Biomedical Engineering and Bioengineering Commons^™

A Scientific Approach To Understanding The Head Trauma Endured By A Mixed Martial Arts Fighter, John William Michael Sorbello

Mechanical & Aerospace Engineering Theses & Dissertations

The purpose of this research is to gain some insight on the type of head trauma an athlete may encounter during mixed martial arts (MMA) competition. These athletes endure continuous blows to the head throughout their training and fighting career. The knowledge obtained from this research may assist MMA athletes and trainers in assessing the way they train, how they compete and, more importantly, how long they choose to compete in their amateur or professional MMA career.

The analysis is performed by first creating a three-dimensional solid model of the human head based on geometric coordinates originally obtained from a …

Carbon Fiber Electrodes For In Vivo Neural Recording, Esma Cetinkaya

Theses

Multi-channel micro electrodes for neural recording is a growing field that thrives on novel materials and fabrication techniques offered by micro fabrication technology. The material and the design of microelectrodes have a critical role on the quality of neural signals recorded. The neural signals collected by chronic implantation of these devices in experimental animals reveal new information about the brain functions and guide the development of new diagnostic and treatment options for neurological disorders.

Ideally, a microelectrode should meet two important criteria: longevity after implantation and minimal tissue insult. Carbon fibers` high tensile strength and flexibility allow fabrication of micro-scale …

Development And Evaluation Of A Connective Tissue Phantom Model For Subsurface Visualization Of Cancers Requiring Wide Local Excision, Kimberly S. Samkoe, Brent D. Bates, Niki N. Tselepidakis, Alisha V. Dsouza, Jason R. Gunn, Dipak B. Ramkumar, Keith D. Paulsen, Brian W. Pogue, Eric R. Henderson

Dartmouth Scholarship

Wide local excision (WLE) of tumors with negative margins remains a challenge because surgeons cannot directly visualize the mass. Fluorescence-guided surgery (FGS) may improve surgical accuracy; however, conventional methods with direct surface tumor visualization are not immediately applicable, and properties of tissues surrounding the cancer must be considered. We developed a phantom model for sarcoma resection with the near-infrared fluorophore IRDye 800CW and used it to iteratively define the properties of connective tissues that typically surround sarcoma tumors. We then tested the ability of a blinded surgeon to resect fluorescent tumor-simulating inclusions with ∼1-cm margins using predetermined target fluorescence intensities …

Subject-Independent Emotion Recognition Based On Physiological Signals: A Three-Stage Decision Method, Jing Chen, Bin Hu, Yue Wang, Philip Moore, Yongqiang Dai, Lei Feng, Zhijie Ding

Biomedical Engineering Faculty Publications

Background: Collaboration between humans and computers has become pervasive and ubiquitous, however current computer systems are limited in that they fail to address the emotional component. An accurate understanding of human emotions is necessary for these computers to trigger proper feedback. Among multiple emotional channels, physiological signals are synchronous with emotional responses; therefore, analyzing physiological changes is a recognized way to estimate human emotions. In this paper, a three-stage decision method is proposed to recognize four emotions based on physiological signals in the multi-subject context. Emotion detection is achieved by using a stage-divided strategy in which each stage deals with …

An Application Of M-Matrices To Preserve Bounded Positive Solutions To The Evolution Equations Of Biofilm Models, Richard S. Landry Jr.

LSU New Orleans Theses and Dissertations

In this work, we design a linear, two step implicit finite difference method to approximate the solutions of a biological system that describes the interaction between a microbial colony and a surrounding substrate. Three separate models are analyzed, all of which can be described as systems of partial differential equations (PDE)s with nonlinear diffusion and reaction, where the biological colony grows and decays based on the substrate bioavailability. The systems under investigation are all complex models describing the dynamics of biological films. In view of the difficulties to calculate analytical solutions of the models, we design here a numerical technique …

Ls301 Fluorescence-Guided Photodynamic Therapy Of Brain Cancer Using Ppix Photosensitizer, Haini Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Incomplete brain tumor removal always causes neurologic deficit, disease recurrence and high mortality. Protoporphyrin IX (PpIX) accumulated in glioma cells with exogenous 5-aminolevulinic acid (5-ALA) serves as contrast agent for fluorescence-guided surgery and as well as acts as a photosensitizer for photodynamic therapy (PDT). However, the accurate tumor delineation using PpIX is limited by autofluorescence and superficial penetration depth. LS301 is a tumor-targeted near-infrared (NIR) contrast agent developed in our lab which allows deeper tumor imaging and avoids autofluorescence. My project aims to investigate whether LS301 can improve PpIX mediated PDT and tumor removal surgery. We have demonstrated co-localization of …

Biomechanical Tolerance Of Whole Lumbar Spines In Straightened Posture Subjected To Axial Acceleration, Brian D. Stemper, Sajal Chirvi, Ninh Doan, Jamie L. Baisden, Dennis J. Maiman, William H. Curry, Narayan Yoganandan, Frank A. Pintar, Glenn Paskoff, Barry S. Shender

