Biomedical Engineering and Bioengineering Commons^™

Identifying And Predicting Rat Behavior Using Neural Networks, Jonathan A. Gettner

Master's Theses

The hippocampus is known to play a critical role in episodic memory function. Understanding the relation between electrophysiological activity in a rat hippocampus and rat behavior may be helpful in studying pathological diseases that corrupt electrical signaling in the hippocampus, such as Parkinson’s and Alzheimer’s. Additionally, having a method to interpret rat behaviors from neural activity may help in understanding the dynamics of rat neural activity that are associated with certain identified behaviors.

In this thesis, neural networks are used as a black-box model to map electrophysiological data, representative of an ensemble of neurons in the hippocampus, to a T-maze, …

Voxel-Level Absorbed Dose Calculations With A Deterministic Grid-Based Boltzmann Solver For Nuclear Medicine And The Clinical Value Of Voxel-Level Calculations, Justin Mikell

Dissertations and Theses (Open Access)

Voxel-level absorbed dose (VLAD) is rarely calculated for nuclear medicine (NM) procedures involving unsealed sources or 90Y microspheres (YM). The current standard of practice for absorbed dose calculations in NM utilizes MIRD S-values, which 1) assume a uniform distribution in organs, 2) do not use patient specific geometry, and 3) lack a tumor model. VLADs overcome these limitations. One reason VLADs are not routinely performed is the difficulty in obtaining accurate absorbed doses in a clinically acceptable time. The deterministic grid-based Boltzmann solver (GBBS) was recently applied to radiation oncology where it was reported as fast and accurate for both …

Effects Of Growth Factor Supplementation And Environmental Conditions On Human Adipose-Derived Stem Cell Differentiation Towards Urothelial Lineage, James Turner

All Dissertations

In recent years, tissue engineering of the bladder has undergone many technological advances. Autologous urothelial cells have been used in animal models and have shown increased performance for ureteral reconstruction compared to unseeded grafts. However, since patients may lack a reliable source of native urothelial cells due to the nature of their specific bladder disease, autologous cells are not an ideal source clinically, and an alternate cell source must be explored. Adipose derived stem cells (ADSCs) are an attractive cell source for such regenerative medicine applications as they have been extensively studied for their multipotential differentiation, immunosuppressive properties, ease of …

Synthesis And Functional Evaluation Of Peptide Modified Poly (Lactic-Co-Glycolic Acid) Nanoparticles To Inhibit Porphyromonas Gingivalis Biofilm Formation., Paridhi Kalia

Electronic Theses and Dissertations

Periodontal disease is an oral inflammatory disorder that afflicts roughly 46% of the adults in the U.S. Currently, treatment of periodontal disease involves the removal of plaque from the gingival pocket (with possible antibiotic treatment) and if necessary, gingival surgery. To our knowledge, no therapeutic approach exists that promotes host-biofilm homeostasis by limiting pathogen recolonization of the oral cavity after prophylaxis or treatment. The interaction of the pathogen Porphyromonas gingivalis with commensal streptococci is critical for initiation of periodontitis and represents a target for limiting P. gingivalis colonization of the oral cavity. Previous studies showed that a synthetic peptide …

Retinal Architecture In ​Rgs9- And ​R9ap-Associated Retinal Dysfunction (Bradyopsia), Rupert W. Strauss, Adam M. Dubis, Robert F. Cooper, Rola Ba-Abbad, Anthony T. Moore, Andrew R. Webster, Alfredo Dubra, Joseph Carroll, Michel Michaelides

Biomedical Engineering Faculty Research and Publications

Purpose

To characterize photoreceptor structure and mosaic integrity in subjects with RGS9- and R9AP-associated retinal dysfunction (bradyopsia) and compare to previous observations in other cone dysfunction disorders such as oligocone trichromacy.

Design

Observational case series.

Methods

setting: Moorfields Eye Hospital (United Kingdom) and Medical College Wisconsin (USA). study population: Six eyes of 3 subjects with disease-causing variants in RGS9 or R9AP. main outcome measures: Detailed retinal imaging using spectral-domain optical coherence tomography and confocal adaptive-optics scanning light ophthalmoscopy.

Results

Cone density at 100 μm from foveal center ranged from 123 132 cones/mm²to 140 013 cones/mm^{2 …}

Feasibility Of Using Raman-Based Techniques For Breast Cancer Detection, Sara Mollamohammada

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Breast cancer is one of the common types of cancer among women all over the world. Early diagnosis is an effective way that improve the treatment process and gives the patients a better chance of survival. Many of the patients infected by breast cancer choose breast conservation surgery (BCS). However, some of those will be subjected to mastectomy, and many will have tumor recurrence as there is no precise technique to show the tumor margins. Raman-based methods are powerful techniques with potential to rapidly differentiate normal from tumor tissues and provides a solution to detect tumor margin. This is because …

Development Of A Vascularized, Induced Pluripotent Stem Cell-Derived Liver-Tissue Mimic For Therapeutic Applications., Venkat Madhav Ramakrishnan

