Biomedical Engineering and Bioengineering Commons^™

Delivery Of Tgfβ3 From Magnetically Responsive Coaxial Fibers Reduces Spinal Cord Astrocyte Reactivity In Vitro, Jessica L. Funnell, Jasper Fougere, Diana Zahn, Silvio Dutz, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

A spinal cord injury (SCI) compresses the spinal cord, killing neurons and glia at the injury site and resulting in prolonged inflammation and scarring that prevents regeneration. Astrocytes, the main glia in the spinal cord, become reactive following SCI and contribute to adverse outcomes. The anti-inflammatory cytokine transforming growth factor beta 3 (TGFβ3) has been shown to mitigate astrocyte reactivity; however, the effects of prolonged TGFβ3 exposure on reactive astrocyte phenotype have not yet been explored. This study investigates whether magnetic core-shell electro spun fibers can be used to alter the release rate of TGFβ3 using externally applied magnetic fields, …

Biomechanical Effects Of Worn-Out Shoe Outsoles And Insoles On The Human Foot, Yuka M. Iwashita, James A. Engebretson, Shreeshan Jena

College of Engineering Summer Undergraduate Research Program

The combination of outsole, midsole and insole layers of new shoes provide proper cushioning to the foot during the daily activities of life. Subsequently, the wear-based degeneration or damage to one or more of these sole layers can reduce the cushioning effect to the plantar surface of the foot. This reduction of cushioning effect can impact the distribution of stress concentration regions along the foot plantar surfaces and lead to foot pathologies. The present proposed research intends to study these effects of shoe-wear on the plantar surface of the human foot, using FEA (ABAQUS) and experimental methods. Commonly, the worn-out …

Wearable Sensor-Based Gait And Balance In Elementary And Middle Schools, Sofie Zalatimo, Catherine Semaan

College of Engineering Summer Undergraduate Research Program

No abstract provided.

Significance Of Noninvasive Endothelial Dysfunction And Other Cardiovascular Measurements In Various Communities, Sofi Z. David, Lily Wilcox, Kalia Richard

College of Engineering Summer Undergraduate Research Program

This pilot study aims to raise awareness of endothelial dysfunction in underrepresented communities, where cardiovascular disease is prevalent. By delivering educational presentations and materials, the study seeks to increase participants' understanding and interest in endothelial dysfunction, potentially leading to proactive health behaviors. The results will inform future initiatives to enhance public knowledge and reduce the burden of cardiovascular disease in these communities.

In the future, there will also be a 3 vs 5-minute hyperemia study. Thirty participants without a history of cardiovascular disease will undergo testing using the Cordex SmartCuff™ device. If the three-minute hold proves to accurately measure endothelial …

Wearable Sensing Systems And Data Analytics For Pressure Sensing Socket Prostheses, Stacey Le, Mio Nakagawa

College of Engineering Summer Undergraduate Research Program

Prosthetics have been widely used as the primary solution for lower limb amputations, but residual limb volume fluctuations have posed challenges to the effectiveness and comfortability of these devices. In this project, we aim to observe pressure distribution patterns in the prosthetic socket during gait using sensing technology and investigate the performance of different machine learning algorithms on determining good or bad fit.

Radiopaque Femnn-Mo Composite Drawn Filled Tubing Wires For Braided Absorbable Neurovascular Devices, Adam J. Griebel, Petra Maier, Henry D. Summers, Benjamin Clausius, Isabella Kanasty, Weilue He, Nicholas Peterson, Carolyn Czerniak, Alexander A. Oliver, David F. Kallmes, Ramanathan Kadirvel, Jeremy E. Schaffer, Roger J. Guillory

Michigan Tech Publications

Flow diverter devices are small stents used to divert blood flow away from aneurysms in the brain, stagnating flow and inducing intra-aneurysmal thrombosis which in time will prevent aneurysm rupture. Current devices are formed from thin (∼25 μm) wires which will remain in place long after the aneurysm has been mitigated. As their continued presence could lead to secondary complications, an absorbable flow diverter which dissolves into the body after aneurysm occlusion is desirable. The absorbable metals investigated to date struggle to achieve the necessary combination of strength, elasticity, corrosion rate, fragmentation resistance, radiopacity, and biocompatibility. This work proposes and …

Simultaneous Modulation Of Pulse Charge And Burst Period Elicits Two Differentiable Referred Sensations, T. R. Benigni, A. E. Pena, S. S. Kuntaegowdanahalli, J. J. Abbas, R. Jung

Biomedical Engineering Faculty Publications and Presentations

Objective. To investigate the feasibility of delivering multidimensional feedback using a single channel of peripheral nerve stimulation by complementing intensity percepts with flutter frequency percepts controlled by burst period modulation. Approach. Two dimensions of a distally referred sensation were provided simultaneously: intensity was conveyed by the modulation of the pulse charge rate inside short discrete periods of stimulation referred to as bursts and frequency was conveyed by the modulation of the period between bursts. For this approach to be feasible, intensity percepts must be perceived independently of frequency percepts. Two experiments investigated these interactions. A series of two alternative forced …

Talar And Calcaneal Coordinate Axes Definitions Across Foot Pathologies, Kassidy Knutson, Erkia P. Muhlrad, Andrew C. Peterson, Thomas Leonard, Abigail M. Anderson, Katelyn C. Aragon, Zachary J. Eatough, Bruce A. Macwilliams, Karen M. Kruger, Amy L. Lenz

