Engineering Commons^™

A 3-Dimensional In Silico Test Bed For Radiofrequency Ablation Catheter Design Evaluation And Optimization, Carolyn Teng

Master's Theses

Atrial fibrillation (AF) is the disordered activation of the atrial myocardium, which is a major cause of stroke. Currently, the most effective, minimally traumatic treatment for AF is percutaneous catheter ablation to isolate arrhythmogenic areas from the rest of the atrium. The standard in vitro evaluation of ablation catheters through lesion studies is a resource intensive effort due to tissue variability and visual measurement methods, necessitating large sample sizes and multiple prototype builds. A computational test bed for ablation catheter evaluation was built in SolidWorks® using the morphology and dimensions of the left atrium adjacent structures. From this geometry, the …

Evaluation Of Human Umbilical Vein Endothelial Cells In Blood Vessel Mimics Through Changes In Gene Expression And Caspase Activity, Conor Charles Hedigan

Master's Theses

Blood vessel mimics (BVMs) are simple tissue engineered blood vessel constructs intended for preclinical testing of vascular devices. This thesis developed and implemented methods to characterize two of these components. The first aim of this thesis investigated the effect of cell culture duration and flow conditions on endothelial cell gene expression, especially regarding endothelial-to-mesenchymal transition (EndMT). A trend of decreased endothelial marker gene expression and increased mesenchymal marker gene expression would indicate EndMT. qPCR analysis revealed that increased cell culture duration did not result in EndMT, and in fact increased endothelial marker expression as cell culture duration increased. Disturbed flow …

Transmission Probability Of Embolic Debris Through The Aortic Arch And Daughter Vessels During A Transcatheter Aortic Valve Replacement Procedure, Jessica Lena Wirth

Master's Theses

Cerebral ischemia leading to an ischemic stroke is a possible complication of a transcatheter aortic valve replacement (TAVR) procedure. This is because embolic debris can become dislodged and travel through the aortic arch, where they either continue to the descending aorta and join the systemic circulation or travel into the cerebral vasculature through the three daughter vessels that branch off the top of the aortic arch. These three vessels are the brachiocephalic artery, the left subclavian artery, and the left common carotid artery. These three vessels lead either directly or indirectly to the cerebral vasculature, where the diameter of vessels …

Cej Ankle Support Report, Christine Prothe, James Baldwin, Erik Espinoza

Biomedical Engineering

This document provides information about an ankle support device designed to allow for ankle dorsiflexion and plantar flexion. In this document the product’s specifications, objectives and expectations are outlined. Included in this document is background information, stage gate process, prototype design development and considerations, and qualification requirements.

House Calls Mobile Virtual Stethoscope, Abigail Lindquist, Abigael Donohue, Trey Nahhas

Biomedical Engineering

The purpose of this scope of work is to outline the progress of the Virtual Stethoscope design and development project as sponsored by House Calls Mobile. This device looks to provide accessible at-home care for patients all over the country through the mobile phone stethoscope attachment. With the virtual stethoscope technology, patients will be able to perform high-quality, in-home observation of heart, stomach, and lung sounds to be transmitted to a physician in real time. Eliminating the need to travel to a doctor’s office encourages patients to perform more regular checkups, increasing their likelihood potentially of life-saving early diagnoses. This …

Sand Foot: A Prosthesis For Walking On Sand, Samantha A. Galicinao, John Dewing, Daniel Dugan Dotson, Christopher Urasaki

Biomedical Engineering

This critical design report describes the product development of a prosthesis for use on sand. Quality of Life Plus (QL+), a national non-profit organization aimed to develop prostheses for veterans and people with disabilities, introduced this project and its accompanying challenger, Sgt. Brady, to Cal Poly’s Interdisciplinary Senior Project class in September 2018. After consulting with Sgt. Brady and QL+ and performing extensive research, the Sand Foot team defined customer requirements and engineering specifications to meet these requirements. Comfortability, durability, and sandproof were key customer requirements. Several conceptual models were brainstormed and a final design was selected based on the …

A Multimodal Approach To Investigate Brain Reorganization After Spinal Cord Injury Using Functional Magnetic Resonance Imaging And Functional Near-Infrared Spectroscopy, Keerthana Deepti Karunakaran

