Biomedical Engineering and Bioengineering Commons^™

Feeling For Failure: Haptic Force Perception Of Soft Tissue Constraints In A Simulated Minimally Invasive Surgery Task, Lindsay Long

All Dissertations

In minimally invasive surgery (MIS), the ability to accurately interpret haptic information and apply appropriate force magnitudes onto soft tissue is critical for minimizing bodily trauma. Force perception in MIS is a dynamic process in which the surgeon's administration of force onto tissue results in useful perceptual information which guides further haptic interaction and it is hypothesized that the compliant nature of soft tissue during force application provides biomechanical information denoting tissue failure. Specifically, the perceptual relationship between applied force and material deformation rate specifies the distance remaining until structural capacity will fail, or indicates Distance-to-Break (DTB). Two experiments explored …

Ion Channel-Mediated Hydrostatic Pressure Mechanotransduction In Urothelial Cells, Kevin Champaigne

All Dissertations

A majority of men and women aged 40 and over experience lower urinary tract symptoms, including urgency, incontinence, and frequency, which often affect the individual's quality of life. Although often considered a simple structure, the bladder is a complex system with sophisticated sensory and motor feedback mechanisms that allow for the sensation of fullness and pain, reflexive responses to bladder filling, and conscious control over the time and place of micturition. Although disruptions of these sensory mechanisms are believed to cause certain lower urinary tract dysfunctions, the specific mechanisms involved in sensing bladder fullness, distension, tension, or pressure at the …

Polysaccharide-Based Nanocarriers For Improved Drug Delivery, Nan Zhang

Dissertations - ALL

The field of drug delivery has provided a solution to the limited efficacy and high toxicity of many drugs. Nano-sized drug carriers are popular because their size allows for selective accumulation in the diseased area. Polysaccharides are non-toxic and biodegradable natural polymers that can serve as the basis for these nano-sized carriers. Polysialic acid (PSA) is such a polysaccharide with strong hydrophilicity that may reduce uptake by the reticuloendothelial system and prolong drug circulation. In this study, we developed PSA-based nanocarriers, specifically micelles and nanoparticles, for improved drug delivery with improved efficacy and minimized toxicity. PSA-based micelle systems were developed …

A Novel Hybrid Hydrogel For Scaffold-Mediated Gene Delivery, Jeremy Zhang

All Dissertations

Scaffold-mediated nonviral gene delivery avoids several drawbacks of systemic injection such as clearance by the reticulo-endothelial system and serum aggregation. Existing synthetic and natural polymers used in gene delivery scaffolds are primarily derived from other tissue engineering applications with design parameters focused on the physicochemical properties of the scaffold and its biocompatibility. Common synthetic materials used in polymeric scaffolds such as PEG are practically bio-inert with minimal cell and protein interaction. Therefore, an opportunity exists for the rational design novel gene delivery scaffolds with components capable of increasing the expression of incorporated transgene by including scaffold components that interact with …

Spatial Control Of Magnetic Nanoparticles Integrated With Cellular Spheroids As Tissue Engineered Building Blocks, Brandon Mattix

All Dissertations

Magnetic nanoparticles (MNPs) have been investigated in tissue engineering applications to provide in situ imaging, drug delivery, and tissue patterning, but direct and prolonged interaction between cells and MNPs can have adverse effects on cell function. Therefore, methods which reduce or limit the interaction of MNPs with cells, or utilize more biocompatible MNP-based strategies will improve upon the commonly used iron oxide MNPs. We investigated a variety of methods to improve upon the use of MNPS in tissue engineering.
Cell aggregates, or spheroids, have been used as tissue engineered building blocks that can closely mimic the native three-dimensional in vivo …

Interleukin Expression After Injury And The Effects Of Interleukin-1 Receptor Antagonist, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Stacey L. Brickson, William L. Murphy, Geoffrey S. Baer, Ray Vanderby

Faculty Work Comprehensive List

Ligament healing follows a series of complex coordinated events involving various cell types, cytokines, as well as other factors, producing a mechanically inferior tissue more scar-like than native tissue. Macrophages provide an ongoing source of cytokines to modulate inflammatory cell adhesion and migration as well as fibroblast proliferation. Studying interleukins inherent to ligament healing during peak macrophage activation and angiogenesis may elucidate inflammatory mediators involved in subsequent scar formation. Herein, we used a rat healing model assayed after surgical transection of their medial collateral ligaments (MCLs). On days 3 and 7 post-injury, ligaments were collected and used for microarray analysis. …