Biomedical Engineering Faculty Research and Publications

Quantification of biomechanical tolerance is necessary for injury prediction and protection of vehicular occupants. This study experimentally quantified lumbar spine axial tolerance during accelerative environments simulating a variety of military and civilian scenarios. Intact human lumbar spines (T12‐L5) were dynamically loaded using a custom‐built drop tower. Twenty‐three specimens were tested at sub‐failure and failure levels consisting of peak axial forces between 2.6 and 7.9 kN and corresponding peak accelerations between 7 and 57 g. Military aircraft ejection and helicopter crashes fall within these high axial acceleration ranges. Testing was stopped following injury detection. Both peak force and acceleration were significant …

Optimizing Filter-Probe Diffusion Weighting In The Rat Spinal Cord For Human Translation, Matthew D. Budde, Nathan P. Skinner, L. Tugan Muftuler, Brian D. Schmit, Shekar N. Kurpad

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Brain Motion, Deformation, And Potential Injury During Soccer Heading, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

This paper addresses the problem of what is happening physically inside the skull during head-ball contact. Mathematical models based upon Newton’s laws of motion and numerical methods are used to create animations of brain motion and deformation inside the skull.

Initially a 1 cm gap filled with cerebrospinal fluid (CSF) separates the brain from the rigid skull in adults and older children. Whole head acceleration induces a pulse of artificial gravity within the skull. Because brain density differs slightly from that of CSF, the brain accelerates and strikes the inner aspect of the skull, undergoing viscoelastic deformation, ranging from 1 …

Next Generation Sequencing Technologies For Real-Time Genotyping And Targeted Sequencing For Precision Medicine, Priyanka Rawat

Biomedical Engineering ETDs

Astounding success of Human genome project and accelerating success of sequencing technologies have enabled $ 1000 genome goals possible. But, this is still far-fetched from the reach of many resource refrained populations with high genetic variations causing lethal genetic diseases. Based on present technology principles, I have developed prototypes for affordable, scalable and customizable point-of-care genotyping and targeted sequencing. Ion-sensitive field effect transistors with novel read-out and signal amplification techniques are used for laying foundation of possible ISFET based allele-arrays. Sequencing-by-synthesis based full-fledge sequencer is made with novel immobilization, flow-cell and data acquisition methods for massive sequenciing.

System Characterizations And Optimized Reconstruction Methods For Novel X-Ray Imaging, Huifeng Guan

McKelvey School of Engineering Graduate Student Theses & Dissertations

In the past decade there have been many new emerging X-ray based imaging technologies developed for different diagnostic purposes or imaging tasks. However, there exist one or more specific problems that prevent them from being effectively or efficiently employed. In this dissertation, four different novel X-ray based imaging technologies are discussed, including propagation-based phase-contrast (PB-XPC) tomosynthesis, differential X-ray phase-contrast tomography (D-XPCT), projection-based dual-energy computed radiography (DECR), and tetrahedron beam computed tomography (TBCT). System characteristics are analyzed or optimized reconstruction methods are proposed for these imaging modalities. In the first part, we investigated the unique properties of propagation-based phase-contrast imaging technique …

Binding Affinity And Specificity Of Sh2 Domain Interactions In Receptor Tyrosine Kinase Signaling Networks, Tom Ronan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Receptor tyrosine kinase (RTK) signaling mechanisms play a central role in intracellular signaling and control development of multicellular organisms, cell growth, cell migration, and programmed cell death. Dysregulation of these signaling mechanisms results in defects of development and diseases such as cancer. Control of this network relies on the specificity and selectivity of Src Homology 2 (SH2) domain interactions with phosphorylated target peptides. In this work, we review and identify the limitations of current quantitative understanding of SH2 domain interactions, and identify severe limitations in accuracy and availability of SH2 domain interaction data. We propose a framework to address some …

Identification Of Prognostic Cancer Biomarkers Through The Application Of Rna-Seq Technologies And Bioinformatics, Nathan Wong

McKelvey School of Engineering Graduate Student Theses & Dissertations

MicroRNAs (miRNAs) are short single-stranded RNAs that function as the guide sequence of the post-transcriptional regulatory process known as the RNA-induced silencing complex (RISC), which targets mRNA sequences for degradation through complementary binding to the guide miRNA. Changes in miRNA expression have been reported as correlated with numerous biological processes, including embryonic development, cellular differentiation, and disease manifestation. In the latter case, dysregulation has been observed in response to infection by human papillomavirus (HPV), which has also been established as both oncogenic in cervical cancers and oropharyngeal cancers and favorable for overall patient survival after tumor formation. The identification of …

Characterizing Anisotropy In Fibrous Soft Materials By Mr Elastography Of Slow And Fast Shear Waves, John Larson Schmidt

