Biomedical Engineering and Bioengineering Commons^™

Quantitative Spatial Frequency Fluorescence Imaging In The Sub-Diffusive Domain For Image-Guided Glioma Resection, Mira Sibai, Israel Veilleux, Jonathan T. Elliott, Frederic Leblond, Brian Wilson

Dartmouth Scholarship

Intraoperative 5- aminolevulinic acid induced-Protoporphyrin IX (PpIX) fluorescence guidance enables maximum safe resection of glioblastomas by providing surgeons with real-time tumor optical contrast. However, visual assessment of PpIX fluorescence is subjective and limited by the distorting effects of light attenuation and tissue autofluorescence. We have previously shown that non-invasive point measurements of absolute PpIX concentration identifies residual tumor that is otherwise non-detectable. Here, we extend this approach to wide-field quantitative fluorescence imaging by implementing spatial frequency domain imaging to recover tissue optical properties across the field-of-view in phantoms and ex vivo tissue.

Ph Responsive, Adhesive Hydrogels Based On Reversible Catechol - Boronic Acid Complexation, Ameya Ravindra Narkar

Dissertations, Master's Theses and Master's Reports - Open

Smart hydrogel adhesives with tunable properties consist of adhesive moieties in the polymer network that respond to external stimuli like pH, temperature, etc. Responsiveness of smart adhesives to pH, in particular, is important because of the simple actuation mechanism and the ability to achieve facile bonding and debonding upon command. Covalently crosslinked hydrogel adhesives were prepared by employing an N-HEAA (hydroxyethyl acrylamide) backbone embedded with dopamine methacrylamide (DMA), a marine mussel inspired adhesive protein and 3-acrylamido phenylboronic acid (AAPBA), to determine the effect of pH on the interfacial binding properties of the hydrogel adhesive with a borosilicate glass substrate. Swelling …

Biom 3110: Medical Physiology (Syllabus), Bradford D. Pendley

Biomedical Engineering Syllabi Archive

Course Description: Basic principles of human physiology and how these are applied in medicine and biomedical engineering problem and devices; physiological principles using appropriate mathematical and engineering models to construct an understanding of how the body works as an integrated system.

Fibrin Gel As An Injectable Biodegradable Scaffold And Cell Carrier For Tissue Engineering, Yuting Li, Hao Meng, Yuan Liu, Bruce P. Lee

Department of Biomedical Engineering Publications

Due to the increasing needs for organ transplantation and a universal shortage of donated tissues, tissue engineering emerges as a useful approach to engineer functional tissues. Although different synthetic materials have been used to fabricate tissue engineering scaffolds, they have many limitations such as the biocompatibility concerns, the inability to support cell attachment, and undesirable degradation rate. Fibrin gel, a biopolymeric material, provides numerous advantages over synthetic materials in functioning as a tissue engineering scaffold and a cell carrier. Fibrin gel exhibits excellent biocompatibility, promotes cell attachment, and can degrade in a controllable manner. Additionally, fibrin gel mimics the natural …

Bioactive Lipid Coating Of Bone Allografts Direct Engraftment And Fate Determination Of Bone Marrow-Derived Cells In Rat Gfp Chimeras, Anusuya Das, Claire E. Segar, Yihsuan Chu, Tiffany W. Wang, Yon Lin, Chunxi Yang, Roy C. Ogle

School of Medical Diagnostics & Translational Sciences Publications

Bone grafting procedures are performed to treat wounds incurred during wartime trauma, accidents, and tumor resections. Endogenous mechanisms of repair are often insufficient to ensure integration between host and donor bone and subsequent restoration of function. We investigated the role that bone marrow-derived cells play in bone regeneration and sought to increase their contributions by functionalizing bone allografts with bioactive lipid coatings. Polymer-coated allografts were used to locally deliver the immunomodulatory small molecule FTY720 in tibial defects created in rat bone marrow chimeras containing genetically-labeled bone marrow for monitoring cell origin and fate. Donor bone marrow contributed significantly to both …

