Biomedical Engineering and Bioengineering Commons^™

Anchoring Of Drifting Spiral And Scroll Waves To Impermeable Inclusions In Excitable Media, Christian W. Zemlin, Arkady M. Pertsov

Bioelectrics Publications

Anchoring of spiral and scroll waves in excitable media has attracted considerable interest in the context of cardiac arrhythmias. Here, by bombarding inclusions with drifting spiral and scroll waves, we explore the forces exerted by inclusions onto an approaching spiral and derive the equations of motion governing spiral dynamics in the vicinity of inclusion. We demonstrate that these forces nonmonotonically depend on distance and can lead to complex behavior: (a) anchoring to small but circumnavigating larger inclusions; (b) chirality-dependent anchoring.

Computational Analysis Of Hybrid Norwood Circulation With Distal Aortic Arch Obstruction And Reverse Blalock-Taussig Shunt, Andres Ceballos, I. Ricardo Argueta-Morales, Eduardo Divo, Ruben Osorio, Christopher A. Caldarone, Alain J. Kassab, William M. Decampli

Mechanical Engineering - Daytona Beach

BACKGROUND: The hemodynamics characteristics of the hybrid Norwood (HN) procedure differ from those of the conventional Norwood and are not fully understood. We present a multi-scale model of HN circulation to understand local hemodynamics and effects of aortic arch stenosis and a reverse Blalock-Taussig shunt (RBTS) on coronary and carotid perfusion. METHODS: Four 3-dimensional models of four HN anatomic variants were developed, with and without 90% distal preductal arch stenosis and with and without a 4-mm RBTS. A lumped parameter model of the circulation was coupled to a local 3-dimensional computational fluid dynamics model. Outputs from the lumped parameter model …

Shape-Shifting Surfaces For Rapid Release And Direct Stamping Of Organized Micro-Tissues, Samuel James Dupont

USF Tampa Graduate Theses and Dissertations

The primary aim of the research in this study is to develop a robust and simple platform for the in vitro organization of cells on surfaces which facilitate rapid cell release and allows for the direct stamping of highly organized micro-tissues. Current approaches towards this goal have been very successful but are lengthy and subject cells to harsh conditions for extended periods of time raising questions regarding cell health and maintenance of physiological state. To address these concerns a platform was developed to allow for rapid cell release by utilizing a release mechanism different from previous work.

Micron-scale structures comprised …

Mathematical Model Development Of Super-Resolution Image Wiener Restoration, Amr H. Yousef, Jiang Li, Mohammad A. Karim

Electrical & Computer Engineering Faculty Publications

In super-resolution (SR), a set of degraded low-resolution (LR) images are used to reconstruct a higher-resolution image that suffers from acquisition degradations. One way to boost SR images visual quality is to use restoration filters to remove reconstructed images artifacts. We propose an efficient method to optimally allocate the LR pixels on the high-resolution grid and introduce a mathematical derivation of a stochastic Wiener filter. It relies on the continuous-discrete-continuous model and is constrained by the periodic and nonperiodic interrelationships between the different frequency components of the proposed SR system. We analyze an end-to-end model and formulate the Wiener filter …

Increased Susceptibility Of Arterial Tissue To Wire Perforation With The Application Of High Frequency Mechanical Vibrations, Mark Wylie, Garrett Mcguinness, Graham Gavin

Articles

High frequency mechanical vibrations (20–50 kHz), delivered via small diameter flexible wire waveguides represent a minimally invasive technology for the treatment of chronic total occlusions (CTOs) and in other tissue ablation applications. Tissue disruption is reported to be caused by repetitive mechanical contact and cavitation. This work focuses on the effects of vibrating wire waveguides in contact with arterial tissue. An apparatus with clinically relevant parameters was used, characterized as operating at 22.5 kHz and delivering amplitudes of vibration of 17.8 - 34.3 µm (acoustic intensity, I_SATA: 1.03 - 3.83 W/cm²) via 1.0 mm diameter waveguides. …

