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Full-Text Articles in Biomedical Engineering and Bioengineering

Construction And Assessment Of A Computer Graphics-Based Model For Wheelchair Propulsion, Brooke Marie Odle Dec 2013

Construction And Assessment Of A Computer Graphics-Based Model For Wheelchair Propulsion, Brooke Marie Odle

Dissertations

Upper limb overuse injuries are common in manual wheelchair using persons with spinal cord injury (SCI), especially those with tetraplegia. Biomechanical analyses involving kinetics, kinematics, and muscle mechanics provide an opportunity to identify modifiable risk factors associated with wheelchair propulsion and upper limb overuse injuries that may be used toward developing prevention and treatment interventions. However, these analyses are limited because they cannot estimate muscle forces in vivo. Patient-specific computer graphics-based models have enhanced biomechanical analyses by determining in vivo estimates of shoulder muscle and joint contact forces. Current models do not include deep shoulder muscles. Also, patient-specific models have ...


The Effect Of Mechanical Vestibular Stimulation On Muscle Tone And Spasticity In Individuals With Neurological Impairment, Ghaith J. Androwis Dec 2013

The Effect Of Mechanical Vestibular Stimulation On Muscle Tone And Spasticity In Individuals With Neurological Impairment, Ghaith J. Androwis

Dissertations

In the desire to better understand spasticity mainly in Cerebral Palsy (CP) and to examine vestibular stimulation as a future intervention for .muscle tone reduction, and to be able to describe the change in level of spasticity in subjects with disability and describe interventions effects, a series of experiments are done on children with spasticity. In addition to understanding the otoliths in the vestibular system and their projections, properties and pathways a more important major objective of this work is to validate the changes in otoliths signal caused by vestibular stimulation based on the Equilibrium Point Hypothesis and the inclusion ...


Mathematically Modeling The Mechanical Constants Of Thoracolumbar Fascia Under Compression, In Vivo, Vrajeshri Patel Dec 2013

Mathematically Modeling The Mechanical Constants Of Thoracolumbar Fascia Under Compression, In Vivo, Vrajeshri Patel

Theses

The thoracolumbar fascia (TLF) is a complex structure made of many interconnecting aponeurosis and muscle fascia. It plays a role in posture, stabilizing the lumbosacral spine, load transfer, and respiration. Its complex structure and connections have mostly been observed through cadaveric studies while its mechanical properties have been addressed in only a few studies. Recently, new advances in ultrasound imaging have made it possible to move towards measuring tissue strain. Since this is an in vivo method, mechanical data of tissues in their natural environment allows a more accurate representation of tissue strain. However, many different methods of analyzing ultrasound ...


Using The Piezoelectric Backscatter Signal For Remote Sensing Of Neural Signals, Eren Alay Dec 2013

Using The Piezoelectric Backscatter Signal For Remote Sensing Of Neural Signals, Eren Alay

Theses

In recent studies, various methods to sense neural signals are used and new methods for remote sensing of neural signals are being developed. However, there are still major difficulties in building long-term implantable neural interface systems that can reliably record neural activity and serve as the basis of brain-machine interfaces (BMI). Therefore, this research is conducted to design a remote neural sensing system that is based on modulation of the backscatter signal from a piezoelectric element by the neural signals. The hypothesis is that if the neural signal is detected with a simple amplifier and the output of this amplifier ...


Differentiating Schizophrenic Patients From Healthy Control; Application Of Machine Learning To Resting State Fmri, Hossein Ebrahimi Nezhad Dec 2013

Differentiating Schizophrenic Patients From Healthy Control; Application Of Machine Learning To Resting State Fmri, Hossein Ebrahimi Nezhad

Theses

In recent years, one analysis approach that has grown in popularity is the use of machine learning algorithms to train classifiers to decode stimuli, mental states, behaviors and other variables of interest from fMRI data. Most of these studies focus on fMRI low frequency oscillations. This study focuses on the amplitude of low-frequency fluctuations (ALFF) and fractional amplitude of low-frequency fluctuations (fALFF). A Voxel-wise analysis is performed on the whole brain for two groups of subjects. A machine learning algorithm is applied to two independent groups of subjects (a total of 160 healthy control and schizophrenic subjects) to classify Schizophrenia ...


Developing A Labview Based Thermally Stimulated Current (Tsc) Controller To Measure Residual Charge In Electrospinning, Jai Abhishekh Veezhinathan Dec 2013

Developing A Labview Based Thermally Stimulated Current (Tsc) Controller To Measure Residual Charge In Electrospinning, Jai Abhishekh Veezhinathan

Theses

Electrospinning is an electrohydrodynamic process for the fabrication of nanofibers which are widely used in therapeutical tissue engineering approaches. It utilizes the potential difference of an electrostatic field to overcome the surface tension of the polymer solution to extrude a fine jet of fluid which deposits on the grounded collector as a nanofiber mat. Using this process, nanofibers with diameters less than a micron can be produced.

Previous studies have shown the presence of residual charge in electrospun nanofibers. The presence and decay of residual charge during cell culture media is still unknown. In an attempt to clarify the presence ...