Dissertations

Traumatic Spinal Cord Injury (SCI) results in structural and functional neurological changes at both the brain and the level of the spinal cord. Anatomical studies indicate decreased grey matter volume in sensorimotor and non-sensorimotor regions of the cortex following SCI; whereas, neurophysiological findings mostly report altered functional activity in the sensorimotor nodes of the cortex, subcortex, and cerebellum. Therefore, it is currently unknown whether tissue atrophy observed in non-motor related areas has any concomitant functional consequences. Furthermore, the neural underpinnings of adaptive neuroplasticity after SCI is not well-defined in the current literature. Hence, this dissertation is a pioneer study investigating …

Dual Modality Optical Coherence Tomography : Technology Development And Biomedical Applications, Farzana Rahmat Zaki

Dissertations

Optical coherence tomography (OCT) is a cross-sectional imaging modality that is widely used in clinical ophthalmology and interventional cardiology. It is highly promising for in situ characterization of tumor tissues. OCT has high spatial resolution and high imaging speed to assist clinical decision making in real-time.

OCT can be used in both structural imaging and mechanical characterization. Malignant tumor tissue alters morphology. Additionally, structural OCT imaging has limited tissue differentiation capability because of the complex and noisy nature of the OCT signal. Moreover, the contrast of structural OCT signal derived from tissue’s light scattering properties has little chemical specificity. Hence, …

Interventions Of Waterjet Technology In Skin Incisions, Nadi Atalla

Dissertations

This research explores the use of waterjet (WJ) technology in performing skin incisions. The study defines the analytical relationships between the skin properties and the operating parameters of the WJ which include the skin thickness, its elastic modulus, the WJ pressure, the nozzle’s orifice diameter, its stand-off distance and the traverse speed of the WJ as well as the duration of applying the WJ pressure. An analytical model is developed to measure the depth incision of the skin, the water pressure and the water velocity, while using a WJ. Systemization and optimization models that determine the optimal operating parameters levels …

Temporal And Functional Cortical Aspects Related To Mirror Visual Feedback During Target-Directed Movement In Healthy And Stroke Individuals, Maryam Rohafza

Dissertations

Stroke is the leading cause of disability in the United States (American Heart Association, American Stroke Association) affecting 800,000 individuals annually (i.e., one person every 45 seconds). Therapy for stroke often uses repetitive task practice, which is difficult to perform for patients due to impairment. Mirror visual feedback (MVF) based rehabilitation uses the effect of observing the mirror reflection of volitional movement of one limb, to activate visuomotor brain areas that process movement of the opposite limb. In persons with hemiplegia due to stroke, exercising the less affected limb while observing its reflection, perceived by them as the motion of …

Stress Shielding In Cemented Hip Implants Assessed From Computed Tomography, Bharadwaj Cheruvu, Indresh Venkatarayappa, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Background: Aseptic loosening is the major cause of revisions for hip replacement. This mode of failure is often caused by stress shielding. Stress shielding in the femur occurs when some of the loads are taken by the prosthesis and shielded from going to the bone. There is little information regarding the stress shielding among cemented hip implants. Purpose: The purpose of this study is to investigate the effect of stress shielding on the proximal femur with a femoral prosthesis. Methods: A patient had undergone open reduction and internal fixation (ORIF) due to a comminuted reversed oblique fracture of the right …

Vergence Eye Movement Parameters For Pre/Post-Obvat And Sham Therapy On Binocularly Normal Controls, Joel V. Rajah

Theses

Vergence is the disjunctive movement of the eyes to maintain single binocular vision. Vergence eye movements are necessary to maintain the object of interest on the fovea of each eye as an individual looks from one object to another. Recent studies show that office based vergence/accommodative therapy (OBVAT) is an effective treatment for the binocular dysfunction known as convergence insufficiency. This study was performed to investigate the changes in oculomotor parameters parameter data for pre- and post-therapy subjects who are binocularly normal controls. A haploscope was used to collect eye movement data pre- and post-therapy. The analysis of the eye …

Composite Biomaterial Repair Strategy To Restore Biomechanical Function And Reduce Herniation Risk In An Ex Vivo Large Animal Model Of Intervertebral Disc Herniation With Varying Injury Severity, Warren W. Hom, Melanie Tschopp, Huizi A. Lin, Philip Nasser, Damien M. Laudier, Andrew C. Hecht, Steven B. Nicoll, James C. Iatridis

