Biomedical Engineering and Bioengineering Commons^™

Computational Replication Of The Patient-Specific Stenting Procedure For Coronary Artery Bifurcations: From Oct And Ct Imaging To Structural And Hemodynamics Analyses, Claudio Chiastra, Wei Wu, Benjamin Dickerhoff, Ali Aleiou, Gabriele Dubini, Hiromasa Otake, Francesco Migliavacca, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

The optimal stenting technique for coronary artery bifurcations is still debated. With additional advances computational simulations can soon be used to compare stent designs or strategies based on verified structural and hemodynamics results in order to identify the optimal solution for each individual’s anatomy. In this study, patient-specific simulations of stent deployment were performed for 2 cases to replicate the complete procedure conducted by interventional cardiologists. Subsequent computational fluid dynamics (CFD) analyses were conducted to quantify hemodynamic quantities linked to restenosis.

Patient-specific pre-operative models of coronary bifurcations were reconstructed from CT angiography and optical coherence tomography (OCT). Plaque location and …

Effect Of Imperceptible Vibratory Noise Applied To Wrist Skin On Fingertip Touch Evoked Potentials – An Eeg Study, Na Jin Seo, Kishor Lakshminarayanan, Leonardo Bonilha, Abigail W. Lauer, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Random vibration applied to skin can change the sense of touch. Specifically, low amplitude white-noise vibration can improve fingertip touch perception. In fact, fingertip touch sensation can improve even when imperceptible random vibration is applied to other remote upper extremity areas such as wrist, dorsum of the hand, or forearm. As such, vibration can be used to manipulate sensory feedback and improve dexterity, particularly during neurological rehabilitation. Nonetheless, the neurological bases for remote vibration enhanced sensory feedback are yet poorly understood. This study examined how imperceptible random vibration applied to the wrist changes cortical activity for fingertip sensation. We measured …

Smartphone Based 3d Printed Colorimeter For Biomedical Applications, Karthik Raj Konnaiyan

USF Tampa Graduate Theses and Dissertations

Here we present a novel Smartphone-based colorimeter and demonstrate its application to the measurements of glucose and protein concentrations in biological samples. The key innovation of our approach was to combine powerful image processing encoded into a mobile phone application with a low cost 3D printed sample holder that allowed to control lighting conditions and significantly improved sensitivity. Different solutions with protein and glucose concentrations ranging from 0 to 2000 mg/dL were prepared and analyzed using our system. The Smartphone-based colorimeter always correctly classified the corresponding reagent strip pads, what confirms that it can be used as a low cost …

Incorporation Of Fibrin Into A Collagen–Glycosaminoglycan Matrix Results In A Scaffold With Improved Mechanical Properties And Enhanced Capacity To Resist Cell-Mediated Contraction, Claire Brougham, Tanya J. Levingstone, Stefan Jockenhoevel, Thomas C. Flanagan, Fergal J. O'Brien

Articles

Fibrin has many uses as a tissue engineering scaffold, however many in vivo studies have shown a reduction in function resulting from the susceptibility of fibrin to cell-mediated contraction. The overall aim of the present study was to develop and characterise a reinforced natural scaffold using fibrin, collagen and glycosaminoglycan (FCG), and to examine the cell-mediated contraction of this scaffold in comparison to fibrin gels. Through the use of an injection loading technique, a homogenous FCG scaffold was developed. Mechanical testing showed a sixfold increase in compressive modulus and a thirtyfold increase in tensile modulus of fibrin when reinforced with …

Department Of Biological Systems Engineering Newsletter, Fall 2015

BSE Department Magazine

No abstract provided.

