Biomedical Engineering and Bioengineering Commons^™

New Engineering Approaches To Arrhythmias And Myocardial Infarction, Frency Varghese

Biomedical Engineering Theses & Dissertations

In this thesis, we present new engineering approaches to several important cardiac diseases. Chapter 1 considers the dynamics of arrhythmias. The most dangerous arrhythmias are reentrant arrhythmias, including ventricular fibrillation and ventricular tachycardia. During these arrhythmias, there are one or several rotating excitation waves present in the heart. Because of their shape, these waves are called scroll waves; their center of rotation is a one-dimensional curve called the filament. Filaments largely constrain the configuration of a scroll wave but are much simpler, so much effort has gone into describing scroll wave dynamics in terms of the dynamics of their filaments. …

Mobile Cloud Computing Based Non Rigid Registration For Image Guided Surgery, Arun Brahmavar Vishwanatha

Computer Science Theses & Dissertations

In this thesis we present the design and implementation of a Mobile Cloud computing platform for non-rigid registration required in Image Guided Surgery (MCIGS). MCIGS contributes in flexible, portable and accurate alignment of pre-operative brain data with intra-operative MRI, for image guided diagnosis and therapy and endoscopic skull base surgery. Improved precision of image guided therapy and specifically neurosurgery procedures is known to result in the improved prognosis for brain tumor patients. MCI GS system is tested with Physics Based Non-Rigid Registration method form ITK. Our preliminary results for brain images indicate that the proposed system over Wi-Fi can be …

Nano Scale Mechanical Analysis Of Biomaterials Using Atomic Force Microscopy, Diganta Dutta

Mechanical & Aerospace Engineering Theses & Dissertations

The atomic force microscope (AFM) is a probe-based microscope that uses nanoscale and structural imaging where high resolution is desired. AFM has also been used in mechanical, electrical, and thermal engineering applications. This unique technique provides vital local material properties like the modulus of elasticity, hardness, surface potential, Hamaker constant, and the surface charge density from force versus displacement curve. Therefore, AFM was used to measure both the diameter and mechanical properties of the collagen nanostraws in human costal cartilage. Human costal cartilage forms a bridge between the sternum and bony ribs. The chest wall of some humans is deformed …

Ablation Of Cardiac Tissue With Nanosecond Pulsed Electric Fields: Experiments And Numerical Simulations, Fei Xie

Biomedical Engineering Theses & Dissertations

Cardiac ablation for the treatment of cardiac arrhythmia is usually performed by heating tissue with radio-frequency (RF) electrical currents to create conduction-blocking lesions in order to stop the propagation of electrical waves. Problems associated with RF ablation are recurrence of arrhythmias after successful treatments, tissue loss beyond the targeted tissue, long duration of the ablation procedure, and thermal side effects including thrombus formation that may lead to stroke. Here, we propose a new, non-thermal ablation method using nanosecond pulsed electric fields (nsPEFs) with better-controlled ablation volume, shorter procedure time, and no thermal side effects. We demonstrate that we can create …

Plasma Activated Air Mediates Gene Transfer, Chelsea M. Edelblute

Biological Sciences Theses & Dissertations

Cold plasma is produced when strong applied electric fields accelerate free electrons, which dissociate, excite, or ionize gaseous molecules [1]. The deposition of ions from the plasma source is dependent on power generation, input gas composition, and gas flow rate. In the presence of reactive species, the membrane of eukaryotic cells is compromised allowing for otherwise impermeant molecules, such as DNA, to enter the inner-cell milieu [2].

The efficacy of a novel cold plasma reactor based on shielded sliding discharge for the delivery of plasmid DNA was assessed. The device is entirely non-contact, wherein the plasma never directly touches the …

Development Of A Practical Visual-Evoked Potential-Based Brain-Computer Interface, Nicholas R. Waytowich

Biomedical Engineering Theses & Dissertations

There are many different neuromuscular disorders that disrupt the normal communication pathways between the brain and the rest of the body. These diseases often leave patients in a `locked-in" state, rendering them unable to communicate with their environment despite having cognitively normal brain function. Brain-computer interfaces (BCIs) are augmentative communication devices that establish a direct link between the brain and a computer. Visual evoked potential (VEP)- based BCIs, which are dependent upon the use of salient visual stimuli, are amongst the fastest BCIs available and provide the highest communication rates compared to other BCI modalities. However. the majority of research …

In Vivo Near Ir Fluorescent Imaging Of Hollow Polymeric Nanocapsules, Venkata Suresh Patthipati

Biological Sciences Theses & Dissertations

Medical Imaging has been an integral component in medical diagnosis and therapeutics. It is frequently used in conjunction with other treatment modalities and has been used for developing applications that range from cancer management to clinical practice. Nanotechnology and its applications are foreseen to have a profound impact on life sciences. Nanomaterial based imaging has a significant potential in addressing medical challenges such as tumor localization, targeted delivery of drugs and real time diagnosis and management of circulation pathology. In particular, polymer based nanoparticles are increasingly being developed as they can be customized according to the diagnostic and/or therapeutic requirements. …

Multichannel Characterization Of Brain Activity In Neurological Impairments, Yalda Shahriari

Biomedical Engineering Theses & Dissertations

Hundreds of millions of people worldwide suffer from various neurological and psychiatric disorders. A better understanding of the underlying neurophysiology and mechanisms for these disorders can lead to improved diagnostic techniques and treatments. The objective of this dissertation is to create a novel characterization of multichannel EEG activity for selected neurological and psychiatric disorders based on available datasets. Specifically, this work provides spatial, spectral, and temporal characterizations of brain activity differences between patients/animal models and healthy controls, with focus on modern techniques that quantify cortical connectivity, which is widely believed to be abnormal in such disorders. Exploring the functional brain …

Multi-Surface Simplex Spine Segmentation For Spine Surgery Simulation And Planning, Rabia Haq

Computational Modeling & Simulation Engineering Theses & Dissertations

This research proposes to develop a knowledge-based multi-surface simplex deformable model for segmentation of healthy as well as pathological lumbar spine data. It aims to provide a more accurate and robust segmentation scheme for identification of intervertebral disc pathologies to assist with spine surgery planning. A robust technique that combines multi-surface and shape statistics-aware variants of the deformable simplex model is presented. Statistical shape variation within the dataset has been captured by application of principal component analysis and incorporated during the segmentation process to refine results. In the case where shape statistics hinder detection of the pathological region, user-assistance is …