Biomedical Engineering and Bioengineering Commons^™

Plasticity Of The Cortical Representation Of Finger Extensors Induced By Paired Associative Stimulation, Ian Anthony Gerard Lafond

Dissertations

This dissertation first explored associative plasticity of the human motor cortical representation with the use of noninvasive transcranial magnetic stimulation (TMS) paired with peripheral electrical stimulation. Paired Associative Stimulation (PAS) has grown in popularity because of its potential clinical applications. PAS techniques are used in combination with electromyography (EMG) measurements to study cortical excitability and features of hand movement. This work focuses on a cohesive approach to answer central questions about: the ideal mechanism to facilitate cortical plasticity via PAS, the interaction between the behavior performed and type of stimulation delivered to the targeted cortical network and the effects of …

Investigating Neural Mechanisms Of Hand Movements In Virtual Reality, Chuang Mu

Theses

Mirror visual feedback (MVF), a technique by which movement of one limb is perceived as movement of the contralateral limb, has the capacity to relieve phantom limb pain or promote motor recovery of the upper limbs after stroke (Ramachandran et al., 1995). Functional MRI studies have demonstrated activation of the motor areas in the hemisphere ipsilateral to the moving hand in response to MVF. However, the neural mechanisms of MVF are still unclear. This Electroencephalography (EEG) study was designed to investigate the timing of neural responses to MVF presented in virtual reality. 16 right-handed, neurologically healthy subjects participated in a …

Realization Of Dynamixel Servo Plant Parameters To Improve Admittance Control For A Compliant Human-Robot Interaction, Ahmad Zahid Rao

Theses

In theory, admittance control offers a very effective method of implementing smooth human-robot interaction. It allows the user’s applied force to control the movement of a powerful robot as if the robot were a small, passive mass. However, the real-world application of admittance control faces limitation posed by the dynamics of servo motors, the accuracy of the force sensors, and the computation speed of processors.

This research investigates the limitations on achieving compliant passive behavior when using state-of-the-art actuators, sensors and processors. The work involves characterizing the dynamic behavior of the servo motors, development of improved differential equations representing admittance …

Human Igg1 Antibodies Suppress Angiogenesis In A Target-Independent Manner, Sasha Bogdanovich, Younghee Kim, Takeshi Mizutani, Reo Yasuma, Laura Tudisco, Valeria Cicatiello, Ana Bastos-Carvalho, Nagaraj Kerur, Yoshio Hirano, Judit Z. Baffi, Valeria Tarallo, Shengjian Li, Tetsuhiro Yasuma, Parthasarathy Arpitha, Benjamin James Fowler, Charles B. Wright, Ivana Apicella, Adelaide Greco, Arturo Brunetti, Menotti Ruvo, Annamaria Sandomenico, Miho Nozaki, Ryo Ijima, Hiroki Kaneko, Yuichiro Ogura, Hiroko Terasaki, Balamurali K. Ambati, Jeanette H. W. Leusen, Wallace Y. Langdon, Michael R. Clark, Bradley D. Gelfand, Jayakrishna Ambati

Ophthalmology and Visual Science Faculty Publications

Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world’s population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in mice. Here we show bevacizumab suppressed angiogenesis in three mouse models not via Vegfa blockade but rather Fc-mediated signaling through FcγRI (CD64) and c-Cbl, impairing macrophage migration. Other approved humanized or human IgG1 antibodies without mouse targets (adalimumab, alemtuzumab, ofatumumab, omalizumab, palivizumab and tocilizumab), mouse IgG2a, and overexpression of human IgG1-Fc or mouse IgG2a-Fc, also inhibited angiogenesis in wild-type …

Bioenergy From Wastewater-Based Biomass, Ronald C. Sims, Sean K. Bedingfield, Reese Thompson, Judith L. Sims