In Vivo Imaging Of Human Retinal Microvasculature Using Adaptive Optics Scanning Light Ophthalmoscope Fluorescein Angiography, Alexander Pinhas, Michael Dubow, Nishit Shah, Toco Y.P. Chui, Drew Scoles, Yusufu N. Sulai, Rishard Weitz, Joseph B. Walsh, Joseph Carroll, Alfredo Dubra, Richard B. Rosen

Biomedical Engineering Faculty Research and Publications

The adaptive optics scanning light ophthalmoscope (AOSLO) allows visualization of microscopic structures of the human retina in vivo. In this work, we demonstrate its application in combination with oral and intravenous (IV) fluorescein angiography (FA) to the in vivo visualization of the human retinal microvasculature. Ten healthy subjects ages 20 to 38 years were imaged using oral (7 and/or 20 mg/kg) and/or IV (500 mg) fluorescein. In agreement with current literature, there were no adverse effects among the patients receiving oral fluorescein while one patient receiving IV fluorescein experienced some nausea and heaving. We determined that all retinal capillary …

Young's Modulus And Volume Porosity Relationships For Additive Manufacturing Applications, Stephen M. Heinrich, M. Barbara Silver-Thorn, John Anthony Choren

Biomedical Engineering Faculty Research and Publications

Recent advancements in additive manufacturing (or rapid prototyping) technologies allow the fabrication of end-use components with defined porous structures. For example, one area of particular interest is the potential to modify the flexibility (bending stiffness) of orthopedic implants through the use of engineered porosity (i.e., design and placement of pores) and subsequent fabrication of the implant using additive manufacturing processes. However, applications of engineered porosity require the ability to accurately predict mechanical properties from knowledge or characterization of the pore structure and the existence of robust equations characterizing the property–porosity relationships. As Young’s modulus can be altered by variations in …

Reducing Radiation Dose To The Female Breast During Ct Coronary Angiography: A Simulation Study Comparing Breast Shielding, Angular Tube Current Modulation, Reduced Kv, And Partial Angle Protocols Using An Unknown-Location Signal-Detectability Metric, Franco Rupcich, Andreu Badal, Lucretiu M. Popescu, Iacovos Kyprianou, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose:

The authors compared the performance of five protocols intended to reduce dose to the breast during computed tomography (CT) coronary angiography scans using a model observer unknown-location signal-detectability metric.

Methods:

The authors simulated CT images of an anthropomorphic female thorax phantom for a 120 kV reference protocol and five “dose reduction” protocols intended to reduce dose to the breast: 120 kV partial angle (posteriorly centered), 120 kV tube-current modulated (TCM), 120 kV with shielded breasts, 80 kV, and 80 kV partial angle (posteriorly centered). Two image quality tasks were investigated: the detection and localization of 4-mm, 3.25 mg/ml and …

Evaluation Of Cast Creep Occurring During Simulated Clubfoot Correction, Tamara L. Cohen, Haluk Altiok, Mei Wang, Linda M. Mcgrady, Joseph Krzak, Adam Graf, Sergey Tarima, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot involving weekly manipulations and cast applications. Qualitative assessments have indicated the potential success of the technique with cast materials other than standard plaster of Paris. However, guidelines for clubfoot correction based on the mechanical response of these materials have yet to be investigated. The current study sought to characterize and compare the ability of three standard cast materials to maintain the Ponseti-corrected foot position by evaluating cast creep response. A dynamic cast testing device, built to model clubfoot correction, was wrapped in plaster of Paris, …

Young’S Modulus And Volume Porosity Relationships For Additive Manufacturing Applications, John Anthony Choren, Stephen M. Heinrich, M. Barbara Silver-Thorn

Civil and Environmental Engineering Faculty Research and Publications

Recent advancements in additive manufacturing (or rapid prototyping) technologies allow the fabrication of end-use components with defined porous structures. For example, one area of particular interest is the potential to modify the flexibility (bending stiffness) of orthopedic implants through the use of engineered porosity (i.e., design and placement of pores) and subsequent fabrication of the implant using additive manufacturing processes. However, applications of engineered porosity require the ability to accurately predict mechanical properties from knowledge or characterization of the pore structure and the existence of robust equations characterizing the property–porosity relationships. As Young’s modulus can be altered by variations in …

Computational Biomechanical Modeling Of The Human Knee During Kneeling, Tariq R. Abo-Alhol

Electronic Theses and Dissertations

Total knee replacement benefits patients who suffer from severe knee pain or joint stiffness and other joint related illnesses that limit everyday activities. There has been an increase in the number of procedures performed each year and a need to evaluate the performance of these implants during specialized activities such as kneeling. Most computational studies lack insight into inter-patient variability and the results do not apply to large population. This study developed: (1) three-dimensional explicit finite element (FE) models to investigate natural and implanted knee joint kinematics and bone strain and (2) a platform to enable population-based evaluation by combining …

