Engineering Commons^™

Fluid Powered Miniature In Vivo Robots For Minimally Invasive Surgery (Mis), Abolfazl Pourghodrat

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Minimizing the invasiveness of surgery is believed to improve patient outcomes. Bleeding, infection, and pain are major concerns in surgery afflicting patients for decades. Minimally invasive techniques have come into play to reduce these concerns and smooth the evolution of abdominal surgery to a scarless process where nearly all surgeries can be performed without a skin incision. Technology continually advances the frontier of development of novel surgical devices to implement less invasive surgical techniques.

Fusion of robotics and Minimally Invasive Surgery (MIS) has created new opportunities to develop diagnostic and therapeutic tools. Surgical robotics is advancing from externally actuated systems …

Construction Of 3d Biomimetic Tissue Niches For Directing Pancreatic Lineage Differentiation Of Human Embryonic Stem Cells, Weiwei Wang

Graduate Theses and Dissertations

The potential of human embryonic stem cells (hESCs) to differentiate into insulin producing beta cells offers great hope for cell-based therapy for diabetes treatment. However, in vitro pancreatic differentiation of hESCs remains challenging. In the past decade, most protocols for differentiating pancreatic cells have been focused on the use of signaling molecule cocktails on 2D substrates. Studies on embryonic development biology strongly suggest that extracellular matrix (ECM) plays a critical role on hESCs behavior. In this work, we first established a 3D collagen scaffold culture system for hESCs differentiating into definitive endoderm (DE), which is the first and most important …

Platform Technologies To Advance Clinically Relevant Tissue Engineered Heart Valve Products, Leslie Neil Sierad

All Dissertations

Diseased heart valves are commonly replaced by mechanical, bioprosthetic, or allograft heart valves. These replacements provide major improvements in cardiac function and quality of life, but have significant limitations and eventually require surgical replacement within 15-20 years. These risks are particularly prominent in pediatric patients and young adults. The field of tissue engineering and regenerative medicine, which combines scaffolds and cells, holds great promise in developing living replacement heart valves that would self-repair and grow in size along with the growing children.

The long-term goal of this project is to generate living, tissue-engineered heart valves from biological scaffolds and autologous …

Self-Assembly Of Gold Nanosphere Dimers By Inertial Force, George Andrew Christopher Sakhel

Graduate Theses and Dissertations

The morphology and composition of a nanoparticle (NP) play a critical role in determining the NP's properties and function. To date, researchers have created a myriad of NPs of different shapes, sizes, and compositions with interesting attributes and applications ushering a revolution in medicine, electronics, microscopy, and microfluidics.

In this study, gold (Au) nanosphere dimers (NSDs) have been synthesized through a novel self-assembly method. These particles were created from Au NPs mono-dispersed in aqueous solution via a process of centrifugation and capping agent replacement. Au NSDs consist of two Au NPs combined together with minimal gaps between them. Optical spectral …

A Novel Cell Based Assay For Mmp Inhibitor Screening, Pantrika Krisanarungson

Graduate Theses and Dissertations

Up to date, a plethora of protein based materials are used as implants to stimulate tissue regeneration or fillers to alleviate tissue or organ impairment. This includes glottal insufficiency, urinary bladder incontinence and especially in cosmetic industrial to improve facial contour. Once in vivo, protein-based materials are decomposed by cell secreted matrix metalloproteinases (MMP) and lose their volume within months. By introducing MMP inhibitor (MMPI), the extent of material degradation over time may be reduced. In this dissertation, the development of cell-based assay capable of identifying MMPI candidates for protein-based implant lifetime prolongation is described. To visualize the degradation, DQ-gelatin, …

Upper Extremity Biomechanics Of Children With Spinal Cord Injury During Wheelchair Mobility, Alyssa J. Schnorenberg, Brooke A. Slavens, Adam Graf, Joseph J. Krzak, Lawrence C. Vogel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

While much work is being done evaluating the upper extremity joint dynamics of adult manual wheelchair propulsion, limited work has examined the pediatric population of manual wheelchair users. Our group used a custom pediatric biomechanical model to characterize the upper extremity joint dynamics of 12 children and adolescents with spinal cord injury (SCI) during wheelchair propulsion. Results show that loading appears to agree with that of adult manual wheelchair users, with the highest loading primarily seen at the glenohumeral joint. This is concerning due to the increased time of wheelchair use in the pediatric population and the impact of this …

Non-Common Path Aberration Correction In An Adaptive Optics Scanning Ophthalmoscope, Yusufu N. Sulai, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