Underwater Sound Transmission Through Arrays Of Disk Cavities In A Soft Elastic Medium., David C. Calvo, Abel L. Thangawng, Christopher N. Layman, Riccardo Casalini, Shadi F. Othman

All Faculty Articles - School of Engineering and Computer Science

Scattering from a cavity in a soft elastic medium, such as silicone rubber, resembles scattering from an underwater bubble in that low-frequency monopole resonance is obtainable in both cases. Arrays of cavities can therefore be used to reduce underwater sound transmission using thin layers and low void fractions. This article examines the role of cavity shape by microfabricating arrays of disk-shaped air cavities into single and multiple layers of polydimethylsiloxane. Comparison is made with the case of equivalent volume cylinders which approximate spheres. Measurements of ultrasonic underwater sound transmission are compared with finite element modeling predictions. The disks provide a …

Quantification Of Blood Flow Velocity Using Color Sensing, Aditya Deepak Sanghani

Master's Theses

Blood flow velocity is an important parameter that can give information on several pathologies including atherosclerosis, glaucoma, Raynaud’s phenomenon, and ischemic stroke [2,5,6,10]. Present techniques of measuring blood flow velocity involve expensive procedures such as Doppler echocardiography, Doppler ultrasound, and magnetic resonance imaging [11,12]. They cost from $8500-$20000. It is desired to find a low-cost yet equally effective solution for measuring blood flow velocity. This thesis has a goal of creating a proof of concept device for measuring blood flow velocity.

Finger blood flow velocity is investigated in this project. The close proximity to the skin of the finger’s arteries …

New Engineering Approaches To Arrhythmias And Myocardial Infarction, Frency Varghese

Biomedical Engineering Theses & Dissertations

In this thesis, we present new engineering approaches to several important cardiac diseases. Chapter 1 considers the dynamics of arrhythmias. The most dangerous arrhythmias are reentrant arrhythmias, including ventricular fibrillation and ventricular tachycardia. During these arrhythmias, there are one or several rotating excitation waves present in the heart. Because of their shape, these waves are called scroll waves; their center of rotation is a one-dimensional curve called the filament. Filaments largely constrain the configuration of a scroll wave but are much simpler, so much effort has gone into describing scroll wave dynamics in terms of the dynamics of their filaments. …

Mattrack: A Matlab-Based Quantitative Image Analysis Platform For Investigating Real-Time Photo-Converted Fluorescent Signals In Live Cells, Jane Courtney, Elena Woods, Dimitri Scholz, William Hall, Virginie Gautier

Articles

We introduce here MATtrack, an open source MATLAB-based computational platform developed to process multi-Tiff files produced by a photo-conversion time lapse protocol for live cell fluorescent microscopy. MATtrack automatically performs a series of steps required for image processing, including extraction and import of numerical values from Multi-Tiff files, red/green image classification using gating parameters, noise filtering, background extraction, contrast stretching and temporal smoothing. MATtrack also integrates a series of algorithms for quantitative image analysis enabling the construction of mean and standard deviation images, clustering and classification of subcellular regions and injection point approximation. In addition, MATtrack features a simple user …

Computational Approaches For Remote Monitoring Of Symptoms And Activities, Ferdaus Kawsar

Dissertations (1934 -)

We now have a unique phenomenon where significant computational power, storage, connectivity, and built-in sensors are carried by many people willingly as part of their life style; two billion people now use smart phones. Unique and innovative solutions using smart phones are motivated by rising health care cost in both the developed and developing worlds. In this work, development of a methodology for building a remote symptom monitoring system for rural people in developing countries has been explored. Design, development, deployment, and evaluation of e-ESAS is described. The system’s performance was studied by analyzing feedback from users. A smart phone …

Noninvasive Assessment Of Photoreceptor Structure And Function In The Human Retina, Robert Francis Cooper

Dissertations (1934 -)

The human photoreceptor mosaic underlies the first steps of vision; thus, even subtle defects in the mosaic can result in severe vision loss. The retina can be examined directly using clinical tools; however these devices lack the resolution necessary to visualize the photoreceptor mosaic. The primary limiting factor of these devices is the optical aberrations of the human eye. These aberrations are surmountable with the incorporation of adaptive optics (AO) to ophthalmoscopes, enabling imaging of the photoreceptor mosaic with cellular resolution. Despite the potential of AO imaging, much work remains before this technology can be translated to the clinic. Metrics …

Biomechanical Characerization And Evaluation Of Conservative Clubfoot Correction, Tamara Loren Cohen