Rate Alterable Traumatic Brain Injury Device For Rodent Models, Radia Abdul Wahab Dec 2013

Rate Alterable Traumatic Brain Injury Device For Rodent Models, Radia Abdul Wahab

Dissertations

Traumatic Brain Injury (TBI) is a physical impact to the head resulting in functional deficits in memory and motor systems. TBI is a prevalent problem occurring in 1.7 million people annually in the United States (Faul et al. 2010). TBIs can differ greatly in terms of the biomechanics of the impact such as magnitude, direction and rate. Indeed, it is likely that the wide range of TBI outcomes may be due to the physical characteristics of the trauma. Studies to date on impact have used injury devices with limited alterable parameters. Therefore, the existing impact studies have considered the ...


Effect Of Scan Time On Resting State Parameters, Dhruti Patel May 2013

Effect Of Scan Time On Resting State Parameters, Dhruti Patel

Theses

In the past decade the interest in studying the spontaneous low-frequency fluctuations (LFF) in a resting-state brain has steadily grown. By measuring LFF (< 0.08 Hz) in blood-oxygen-level-dependent (BOLD) signals, resting-state functional magnetic resonance imaging (rs-fMRI) has proven to be a powerful tool in exploring brain network connectivity and functionality. Rs-fMRI data can be used to organize the brain into resting state networks (RSNs). In this thesis, rs-fMRI data are used to determine the minimum data acquisition time necessary to detect local intrinsic brain activity as a function of both the amplitude of low frequency fluctuations (ALFF) and the fractional amplitude of low frequency fluctuations (fALFF) in BOLD signals in healthy subjects. The data are obtained from 22 healthy subjects to use as a baseline for future rs-fMRI analysis. Voxel-wise analysis is performed on the whole brain, gray matter volume, and two previously established RSNs: the default mode network (DMN) and the visual system network, for all the subjects in this study.

Pearson’s correlation coefficients (r-values) are calculated from each subject. The entire time series for one subject is divided into 31 subsections and the r-values are calculated between each consecutive subsection in a subject. In total, there are 30 r- values. To better understand what the results mean across subjects and within subjects Fisher transformations are applied to the 30 calculated r-values for each subject to get a normal z-distribution. The mean across 22 subjects’ z-values is ...


Brain Computer Interface Based Neurorehabilitation Technique Using A Commercially Available Eeg Headset, Abhineet Mishra May 2013

Brain Computer Interface Based Neurorehabilitation Technique Using A Commercially Available Eeg Headset, Abhineet Mishra

Theses

Neurorehabilitation has recently been augmented with the use of virtual reality and rehabilitation robotics. In many systems, some known volitional control must exist in order to synchronize the user intended movement with the therapeutic virtual or robotic movement. Brain Computer Interface (BCI) aims to open up a new rehabilitation option for clinical population having no residual movement due to disease or injury to the central or peripheral nervous system. Brain activity contains a wide variety of electrical signals which can be acquired using many invasive and non-invasive acquisition techniques and holds the potential to be used as an input to ...


Nir Light Transmission Through Skin And Muscle, Deniz Ozgulbas May 2013

Nir Light Transmission Through Skin And Muscle, Deniz Ozgulbas

Theses

Light has been used extensively in the medical field for both therapeutic and diagnostic applications. Tissue optical window or therapeutic window defines the range of wavelengths where the light has the maximum transmittance through tissue. In this range, absorption and scattering effects are relatively lower when compared to the visible or middle infrared wavelengths. Knowledge of the transmittance through tissue can help determine the effective light intensities in medical applications.

The objective of this thesis is to determine the NIR light transmission through different thicknesses of animal tissue and its spatial spread due to the scattering effect. Primarily pork skin ...


Admittance Control Of The Intelligent Assist Robot Manipulator For People With Duchenne Muscular Dystrophy, Madeline Corrigan May 2013

Admittance Control Of The Intelligent Assist Robot Manipulator For People With Duchenne Muscular Dystrophy, Madeline Corrigan

Theses

Duchenne muscular dystrophy (DMD), a neuromuscular disease with a prevalence of 1 in 3500 male births, results in characteristic muscle weakness which is progressive with age and leads to loss of independence. And, in this population, maintaining optimal quality of life depends on the preservation of self-sufficiency. Despite the loss of function, non-ambulant people with DMD retain some muscle strength, just not sufficient strength to overcome the force of gravity. There are a number of upper-limb passive and active orthotic devices that attempt to augment the loss of upper limb function in people with DMD by taking advantage of this ...


Finite Element Modeling Of Temperature Elevation Due To Nir Exposure In Neural Tissue, Atabek Can Yucel May 2013

Finite Element Modeling Of Temperature Elevation Due To Nir Exposure In Neural Tissue, Atabek Can Yucel

Theses

Near infrared (NIR) lasers have been used in various types of medical applications. Heating is one of the most important concerns in the neural tissue when illuminated with NIR light. Rodent models are frequently used to study laser-tissue interactions. As a part of ongoing research project in the neural interface laboratory, direct measurements of temperature in the rat brain cortex as a response to a pulsed sequence of NIR laser beam are available. In this thesis, finite element modeling approach is used to model and simulate the temperature elevation in neural tissue under the effect of NIR laser pulsing. Steady ...