Biomechanical Engineering Commons^™

Insights Into The Characterization And Degradation Of Electrospun Polycaprolactone Scaffolds For Tissue Engineering Applications, Caleb B. Wells

Theses and Dissertations

Electrospun polymeric biodegradable scaffolds are essential in tissue engineering, particularly for Engineered Tissue Vascular Grafts (ETVGs), which promise advancements in treating coronary artery disease, peripheral arterial disease, congenital cardiovascular defects, and renal disease. These scaffolds present a solution to issues with autologous graft availability and durability. While large-diameter grafts in low-pressure environments have seen success, small-diameter grafts in high-flow scenarios remain challenging. Understanding polymeric scaffold degradation and behavior during incubation, especially under dynamic mechanical loading, is vital for clinical translation of small-caliber ETVGs.

This research focuses on characterizing the mechanical and microstructural properties of electrospun polycaprolactone (PCL) scaffolds and their …

Shape Inverse Prediction Of Magnetic Field-Actuated Soft Robots By Neural Network Machine Learning, Lineth J. Perez Monsalve

Theses and Dissertations

Soft robotics has drawn tremendous interest in recent years because the compliance and motion of soft robotics enable biocompatibility and versatility for many applications, such as human-machine interaction, wearable and assistive devices, and health monitoring. This study introduces a novel predictive modeling approach using neural networks for shape control of magnetic soft robots. The robots are made of silicone materials embedded with hard magnetic particles, which respond to the external magnetic field provided by a ring-type of permanent magnet. These robots, free from physical connections to external devices, i.e., non-tethered actuation, hold significant potential for applications in healthcare, such as …

Finite Element Analysis Of 3d-Printed Pcl Scaffolds, Ireolu K. Orenuga, Joao Soares, Phillip D. Glass, Daeha Joung Ph.D.

Undergraduate Research Posters

Finite Element Analysis of 3D-printed PCL Scaffolds for Synergizing Cellular Micro-Environment and Mechanical Stimuli to Enhance Engineered Tissue Growth in Vitro

Ireolu Orenuga,1 Phillip Glass,2 Daeha Joung,2 Joao S. Soares1

1. Department of Mechanical and Nuclear Engineering, College of Engineering, Virginia Commonwealth University
2. Department of Physics, College of Humanities & Sciences, Virginia Commonwealth University

Introduction: Tissue engineering aims to create viable and functional engineered tissues via biodegradable scaffolds and autologous cells. Scaffolds play an essential part in organizing the architecture of developing tissues and aid in the proper function of implants acutely by serving as mechanical support and long-term by …

Optimization Of An Automated Algorithm For Analysis Of Spontaneous Rhythmic Bladder Contractions During Urodynamics Testing, Isabelle Pummill, Rui Li, Zachary Cullingsworth, Adam Klausner, John Speich

Summer REU Program

No abstract provided.

Modeling Of Patient-Specific Periaortic Mechanics And Pulmonary Artery Hemodynamics Based On Phase-Contrast Magnetic Resonance Imaging Sequences., Johane H. Bracamonte

Theses and Dissertations

Inverse modeling in cardiovascular medicine is a collection of methodologies that can provide non-invasive patient-specific estimations of clinical risk factors using medical imaging as inputs. Its incorporation into clinical practice has the potential to improve diagnosis and treatment planning with low associated risks and costs.

Herein, three different phase contrast magnetic resonance imaging (MRI) modalities were implemented as input data, displacement encoding with stimulated echoes (DENSE MRI) applied, and time-resolved velocity encoding phase-contrast MRI, in 1D and 3D, applied to pulmonary artery (PA) hemodynamics.

A model to account for the effect of periaortic interactions due to static and dynamic structures …

Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence

Theses and Dissertations

Combining vibrating mesh nebulizers with additional new technologies leads to substantial improvements in pharmaceutical aerosol delivery to the lungs across therapeutic administration methods. In this dissertation, streamlined components, aerosol administration synchronization, and/or Excipient Enhanced Growth (EEG) technologies were utilized to develop and test several novel devices and aerosol delivery systems. The first focus of this work was to improve the poor delivery efficiency, e.g., 3.6% of nominal dose (Dugernier et al. 2017), of aerosolized medication administration to adult human subjects concurrent with high flow nasal cannula (HFNC) therapy, a form of continuous-flow non-invasive ventilation (NIV). The developed Low-Volume Mixer-Heater (LVMH) …