The correction of non-common path aberrations (NCPAs) between the imaging and wavefront sensing channel in a confocal scanning adaptive optics ophthalmoscope is demonstrated. NCPA correction is achieved by maximizing an image sharpness metric while the confocal detection aperture is temporarily removed, effectively minimizing the monochromatic aberrations in the illumination path of the imaging channel. Comparison of NCPA estimated using zonal and modal orthogonal wavefront corrector bases provided wavefronts that differ by ~λ/20 in root-mean-squared (~λ/30 standard deviation). Sequential insertion of a cylindrical lens in the illumination and light collection paths of the imaging channel was used to compare image resolution …

The Reliability Of Parafoveal Cone Density Measurements, Benjamin S. Liu, Sergey Tarima, Alexis D. Visotcky, Alex Pechauer, Robert F. Cooper, Leah Landsem, Melissa A. Wilk, Pooja Godara, Vikram Makhijani, Yusufu N. Sulai, Najia Syed, Galen Yasumura, Anupam K. Garg, Mark E. Pennesi, Brandon J. Lujan, Alfredo Dubra, Jacque L. Duncan, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Background Adaptive optics scanning light ophthalmoscopy (AOSLO) enables direct visualisation of the cone mosaic, with metrics such as cone density and cell spacing used to assess the integrity or health of the mosaic. Here we examined the interobserver and inter-instrument reliability of cone density measurements.

Methods For the interobserver reliability study, 30 subjects with no vision-limiting pathology were imaged. Three image sequences were acquired at a single parafoveal location and aligned to ensure that the three images were from the same retinal location. Ten observers used a semiautomated algorithm to identify the cones in each image, and this was repeated …

Design Of The High-Speed Stereo Radiography System, John C. Ivester Iv

Electronic Theses and Dissertations

Orthopaedic pathologies often involve disruption of the mechanical environment of a joint at/below the mm scale. The ability to measure biomechanical kinematics at the sub-mm scale is essential for obtaining valuable insight into pathologies, but small motions of the joints are difficult to quantify. Estimates of skeletal kinematics are commonly made from optical motion capture systems and markers placed on the skin. The error caused by external marker movement is largely avoided with x-ray motion capture. Dynamic radiography uses a series of x-ray images recorded at high-speed and captures in-vivo joint motion. Uncovering the mechanical foundation of orthopaedic pathologies requires …

The Effect Of Platelet-Rich Plasma (Prp) On Muscle Contusion Healing In A Rat Model., Demetris Delos, Matthew J. Leineweber, Salma Chaudhury, Saif Alzoobaee, Yingxin Gao, Scott Alan Rodeo

Faculty Publications

Background: Current therapy for muscle contusions is usually limited to nonsteroidal anti-inflammatory drugs and/or use of the RICE principle (rest, ice, compression, elevation); thus, other forms of treatment that can potentially accelerate the rate of healing are desirable. Hypotheses: A local injection of platelet-rich plasma (PRP) would lead to accelerated healing rates compared with controls; also, delayed administration of PRP would lead to a blunted response compared with immediate treatment. Study Design: Controlled laboratory study. Methods: Forty-six male Lewis rats each underwent a single blunt, nonpenetrating impact to the gastrocnemius muscle via a drop-mass technique and subsequently received either a …

Development Of An Efficient Human Hepatocyte Culture Platform For Assessing Novel Therapeutic Efficacy Against Plasmodium Liver Parasites, Steven Patrick Maher

USF Tampa Graduate Theses and Dissertations

Malaria is a critical and global public health problem, affecting over 200 million people every year, resulting in over 500,000 deaths. A vaccine is not currently available and only one drug, primaquine, is effective against the dormant stages of Plasmodium vivax. Preclinical assessment of novel therapeutic drugs and vaccines is hampered by the lack of an in vitro liver model for P. falciparum and P. vivax. To provide a stable human hepatocyte-based culture platform for parasite development, we engineered a microfluidic bilayer device capable of both simple and complex culture methods, including perfusion and co-culture, to better understand the requirements …

31p Dynamic Nuclear Polarization Applied To Dimethyl Methyl Phphonate For Functional Imaging And Spectroscopic Studies, Roha Afzal

USF Tampa Graduate Theses and Dissertations

In the recent years, Dynamic Nuclear Polarization (DNP) has emerged as a very promising technique for enhancing the sensitivity of the magnetic resonance spectroscopy and imaging (MRSI). A number of nuclei, namely 13C, 15N, 29Si, 89Y, and 129Xe, have been successfully polarized and a few of them have been employed in the in-vivo studies for functional imaging and metabolism. Hyperpolarized 13C-labeled compounds have wide applications in the metabolic and perfusion studies and can be used for early stage disease diagnosis, response to treatment, prognosis etc. DNP has been demonstrated in the 31P nucleus in nucleotides triphosphates as an application for …

