Biomedical Engineering and Bioengineering Commons^™

Feasibility Of Pulsed Proton Induced Acoustics For 3d Dosimetry, Fahed M. Alsanea

Open Access Theses

Proton therapy has the potential to deposit its energy in tissue with high conformity to the tumor and significantly reduced integral dose to normal tissue compared to conventional radiation, such as x-rays. As a result, local control can be enhanced while reducing side-effects and secondary cancers. This is due to the way charged Particles deposit their energy or dose, where protons form a Bragg peak and establish a well-defined distal edge as a function of depth (range). To date, the dose delivered to a patient from proton therapy remains uncertain, in particular the positioning of the distal edge of the …

Developing A Hardware Platform For A Low-Power, Low-Cost, Size-Constrained Biomechanical Telemetry System, Aditya Balasubramanian

Open Access Theses

As sport-related traumatic brain injuries face increasing attention from the media and the general public, the need to be able to detect brain injury quickly, inexpensively and accurately is more important than ever. Commercially-available event-based systems exist that claim to achieve this goal; however, they collect little to no continuous-time data and primarily indicate when a pre-determined acceleration threshold has been exceeded under the unvalidated assumption that a potentially concussive blow has occurred. Recent findings by the Purdue Neurotrauma Group (PNG) have indicated that repeated exposure to both concussive and subconcussive blows can result in cumulative trauma disorder. To track …

Characteristics Of Fibrous Tissue At High Rates Of Tensile Loading, Benjamin J. Claus

Open Access Theses

The mechanical behavior of fibrous tissue is generally characterized at very low strain rates. However, many injuries occur at high rates of loading, such as those encountered in sporting events or vehicle accidents. An understanding of injury behavior requires the injury process to be recorded at high strain rates. Even at low rates of loading, the injury/failure within tissues occurs quickly. Furthermore, using conventional imaging systems, the surface of a specimen may be well documented throughout an experiment. However, damage formation does not necessarily begin at the surface of the specimen or even on the surface exposed to a camera. …

Biomechanics And Relaxivity For Functional Imaging Of Articular Cartilage Injury And Degradation, Kateri Elizabeth Fites

Open Access Theses

Osteoarthritis (OA) is a major debilitating health concern and economic burden worldwide, affecting 27 million people in the United States alone. OA often follows tissue injury, and is marked by changes in the structure and biomechanical function of cartilage, including breakdown of extracellular matrix molecules, loss of bulk tissue stiffness, and increase in articular surface friction and wear. Unlike bone and many other tissues, cartilage lacks an intrinsic capacity for regeneration. Advanced OA is typically diagnosed by patient symptoms (e.g. joint pain) and confirmed by radiographic evaluation of joint space narrowing. However, the application of functional imaging to assess cartilage …

Quantification Of Local Hemodynamic Alterations Caused By Virtual Implantation Of Three Commercially Available Stents For The Treatment Of Aortic Coarctation, Sung Kwon, Jeffrey A. Feinstein, Ronak Jashwant Dholakia, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Patients with coarctation of the aorta (CoA) are prone to morbidity including atherosclerotic plaque that has been shown to correlate with altered wall shear stress (WSS) in the descending thoracic aorta (dAo). We created the first patient-specific computational fluid dynamics (CFD) model of a CoA patient treated by Palmaz stenting to date, and compared resulting WSS distributions to those from virtual implantation of Genesis XD and modified NuMED CP stents, also commonly used for CoA. CFD models were created from magnetic resonance imaging, fluoroscopy and blood pressure data. Simulations incorporated vessel deformation, downstream vascular resistance and compliance to match measured …

A Strategy For Integrating Essential Three-Dimensional Microphysiological Systems Of Human Organs For Realistic Anticancer Drug Screening, Christopher Heylman, Agua Sobrino, Venktesh S. Shirure, Christopher Cw Hughes, Steven C. George

Biomedical Engineering

Cancer is one of the leading causes of morbidity and mortality around the world. Despite some success, traditional anticancer drugs developed to reduce tumor growth face important limitations primarily due to undesirable bone marrow and cardiovascular toxicity. Many drugs fail in clinical development after showing promise in preclinical trials, suggesting that the available in vitro and animal models are poor predictors of drug efficacy and toxicity in humans. Thus, novel models that more accurately mimic the biology of human organs are necessary for high-throughput drug screening. Three-dimensional (3D) microphysiological systems can utilize induced pluripotent stem cell technology, tissue engineering, and …