Electronic Theses and Dissertations

This dissertation describes the incorporation of several technologies (stem cells, gene therapy, tissue engineering and regenerative medicine) into a single project that aims to produce a liver-tissue mimic for therapeutic applications. The liver is arguably one of the most complex organs in the body. In addition to its remarkable capacity to regenerate, it performs a host of vital functions. As a result, its impairment has widespread systemic consequences. The work described herein focused on the liver in the context of cardiovascular disease and used the heritable disorder Familial Hypercholesterolemia (FH) as a clinical disease model. As (a) the only definitive …

Novel Biomechanical Test Method For Cancellous Bone Screws And Screw Augmentation With Cement., Kevin Lancaster

Electronic Theses and Dissertations

It is often difficult to achieve adequate screw fixation for plate constructs in fractures with poor quality bone or in metaphyseal bone with extensive bone loss or comminution[7][17]. Furthermore, rescuing or augmenting failed screw fixation in inadequate bone with various cement products has yielded mixed results when tested with pure axial pullout loading[20][21]. In most cases, plate/screw constructs experience both vertical (translational) and horizontal (pullout) forces during physiologic loading[17][20][21]. The increased use of locked screws in plate constructs has also changed the loading patterns of bone screws. For this study, a novel “toggle-out” testing method was developed to more realistically …

Biomineralization And Biocompatibility Studies Of Bone Conductive Scaffolds Containing Poly(3,4-Ethylenedioxythiophene):Poly(4-Styrene Sulfonate) (Pedot:Pss), Mostafa Yazdimamaghani, Mehdi Razavi, Masoud Mozafari, Daryoosh Vashaee, Hari Kotturi, Lobat Tayebi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Considering the well-known phenomenon of enhancing bone healing by applying electromagnetic stimulation, manufacturing conductive bone scaffolds is on demand to facilitate the delivery of electromagnetic stimulation to the injured region, which in turn significantly expedites the healing procedure in tissue engineering methods. For this purpose, hybrid conductive scaffolds composed of poly(3,4-ethylenedioxythiophene), poly (4-styrene sulfonate) (PEDOT:PSS), gelatin (Gel), and bioactive glass (BaG) were produced employing freeze drying technique. Concentration of PEDOT:PSS were optimized to design the most appropriate conductive scaffold in terms of biocompatibility and cell proliferation. More specifically, scaffolds with four different compositions of 0, 0.1, 0.3 and 0.6 % …

Image Processing And Visualization Of Terahertz Pulsed Imaging Of Breast Cancer Tumors, Yuhao Wu

Graduate Theses and Dissertations

Terahertz imaging technology has grown substantially in recent years. With new advances made in the generation, manipulation, and detection of terahertz radiation, terahertz imaging has found its application as inspection tools in a wide range of areas including biomedicine, materials science, and aerospace industries. In the field of medical imaging, terahertz (THz) has emerged as a new imaging modality due to some fundamental physical properties of the THz wave. THz imaging has been used to examine various biological structures, and THz tomography has been developed to probe the 3D structures of those samples.

THz pulsed imaging (TPI) is one of …

Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu

Graduate Theses and Dissertations

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in …

Storage Of Round And Square Switchgrass Bales: Effect Of Storage Time And Fungal Inoculation On Saccharification Efficiency, Noaa Frederick

Graduate Theses and Dissertations

To produce fermentable sugars from lignocellulosic biomass feedstock, severe pretreatment conditions are needed (either high acid concentration, temperature, or retention times). High severities can produce toxic byproducts which inhibit enzymatic hydrolysis or fermentation. In order to reduce pretreatment severities (and thus increase enzyme and fermentation efficiency), the white-rot fungus Pleurotus ostreastus was seeded into square and round bales of Kanlow switchgrass (Panicum virgastum L.) and left in the field over a period of 9 month. The laccase producing fungus is believed to selectively degrade lignin, a common plant structural polymer, which can function as an enzymatic inhibitor. Samples were taken …

Rupture In Abdominal Aortic Aneurysm, Qusay Alfaori

Graduate Theses and Dissertations

Quantification of abdominal aortic aneurysm development, its growth kinetics, and rupture criteria are important to decrease the risk of this life-threatening event. Uniaxial testing of healthy and collagen degraded aortic specimens from pigs was performed. A mathematical model, from the literature, for the stress-strain relationship that is suitable for describing the behavior of abdominal aortic tissue was used to derive specific tissue properties/parameters as a function of strain rate and as a function of specimen orientation. Analyses consisting of Finite Element Modeling of healthy and collagen degraded abdominal aortas were performed using ABAQUS finite element code and the measured properties. …

Modulation Of Valve Interstitial Cell Function Through Cell Shape And Phenotype, Atefeh Razavi

Graduate Theses and Dissertations

The aortic valve is a highly dynamic structure responding to actively to the chemical, mechanical and physical cues of the valve microenvironment. Valve interstitial cells are dispersed throughout the valve tissue and play an important role in maintaining the integrity and optimum function of the valve. They are a heterogeneous population composed of various phenotype. These phenotypes have specific functions characteristic of valve physiological and pathological conditions. The effect of mechanical loading and chemical modulators on the behavior of the valve interstitial cells have largely been studied. However the role of valve interstitial cell shape as an intrinsic physical cue …