Enhancing The Mechanical Properties Of A Hydroxyapatite-Collagen Bone Surrogate, Richard Franz Banglmaier

Wayne State University Dissertations

The synthesis of biomimetic hydroxyapatite-collagen composites is desirable from the perspective of graft elimination and load-bearing support when treating damaged or diseased bone. Bone is an organized network of carbonated hydroxyapatite mineralized collagen, whose strength and toughness is dependent on the organized array of mineralized collagen fibers that align with applied physiologic stresses. The apatitic calcium phosphate phase, hydroxyapatite, is promising for the biomimetic mineralization of collagen. Hydroxyapatite-collagen composites are osteoconductive and resorbable. However, the mechanical properties of these composites are one or more orders of magnitude less than bone. The aim of this study was to produce a bone-like …

Cell Adhesion And Migration On Ndga Cross-Linked Fibrillar Collagen Matrices For Tendon Tissue Engineering, Ana Ysabel Rioja

USF Tampa Graduate Theses and Dissertations

Tendons, essential tissues that connect muscles to bones, are susceptible to rupture/degeneration due to their continuous use for enabling movement. Often surgical intervention is required to repair the tendon; relieving the pain and fixing the limited mobility that occurs from the damage. Unfortunately, post-surgery immobilization techniques required to restore tendon properties frequently lead to scar formation and reduced tendon range of motion. Our ultimate goal is to create an optimal tendon prosthetic that can stabilize the damaged muscle-bone connection and then be remodeled by resident cells from the surrounding tissues over time to ensure long-term function. To achieve this, we …

Upper Extremity Kinematics In Children With Spinal Cord Injury During Wheelchair Mobility, Brooke Slavens, Alyssa Paul, Adam Graf, Joseph Krzak, Lawrence Vogel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Foot And Ankle Motion Analysis Using Dynamic Radiographic (Fluoroscopic) Imaging, Benjamin Mchenry, Jason T. Long, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Assessing Spinal Motion At Different Fusion Levels In Adolescents With Idiopathic Scoliosis, Sahar Hassani, Adam Graf, Joseph Krzak, K. Hammerberg, P. Sturm, P. Gupta, M. Riordan, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Estimation Of Organ And Effective Dose Due To Compton Backscatter Security Scans, Michael Hoppe, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose: To estimate organ and effective radiation doses due to backscatter security scanners using Monte Carlo simulations and a voxelized phantom set. Methods: Voxelized phantoms of male and female adults and children were used with the GEANT4 toolkit to simulate a backscatter security scan. The backscatter system was modeled based on specifications available in the literature. The simulations modeled a 50 kVp spectrum with 1.0 mm-aluminum-equivalent filtration and a previously measured exposure of approximately 4.6 μR at 30 cm from the source. Photons and secondary interactions were tracked from the source until they reached zero kinetic energy or exited from …

Long-Term Follow Up Of Van Nes Rotationplasty For Congenital Proximal Focal Femoral Deficiency [Proceedings], Haluk Altiok, Jeffrey D. Ackman, Ann Flanagan, Mary Peer, Adam Graf, Joseph Krzak, Sahar Hassani, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

INTRODUCTION: Proximal focal femoral deficiency (PFFD) is a congenital anomaly that presents challenges for orthopaedic and prosthetic management. The Van Nes rotationplasty is one treatment in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. The purpose of this study is to determine the long-term functional and quality of life (QOL) outcomes for individuals who have undergone rotationplasty surgery for congenital PFFD compared to age and gender matched controls.