Localized Expansion Of Pedicle Screws For Increased Stability And Safety In The Osteoporotic Spine, Thomas Michael Shea

USF Tampa Graduate Theses and Dissertations

When a patient is diagnosed with various spinal injuries, deformities, or advanced degeneration, it is commonly suggested that he/she undergoes surgery for spinal fusion. Most current procedures in spinal fusion restrict mobility in one or multiple levels of the spine so that, over time, new bone will grow between the levels creating a single motionless unit of bone. The bilateral pedicle screw system (BPSS) has long been considered to be the "gold standard" in spinal fusion. However, for patients with osteoporosis, adequate fixation within the bone-screw interface has continuously been difficult to achieve or has come with high risk of …

Biomechanical Evaluation Of Fracture Fixation Constructs Using A Variable-Angle Locked Periprosthetic Femur Plate System, Martin F. Hoffmann, Travis A. Burgers, James J. Mason, Bart O. Williams, Debra L. Sietsema

Mechanical Engineering Faculty Publications

Background
In the United States there are more than 230,000 total hip replacements annually, and periprosthetic femoral fractures occur in 0.1–4.5% of those patients. The majority of these fractures occur at the tip of the stem (Vancouver type B1). The purpose of this study was to compare the biomechanically stability and strength of three fixation constructs and identify the most desirable construct.
Methods
Fifteen medium adult synthetic femurs were implanted with a hip prosthesis and were osteotomized in an oblique plane at the level of the implant tip to simulate a Vancouver type B1 periprosthetic fracture. Fractures were fixed with …

Investigation Of Membrane Mechanics Using Spring Networks: Application To Red-Blood-Cell Modelling, Mingzhu Chen, Fergal Boyle

Articles

In recent years a number of red-blood-cell (RBC) models have been proposed using spring networks to represent the RBC membrane. Some results predicted by these models agree well with experimental measurements. How- ever, the suitability of these membrane models has been questioned. The RBC membrane, like a continuum mem- brane, is mechanically isotropic throughout its surface, but the mechanical properties of a spring network vary on the network surface and change with deformation. In this work spring-network mechanics are investigated in large deformation for the first time via an assessment of the effect of network parameters, i.e. network mesh, spring …

Thermoelectric Elisa For Quantification Of 8ohdg In A Microfluidic Device, Gergana Nestorova

Doctoral Dissertations

This research demonstrates the feasibility of a novel method for performing thermoelectric enzyme-linked immunosorbent assay (ELISA) in a microfluidic device. The feasibility of the thermoelectric ELISA is demonstrated by measuring the concentration of 8-hydroxy 2-deoxyguanosine (8OHdG) in urine samples from amyloid precursor protein (APP) transgenic mice. The detection method is based on formation of a complex between 8OHdG and anti-8OHdG capture antibody conjugated to biotin. The complex is immobilized over the measuring junctions of a thermopile via biotin streptavidin interaction. The concentration of the analyte is determined by using enzyme linked secondary IgG antibody specific to the primary one. The …

The Effects Of Chronic Neural Implantation On Localized Vasculature, Andrew L. Ready

Open Access Theses

Prosthetic solutions currently available range from simple devices intended for aesthetics purposes to complex systems attempting to restore lost function and sensation; of these methods, none show more promise in restoration of normal function and life satisfaction than neural prosthetics. These devices directly interface with the nervous system in order to restore realistic function and feeling to the patient, potentially returning them to how their life once was. While in some cases patients requiring prosthetics can utilize peripheral nerves, those who suffer from injuries or disease which cause damage to the central nervous system can necessitate the usage of devices …

Particle Swarm Optimization Using Multiple Neighborhood Connectivity And Winner Take All Activation Applied To Biophysical Models Of Inferior Colliculus Neurons, Brandon S. Coventry

Open Access Theses

Age-related hearing loss is a prevalent neurological disorder, affecting as many as 63% of adults over the age of 70. The inability to hear and understand speech is a cause of much distress in aged individuals and is becoming a major public health concern as age-related hearing loss has also been correlated with other neurological disorders such as Alzheimer's dementia. The Inferior Colliculus (IC) is a major integrative auditory center, receiving excitatory and inhibitory inputs from several brainstem nuclei. This complex balance of excitation and inhibition gives rise to complex neural responses, which are measured in terms of firing rate …

Standardizing The Collection And Measurement Of Glucose In Exhaled Breath And Its Relationship To Blood Glucose Concentrations, Mark Hamilton

Open Access Theses

Blood glucose level control (glycemic control) is crucial in diabetes. Limitations in current commercially available monitoring devices include causing patient pain leading to poor blood glucose level management. The development of a non-invasive measurement system may lead to improved patient glycemic control, reducing unwanted side-effects and complications of poor blood glucose level maintenance.

