Biomedical Engineering and Bioengineering Commons^™

Evaluation Of A Novel Myoelectric Training Device, Joshua A. Arenas

Theses and Dissertations

Recent technological developments have implemented the use of proportional control in prosthetic hands, giving rise to the importance of appropriate myoelectric control. EMG models in the past have assumed a linear proportionality to simplify the EMG-force relationships. However, it has been shown that a non-linear EMG-force relationship may be a more effective model. This study focused on evaluating three different control algorithms for a novel myoelectric training device, consisting of a toy car controlled by EMG signals from the distal muscles in the arm. Sixteen healthy adult subjects (5 male and 11 female) with an average age of 23.6 years …

The Effects Of Fatigue On Lower Extremity Kinetics And Kinematics In Subjects With Known Ankle Instability, Lindsay E. Clayton

Theses and Dissertations

The goal of this study was to evaluate biomechanical differences between healthy subjects and those with ankle instability during the gradual onset of lower extremity fatigue from a landing activity. An understanding of these differences is needed in order to prevent future injury to or further debilitation in individuals with ankle instability. A functional fatiguing activity was designed to focus fatigue on the quadriceps muscles, as those are the muscles most frequently fatigued during sport. Measures were taken throughout the progression of fatigue with a force plate and a motion tracking system and included vertical ground reaction force and lower …

Peracetic Acid: A Practical Agent For Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds, William R. Trahan

Theses and Dissertations

Advanced biomaterials and sophisticated processing technologies aim to fabricate tissue-engineering scaffolds that can predictably interact within a biological environment at a cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed prior to clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone (PCL), a low melting polymer, and …

Modification And Evaluation Of A Brain Computer Interface System To Detect Motor Intention, Christopher V. Hagerty-Hoff

Theses and Dissertations

It is widely understood that neurons within the brain produce electrical activity, and electroencephalography—a technique used to measure biopotentials with electrodes placed upon the scalp—has been used to observe it. Today, scientists and engineers work to interface these electrical neural signals with computers and machines through the field of Brain-Computer Interfacing (BCI). BCI systems have the potential to greatly improve the quality of life of physically handicapped individuals by replacing or assisting missing or debilitated motor functions. This research thus aims to further improve the efficacy of the BCI based assistive technologies used to aid physically disabled individuals. This study …

Femtosecond Laser Beam Propagation Through Corneal Tissue: Evaluation Of Therapeutic Laser-Stimulated Second And Third-Harmonic Generation, William R. Calhoun Iii

Theses and Dissertations

One of the most recent advancements in laser technology is the development of ultrashort pulsed femtosecond lasers (FSLs). FSLs are improving many fields due to their unique extreme precision, low energy and ablation characteristics. In the area of laser medicine, ophthalmic surgeries have seen very promising developments. Some of the most commonly performed surgical operations in the world, including laser-assisted in-situ keratomileusis (LASIK), lens replacement (cataract surgery), and keratoplasty (cornea transplant), now employ FSLs for their unique abilities that lead to improved clinical outcome and patient satisfaction.

The application of FSLs in medical therapeutics is a recent development, and although …

The Synthesis And Characterization Of Dual-Modified Carboxymethylcellulose For Bioadhesive Applications, Fabrice Bernard

Dissertations and Theses

Reparative medical techniques, in conjunction with existing and emerging tissue adherents and sealants, offer practicing physicians a wide variety of tools to improve the functionality, performance, and safety of surgical interventions. Carboxymethylcellulose (CMC) is a plant-derived polymer that is cytocompatible, biocompatible, biodegradable, and inexpensive. The need for a non-toxic but strongly adherent material motivated the development of an injectable bioadhesive system containing CMC modified with functional methacrylate and aldehyde groups that could potentially be used as an annulus fibrosus sealant or as a supplement to existing wound closure materials. After modification, the polymer was characterized via NMR spectroscopy, Schiff’s base …

Calibration And Validation Of An In Vitro Ultrasound Device To Deliver Targeted Thermal Enhancement Of Hmsc Osteogenesis, Dionne Dawkins