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Graduate Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made …

Utilizing Municipal And Industrial Wastes For The Production Of Bioproducts: From Metagenomics To Bioproducts, Joshua T. Ellis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Developing renewable sources of energy is gaining interest due to limited supplies, rising costs, and environmental impacts of exploiting fossil fuels. Biosolvents such as acetone, butanol, and ethanol are attractive sources of fuel which can aid in replacing our dependence on foreign oil. Butanol is of particular interest due to its ability to directly replace gasoline, thus considered a drop-in-fuel. Biological hydrogen and methane gas are also attractive energy sources that can lower dependence on fossil energy.

This research focused on incorporating DNA sequencing technologies in parallel with fermentation methods for understanding and producing energy. The natural environment provides diverse …

Analyzing Surface Protein Expression And Internalization, William Truong, Josergio Zaragoza

Bioengineering Senior Theses

G-protein coupled receptors (GPCRs) are currently the largest class of membrane receptors and are targeted by a majority of the modern drug therapeutics. In addition, they partake in many physiological and pathological processes such as inflammation, growth, and hormone responses. Most importantly, GPCRs are targets of many disease-specific pathways such as Alzheimers, hypertension, leukemia, and depression. As a result, there is an immense interest in studying GPCRs as this area provides further knowledge into the specific disease pathways and allows the discovery of novel therapeutics. In order to have a better understanding of pathways, scientists have studied GPCR activation. The …

Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu

Theses and Dissertations

Common therapy for diabetes mellitus is subcutaneous administration of insulin that is subject to serious disadvantages, such as patient noncompliance and occasional hypoglycemia. Hence, oral administration of insulin could be more convenient and serve as a desired route. However, oral administration of insulin is severely limited by the low bioavailability of insulin through the gastrointestinal tract. In this study, a semi-interpenetrating network gelatin fiber scaffold (sIPN GF) was fabricated for oral mucosal delivery of insulin as an alternative route. This sIPN GF was engineered from an electrospun gelatin fiber scaffold (GF), which was further crosslinked with polyethylene glycol diacrylate (PEG-DA) …

The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov

Theses and Dissertations

This thesis investigated the effect of visuomotor and working memory 1) task difficulty and 2) multitasking on dynamic functional connectivity in the brain. Studies have only recently begun to investigate functional connectivity within the scope of concurrent dual task or varying task difficulty conditions (Cocchi, Zalesky, et al. 2011; Rietschel et al. 2012). A series of EEG recordings were conducted during execution of visuomotor or working memory tasks within a novel paradigm using BCI2VR custom MATLAB toolbox. Functional connectivity was correlated with task-related coherence (TRCoh) analysis between two task conditions involving either variation in task difficulty or concurrent execution during …

Method And Apparatus For Electrical Stimulation Of Tissues Using Signals That Minimize The Effects Of Tissue Impedance, Jeffrey Hargrove

Mechanical Engineering Patents

A tissue stimulation system that generates an electrical tissue stimulation signal configured to reduce tissue impedance and increase depth of signal penetration. The use of leads is dynamically controlled and altered between conducting biopotential voltages, conducting electrical tissue stimulation signals, and grounding, in response to a computational analysis of biopotential data acquired from a region of tissue to be stimulated.

Efferent Copy And Corollary Discharge Motor Control Behavior Associated With A Hopping Activity, Wangdo Kim, António P. Veloso, Filipa João, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Hoppers respond not only to stimuli from the ground surfaces but also to cues generated by their own behaviors. This leads to desensitization because although the afferent and reafferent signals have distinct causes, they are carried by the same sensory channels. From a behavioral viewpoint, it may be necessary to distinguish between signals from the two causes especially when monitoring changes in the external environment separate from those due to self-movement. We were able to separate afferent sensory stimuli from self-generated, reafferent signals using an action oriented perception system and dynamic programming approach. This effort addressed the question of how …

Footwear-Centric Body Area Network With Directional Uwb Antenna, Domenico Gaetano, Vit Sipal, Patrick Mcevoy, Max Ammann, C Brannigan, Louise Keating, Frances Horgan

Articles

A footwear-centric body area network employing a directional antenna is compared with waist-centric systems using omnidirectional and directional antennas. The impact of body movements on path gain is analysed for two bands at 3.99 GHz and 7.99 GHz. The path gain and data rate results demonstrate that footwear-centric configurations are equivalent or better than waist-centric body area networks.