Wireless Monitoring Of Driver's Pulse Rate And Temperature Using Hand Gloves Approach, Rohith Reddy Narala

Graduate Theses and Dissertations

There is growing concern about dangers correlated with driving, for people with known cardiovascular diseases. However, the association between having a chronic cardiovascular disease and being involved in a motor vehicle crash remains controversial. This study aims to monitor people with known medical emergencies or other medical conditions while driving [1]. It also helps the co-passengers to be cautious while the person is driving with an abnormal health condition. Designed it to be convenient and also can be easily adaptable by the end user.

The proposed project focuses on a wearable sensor glove that equipped with a pulse rate sensor, …

Prediction Of Rupture In Abdominal Aortic Aneurysm, Qusay Alfaori

Graduate Theses and Dissertations

Studying the development of abdominal aortic aneurysm (AAA) through quantification of its growth kinetics and rupture criteria is important to decrease the risk of this life-threatening event. Uniaxial and biaxial testing of healthy and time-dependent Type-I collagen degraded aortic specimens from pigs was performed. Stress-strain suitable mathematical models describing the behavior of abdominal aortic tissue were utilized to derive specific tissue properties and parameters. Reduction in Type-I collagen fraction was observed using picrosirius red staining method, bright field microscopy, and MATLAB. Finite Element Modeling (FEM) of healthy and time-dependent Type-I collagen degraded abdominal aortas were performed using ABAQUS finite element …

Improved Sensitivity To Fluorescence For Cancer Detection In Wide-Field Image-Guided Neurosurgery, Michael Jermyn, Yoann Gosselin, Pablo A. Valdes, Mira Sibai, Kolbein Kolste

Dartmouth Scholarship

In glioma surgery, Protoporphyrin IX (PpIX) fluorescence may identify residual tumor that could be resected while minimizing damage to normal brain. We demonstrate that improved sensitivity for wide-field spectroscopic fluorescence imaging is achieved with minimal disruption to the neurosurgical workflow using an electron-multiplying charge-coupled device (EMCCD) relative to a state-of-the-art CMOS system. In phantom experiments the EMCCD system can detect at least two orders-of-magnitude lower PpIX. Ex vivo tissue imaging on a rat glioma model demonstrates improved fluorescence contrast compared with neurosurgical fluorescence microscope technology, and the fluorescence detection is confirmed with measurements from a clinically-validated spectroscopic probe. Greater PpIX …

Optofluidic Spectroscopy Platform For Detection Of Hemolysis, Edikan Archibong

USF Tampa Graduate Theses and Dissertations

In the United States alone, hundreds of millions of blood tests are performed annually, and a significant number of those tests are compromised due to hemolysis: e.g., 31% compromised in emergency rooms (inpatient) and 10% at blood banks, clinics, and other outpatient venues. Currently there is no way to reliably detect hemolysis without plasma separation. As a result, significant delays ensue, potentially negatively affecting patient diagnosis and treatment. In addition to in vitro hemolysis, which compromises the quality of blood tests, hemolysis can also occur in vivo. The in vivo occurrence of hemolysis is an indication of life-threatening complications. …

Calibration And Optimization Of 3d Digital Breast Tomosynthesis Guided Near Infrared Spectral Tomography, Kelly E. Michaelsen, Venkataramanan Krishnaswamy, Linxi Shi, Srinivasan Vedantham, Steven Poplack, Andrew Karellas, Brian Pogue, Keith Paulsen

Dartmouth Scholarship

Calibration of a three-dimensional multimodal digital breast tomosynthesis (DBT) x-ray and non-fiber based near infrared spectral tomography (NIRST) system is challenging but essential for clinical studies. Phantom imaging results yielded linear contrast recovery of total hemoglobin (HbT) concentration for cylindrical inclusions of 15 mm, 10 mm and 7 mm with a 3.5% decrease in the HbT estimate for each 1 cm increase in inclusion depth. A clinical exam of a patient's breast containing both benign and malignant lesions was successfully imaged, with greater HbT was found in the malignancy relative to the benign abnormality and fibroglandular regions (11 μM vs. …

Determination Of The Frequency Response Of An End Tidal Co2 Analyser, Kabita Shakya, Catherine Deegan, Fran Hegarty

The ITB Journal

In a health care environment, mechanical ventilation is used to support patients during acute illness and surgery. Mechanical ventilation is the process by which the patient’s respiratory function is artificially supported using a respirator. During mechanical ventilation, it is necessary to ensure the adequacy of ventilation. The patient is thus monitored for several ventilatory parameters. The end-tidal CO2 (EtCO2) is one of the primary monitoring parameters. EtCO2 is the partial pressure or maximal concentration of carbon dioxide (CO2) at the end of an exhaled breath, which is expressed as a percentage of CO2 or mmHg . Capnography is the technique …