Dissertations and Theses

Osteoarthritis (OA) is a disease that affects millions of people annually, often the elderly, and limits their physical abilities. Current methods of treating OA are often very invasive, and expensive, costing the Medicare system billions of dollars annually. A minimally invasive therapy that can be localized to the affected area that provides both relief and a short recovery time is optimal for treating the disease. For targeted therapy and clinical use, therapeutic ultrasound in the 0.7 MHz to 3 MHz frequency range can provide relief and is convenient, portable and localized. Low-intensity pulsed ultrasound (LIPUS) has been proven in clinical …

Chemotaxis Of Central Nervous System-Derived Tumor Cells Within Controlled Microenvironments, Jennifer Rico Varela

Dissertations and Theses

Medulloblastoma (MB) is a malignant pediatric brain tumor known for its aggressive metastatic potential. Despite the well-documented migration of MB cells to other parts of the brain and spinal column, MB chemotaxis is poorly understood. Herein, we examined the in vitro migratory and cellular responses of MB-derived cells to external signaling of Epidermal Growth Factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF-BB), and the stromal cell-derived factors 1-alpha (SDF-1). Experiments utilized transwell assays and immunocytochemistry to identify receptor activation in MB migration, and used a microfluidic platform to examine directionality, trajectory, and gradient- dependence of motile cells. Data …

Assessment Of Injection Behavior Of Commercially-Available Bone Bsms For Subchondroplasty Procedures, Dinely A. Colon

Dissertations and Theses

Subchondroplasty is a procedure that utilized bone substitutes materials (BSMs) or bone cement to correct bone defects in the subchondral bone. The two main materials used to compose BSMs are poly-methyl-methacrylate (PMMA) and calcium phosphate cement (CaP). Currently, there is no optimal bone material substitute in the market that can provide both the adequate mechanical support and the right viscosity to reach the affected area in the subchondral bone. In addition, there is also no established parameter for their proper use, based on the defect size and location. PMMA possesses comparable mechanical properties to bone (i.e. 96 MPa in compressive …

Computational Modeling To Assess Surgical Procedures For The Treatment Of Adult Acquired Flatfoot Deformity, Brian A. Smith

Theses and Dissertations

Several surgically corrective procedures are considered to treat Adult Acquired Flatfoot Deformity (AAFD) patients, relieve pain, and restore function. Procedure selection is based on best practices and surgeon preference. Recent research created patient specific models of Adult Acquired Flatfoot Deformity (AAFD) to explore their predictive capabilities and examine effectiveness of the surgical procedure used to treat the deformity. The models’ behavior was governed solely by patient bodyweight, soft tissue constraints, and joint contact without the assumption of idealized joints. The current work expanded those models to determine if an alternate procedure would be more effective for the individual. These procedures …

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

Computer Aided Detection Of Oral Lesions On Ct Images, Shaikat Mahmood Galib

Masters Theses

"Oral lesions are important findings on computed tomography images. They are difficult to detect on CT images because of low contrast, arbitrary orientation of objects, complicated topology and lack of clear lines indicating lesions. In this thesis, a fully automatic method to detect oral lesions from dental CT images is proposed to identify (1) Closed boundary lesions and (2) Bone deformation lesions. Two algorithms were developed to recognize these two types of lesions, which cover most of the lesion types that can be found on CT images. The results were validated using a dataset of 52 patients. Using non training …

Computer Aided Diagnosis Of Oral Cancer: Using Time-Step Ct Images, Jonathan T. Scott

Masters Theses

"In medical imaging it is a very common practice to use a technique known as Time-Step imaging in patients who might develop cancer. Time-Step imaging it a very powerful technique, however it can lead to unmanageable amounts of image data. Previously the only way to search all of this data was to manually look through all of the files. This had to be done by trained professionals who knew what to look for within the images and make a judgment about the patient based on the images. This paper discusses the development of an algorithm to have a computer search …

Healing Of Bone Defects In A Rodent Calvarial Defect Model Using Strong Porous Bioactive Glass (13-93) Scaffolds, Yinan Lin