METHODS: This prospective study had 12 prosthetic participants (PFFD Group: 8 M, 4F, age range 16-57 years) average 31.6±13.5 years …

A Database For Estimating Organ Dose For Chest And Head Ct Scans For Arbitrary Spectra And Angular Tube Current Modulation, Franco Rupcich, Andreu Badal, Iacovos Kyprianou, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose: The purpose of this study was to develop a database for estimating organ dose in a voxelized patient model for coronary angiography and brain perfusion CT acquisitions with any spectra and angular tube current modulation setting. The database enables organ dose estimation for existing and novel acquisition techniques without requiring Monte Carlo simulations. Methods: The study simulated transport of monoenergetic photons between 5 and 150 keV for 1000 projections over 360◦ through anthropomorphic voxelized female chest and head (0◦ and 30◦ tilt) phantoms and standard head and body CTDI dosimetry cylinders. The simulations resulted in tables of normalized dose …

Multisegmental Foot And Ankle Motion Analysis After Hallux Valgus Surgery, Karl Canseco, Jason T. Long, Thomas Smedberg, Sergey Tarima, Richard Marks, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background: Gait changes in patients with hallux valgus, including altered kinematic and temporal-spatial parameters, have been documented in the literature. Although operative treatment can yield favorable clinical and radiographic results, restoration of normal gait in this population remains unclear. Segmental kinematic changes within the foot and ankle during ambulation after operative correction of hallux valgus have not been reported. The aim of this study was to analyze changes in multisegmental foot and ankle kinematics in patients who underwent operative correction of hallux valgus. Methods: A 15-camera Vicon Motion Analysis System was used to evaluate 24 feet in 19 patients with …

Exploring Functional Networks Of The Brain Relating To Upper Extremity Motor Skill Using Graph Theory, Dominic Nathan, Stephen J. Guastello, Robert W. Prost, Dean C. Jeutter

Biomedical Engineering Faculty Research and Publications

No abstract provided.

An Investigation Of Reflective Mulches For Use Over Capillary Mat Systems For Winter-Time Greenhouse Strawberry Production, George E. Meyer, Ellen T. Paparozzi, Elizabeth Walter-Shea, Erin E. Blankenship, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Photosynthethically active radiation (PAR) is a principle environmental variable used by horticultural specialists, agronomists and ecosystem modelers to characterize the quantity and quality of light conducive to plant growth and development. Spatial distribution of PAR in a greenhouse can be quite variable and diffuse throughout the day time photoperiod, especially at low sun angles in northern regions of the United States. Four colors of reflective plastic mulches (white, red, olive, and black) were evaluated for winter-time strawberry (Fragaria × ananassa Duch.) production based on their reflectance and transmittance properties in a double-polyethylene, plastic-glazed Quonset greenhouse inNebraska. The spectral properties …

Feasibility Analysis Of Estrification Systems With Entrainers, Kang Wook Lee

Dissertations and Theses

(Ethyl Acetate) and IPA (Isopropyl Acetate) production systems are studied in terms of the feasibility analysis. It is not feasible to retrieve pure products by a simple reactive distillation for IPA production system because CCR (Critical Composition Region) covers the entire desired binary edge for IPA system. On the other hand, even though CCR does not cover the entire desired binary edge of the EA system completely, internal reflux ratio (IRR) analysis does not allow the production of the pure product via reactive distillation for EA production system. To overcome the restraints, external entrainers are utilized to take advantage of …

Characterization Of Rheological Properties And Degradation Of Genipin Crosslinked Fibrin Hydrogel For Annulus Repair, Dave Khyati

Dissertations and Theses

No abstract provided.

The Role Of Rugose, A Drosophila Akap And Loco, A Rgs Protein In Synaptogenesis And Development, Kemeh Georgina

Dissertations and Theses

No abstract provided.

Development Of A Human Lung Cancer Cytochrome C-Gfp Reporter Cell Line To Study Anti-Cancer Drug Responses In Apoptosis Pathways, Sidra A Piracha

Dissertations and Theses

"Currently chemotherapy and radiotherapy are the most popular methods for cancer treatments after surgery, but lack of specificity and are thus toxic to the healthy human cells. Studies have shown that targeted therapies have been linked to activation of apoptosis signal pathways (cascade of caspases) in cancer cells including intrinsic and extrinsic pathways. One of the major pathways leading to caspase activation involves the release of cytochrome-c from mitochondria. However, in some tumor cells this pathway is inactivated due to the mutation of mitochondria membrane stabilizing proteins (e.g. Bcl-2, Bcl-xL). Therefore, the overall objective of this proposal was to understand …