Evaluation Of Regional Extrathoracic Deposition Of Low- And High-Momentum Aerosol Using Anatomically-Correct In Vitro Airway Models, Sana Hosseini

Theses and Dissertations

The popularity of pulmonary aerosol delivery is increasing due to numerous advantages including non-invasiveness, fast onset of action, avoidance of the first-pass metabolism, and relatively good patient compliance. However, aerosol delivery to the site of action within the extrathoracic regions is challenging to quantify from a regulatory perspective due to the combined effects of the device and formulation characteristics, complex morphology of the airways resulting in extreme anatomical variabilities, and user dependent administration methods. Besides the therapeutic aerosol delivery, electronic nicotine delivery systems (ENDS) are a user-driven aerosol technology used to deliver nicotine as one of the electronic liquid (e-liquid) …

Development Of An Anatomically And Electrically Conductive Brain Phantom For Transcranial Magnetic Stimulation, Hamzah A. Magsood

Theses and Dissertations

Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for diagnostics, prognostic, and treatments of various neurological diseases. However, the lack of anatomically realistic brain phantoms has made the experimental verification of stimulation strength in the form of induced electric fields/voltages in the brain tissues an impediment to developing new TMS coils, stimulators, and treatment protocols. There are significant technological, safety, and ethical limitations to test the potential TMS treatment procedures or develop enhancements and refine them on humans or animals. This work aims to bridge the gap by introducing and developing an innovative manufacturing and fabrications process to produce a …

Development Of A Single Use Device Intended To Wash Blood Clot Debris From A Stent Retriever In The Operating Room, Shane Diller

Theses and Dissertations

Ischemic stroke is a life-threatening condition that requires immediate surgical intervention to remove the blood clot that is lodged in the blood vessels of the brain. Mechanical thrombectomy, performed by an endovascular surgeon, involves inserting a stent retriever, which deploys distally and attempts to capture the clot when dragged backwards. A complication prevalent in 50% - 67% of cases is that the blood clot is only partially removed and clings to the mesh framework of the stent. The operating surgeon must either clean the debris from the stent retriever, to be reinserted or throw the stent retriever away and open …

Quantification And Modeling Of Bladder Biomechanics Mechanisms Linking Spontaneous Rhythmic Contractions And Dynamic Elasticity To Detrusor Overactivity, Zachary E. Cullingsworth

Theses and Dissertations

Overactive bladder (OAB) is a chronic condition affecting approximately 20% of adults in the United States. Detrusor overactivity (DO) is the presence of non-voiding contractions in the detrusor (bladder) muscle during filling and is present in some individuals with OAB. DO is currently identified visually during a urodynamics (UD) study involving pressure catheters and filling and voiding of the bladder to evaluate function. UD provides limited subtyping of DO, and an incomplete understanding of mechanisms contributing to OAB.

Aim 1 of this study was to develop objective tools to quantify, subgroup and better understand …

Skintronics: Wireless, Skin-Wearable Electronics For Monitoring Of Electrocardiogram, Matthew B. Piper, Woon-Hong Yeo, Yongkuk Lee

Undergraduate Research Posters

The ECGs I micro-fabricate are designed to be flexible, stretchable and wireless circuits that can be applied to the skin directly. The device is encased in a conformal, silicon-like substrate, that allows the ECG to be attached with the electrodes. Each electrode has been previously measured and verified that it will be correctly placed for an accurate reading. Prototyping this ECG/electrode device allows the user to mount the prototype directly to the patient without having to attach and wire ten other electrodes. This prototype solves the issue that comes about when a doctor, nurse or emergency medical technician must attach …

A Computational Study Of The Kinematics Of Femoroacetabular Morphology During A Sit-To-Stand Transfer, Brandon K. Marine

Theses and Dissertations

Computational modeling in the field of biomechanics is becoming increasingly popular and successful in practice for its ability to predict function and provide information that would otherwise be unobtainable. Through the application of these new and constantly improving methods, kinematics and joint contact characteristics in pathological conditions of femoroacetabular impingement (FAI) and total hip arthroplasty (THA) were studied using a lower extremity computational model. Patients presenting with FAI exhibit abnormal contact between the femoral neck and acetabular rim leading to surrounding tissue damage in daily use. THA is the replacement of both the proximal femur and acetabular region of the …