Masters Theses

"The main objective of this project was to evaluate the capacity of strong porous silicate (13-93) bioactive glass scaffolds prepared by a robocasting technique to regenerate bone and stimulate angiogenesis in a rat calvarial defect model. The scaffolds were created with the same grid-like microstructure but in a variety of formulations: (i) as-fabricated, (ii) pretreated in an aqueous phosphate solution to convert the glass surface to hydroxyapatite, (iii) loaded with bone morphogenetic protein-2 (BMP2) (1 µg per scaffold), and (iv) doped with copper (0.4-2.0 wt. % CuO). When compared to the as-fabricated scaffolds, the pretreated scaffolds enhanced bone regeneration at …

Freeform Extrusion Fabrication Of Titanium Fiber Reinforced 13-93 Bioactive Glass Scaffolds, Albin Thomas

Masters Theses

"Although implants made with bioactive glass have shown promising results for bone repair, their application in repairing load-bearing long bones is limited due to their poor mechanical properties as compared to human bones. This thesis study is on freeform extrusion fabrication of silicate based 13-93 bioactive glass scaffolds reinforced with titanium fibers. A composite paste was prepared with 13-93 bioactive glass filled with titanium fibers (~16 µm in diameter and aspect ratio of ~250) having 0.1 to 0.4 vol. % of the bioactive glass scaffold. This paste was then filled into a syringe manually, and then extruded through a nozzle …

In Vitro Study Of Wound-Healing Capabilities Of Bioactive Glass Fibers Under Various Culture Conditions, Sisi Chen

Masters Theses

"Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying physiological and cellular mechanism behind this function remains unclear. In this study, in vitro dynamic flow modules were designed to mimic the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, and were used to investigate the biocompatibility and functionality of borate glass nano-/micro-fibers. Glass-cell interactions were investigated either by dosing fibers to the upstream of or co-cultured with cells, and two types of borate glasses (with or without CuO/ZnO doped were …

Bioactive Lipid Coating Of Bone Allografts Direct Engraftment And Fate Determination Of Bone Marrow-Derived Cells In Rat Gfp Chimeras, Anusuya Das, Claire E. Segar, Yihsuan Chu, Tiffany W. Wang, Yon Lin, Chunxi Yang, Roy C. Ogle

School of Medical Diagnostics & Translational Sciences Publications

Bone grafting procedures are performed to treat wounds incurred during wartime trauma, accidents, and tumor resections. Endogenous mechanisms of repair are often insufficient to ensure integration between host and donor bone and subsequent restoration of function. We investigated the role that bone marrow-derived cells play in bone regeneration and sought to increase their contributions by functionalizing bone allografts with bioactive lipid coatings. Polymer-coated allografts were used to locally deliver the immunomodulatory small molecule FTY720 in tibial defects created in rat bone marrow chimeras containing genetically-labeled bone marrow for monitoring cell origin and fate. Donor bone marrow contributed significantly to both …

Design And Creation Of A Device To Induce Vergence Eye Movements, Jacob B. Jaminet, Paul A. Wetzel

UROP Posters

Automated eye-tracking systems can detect and analyze eye movements as a means to accurately diagnose more than 20 neurological diseases including mild traumatic brain injury. Mild traumatic brain injury is an occurrence of injury to the head resulting from blunt trauma or from acceleration or deceleration forces. Eye movement refers to the voluntary or involuntary movement of the eyes, helping in acquiring, fixating and tracking visual stimuli. There are three types of voluntary eye movement to track objects: smooth pursuit, vergence shifts and saccades. Vergence shifts are eye movements where the eyes move in opposite directions: moving to the midline …

Evaluation Of Pediatric Manual Wheelchair Mobility Using Advanced Biomechanical Methods, Brooke A. Slavens, Alyssa J. Schnorenberg, Christine M. Aurit, Adam Graf, Joseph J. Krzak, Kathryn Reiners, Lawrence C. Vogel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