McKelvey School of Engineering Graduate Student Theses & Dissertations

The general objective of this work was to develop experimental methods based on magnetic resonance elastography (MRE) to characterize fibrous soft materials. Mathematical models of tissue biomechanics capable of predicting injury, such as traumatic brain injury (TBI), are of great interest and potential. However, the accuracy of predictions from such models depends on accuracy of the underlying material parameters. This dissertation describes work toward three aims. First, experimental methods were designed to characterize fibrous materials based on a transversely isotropic material model. Second, these methods are applied to characterize the anisotropic properties of white matter brain tissue ex vivo. Third, …

Characterization Of Structural Dynamics Of The Human Head Using Magnetic Resonance Elastography, Andrew Arun Badachhape

McKelvey School of Engineering Graduate Student Theses & Dissertations

In traumatic brain injury (TBI), the skull-brain interface, composed of three meningeal layers: the dura mater, arachnoid mater, and pia mater, along with cerebrospinal fluid (CSF) between the layers, plays a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is a noninvasive imaging modality capable of providing in vivo estimates of tissue motion and material properties. The objective of this work is to augment human and phantom MRE studies to better characterize the mechanical contributions of the skull-brain interface to improve the parameterization and validation of computational models of TBI. Three specific aims …

Comparison Of The Bi-Directional Performance Of Micro-Channel Sieve And Thin-Film Time Peripheral Nerve Interfaces, Robert Coker

McKelvey School of Engineering Graduate Student Theses & Dissertations

Sophisticated motorized prosthetic limbs contain multiple degrees of freedom of motion as well as embedded pressure and angle transducers to provide sensory feedback in amputees. Although several central neural recording and stimulation modalities exist for both controlling these motions and providing sensory feedback from a prosthetic limb, directly interfacing the peripheral nerves which originally innervated the limb has many advantages. A difficulty with this bi-directional approach is that electrically stimulating axons to provide haptic feedback creates stimulation artifacts at neighboring recording sites within the nerve that are several orders of magnitude larger than the electroneurogram used for control. In this …

Functional Bio-Nano Hybrids Through A Precise Control Of Interfacial Interactions At The Nanoscale, Sirimuvva Tadepalli

McKelvey School of Engineering Graduate Student Theses & Dissertations

During the course of evolution, proteins have evolved to perform exquisite functions including structural support, signal transduction, actuation, sensing, catalysis, trafficking, gating, light-harvesting, charge transfer, molecular recognition, self-assembly, self-organization, or combinations of two or more of these functions. A precise control and manipulation of the structure and function of proteins is conceivable with the advent of nanotechnology, which has facilitated the integration of nanomaterials with functional biomolecules to realize bio-nano hybrids with synergistically enhanced functionalities.

At the genesis of bionanotechnology, a paucity in the fundamental understanding of the bio-nano interfaces is a grave impediment to the progress of the field. …

Bio-Inspired Multi-Spectral And Polarization Imaging Sensors For Image-Guided Surgery, Nimrod Missael Garcia

McKelvey School of Engineering Graduate Student Theses & Dissertations

Image-guided surgery (IGS) can enhance cancer treatment by decreasing, and ideally eliminating, positive tumor margins and iatrogenic damage to healthy tissue. Current state-of-the-art near-infrared fluorescence imaging systems are bulky, costly, lack sensitivity under surgical illumination, and lack co-registration accuracy between multimodal images. As a result, an overwhelming majority of physicians still rely on their unaided eyes and palpation as the primary sensing modalities to distinguish cancerous from healthy tissue. In my thesis, I have addressed these challenges in IGC by mimicking the visual systems of several animals to construct low power, compact and highly sensitive multi-spectral and color-polarization sensors. I …

Image Reconstruction Of The Speed Of Sound And Initial Pressure Distributions In Ultrasound Computed Tomography And Photoacoustic Computed Tomography, Thomas Paul Matthews

McKelvey School of Engineering Graduate Student Theses & Dissertations

Ultrasound computed tomography (USCT) and photoacoustic computed tomography (PACT) are two emerging imaging modalities that have a wide range of potential applications from pre-clinical small animal imaging to cancer screening in human subjects. USCT is typically employed to measure acoustic contrasts, including the speed of sound (SOS) distribution, while PACT typically measures optical contrasts or some related quantity such as the initial pressure distribution. Their complementary contrasts and similar implementations make USCT and PACT a natural fit for a hybrid imaging system. Still, much work remains to realize this promise. First, USCT image reconstruction methods based on the acoustic wave …

Reconstruction Algorithms For Novel Joint Imaging Techniques In Pet, Homayoon Ranjbar

McKelvey School of Engineering Graduate Student Theses & Dissertations

Positron emission tomography (PET) is an important functional in vivo imaging modality with many clinical applications. Its enormously wide range of applications has made both research and industry combine it with other imaging modalities such as X-ray computed tomography (CT) or magnetic resonance imaging (MRI). The general purpose of this work is to study two cases in PET where the goal is to perform image reconstruction jointly on two data types.

The first case is the Beta-Gamma image reconstruction. Positron emitting isotopes, such as ¹¹C, ¹³N, and ¹⁸F, can be used to label molecules, and tracers, such …