Dissertations (1934 -)

Congential talipes equinovarus, or clubfoot, affects approximately 200,000 newborns worldwide each year and presents with equinovarus of the hindfoot, as well as cavus and adduction of the midfoot. In addition to bone malformation and displacement, soft tissue contractures encapsulate the medial and posterior aspects of the affected foot. The Ponseti method is a conservative treatment that progressively repositions the clubfoot through weekly casting, followed by bracing. Concerns exist regarding the variability in outcomes, resistance to treatment, and risk of relapse, which occur in approximately 10% of the population. Potential factors contributing to variability and resistant clubfoot include cast material performance, …

Alagebrium Inhibits Neointimal Hyperplasia And Restores Distributions Of Wall Shear Stress By Reducing Downstream Vascular Resistance In Obese And Diabetic Rats, Hongfeng Wang, Dorothee Weihrauch, Judy R. Kersten, Jeffrey M. Toth, Anthony G. Passerini, Anita Rajamani, Sonja Schrepfer, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

Mechanisms of restenosis in type 2 diabetes mellitus (T2DM) are incompletely elucidated, but advanced glycation end-products (AGEs)-induced vascular remodeling likely contributes. We tested the hypothesis that AGEs-related collagen cross-linking (ARCC) leads to increased downstream vascular resistance (DVR), and altered in-stent hemodynamics, thereby promoting neointimal hyperplasia (NH) in T2DM. We proposed that decreasing ARCC with ALT-711 (Alagebrium) would mitigate this response. Abdominal aortic stents were implanted in Zucker lean (ZL), obese (ZO), and diabetic (ZD) rats. Blood flow, vessel diameter, and wall shear stress (WSS) were calculated after 21 days, and NH was quantified. Arterial segments (aorta, carotid, iliac, femoral, arterioles) …

Fellow Eye Changes In Patients With Nonischemic Central Retinal Vein Occlusion: Assessment Of Perfused Foveal Microvascular Density And Identification Of Nonperfused Capillaries, Alexander Pinhas, Michael Dubow, Nishit Shah, Eric Cheang, Chun L. Liu, Moataz Razeen, Alexander Gan, Rishard Weitz, Yusufu N. Sulai, Toco Y.P. Chui, Alfredo Dubra, Richard B. Rosen

Biomedical Engineering Faculty Research and Publications

Purpose: Eyes fellow to nonischemic central retinal vein occlusion (CRVO) were examined for abnormalities, which might explain their increased risk for future occlusion, using adaptive optics scanning light ophthalmoscope fluorescein angiography.

Methods: Adaptive optics scanning light ophthalmoscope fluorescein angiography foveal microvascular densities were calculated. Nonperfused capillaries adjacent to the foveal avascular zone were identified. Spectral domain optical coherence tomography, ultrawide field fluorescein angiographies, and microperimetry were also performed.

Results: Ten fellow eyes of nine nonischemic CRVO and 1 nonischemic hemi-CRVO subjects and four affected eyes of three nonischemic CRVO and one nonischemic hemi-CRVO subjects were imaged. Ninety percent of fellow …

Quantifying Cross-Scatter Contamination In Biplane Fluoroscopy Motion Analysis Systems, Janelle A. Cross, Ben Mchenry, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Biplane fluoroscopy is used for dynamic in vivo three-dimensional motion analysis of various joints of the body. Cross-scatter between the two fluoroscopy systems may limit tracking accuracy. This study measured the magnitude and effects of cross-scatter in biplane fluoroscopic images. Four cylindrical phantoms of 4-, 6-, 8-, and 10-in. diameter were imaged at varying kVp levels to determine the cross-scatter fraction and contrast-to-noise ratio (CNR). Monte Carlo simulations quantified the effect of the gantry angle on the cross-scatter fraction. A cadaver foot with implanted beads was also imaged. The effect of cross-scatter on marker-based tracking accuracy was investigated. Results demonstrated …

Lpcoms: Towards A Low Power Wireless Smart-Shoe System For Gait Analysis In People With Disabilities, Ishmat Zerin

Master's Theses (2009 -)