Biological Engineering Faculty Publications

The U.S. Department of Energy (DOE) has stated that biomass is the only renewable resource that can supplant petroleum-based liquid transportation fuels in the near term. Wastewater is beginning to be viewed as a potential resource that can be exploited for biomass production and conversion to bioenergy. We suggest that using wastewater from municipalities and industries as a resource for cultivating biomass and combining wastewater treatment with the production of biomass for bioenergy would provide benefits to both industries. Two waste-based biomass production systems that currently have large nationwide infrastructures include: (1) wastewater treatment systems that can be used to …

Development Of A Glucose-Powered Biobattery For Implantation And Use In Humans, Carson Sparks, Cody Maughan, Lucas Smith, Carson Sparks

Research on Capitol Hill

With current demands for implantable electrical devices increasing, the need for a more stable and biocompatible source of power is becoming increasingly necessary. Several battery types and materials were evaluated. Ultimately, an abiotic biobattery was designed with the goal of implantation in the human body. Nafion, single-walled carbon nanotubes (SWCNTs), and gold were used to create an abiotic biobattery that is powered by glucose.

The SWCNTs were used to create the cathode, the gold was used to fabricate the anode, and the Nafion acted as the separator between the cathode and anode. A thin Nafion membrane was evaluated for overlaying …

Improved Production Of Promising Antioxidant, Resveratrol, In Escherichia Coli, Chad Skidmore

Research on Capitol Hill

Resveratrol is a promising antioxidant natural product. Studies have shown that it is effective against heart disease, cancer, Alzheimer's disease, diabetes, and harmful UV rays. This health-benefiting molecule is present in plants such as peanuts, berries, and the skin of red grapes.

A growth time of 10 months makes Japanese knotweed an impractical source of resveratrol. A more efficient way to produce resveratrol has been found by using E. coli as tiny biological factories.

Zeta Potential: Key To Harvesting Algae For Biofuels And Bioproducts, Celeste Hancock, Michael Flores

Research on Capitol Hill

• Algae is an effective and sustainable resource for creating a broad spectrum of bioproducts.
• Scientists have found it challenging to harvest algae due to the difficulty of collecting algae when in an aqueous solution such as wastewater.
• Rotating Algal Biofilm Reactors (RABRs) coated with carbon nanotubes have proved effective. The RABR floats in an aqueous environment and attracts charged algal particles in suspension.
• The tendency for algae to favor suspension over coagulation occurs only when particles of algae are sufficiently charged. This charge can be measured by analyzing the electric potential at the interface between the surface of a particle …

Beyond The Fiber: Novel Spider Silk Coatings And Adhesives, Danielle A. Gaztambide, Breton A. Day

Research on Capitol Hill

Natural spider silks have long been recognized for their combination of incredible strength and elasticity. Spider silk is more elastic than nylon, tougher than Kevlar, and stronger than steel by weight. Due to an inability to farm spiders, much work has been done to produce spider silks in transgenic hosts for large -scale production. Our work was done using recombinant spider silk proteins produced in transgenic goats and the bacteria E. coli.

More recently spider silks have also been recognized for their biocompatibility and lack of immunogenicity. Spider silks' incredible strength and ability to be implanted safely within the body …

Wavelet Coherence Analysis Of Dynamic Cerebral Autoregulation In Neonatal Hypoxic–Ischemic Encephalopathy, Fenghua Tian, Takashi Tarumi, Hanli Liu, Rong Zhang, Lina Chalak

Bioengineering Faculty Publications - Archive

Cerebral autoregulation represents the physiological mechanisms that keep brain perfusion relatively constant in the face of changes in blood pressure and thus plays an essential role in normal brain function. This study assessed cerebral autoregulation in nine newborns with moderate-to-severe hypoxic–ischemic encephalopathy (HIE). These neonates received hypothermic therapy during the first 72 h of life while mean arterial pressure (MAP) and cerebral tissue oxygenation saturation (SctO2) were continuously recorded. Wavelet coherence analysis, which is a time-frequency domain approach, was used to characterize the dynamic relationship between spontaneous oscillations in MAP and SctO2. Wavelet-based metrics of phase, coherence and gain were …