Iterative Ct Reconstruction From Few Projections For The Nondestructive Post Irradiation Examination Of Nuclear Fuel Assemblies, Muhammad Imran Khan Abir

Doctoral Dissertations

The core components (e.g. fuel assemblies, spacer grids, control rods) of the nuclear reactors encounter harsh environment due to high temperature, physical stress, and a tremendous level of radiation. The integrity of these elements is crucial for safe operation of the nuclear power plants. The Post Irradiation Examination (PIE) can reveal information about the integrity of the elements during normal operations and off‐normal events. Computed tomography (CT) is a tool for evaluating the structural integrity of elements non-destructively. CT requires many projections to be acquired from different view angles after which a mathematical algorithm is adopted for reconstruction. Obtaining many …

Selective Laser Sintering Of Bioactive Glass Scaffolds And Their Biological Assessment For Bone Repair, Krishna C. R. Kolan

Doctoral Dissertations

"Bone scaffold fabrication using powder-bed based additive manufacturing techniques, like the selective laser sintering (SLS) process, provides control over pore interconnectivity, pore geometry, and the overall shape of the scaffold, which aids in repairing different regions of the bone. The main objectives of this dissertation were to develop bioactive glass (BG) scaffolds using the SLS process and evaluate the scaffolds for their effectiveness in bone repair both in vitro and in vivo. 13-93 glass, a silicate based BG, and 13-93B3 glass, a borate based BG, are designed to accelerate the body's natural ability to heal itself and are used …

Du05, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Du04, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Du03, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Du01, Center For Orthopaedic Biomechanics, Michael D. Harris, Phd, Kevin Shelburne, Phd

Natural Knee Data

No abstract provided.

Non-Invasive Right Ventricular Efficiency Using 4d Flow Mri, Alejandro Roldán-Alzate, Scott Grogan, Heidi Kellihan, Alessandro Bellofiore, Naomi Chesler, Oliver Wieben, Christopher Francois

Faculty Publications

Pulmonary arterial hypertension (PH) is a progressive disease of increased resistance to flow through the lungs, leading to right ventricular (RV) failure [1]. MRI is increasingly used to assess right ventricular (RV) function in PH. RV stroke work (SW) based on invasive pressure and volume measurements, is used to assess ventricular work. Determining RV work from MRI could enable a more complete characterization of RV and PA interactions in PH. The purpose of this study was to non-invasively estimate RV work from simultaneously acquired RV volume (VRV) and pulmonary artery flow (QPA) using a 4D flow-sensitive MRI sequence …

Material Considerations For Development Of 3d Printed Bronchial And Tracheal Stents, Nidah M. Hussain

Theses and Dissertations

Tracheobronchial malacia is a commonly under-diagnosed condition that results in difficulty breathing. The use of a tracheobronchial stent is the best course of treatment for patients whose quality of life has deteriorated due to malacia; unfortunately stents need replacing after issues with inflammation, migration, or eventual stent-breakdown resulting in fistula formation.

The purpose of this thesis is to use three-dimensional (3D) printing technology to improve on existing stents through designing and printing a bioresorbable/biodegradable tracheobronchial stent that can treat tracheobronchial malacia. This was undertaken by testing three biologically favorable materials, type I collagen, polycaprolactone (PCL), and thermoplastic polyurethane (TPU), with …

Design And Development Of A Ventilation Chamber For Testing Efficacy Of Tracheal Stents, Caroline N. Horton

Theses and Dissertations

Tracheobronchial malacia results in a weakening of the tracheal walls, leading to increased difficulty breathing. Stents are used to reopen the lumen of the trachea, however, current models are not personalized to each patient, leading to migration, inflammation, and breakage of the stents. In order to successfully test novel stent designs, a ventilation chamber is needed to recreate the breathing conditions of the body.

The following describes the iterative development of a ventilation chamber, which allows inflation and deflation of lungs via negative pressure ventilation, as representative of an actual body undergoing respiration. Previous work shows that lungs are not …

Adaptive Graph Construction For Isomap Manifold Learning, Loc Tran, Zezhong Zheng, Guoquing Zhou, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.)