Publications and Research

Back pain commonly arises from intervertebral disc (IVD) damage including annulus fibrosus (AF) defects and nucleus pulposus (NP) loss. Poor IVD healing motivates developing tissue engineering repair strategies. This study evaluated a composite injectable IVD biomaterial repair strategy using carboxymethylcellulose-methylcellulose (CMC-MC) and genipincrosslinked fibrin (FibGen) that mimic NP and AF properties, respectively. Bovine ex vivo caudal IVDs were evaluated in cyclic compression-tension, torsion, and compression-to-failure tests to determine IVD biomechanical properties, height loss, and herniation risk following experimentally-induced severe herniation injury and discectomy (4 mm biopsy defect with 20% NP removed). FibGen with and without CMC-MC had failure strength similar …

Two And Three-Dimensional Models For Material And Cells Interaction, Nam H. Nguyen

Doctoral Dissertations

Three-dimensional (3D) cell spheroid model has been long considered a better model to mimic in vivo physiology compared to two-dimensional (2D) cell culture model. Traditional 2D cell models provide a simple, convenient and quick technique for drug screening but fail to simulate the complexity and heterogeneity of cells in the in vivo environment. The last few decades have remarked substantial progress toward the advancement of three-dimensional (3D) cell cultures as systems which better mimic cellcell and cell-matrix interaction in the in vivo physiology. Nowadays, 3D cell models have been emerging, not only as an important approach in drug discovery and …

Developing An Optomechanical Approach For Characterizing Mechanical Properties Of Single Adherent Cells, Ali Mehrnezhad

LSU Doctoral Dissertations

Mechanical properties of a cell reflect its biological and pathological conditions including cellular disorders and fundamental cellular processes such as cell division and differentiation. There have been active research efforts to develop high-throughput platforms to mechanically characterize single cells. Yet, many of these research efforts are focused on suspended cells and use a flow-through configuration. Therefore, adherent cells are detached prior to the characterization, which seriously perturbs the cellular conditions. Also, methods for adherent cells are limited in their throughput.

My study is aimed to fill the technical gap in the field of single cell analysis, which is a high-throughput …

Static Accuracy Analysis Of Vicon T40s Motion Capture Cameras Arranged Externally For Motion Capture In Constrained Aquatic Environments, Shreyas L. Raghu, Chang-Kwon Kang, Paul Whitehead, Akifumi Takeyama, Ryan Conners

PRC-Affiliated Research

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the …

Static Accuracy Analysis Of Vicon T40s Motion Capture Cameras Arranged Externally For Motion Capture In Constrained Aquatic Environments, Shreyas L. Raghu, Chang-Kwon Kang, Paul Whitehead, Akifumi Takeyama, Ryan Conners

PRC-Affiliated Research

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the …

Static Accuracy Analysis Of Vicon T40s Motion Capture Cameras Arranged Externally For Motion Capture In Constrained Aquatic Environments, Shreyas L. Raghu, Chang-Kwon Kang, Paul Whitehead, Akifumi Takeyama, Ryan Conners

PRC-Affiliated Research

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the …

Stackcbpred: A Stacking Based Prediction Of Protein-Carbohydrate Binding Sites From Sequence, Suraj Gattani

LSU New Orleans Theses and Dissertations

Carbohydrate-binding proteins play vital roles in many vital biological processes and study of these interactions, at residue level, are useful in treating many critical diseases. Analyzing the local sequential environments of the binding and non-binding regions to predict the protein-carbohydrate binding sites is one of the challenging problems in molecular and computational biology. Prediction of such binding sites, directly from sequences, using computational methods, can be useful to fast annotate the binding sites and guide the experimental process. Because the number of carbohydrate-binding residues is significantly lower than non-carbohydrate-binding residues, most of the methods developed are biased towards over predicting …

A Simplified Crossing Fiber Model In Diffusion Weighted Imaging, Sheng Yang, Kaushik Ghosh, Ken Sakaie, Satya S. Sahoo, Sarah J. Ann Carr, Curtis Tatsuoka

Mathematical Sciences Faculty Research

Diffusion MRI (dMRI) is a vital source of imaging data for identifying anatomical connections in the living human brain that form the substrate for information transfer between brain regions. dMRI can thus play a central role toward our understanding of brain function. The quantitative modeling and analysis of dMRI data deduces the features of neural fibers at the voxel level, such as direction and density. The modeling methods that have been developed range from deterministic to probabilistic approaches. Currently, the Ball-and-Stick model serves as a widely implemented probabilistic approach in the tractography toolbox of the popular FSL software package and …

Predicting Tgf-Β-Induced Epithelial-Mesenchymal Transition Using Data Assimilation, Mario J. Mendez, Matthew J. Hoffman, Elizabeth M. Cherry, Dr. Christopher Lemmon, Seth Weinberg

Biology and Medicine Through Mathematics Conference

No abstract provided.