Multimodal, Biomaterial-Focused Anticoagulation Via Superlow Fouling Zwitterionic Functional Groups Coupled With Anti-Platelet Nitric Oxide Release, Kagya Amoako, Harihara S. Sundaram, Ahmed Suhaib, Shaoyi Jiang, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

The functions of anti-fouling, zwitterionic polycarboxybetaine (pCB) and anti-platelet nitric oxide (NO) release replicate key anticoagulant properties of the endothelium. The two approaches, only tested separately thus far, were paired on gas permeable polydimethylsiloxane (PDMS) membranes and evaluated for anti-coagulation. Uncoated PDMS (control) and PDMS coated with pCB were screened for fibrinogen (Fg) fouling followed by platelet adsorption testing to evaluate the effects of coating and/or NO using bioreactors. Bare or coated PDMS membranes separated sheep plasma (108 platelets/ml) and gas flow chambers within the bioreactors. Either 100 or 0 ppm of NO/N2 flowed through the gas chamber for NO …

Uncoupling Shear And Uniaxial Elastic Moduli Of Semiflexible Biopolymer Networks: Compression-Softening And Stretch-Stiffening., Anne S G Van Oosten, Mahsa Vahabi, Albert J Licup, Abhinav Sharma, Peter Galie, Fred C Mackintosh, Paul A Janmey

Henry M. Rowan College of Engineering Departmental Research

Gels formed by semiflexible filaments such as most biopolymers exhibit non-linear behavior in their response to shear deformation, e.g., with a pronounced strain stiffening and negative normal stress. These negative normal stresses suggest that networks would collapse axially when subject to shear stress. This coupling of axial and shear deformations can have particularly important consequences for extracellular matrices and collagenous tissues. Although measurements of uniaxial moduli have been made on biopolymer gels, these have not directly been related to the shear response. Here, we report measurements and simulations of axial and shear stresses exerted by a range of hydrogels subjected …

Transcranial Laser Stimulation Improves Human Cerebral Oxygenation, Fenghua Tian, Snehal Niwrutti Hase, F. Gonzalez-Lima, Hanli Liu

Bioengineering Faculty Publications - Archive

Transcranial laser stimulation of the brain with near-infrared light is a novel form of non-invasive photobiomodulation or low-level laser therapy (LLLT) that has shown therapeutic potential in a variety of neurological and psychological conditions. Understanding of its neurophysiological effects is essential for mechanistic study and treatment evaluation. This study investigated how transcranial laser stimulation influences cerebral hemodynamics and oxygenation in the human brain in vivo using functional near-infrared spectroscopy (fNIRS).

In Vitro Formation Of Neuroclusters In Microfluidic Devices And Cell Migration As A Function Of Stromal-Derived Growth Factor 1 Gradients, Sean Mccutcheon, Uchenna Unachukwu, Ankush Thakur, Robert Majeska, Stephen Redenti, Maribel Vazquez

Publications and Research

Central nervous system (CNS) cells cultured in vitro as neuroclusters are useful models of tissue regeneration and disease progression. However, the role of cluster formation and collective migration of these neuroclusters to external stimuli has been largely unstudied in vitro. Here, 3 distinct CNS cell types, medulloblastoma (MB), medulloblastoma-derived glial progenitor cells (MGPC), and retinal progenitor cells (RPC), were examined with respect to cluster formation and migration in response to Stromal-Derived Growth Factor (SDF-1). A microfluidic platform was used to distinguish collective migration of neuroclusters from that of individual cells in response to controlled concentration profiles of SDF-1. Cell …

Supernormal Conduction And Suppression Of Spatially Discordant Alternans Of Cardiac Action Potentials, Linyuan Jing, Anuj Agarwal, Abhijit R. Patwardhan

