaging and an algorithm developed in MATLAB, …

A Study Of Kinematics And Kinetics In Time-Constrained Arm Movements, Oyindamola Owoeye

Theses

Several studies such as the equilibrium point hypothesis (EPH) purport that the motor signals that descend from the brain instead of encoding muscle torques, influence an existing relationship between muscle torque and body configuration.

In the present study, the possibility of torque depending explicitly on position was tested using a task in which subjects (N=5) moved a simulated weightless frictionless mass through a small (<8 degree) elbow extension in order to move a cursor on a screen to a target location. Each subject completed 720 trials. On ~10% of trials the simulated mass was increased unknown to the subject. The relationship between the cursor’s position and the torque applied to the system was held constant even when the simulated mass was increased. Thus, any change in torque produced was neither due the subjects’ perception of the mass nor due to their perception of the cursor. The time at which the subjects torque changed direction was seen to be significantly different (p<0.005) during trials which the mass changed. This change in torque is concluded to be position-dependent. However the possibility of this being a merely mechanical effect could not be ruled out by due to poor EMG collection.

A post-hoc analysis of different position-dependent motor control models, was done. Particularly, an exponential spring model, a linear spring model, and a linear spring with relative damping model were each tested to see how well …

Investigating Neural Mechanisms Of Hand Movements In Virtual Reality, Chuang Mu

Theses

Mirror visual feedback (MVF), a technique by which movement of one limb is perceived as movement of the contralateral limb, has the capacity to relieve phantom limb pain or promote motor recovery of the upper limbs after stroke (Ramachandran et al., 1995). Functional MRI studies have demonstrated activation of the motor areas in the hemisphere ipsilateral to the moving hand in response to MVF. However, the neural mechanisms of MVF are still unclear. This Electroencephalography (EEG) study was designed to investigate the timing of neural responses to MVF presented in virtual reality. 16 right-handed, neurologically healthy subjects participated in a …

Realization Of Dynamixel Servo Plant Parameters To Improve Admittance Control For A Compliant Human-Robot Interaction, Ahmad Zahid Rao

Theses

In theory, admittance control offers a very effective method of implementing smooth human-robot interaction. It allows the user’s applied force to control the movement of a powerful robot as if the robot were a small, passive mass. However, the real-world application of admittance control faces limitation posed by the dynamics of servo motors, the accuracy of the force sensors, and the computation speed of processors.

This research investigates the limitations on achieving compliant passive behavior when using state-of-the-art actuators, sensors and processors. The work involves characterizing the dynamic behavior of the servo motors, development of improved differential equations representing admittance …

Comparison Of Muscle Synergies Elicited From Transcranial Meganetic Stimulation (Tms) And Voluntary Movements, Yifei Wei

Theses

A key question in motor control is the redundancy of musculoskeletal elements involved. This problem refers to as the degree of freedom problem. The Muscle Synergy Hypothesis is one of the hypotheses that aim to resolve the problem which defines that a muscle synergy is a combination of a small set of muscles activated at different levels, serving as a building block that constructs motor behaviors. A recent study (Overduin et al. 2012) demonstrated that muscle synergies decomposed by Nonnegative Matrix Factorization (NMF) from EMG patterns evoked by intra-cortical microsimulation (ICMS) in the monkey remarkably matched ones observed in naturalistic …

Rodent Testing Device Surrogate For Shockwave Blast Testing, Anthony C. Misistia

Theses

Many laboratories around the world are conduct shockwave blast injury tests on rodents to simulate blast traumatic brain injury (TBI). Each of these laboratories has different techniques for creating the shockwave blasts as well as positioning the rats. There is no device to determine whether or not the rodent animal models actually experiences a true blast wave in a given set up. This device was developed as a method for verifying rodents undergoing true shockwave blasts through biometrics, instrumentation and the basic biomechanical responses a rodent experiences during such tests. Since the goal of shockwave blast testing is to replicate …