Gait analysis using smart sensor technology is an important medical diagnostic process and has many applications in rehabilitation, therapy and exercise training. In this thesis, we present a low power wireless smart-shoe system (LPcomS) to analyze different functional postures and characteristics of gait while walking. We have designed and implemented a smart-shoe with a Bluetooth communication module to unobtrusively collect data using smartphone in any environment. With the design of a shoe insole equipped with four pressure sensors, the foot pressure is been collected, and those data are used to obtain accurate gait pattern of a patient. With our proposed …

Hockey Skating Kinematics And The Effect Of Skate Design And Technique Training, Rebecca Mae Tidman

Master's Theses (2009 -)

The purpose of this study was to investigate the effects of technique training and hockey skate design on hockey skating performance. Fourteen male subjects, aged 12-16 years, with no recent skate treadmill experience completed ten training sessions on a skating treadmill. Instruction emphasized maximizing stride width by pushing laterally with the skate pointed anteriorly. Subjects were randomly placed into one of two experimental groups based on initial skate type: traditional or Easton Mako. After completion of five sessions, skate type was switched so that skate design effects could be assessed. In contrast to a traditional hockey skate design, the Easton …

Mechanical Characterization Of Carbon Fiber And Thermoplastic Ankle Foot Orthoses, Amanda Wach

Master's Theses (2009 -)

The needs of an increasingly young and active orthotic patient population has led to advancements in ankle foot orthosis (AFO) design and materials to enable higher function. The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a custom energy-storing carbon fiber AFO that has demonstrated improved clinical function, allowing patients to return to high-intensity activities such as sports and military service. An improved understanding of AFO mechanical function will aid prescription and fitting, as well as assist in design modifications for different patient populations. This study investigated the mechanical properties of AFOs, specifically structural stiffness, rotational motion, and strut deflection, to discern …

Integrating Meal And Exercise Into Personalized Glucoregulation Models: Metabolic Dynamics And Diabetic Athletes, Sofie Schunk

Master's Theses (2009 -)

Diabetes affects nearly 26 million Americans, according to the American Diabetes Association, with as many as three million Americans who have Type 1 Diabetes (ADA, 2015). Type 1 Diabetes (T1D) is autoimmune and characterized by little to no insulin production whereas Type 2 Diabetes (T2D) concerns insulin resistance and inability to use produced insulin. Factors contributing to current diabetes management and regulation include exercise type, daily movement activities, and distinct tissue compartment metabolism, each challenging to model in a robust and comprehensive manner. Past models are highly limited in regard to exercise and varying glucose fluctuations dependent on type, intensity, …

Initial Validation Of A Novel Method Of Presurgical Language Localization Through Functional Connectivity (Fcmri), Stephanie M. Noble, Dustin Scheinost, Susan Y. Bookheimer, Patricia Walshaw, R Todd Constable, Christopher F. Benjamin

Yale Day of Data

OBJECTIVE: Neurosurgery is potentially curative in chronic epilepsy but can only be offered to patients if the surgical risk to language is known. Clinical functional magnetic resonance imaging (fMRI) is an ideal, noninvasive method for localizing language cortex yet remains to be validated for this purpose. We have recently presented a novel method for localizing language cortex. Here we present a preliminary evaluation of this method’s validity. We hypothesized language regions identified using this novel method would demonstrate stronger functional connectivity than randomly generated set of proximal networks. METHOD: fMRI data were collected from sixteen temporal lobe patients …

Biomechanics Of Pediatric Manual Wheelchair Mobility, Brooke A. Slavens, Alyssa J. Schnorenberg, Christine M. Aurit, Sergey Tarima, Lawrence C. Vogel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Currently, there is limited research of the biomechanics of pediatric manual wheelchair mobility. Specifically, the biomechanics of functional tasks and their relationship to joint pain and health is not well understood. To contribute to this knowledge gap, a quantitative rehabilitation approach was applied for characterizing upper extremity biomechanics of manual wheelchair mobility in children and adolescents during propulsion, starting, and stopping tasks. A Vicon motion analysis system captured movement, while a SmartWheel simultaneously collected three-dimensional forces and moments occurring at the handrim. A custom pediatric inverse dynamics model was used to evaluate three-dimensional upper extremity joint motions, forces, and moments …