This work explores the use of glucose within exhaled breath in attempt to establish an indirect method of blood glucose level measurement. Specifically, exhaled breath condensate (EBC) is examined. A breath condensing unit was designed to measure the temperature of the system, flow rate, volume of expired …

Frontal White Matter Integrity In Adults With Down Syndrome With And Without Dementia, David K. Powell, Allison Caban-Holt, Greg A. Jicha, William C. Robertson, Roberta Davis, Brian T. Gold, Frederick A. Schmitt, Elizabeth Head

Magnetic Resonance Imaging and Spectroscopy Center Faculty Publications

Adults with Down syndrome (DS) are at high risk for developing Alzheimer's disease after the age of 40 years. To detect white matter (WM) changes in the brain linked to dementia, fractional anisotropy (FA) from diffusion tensor imaging was used. We hypothesized that adults with DS without dementia (DS n = 10), DS with dementia (DSAD n = 10) and age matched non-DS subjects (CTL n = 10) would show differential levels of FA and an association with scores from the Brief Praxis Test and the Severe Impairment Battery. WM integrity differences in DS compared with CTL were found predominantly …

Relationship Between Foveal Cone Specialization And Pit Morphology In Albinism, Melissa A. Wilk, John T. Mcallister, Robert F. Cooper, Adam M. Dubis, Teresa N. Patitucci, Phyllis Summerfelt, Jennifer L. Anderson, Deborah M. Costakos, Thomas B. Connor Jr., William J. Wirostko, Pei-Wen Chiang, Alfredo Dubra, Christine A. Curcio, Murray H. Briliant, C. Gail Summers, Joseph Carroll, Jennifer L. Anderson

Biomedical Engineering Faculty Research and Publications

Purpose. Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism.

Methods. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects …

Automated Selection Of The Optimal Cardiac Phase For Single-Beat Coronary Ct Angiography Reconstruction, Daniel Stassi

Master's Theses (2009 -)

This thesis investigates an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. Reconstructing a low-motion cardiac phase improves coronary artery visualization in coronary CT angiography (CCTA) exams. Currently, standard end-systole and/or mid-diastole default phases are prescribed or alternatively, quiescent phases are determined by the user. As manual selection may be time-consuming and standard locations may be suboptimal due to patient variability, an automated method is investigated. An automated algorithm was developed to select the optimal phase based on quantitative image quality (IQ) metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated …

The Effects Of Organ-Based Tube Current Modulation On Radiation Dose And Image Quality In Computed Tomography Imaging, Diksha Gandhi

Master's Theses (2009 -)

The purpose of this thesis was to quantify dose and noise performance of organ-dose-based tube current modulation (ODM) through experimental studies with an anthropomorphic phantom and simulations with a voxelized phantom library. Tube current modulation is a dose reduction technique that modulates radiation dose in angular and/or slice directions based on patient attenuation. ODM technique proposed by GE Healthcare further reduces tube current for anterior source positions, without increasing current for posterior positions. Axial CT scans at 120 kV were performed on head and chest phantoms (Rando Alderson Research Laboratories, Stanford, CA) on an ODM-equipped scanner (Optima CT660, GE Healthcare, …

Empirical Modeling Of Asynchronous Scalp Recorded And Intracranial Eeg Potentials, Komalpreet Kaur

Electrical & Computer Engineering Theses & Dissertations

A Brain-Computer Interface (BCI) is a system that allows people with severe neuromuscular disorders to communicate and control devices using their brain signals. BCIs based on scalp-recorded electroencephalography (s-EEG) have recently been demonstrated to provide a practical, long-term communication channel to severely disabled users. These BCIs use time-domain s-EEG features based on the P300 event-related potential to convey the user's intent. The performance of s-EEG-based BCIs has generally stagnated in recent years, and high day-to-day performance variability exists for some disabled users. Recently intracranial EEG (i-EEG), which is recorded from the cortical surface or the hippocampus, has been successfully used …

Numerical Study Of Poration And Ionic Conduction In Nanopores Caused By High-Intensity, Nanosecond Pulses In Cell, Hao Qiu

Electrical & Computer Engineering Theses & Dissertations

This dissertation focuses on the dynamics and bioeffects of electroporation of biological cell and ionic conduction in nanopores under high-intensity, nanosecond pulses. The electroporation model utilized the current continuity equation and the asymptotic Smoluchowski equation to explore the transmembrane potential and pore density of the plasma and intracellular membranes; the ionic conduction model employed the Poisson-Nernst-Planck equations and the Navier-Stokes equations to analyze the ionic current and ion concentration profile.