Biomedical Engineering Faculty Publications

Spatially discordant alternans (DA) of action potential durations (APD) is thought to be more pro-arrhythmic than concordant alternans. Super normal conduction (SNC) has been reported to suppress formation of DA. An increase in conduction velocity (CV) as activation rate increases, i.e., a negative CV restitution, is widely considered as hallmark of SNC. Our aim in this study is to show that it is not an increase in CV for faster rates that prevents formation of DA, rather, it is the ratio of the CV for the short relative to the long activation that is critical in DA suppression. To illustrate …

Pulmonary Patency Stent, Kranthidhar Bathula, Suraj Kandalam, Akhil Kolluri, Roshni Malik

Capstone Design Expo Posters

Patients with malignancies in the central airways often experience significant breathing difficulties due to occlusion of the airways. One common palliative treatment option for this is a stent placement procedure. While patients often experience immediate symptom relief, long term use can result in the formation of granulation tissue, causing restenosis of the airway. The objective of this project is to design and prototype a modification to the Boston Scientific Ultraflex partially-covered stent in order to reduce granulation tissue and maintain airway patency. Deliverables include the detailed design, a working prototype, and supporting data. The main product specifications include effectiveness in …

Design Of A Drug Delivery System Through The Gastrointestinal Tract, Kaixin Chen, Adel Husayni, Kayvon Mobarakeh, Ankit Soni

Capstone Design Expo Posters

Alzheimer’s Disease (AD) afflicts an estimated 5.3 million individuals and is the sixth leading cause of death in America. The drug delivery method of interest is an orally administered sustained-release delivery system that addresses the needs of the associated patient population. By augmenting drug delivery with a higher effective payload per dose compared to current methods, drug efficacy and bioavailability would improve. This will result in a decrease of the overall cost for medication as a greater percentage of the administered drug will be viable.

This design addresses the release of AD drug from the drug delivery system at the …

Suture Trainer: Improving Tissue Handling Technique, Albara Elshaer, Sindora Baddam, Veronica Peterkin, Millie Shah

Capstone Design Expo Posters

Tissue handling is fundamental to performing mechanical tasks of suturing and surgery on live humans and animals. While the mechanics of suturing can be taught, there is no available simulation product designed to specifically teach tissue handling skills. It is important as a future medical professional to gain better tissue handling skills in order to prevent unnecessary injury to the tissue via scarring. The suture trainer focuses on providing feedback in order to standardize tissue handling technique in order to prevent poor habits from developing. Our project deliverables included a model, working prototype, and test data collected from practicing physicians …

A Tilting System For Powered Wheelchairs, Liam Cornwall, Brandon Heath, Justin Mcdaniel, Alexander Stevenson

Capstone Design Expo Posters

The objective of our project is to create a wheelchair platform that can tilt a power wheelchair and its user back into a nearhorizontal position. The purpose of this is to allow a dentist to work on the patient in the manner and position with which they are most accustomed.

The device currently used by our sponsor, The Virginia Home, is the Versatilt platform. The Versatilt is capable of lifting a maximum weight of 750 lbs. and tilting patients back, up to 65 degrees. However, the platform is too small to accept the power wheelchairs used by the majority of …

Mri Hip Joint Traction Device, Rawan Alfadly, Carla Gomez, Sara Um

Capstone Design Expo Posters

Radiologists commonly use contrast agents to improve resolution and acuity when employing MRI (Magnetic Resonance Imaging). Introducing MRI contrast agents to the tissue in the innermost part of the femoroacetabular joint is extremely difficult because the anatomy prevents the contrast agents from infiltrating those surfaces. Therefore, getting the ideal image resolution and making diagnosis of the hip is difficult. The objective was to design a product that would successfully distract one hip joint while also stabilizing the patient’s pelvis to improve visualization so that physicians are able to better diagnose the hip. The deliverables included a preliminary model that illustrates …