Carboxymethylcellulose Hydrogels Support Cns-Derived Tumor Cell Chemotactic Migration, Tanya Singh, Chandrasekhar Kothapalli, Devika Verma, Steven Nicoll, Maribel Vazquez

Publications and Research

The local microenvironment plays an important role in maintaining the dynamics of the extracellular matrix (ECM) and the cell-ECM relationship. ECM is a complex network of molecules with distinct mechanical and biochemical characteristics. When the mechanisms that are in place to maintain ECM homeostasis are deregulated, most likely, this is the onset of cancer. The ECM becomes highly disorganized and the cell-matrix relationship changes, thus promoting alternations in cell mechanisms and metastasis. Medulloblastoma (MB) is one of the most common, malignant pediatric brain tumors in the United States. In order to gain a better understanding between the cell-ECM relationship and …

Analysis Of A Clinically Failed, Mechanically Intact, Reconstructive Compression Plate, Bharadwaj Cheruvu, Sunil Karmacharya, Richard T. Laughlin, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

A reconstructive orthopedic bone plate was submitted for analysis. Traditional failure analysis methods were used to assess the mode of the plate failure. Metallographic investigation of the plate was carried out in this report. Since limited data was available in the literature and clinical data related to subject demography, date of removal as well as reasons for removal unknown, in depth analysis was not possible. However, the plate was received in in-tact condition with minor biological deposits and scratches, it is speculated that the failure of the plate may have been due to biological/clinical reasons, likely infection, rejecting the device …

The Effect Of Surface Modification Of Aligned Poly-L-Lactic Acid Electrospun Fibers On Fiber Degradation And Neurite Extension, Nicholas J. Schaub, Clémentine Le Beux, Jianjun Miao, Robert J. Linhardt, Johan G. Alauzun, Danielle Laurencin, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The surface of aligned, electro spun poly-L-lactic acid (PLLA) fibers was chemically modified to determine if surface chemistry and hydrophilicity could improve neurite extension from chick dorsal root ganglia. Specifically, diethylenetriamine (DTA, for amine functionalization), 2-(2-aminoethoxy) ethanol (AEO, for alcohol functionalization), or GRGDS (cell adhesion peptide) were covalently attached to the surface of electro spun fibers. Water contact angle measurements revealed that surface modification of electro spun fibers significantly improved fiber hydrophilicity compared to unmodified fibers (p < 0.05). Scanning electron microscopy (SEM) of fibers revealed that surface modification changed fiber topography modestly, with DTA modified fibers displaying the roughest surface structure. Degradation of chemically modified fibers revealed no change in fiber diameter in any group over a period of seven days. Unexpectedly, neurites from chick DRG were longest on fibers without surface modification (1651 ± 488 μm) and fibers containing GRGDS (1560 ± 107 μm). Fibers modified with oxygen plasma (1240 ± 143 μm) or DTA (1118 ± 82 μm) produced shorter neurites than the GRGDS or unmodified fibers but were not statistically shorter than unmodified and GRGDS modified fibers. Fibers modified with AEO (844 ± 151 μm) were significantly shorter than unmodified and GRGDS modified fibers (p< 0.05). Based on these results, we conclude that fiber hydrophilic enhancement alone on electro spun PLLA fibers does not enhance neurite outgrowth. Further work must be conducted to better understand why neurite extension was not improved on more hydrophilic fibers, but the results presented here do not recommend hydrophilic surface modification for the purpose of improving neurite extension unless a bioactive ligand is used.