Electrical & Computer Engineering Faculty Publications

Isomap is a classical manifold learning approach that preserves geodesic distance of nonlinear data sets. One of the main drawbacks of this method is that it is susceptible to leaking, where a shortcut appears between normally separated portions of a manifold. We propose an adaptive graph construction approach that is based upon the sparsity property of the ℓ₁ norm. The ℓ₁ enhanced graph construction method replaces k-nearest neighbors in the classical approach. The proposed algorithm is first tested on the data sets from the UCI data base repository which showed that the proposed approach performs better than …

A Comparative Study Of Two Prediction Models For Brain Tumor Progression, Deqi Zhou, Loc Tran, Jihong Wang, Jiang Li, Karen O. Egiazarian (Ed.), Sos S. Agaian (Ed.), Atanas P. Gotchev (Ed.)

Electrical & Computer Engineering Faculty Publications

MR diffusion tensor imaging (DTI) technique together with traditional T1 or T2 weighted MRI scans supplies rich information sources for brain cancer diagnoses. These images form large-scale, high-dimensional data sets. Due to the fact that significant correlations exist among these images, we assume low-dimensional geometry data structures (manifolds) are embedded in the high-dimensional space. Those manifolds might be hidden from radiologists because it is challenging for human experts to interpret high-dimensional data. Identification of the manifold is a critical step for successfully analyzing multimodal MR images.

We have developed various manifold learning algorithms (Tran et al. 2011; Tran et al. …

Evaluation Of The Effects Of A Plasma Activated Medium On Cancer Cells, S. Mohades, M. Laroussi, J. Sears, N. Barekzi, H. Razavi

Electrical & Computer Engineering Faculty Publications

The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma to …

Experimental Comparison Of Empirical Material Decomposition Methods For Spectral Ct, Kevin C. Zimmerman, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Material composition can be estimated from spectral information acquired using photon counting x-ray detectors with pulse height analysis. Non-ideal effects in photon counting x-ray detectors such as charge-sharing, k-escape, and pulse-pileup distort the detected spectrum, which can cause material decomposition errors. This work compared the performance of two empirical decomposition methods: a neural network estimator and a linearized maximum likelihood estimator with correction (A-table method). The two investigated methods differ in how they model the nonlinear relationship between the spectral measurements and material decomposition estimates. The bias and standard deviation of material decomposition estimates were compared for the two methods, …

Kinematic Foot Types In Youth With Equinovarus Secondary To Hemiplegia, Joseph Krzak, Daniel M. Corcos, Diane L. Damiano, Adam Graf, Donald Hedeker, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background

Elevated kinematic variability of the foot and ankle segments exists during gait among individuals with equinovarus secondary to hemiplegic cerebral palsy (CP). Clinicians have previously addressed such variability by developing classification schemes to identify subgroups of individuals based on their kinematics.

Objective

To identify kinematic subgroups among youth with equinovarus secondary to CP using 3-dimensional multi-segment foot and ankle kinematics during locomotion as inputs for principal component analysis (PCA), and K-means cluster analysis.

Methods

In a single assessment session, multi-segment foot and ankle kinematics using the Milwaukee Foot Model (MFM) were collected in 24 children/adolescents with equinovarus and …

A Portable, Low-Cost Wheelchair Ergometer Design Based On A Mathematical Model Of Pediatric Wheelchair Dynamics, Jacob R. Rammer, Susan A. Riedel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Evaluation and training of wheelchair propulsion improves efficiency and prevents orthopaedic injury in pediatric manual wheelchair users. Ergometers allow static propulsion and emulate typical conditions. Currently available ergometers have deficiencies that limit their use in motion analysis. A new ergometer is developed and evaluated based on a model of wheelchair inertial dynamics that eliminates these deficiencies. This makes integrated motion analysis of wheelchair propulsion in current community, home, and international outreach efforts possible.