There is minimal research of upper extremity joint dynamics during pediatric wheelchair mobility despite the large number of children using manual wheelchairs. Special concern arises with the pediatric population, particularly in regard to the longer duration of wheelchair use, joint integrity, participation and community integration, and transitional care into adulthood. This study seeks to provide evaluation methods for characterizing the biomechanics of wheelchair use by children with spinal cord injury (SCI). Twelve subjects with SCI underwent motion analysis while they propelled their wheelchair at a self-selected speed and propulsion pattern. Upper extremity joint kinematics, forces, and moments were computed using …

Technical Note: Phantom Study To Evaluate The Dose And Image Quality Effects Of A Computed Tomography Organ-Based Tube Current Modulation Technique, Diksha Gandhi, Dominic J. Crotty, Grant M. Stevens, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose

This technical note quantifies the dose and image quality performance of a clinically available organ-dose-based tube current modulation (ODM) technique, using experimental and simulation phantom studies. The investigated ODM implementation reduces the tube current for the anterior source positions, without increasing current for posterior positions, although such an approach was also evaluated for comparison.

Methods

Axial CT scans at 120 kV were performed on head and chest phantoms on an ODM-equipped scanner (Optima CT660, GE Healthcare, Chalfont St. Giles, England). Dosimeters quantified dose to breast, lung, heart, spine, eye lens, and brain regions for ODM and 3D-modulation (SmartmA) settings. …

Critical Changes In Cortical Neuronal Interactions In Anesthetized And Awake Rats, Anthony G. Hudetz, Jeannette A. Vizuete, Siveshigan Pillay, Kristina M. Ropella

Biomedical Engineering Faculty Research and Publications

Background: Neuronal interactions are fundamental for information processing, cognition, and consciousness. Anesthetics reduce spontaneous cortical activity; however, neuronal reactivity to sensory stimuli is often preserved or augmented. How sensory stimulus–related neuronal interactions change under anesthesia has not been elucidated. In this study, the authors investigated the visual stimulus–related cortical neuronal interactions during stepwise emergence from desflurane anesthesia.

Methods: Parallel spike trains were recorded with 64-contact extracellular microelectrode arrays from the primary visual cortex of chronically instrumented, unrestrained rats (N = 6) at 8, 6, 4, and 2% desflurane anesthesia and wakefulness. Light flashes were delivered to the retina …

Non-Invasive Right Ventricular Efficiency Using 4d Flow Mri, Alejandro Roldán-Alzate, Scott Grogan, Heidi Kellihan, Alessandro Bellofiore, Naomi Chesler, Oliver Wieben, Christopher Francois

Faculty Publications

Pulmonary arterial hypertension (PH) is a progressive disease of increased resistance to flow through the lungs, leading to right ventricular (RV) failure [1]. MRI is increasingly used to assess right ventricular (RV) function in PH. RV stroke work (SW) based on invasive pressure and volume measurements, is used to assess ventricular work. Determining RV work from MRI could enable a more complete characterization of RV and PA interactions in PH. The purpose of this study was to non-invasively estimate RV work from simultaneously acquired RV volume (VRV) and pulmonary artery flow (QPA) using a 4D flow-sensitive MRI sequence …

Material Considerations For Development Of 3d Printed Bronchial And Tracheal Stents, Nidah M. Hussain

Theses and Dissertations

Tracheobronchial malacia is a commonly under-diagnosed condition that results in difficulty breathing. The use of a tracheobronchial stent is the best course of treatment for patients whose quality of life has deteriorated due to malacia; unfortunately stents need replacing after issues with inflammation, migration, or eventual stent-breakdown resulting in fistula formation.

The purpose of this thesis is to use three-dimensional (3D) printing technology to improve on existing stents through designing and printing a bioresorbable/biodegradable tracheobronchial stent that can treat tracheobronchial malacia. This was undertaken by testing three biologically favorable materials, type I collagen, polycaprolactone (PCL), and thermoplastic polyurethane (TPU), with …

Brainstorm Radiation Systems Inc, Calia Battista, Leah Krichbaum, Lauren Wickert, Cody George, Ryan Manges