Nanocomposite Bioelectronics For Biopotential Enabled Prosthesis, Dong Sup Lee

Theses and Dissertations

Soft material-enabled electronics can demonstrate extreme mechanical flexibility and stretchability. Such compliant, comfortable electronics allow continuous, long-term measurement of biopotentials on the skin. Manufacturing of the stretchable electronic devices is enabled by the recent development combining materials transfer printing and microfabrication. However, the existing method using inorganic materials and multi-layered polymers requires long material preparation time and expensive processing cost due to the requirement of microfabrication tools and complicated transfer printing steps. Here, this study develops a new fabrication method of soft electronics via a micro-replica-molding technique, which allows fast production, multiple use, and low cost by avoiding microfabrication and …

Numerical Modeling Of Fluid-Porous Structure Interaction In Arteries, Rana Zakerzadeh, Paolo Zunino

Biology and Medicine Through Mathematics Conference

No abstract provided.

Efficiency Evaluation Of A Magnetically Driven Multiple Disk Centrifugal Blood Pump, Kayla H. Moody

Theses and Dissertations

Heart failure is expected to ail over 8 million people in America by 2030 leaving many in need of cardiac replacement. To accommodate this large volume of people, ventricular assist devices (VADs) are necessary to provide mechanical circulatory support. Current VADs exhibit issues such as thrombosis and hemolysis caused by large local pressure drops and turbulent flow within the pump. Multiple disk centrifugal pumps (MDCPs) use shearing and centrifugal forces to produce laminar flow patterns and eliminate large pressure drops within the pump which greatly reduce risks that are in current VADs. The MDCP has a shaft drive system (SDS) …

In-Shoe Plantar Pressure System To Investigate Ground Reaction Force Using Android Platform, Ahmed A. Mostfa

Theses and Dissertations

Human footwear is not yet designed to optimally relieve pressure on the heel of the foot. Proper foot pressure assessment requires personal training and measurements by specialized machinery. This research aims to investigate and hypothesize about Preferred Transition Speed (PTS) and to classify the gait phase of explicit variances in walking patterns between different subjects. An in-shoe wearable pressure system using Android application was developed to investigate walking patterns and collect data on Activities of Daily Living (ADL). In-shoe circuitry used Flexi-Force A201 sensors placed at three major areas: heel contact, 1st metatarsal, and 5th metatarsal with a PIC16F688 microcontroller …

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 …

Analysis And Modeling Of The Roles Of Actin-Myosin Interactions In Bladder Smooth Muscle Biomechanics, Seyed Omid Komariza

Theses and Dissertations

Muscle mechanical behavior potentially plays an important role in some of the most common bladder disorders. These include overactive bladder, which can involve involuntary contractions during bladder filling, and impaired contractility or underactive bladder, which may involve weak or incomplete contractions during voiding. Actin-myosin cross-bridges in detrusor smooth muscle (DSM) are responsible for contracting and emptying the bladder. The total tension produced by muscle is the sum of its preload and active tensions. Studies suggest that actin-myosin cross-links are involved in adjustable preload stiffness (APS), which is characterized by a preload tension curve that can be shifted along the length …

Modeling Acute Changes In Bladder Wall Tension, Shape And Compliance During Filling, Firdaweke Habteyes

Theses and Dissertations

The bladder wall consists primarily of detrusor smooth muscle. Tension-sensitive nerves in the bladder wall are responsible for providing bladder fullness information that is interpreted as urgency. Bladder wall tension, and therefore nerve output, is a function of bladder volume, shape and material properties. Studies have shown that the bladder wall exhibits acutely regulated detrusor compliance. In addition, bladder shape throughout filling depends on intra-abdominal forces and material properties of the bladder wall, such as regulated detrusor compliance. This thesis focused on modeling the potential influence of acute changes in bladder compliance, shape and bladder wall tension during filling. Laplace’s …

Cfd Assessment Of Respiratory Drug Delivery Efficiency In Adults And Improvements Using Controlled Condensational Growth, Ross L. Walenga

Theses and Dissertations

Pharmaceutical aerosols provide a number of advantages for treating respiratory diseases that include targeting high doses directly to the lungs and reducing exposure of other organs to the medication, which improve effectiveness and minimize side effects. However, difficulties associated with aerosolized drug delivery to the lungs include drug losses in delivery devices and in the extrathoracic region of human upper airways. Intersubject variability of extrathoracic and thoracic drug deposition is a key issue as well and should be minimized. Improvements to respiratory drug delivery efficiency have been recently proposed by Dr. P. Worth Longest and Dr. Michael Hindle through the …