Review Of Fluorescence Guided Surgery Visualization And Overlay Techniques, Jonathan T. Elliott, Alisha V. Dsouza, Scott C. Davis, Jonathan D. Olson, Keith Paulsen, David Roberts, Brian Pogue

Dartmouth Scholarship

In fluorescence guided surgery, data visualization represents a critical step between signal capture and display needed for clinical decisions informed by that signal. The diversity of methods for displaying surgical images are reviewed, and a particular focus is placed on electronically detected and visualized signals, as required for near-infrared or low concentration tracers. Factors driving the choices such as human perception, the need for rapid decision making in a surgical environment, and biases induced by display choices are outlined. Five practical suggestions are outlined for optimal display orientation, color map, transparency/alpha function, dynamic range compression, and color perception check.

Spectroscopic Separation Of Čerenkov Radiation In High-Resolution Radiation Fiber Dosimeters, Arash Darafsheh, Rongxiao Zhang, Stephen Chad Kanick, Brian W. Pogue, Jarod C. Finlay

Dartmouth Scholarship

We have investigated Čerenkov radiation generated in phosphor-based optical fiber dosimeters irradiated with clinical electron beams. We fabricated two high-spatial resolution fiber-optic probes, with 200 and 400  μm core diameters, composed of terbium-based phosphor tips. A generalizable spectroscopic method was used to separate Čerenkov radiation from the transmitted signal by the fiber based on the assumption that the recorded signal is a linear superposition of two basis spectra: characteristic luminescence of the phosphor medium and Čerenkov radiation. We performed Monte Carlo simulations of the Čerenkov radiation generated in the fiber and found a strong dependence of the recorded Čerenkov …

Towards Continuous Aqueous Two-Phase Extraction (Catpe), Bettina Bommarius, Andres Bommarius, Irene Kaplanow, Julianne Merz, Gerhard Schembecker

Integrated Continuous Biomanufacturing II

Aqueous Two-Phase Extraction (ATPE) in mixer-settlers offers a gentle and biocompatible environment to separate proteins from complex mixtures. We have developed an aqueous two-phase system with inexpensive and biocompatible PEG 1500 or 4000 and ammonium citrate. We have purified several dehydrogenases [1] to near homogeneity after forward extraction into a PEG-heavy top phase at pH > 9 and back extraction into a bottom phase at pH 4-6; in selected cases, we were able to obtain pure protein in the bottom phase without forward extraction into the top phase. We have scaled up the PEG 1500/4000-ammonium citrate to a 5-10 L scale, …

Characterization Of Electrophorectic Separations On A Cellulose Paper-Microfluidic Chip, Kyle Robert Fast

Master's Theses

The purpose of this thesis project is to demonstrate the ability to utilize electrophoresis in a cellulose paper microfluidic chip to manipulate charged particles. Materials were selected and a manufacturing protocol was created to successfully apply the electric field onto the paper chip. Experiments were performed to characterize the separation rates for charged, colorimetric dye, Orange G in the membrane as a function of an applied electric field, dye concentration, and distance traveled. The experiments confirmed that the electric field can be applied to the chip and particle separation rates were characterized. Next, the determined rates results were used to …

The Role Of Biological Fluid And Dynamic Flow In The Behavior And Cellular Interactions Of Gold Nanoparticles, Emily K. Breitner, Saber M. Hussain, Kristen K. Comfort

Chemical and Materials Engineering Faculty Publications

Background: Due to their distinctive physicochemical properties, nanoparticles (NPs) have proven to be extremely advantageous for product and application development, but are also capable of inducing detrimental outcomes in biological systems. Standard in vitro methodologies are currently the primary means for evaluating NP safety, as vast quantities of particles exist that require appraisal. However, cell-based models are plagued by the fact that they are not representative of complex physiological systems. The need for a more accurate exposure model is highlighted by the fact that NP behavior and subsequent bioresponses are highly dependent upon their surroundings. Therefore, standard in vitro models …

Investigation Of Bovine Serum Albumin (Bsa) Attachment Onto Self-Assembled Monolayers (Sams) Using Combinatorial Quartz Crystal Microbalance With Dissipation (Qcm-D) And Spectroscopic Ellipsometry (Se), Hanh T.M. Phan, Shannon L. Bartelt-Hunt, Keith B. Rodenhausen, Mathias Schubert, Jason C. Bartz

Department of Civil and Environmental Engineering: Faculty Publications

Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various selfassembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The …