Nanosecond electric pulses of high-intensity amplitude can initiate electroporation of intracellular organelles. The pulse parameters and cell electrical properties, that can selectively electroporate liposomes but keep the plasma and nuclear …

Implementation Of Analytical Fatigue Models Into Opensim To Predict The Effects Of Fatigue On Anterior Cruciate Ligament Loading, Michael A. Samann

Mechanical & Aerospace Engineering Theses & Dissertations

The anterior cruciate ligament (ACL) provides stability to the knee joint while performing activities such as a side step cut. Neuromuscular fatigue, a reduction in muscle force producing capabilities, alters lower extremity mechanics while performing a side step cut and may increase the risk of ACL injury, particularly in females. Musculoskeletal modeling allows for the measurement of muscle forces, which are difficult to measure in-vivo. Therefore, musculoskeletal modeling, may improve our understanding of the effects of neuromuscular fatigue on muscle force production and loading of the ACL. Therefore, the purpose of this study was to develop a musculoskeletal model which …

Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson

Department of Mechanical and Materials Engineering: Faculty Publications

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further understand …

Effect Of Lowest Instrumented Vertebra On Trunk Mobility In Patients With Adolescent Idiopathic Scoliosis Undergoing A Posterior Spinal Fusion, Ubong I. Udoekwere, Joseph Krzak, Adam Graf, Sahar Hassani, Sergey Tarima, Mary Riordan, Peter F. Sturm, Kim W. Hammerberg, Purnendu Gupta, Alireza K. Anissipour, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Study Design

Prospective.

Objectives

The goal of this study was to evaluate the effect of posterior spinal fusion surgery terminating at different lowest instrumented vertebrae (LIV) on trunk mobility in individuals with adolescent idiopathic scoliosis (AIS).

Summary of Background Data

Posterior spinal fusion with instrumentation is the standard surgical technique employed in AIS for correcting spine deformities with Cobb angles exceeding 50°. Surgical correction of curve deformity reduces trunk mobility and range of motion. However, conflicting findings from previous studies investigating the impact of different LIV levels on the reduction in trunk mobility after surgery have been reported.

Methods

The …

Microscopic Inner Retinal Hyper-Reflective Phenotypes In Retinal And Neurologic Disease, Drew Scoles, Brian P. Higgins, Robert F. Cooper, Adam M. Dubis, Phyllis Summerfelt, David V. Weinberg, Judy E. Kim, Kimberly E. Stepien, Joseph Carroll, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

Purpose.

We surveyed inner retinal microscopic features in retinal and neurologic disease using a reflectance confocal adaptive optics scanning light ophthalmoscope (AOSLO).

Methods.

Inner retinal images from 101 subjects affected by one of 38 retinal or neurologic conditions and 11 subjects with no known eye disease were examined for the presence of hyper-reflective features other than vasculature, retinal nerve fiber layer, and foveal pit reflex. The hyper-reflective features in the AOSLO images were grouped based on size, location, and subjective texture. Clinical imaging, including optical coherence tomography (OCT), scanning laser ophthalmoscopy, and fundus photography was analyzed for comparison.

Results.

Seven …

Measuring Tumor Cycling Hypoxia And Angiogenesis Using A Side-Firing Fiber Optic Probe, Bing Yu, Amy Shah, Bingqing Wang, Narasimhan Rajaram, Quanli Wang, Nirmala Ramanujam, Gregory M. Palmer, Mark W. Dewhirst

Biomedical Engineering Faculty Research and Publications

Hypoxia and angiogenesis can significantly influence the efficacy of cancer therapy and the behavior of surviving tumor cells. There is a growing demand for technologies to measure tumor hypoxia and angiogenesis temporally in vivo to enable advances in drug development and optimization. This paper reports the use of frequency-domain photon migration with a side-firing probe to quantify tumor oxygenation and hemoglobin concentrations in nude rats bearing human head/neck tumors administered with carbogen gas, cycling hypoxic gas or just room air. Significant increase (with carbogen gas breathing) or decrease (with hypoxic gas breathing) in tumor oxygenation was observed. The trend in …