Color Transparency From Motions Of Backgrounds And Overlays, Zhehao Huang, Qasim Zaidi

MODVIS Workshop

No abstract provided.

Computations Of Top-Down Attention By Modulating V1 Dynamics, David Berga, Xavier Otazu

MODVIS Workshop

The human visual system processes information defining what is visually conspicuous (saliency) to our perception, guiding eye movements towards certain objects depending on scene context and its feature characteristics. However, attention has been known to be biased by top-down influences (relevance), which define voluntary eye movements driven by goal-directed behavior and memory. We propose a unified model of the visual cortex able to predict, among other effects, top-down visual attention and saccadic eye movements. First, we simulate activations of early mechanisms of the visual system (RGC/LGN), by processing distinct image chromatic opponencies with Gabor-like filters. Second, we use a cortical …

Fabrication Of Enhanced Carbon Based Biocompatible And Biodegradable Microelectronic Materials Derived From Lignocellulosic Biomass, Harrison Thomas Hawkins

Theses and Dissertations

The development of materials capable of harmlessly being broken down and removed from the body is a crucial step towards the development of short-term application electronic biomedical implants. Once developed, these implants, known as bioresorbable electronics, will open a wide array of temporary applications in the field of biomedical implantable devices. Necessary to the operation of bioresorbable electronics within the body is a power source that is similarly biocompatible and biodegradable. To this end, enhanced carbon-based materials and a bio-ionic liquid were developed for the fabrication of a preliminary implantable and bioresorbable battery and tested for functional properties. Electrodes were …

Age Dependent Regulation Of Cardiac Sodium Channel Gain Of Function, Madison Nowak, David Ryan King, Steven Poelzing, Seth Weinberg

Biology and Medicine Through Mathematics Conference

No abstract provided.

Coupled Influence Of Heart Rate Variability And Subcellular Calcium Heterogeneity On Cardiac Electromechanical Dynamics, Vrishti M. Phadumdeo, Seth H. Weinberg Ph.D

Biology and Medicine Through Mathematics Conference

No abstract provided.

Immunofluorescence Image Feature Analysis And Clustering Pipeline For Distinguishing Epithelial-Mesenchymal Transition, Shreyas Hirway, Nadiah Hassan, Dr. Christopher Lemmon, Dr. Seth Weinberg

Biology and Medicine Through Mathematics Conference

No abstract provided.

Quantified Measurement Of The Tilt Effect In A Family Of Café Wall Illusions, Nasim Nematzadeh Dr., David Martin Powers Prof.

MODVIS Workshop

This abstract explores the tilt effect in a family of Café Wall illusions using a Classical Gaussian Receptive Field model (CRF). Our model constructs an intermediate representation called edge map at multiple scales (Fig. 1) that reveals tilt cues and clues involved in the illusory perception of the Café Wall pattern. We investigate a wide range of parameters of the stimulus including mortar width, luminance, tiles contrast, and phase of the tile displacement (the stimuli in Fig. 2). We show that this simple bioplausible model, simulating the contrast sensitivity of the retinal ganglion cells, can not only detect the tilts …

An Observer Model Version Of General Recognition Theory, Fabian Soto Phd

MODVIS Workshop

No abstract provided.

Approaches To Understanding The Function Of Intrinsic Activity And Its Relationship To Task-Evoked Activity In The Human Brain, Dohyun Kim

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditionally neuroscience research has focused on characterizing the topography and patterns of brain activation evoked by specific cognitive or behavioral tasks to understand human brain functions. This activation-based paradigm treated underlying spontaneous brain activity, a.k.a. intrinsic activity, as noise hence irrelevant to cognitive or behavioral functions. This view, however, has been profoundly modified by the discovery that intrinsic activity is not random, but temporally correlated at rest in widely distributed spatiotemporal patterns, so called resting state networks (RSN). Studies of temporal correlation of spontaneous activity among brain regions, or functional connectivity (FC), have yielded important insights into the network organization …