Generation Of Bipolar Nanosecond Pulses, Sambasiva Rao Rajulapati

Electrical & Computer Engineering Theses & Dissertations

Bipolar pulse generation has been studied using transmission line technology, which was mainly used for monopolar pulse generation. In this thesis, low impedance, high current, nanosecond pulse generators were designed, constructed and tested. Five transmission lines were connected in parallel, so the impedance was 10 n. The transmission lines were switched by a spark gap switch operated in air. The closing of the switch creates a matched condition on one side of the transmission lines and a short circuit on the other side of the transmission lines. When the transmission lines are precharged, one of the two waves in opposite …

Field Penetration In Mri-Based Breast Models: A Numerical Investigation, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Max Ammann

Articles

The use of reliable computational tools is fundamental to investigate different aspects of microwave breast cancer imaging. From the development of high-definition and realistic numerical breast models, different coupling mechanisms and the reaction of different tissues to microwave signals can be characterized. In this paper, field penetration inside four numerical breast phantoms with varying adipose content is evaluated in the frequency range 0.5 - 10 GHz across sagittal cuts.

Modeling And Experimental Methods To Predict Oxygen Distribution In Bone Defects Following Cell Transplantation, Christopher M. Heylman, Sharon Santoso, Melissa D. Krebs, Gerald M. Saidel, Eben Alsberg, George F. Muschler

Biomedical Engineering

We have developed a mathematical model that allows simulation of oxygen distribution in a bone defect as a tool to explore the likely effects of local changes in cell concentration, defect size or geometry, local oxygen delivery with oxygen-generating biomaterials (OGBs), and changes in the rate of oxygen consumption by cells within a defect. Experimental data for the oxygen release rate from an OGB and the oxygen consumption rate of a transplanted cell population are incorporated into the model. With these data, model simulations allow prediction of spatiotemporal oxygen concentration within a given defect and the sensitivity of oxygen tension …

Computational Evaluation Of Shear Stress And Restenosis In Stented Coronary Arteries Using Optical Coherence Tomography, Joshua K. Hughey

Master's Theses (2009 -)

The cause of coronary artery neointimal thickness (NT) leading to restenosis in ~10% of drug-eluting stents (DES) is unknown, but adverse wall shear stress (WSS) may contribute. Prior studies comparing WSS to restenosis for first generation DES yielded conflicting results, and cited different mechanisms of action for DES agents. Studies to date have not accounted for stent geometry, which dictates local WSS patterns influencing drug concentration. The objective of this investigation was to evaluate current generation stent platforms via their WSS patterns and their respective impact on NT. We prospectively enrolled 19 patients, who were randomized to thin-strut (81μm) 2-link …

Material Differences In Equine Cortical And Trabecular Bone, Ryan B. Allen

Master's Theses

A greater understanding of bone materials would be beneficial in creating more accurate computer models and in the making of biomedical products involving bone. This study set out to determine whether cortical and trabecular bone are two separate materials, or whether they are the same material with a variance in porosity. To answer this question, samples were taken from different sections of the equine metacarpus, underwent densitometry analysis and were statistically analyzed. The majority of results suggest that the material is the same between varying densities of bone and thus the same between cortical and trabecular bone. These particular results …

A Comparative Study Of Gmo Labeling And Liability Systems In The Us, Eu, And South Korea: The Circumstances And A Future Potential For Harmonization, Moonsook Park

Maurer Theses and Dissertations

With the remarkable development of GMOs, GMO trade has also increased. The different attitudes on GMOs among the countries all over the world, specifically the US, EU, and South Korea, have the potential to create international trade conflicts. In order to mediate the conflicts, reasonable labeling and liability systems need to be established to prevent potential GMO risks. The Biosafety Protocol regarding the transboundary movement of GMOs exists to resolve such tensions, but it fails to sufficiently solve the problems and provide clear regulations concerning GMO labeling and liability systems.

A successful GMO labeling and liability system should emphasize the …

Differential Effects Of Refractive Blur On Day And Nighttime Driving Performance, Joanne M. Wood, Michael J. Collins, Alex Chaparro, Ralph Marszalek, Trent Carberry, Philippe Lacherez, Byoung Sun Chu

Publications

PURPOSE. To investigate the effect of different levels of refractive blur on real-world driving performance measured under day and nighttime conditions.

METHODS. Participants included 12 visually normal, young adults (mean age = 25.+- 5.2 years) who drove an instrumented research vehicle around a 4 km closed road circuit with three different levels of binocular spherical refractive blur (+0.50 diopter sphere [DS], +1.00 DS, +2.00 DS) compared with a baseline condition. The subjects wore optimal spherocylinder correction and the additional blur lenses were mounted in modified fullfield goggles; the order of testing of the blur conditions was randomized. Driving …

Markerless Analysis Of Upper Extremity Kinematics During Standardized Pediatric Assessment, Jacob R. Rammer

Master's Theses (2009 -)