Williams Honors College, Honors Research Projects

Many different designs have been created to immobilize patients for radiation therapy of the head and neck. Options exist which result in varying degrees of patient comfort, radiation attenuation, and limitation of movement. While one requirement can be met effectively, it is difficult to design a system which adequately meets all requirements for radiation therapy. Brainstorm Radiation Systems aims to address all of these variables and transform the patient and technician experience during radiation treatment. The requirements for our head and neck immobilization design were to immobilize the patient within 3mm of movement for at least 30 minutes, and must …

Development Of A Modified Cervical Collar To Eliminate Overheating And Dysphagia Side Effects, Elizabeth M. Rondinelli, Katharine J. Hodgson, Samantha L. Ballash, Jessica C. Augustynovich

Williams Honors College, Honors Research Projects

Currently, thousands of people each year require the use of a rigid cervical collar. The collars are used in situations of emergency, as well as in situations of precaution, when spinal injury is or may be present. There are many different styles and sizes of cervical collars available on the market today; however, common side effects are noticed when wearing the collars that may reduce the effectiveness to the patient. Often patients complain of general discomfort issues or may suffer from more serious side effects such as pressure sores, increased intracranial pressure, dysphagia, and abnormal distraction within the upper spine. …

Shotblocker® - Bionix® Senior Design, Samuel Dockery

Williams Honors College, Honors Research Projects

No abstract provided.

Automating The Process Of Fabricating Uniform-Sized Cell Spheroids For Three-Dimensional Bioprinting, Ganesh Sosale

Theses and Dissertations

Although researchers have been able to print small, simple, and avascular tissues, they have been unsuccessful in creating large, complex and vascularized organs. Printing large and complex three-dimensional tissues or organs involves utilizing a large quantity of cellular spheroids and layer-by-layer addition of spheroids. In this study, an in-house cell spheroid fabrication system was developed to produce cell spheroids with human liver cells (hepG2), human endothelial cells (hEC), human neural stem cells (hNSC), and induced pluripotent stem cells (iPSC). It offers the ability of fabricating uniform-sized spheroids repeatedly, which is essential when large and complex structures need to be produced. …

Multi-Platform Arabinoxylan Scaffolds As Potential Wound Dressing Materials, Donald C. Aduba Jr

Theses and Dissertations

Biopolymers are becoming more attractive as advanced wound dressings because of their naturally derived origin, abundance, low cost and high compatibility with the wound environment. Arabinoxylan (AX) is a class of polysaccharide polymers derived from cereal grains that are primarily used in food products and cosmetic additives. Its application as a wound dressing material has yet to be realized. In this two-pronged project, arabinoxylan ferulate (AXF) was fabricated into electrospun fibers and gel foams to be evaluated as platforms for wound dressing materials. In the first study, AXF was electrospun with varying amounts of gelatin. In the second study, AXF …

Peracetic Acid Sterilization Of Electrospun Polycaprolactone Scaffolds, Suyog Yoganarasimha

Theses and Dissertations

Sterilization of tissue engineered scaffolds is an important regulatory issue and is at the heart of patient safety. With the introduction of new biomaterials and micro/nano structured scaffolds, it is critical that the mode of sterilization preserve these built-in features. Conventional sterilization methods are not optimal for engineered polymeric systems and hence alternate systems need to be identified and validated. PCL is polyester with a low melting point (heat labile), susceptible to hydrolysis and is popular in tissue engineering. Electrospinning generates some nanoscale features within the scaffold, the integrity of which can be affected by sterilization method. Chapter 1 explores …

Engineering Of Polyamidoamine Dendrimers For Cancer Therapy, Leyuan Xu

Theses and Dissertations

Dendrimers are a class of polymers with a highly branched, three-dimensional architecture comprised of an initiator core, several interior layers of repeating units, and multiple active surface terminal groups. Dendrimers have been recognized as the most versatile compositionally and structurally controlled nanoscale building blocks for drug and gene delivery. Polyamidoamine (PAMAM) dendrimers have been most investigated because of their unique structures and properties. Polycationic PAMAM dendrimers form compacted polyplexes with nucleic acids at physiological pH, holding great potential for gene delivery.

Folate receptor (FRα) is expressed at very low levels in normal tissues but expressed at high levels in cancers …