Children with hemiplegic cerebral palsy experience reduced motor performance in the affected upper extremity and are typically evaluated based on degree of functional impairment using activity-based assessments such as the Shriners Hospitals for Children Upper Extremity Evaluation (SHUEE), a validated clinical measure, to describe performance prior to and following rehabilitative or surgical interventions. Evaluations rely on subjective therapist scoring techniques and lack sensitivity to detect change. Objective clinical motion analysis systems are an available but time-consuming and cost-intensive alternative, requiring uncomfortable application of markers to the patient. There is currently no available markerless, low-cost system that quantitatively assesses upper extremity …

Long-Term Results Of Comprehensive Clubfoot Release Versus The Ponseti Method: Which Is Better?, Peter A. Smith, Ken N. Kuo, Adam Graf, Joseph Krzak, Ann Flanagan, Sahar Hassani, Angela Caudill, Frederick Dietz, Jose Morcuende, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background

Clubfoot can be treated nonoperatively, most commonly using a Ponseti approach, or surgically, most often with a comprehensive clubfoot release. Little is known about how these approaches compare with one another at longer term, or how patients treated with these approaches differ in terms of foot function, foot biomechanics, or quality-of-life from individuals who did not have clubfoot as a child.

Questions/purposes

We compared (1) focused physical and radiographic examinations, (2) gait analysis, and (3) quality-of-life measures at long-term followup between groups of adult patients with clubfoot treated either with the Ponseti method of nonsurgical management or a comprehensive …

A Robotic Test Of Proprioception Within The Hemiparetic Arm Post-Stroke, Lucia Simo, Lior Botzer, Claude Ghez, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Background: Proprioception plays important roles in planning and control of limb posture and movement. The impact of proprioceptive deficits on motor function post-stroke has been difficult to elucidate due to limitations in current tests of arm proprioception. Common clinical tests only provide ordinal assessment of proprioceptive integrity (eg. intact, impaired or absent). We introduce a standardized, quantitative method for evaluating proprioception within the arm on a continuous, ratio scale. We demonstrate the approach, which is based on signal detection theory of sensory psychophysics, in two tasks used to characterize motor function after stroke.

Methods: Hemiparetic stroke survivors and neurologically intact …

Summer 2014 Biomedical Engineering Newsletter, Department Of Biomedical Engineering, Michigan Technological University

Department of Biomedical Engineering Newsletters

Table of Contents

• New IEEE, AIMBE and SPIE fellows
• Arteries on aisle 9
• Implants with sensors that shake off infection
• Mitch Kirby wins Whitaker International Fellowship
• Skin patch warns when it’s time to get out of the sun

Tissue Engineering Bone Using Autologous Progenitor Cells In The Peritoneum, Jinhui Shen, Ramesh Saxena, Cheng Cheng Zhang, Joseph Borrelli Jr., Liping Tang, Ashwin Nair

Bioengineering Faculty Publications - Archive

No abstract provided.

Neural Correlates Of Spectral, Temporal And Spectro-Temporal Modulation, Anusha Mohan

USF Tampa Graduate Theses and Dissertations

Natural sounds are characterized by the distribution of acoustic power over different frequency regions and/or time. This is termed spectral, temporal or spectro-temporal modulation. The auditory system is equipped with banks of filters tuned to different spectral, temporal and spectro-temporal modulation frequencies (SM, TM, STM). The sensitivity of the peripheral system to these modulations can be measured by undertaking a linear systems approach. In addition to understanding the psychophysical sensitivity, studying the neural patterns of their processing is also critical. The current study is an attempt to understand the relationship between the behavioral and neural correlates of spectral, temporal and …

Submicron-Resolution Photoacoustic Microscopy Of Endogenous Light-Absorbing Biomolecules, Chi Zhang

All Theses and Dissertations (ETDs)

Photoacoustic imaging in biomedicine has the unique advantage of probing endogenous light absorbers at various length scales with a 100% relative sensitivity. Among the several modalities of photoacoustic imaging, optical-resolution photoacoustic microscopy (OR-PAM) can achieve high spatial resolution, on the order of optical wavelength, at <1 mm depth in biological tissue (the optical ballistic regime). OR-PAM has been applied successfully to structural and functional imaging of blood vasculature and red blood cells in vivo. Any molecules which absorb sufficient light at certain wavelengths can potentially be imaged by PAM. Compared with pure optical imaging, which typically targets fluorescent markers, label-free PAM avoids the major concerns that the fluorescent labeling probes may disturb the function of biomolecules and may have an insufficient density. This dissertation aims to advance label-free OR-PAM to the subcellular scale.

The first part of this dissertation describes the technological advancement of PAM yielding high spatial resolution in 3D. The lateral resolution was improved by using optical objectives with high numerical apertures for optical focusing. The axial resolution was improved by using broadband ultrasonic transducers for ultrasound detection. We achieved 220 nm lateral resolution in transmission …