Biomedical Engineering Faculty Research and Publications

The understanding of foot and ankle biomechanics is improving as new technology provides more detailed information about the motion of foot and ankle bones with biplane fluoroscopy, as well as the ability to analyze the hindfoot under weightbearing conditions with weightbearing computed tomography. Three-dimensional anatomical coordinate systems are necessary to describe the 3D alignment and kinematics of the foot and ankle. The lack of standard coordinate systems across research study sites can significantly alter experimental data analyses used for pre-surgical evaluation and post-operative outcome assessments. Clinical treatment paradigms are changing based on the expanding knowledge of complex pes planovalgus morphologies …

A Sophisticated Model Of Human Atherosclerosis On A Chip, Brandon J. Tefft

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Lumbar Spine Orientation Affects Compressive Fracture Outcome, Rachel Cutlan, Muhammaed Khokhar, Nader Shammout, Alok Shah, Lance Frazer, Narayan Yoganandan, Barry S. Shender, James Sheehy, Glenn Paskoff, Daniel Nicolella, Timothy B. Bentley, Saman Shabani, Brian D. Stemper

Biomedical Engineering Faculty Research and Publications

Purpose

Understanding how spinal orientation affects injury outcome is essential to understand lumbar injury biomechanics associated with high-rate vertical loading.

Methods

Whole-column human lumbar spines (T12–L5) were dynamically loaded using a drop tower to simulate peak axial forces associated with high-speed aircraft ejections and helicopter crashes. Spines were allowed to maintain natural lordotic curvature for loading, resulting in a range of orientations. Pre-test X-rays were used to quantify specimen orientation at the time of loading. Primary fracture types were identified (wedge, n = 6; burst, n = 4; hyperextension, n = 4) and compared for loading parameters and lumbar orientation. …

Editorial: Novel Computational Fluid Dynamics Methods For Diagnosis, Monitoring, Prediction, And Personalized Treatment For Cardiovascular Disease And Cancer Metastasis, Zahra Keshavarz Motamed, Nima Maftoon, Lakshmi Prasad Dasi, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Realtime And Noninvasive Assessment Of Endotracheal Tube Displacement Using Near-Infrared And Visible Cameras, Tongtong Lu, Pawjai Khampang, Ahmed Beydoun, Rebecca Rodhe, Wenzhou Hong, Joseph E. Kerschner, Bing Yu

Biomedical Engineering Faculty Research and Publications

Endotracheal tube (ETT) intubation is a medical procedure routinely used for achieving mechanical ventilation in critically ill patients. Appropriate ETT placement is crucial as undetected tube migration may cause multiple complications or even fatalities. Therefore, prompt detection of unplanned movement of the ETT and immediate action to restore proper placement are essential to ensure patient safety. Despite this necessity, there is not a widely adopted tool for real-time assessment of ETT displacement. We have developed a device, a dual-camera endotracheal tube or DC-ETT, to address this unmet clinical need. This device uses a near-infrared (NIR) LED and a side-firing optical …

Vascular Calcification In A Mouse Model Of Chronic Kidney Disease And In Human Peripheral Arterial Disease, Breanna Pederson

Theses and Dissertations

Vascular calcification is a process in which calcium and phosphate crystallize to form hydroxyapatite in the extracellular matrix of blood vessels. There are two forms of arterial calcification: intimal and medial, which occur via different etiologies. Intimal calcification is associated with atherosclerosis and occurs in the layer of endothelial cells adjacent to the artery lumen. Medial arterial calcification (MAC) is independent of atherosclerosis and occurs in the middle, muscular layer of the artery. MAC is strongly associated with aging, diabetes mellitus, and chronic kidney disease (CKD). MAC is frequently in patients with peripheral arterial disease (PAD). Most studies to date …

Intercellular Mitochondrial Transfer Contributes To Microenvironmental Fate Redirection Of Mammary Cancer Cells, Julie Sofie Bjerring

Biomedical Sciences Theses & Dissertations

The dynamic cellular microenvironment, made up of resident cells and various macromolecules, differs markedly across tissues in the body. The multidirectional signals that cells receive from this microenvironment, along with the signaling they send back, heavily influence their physiology and behavior. Recent important findings have further validated this notion as the mammary microenvironment has been shown to suppress tumor progression by redirecting cancer cells to adopt a normal mammary epithelial progenitor fate in vivo. However, the mechanism(s) driving changes in metabolic reprogramming and cancer fate redirection is understudied. The work presented in this dissertation focuses on exploring the impact of …

Effect Of Storage Time And Temperature On Aggregation Of Alzheimer's Disease Amyloid-Β Protein, Amy Veihdeffer

Theses and Dissertations

Amyloid-β protein (Aβ) is widely studied due to its key role in Alzheimer’s disease (AD) pathology. One characteristic of patients suffering from AD is the deposition of amyloid plaques comprised of Aβ aggregates, which are associated with synapse damage. Thus, studying Aβ aggregation and aggregation inhibition may provide pathological and therapeutic insights. Aggregation of Aβ is a nucleation dependent process that may be influenced by the presence of pre-formed Aβ aggregate seeds that can facilitate formation of protein aggregates. These seeds may appear during preparation or storage of monomer, posing impact on experiments that study the aggregation process and the …

Phenotypes Of Velopharyngeal Tube Law In Obstructive Sleep Apnea, Devesh Kumar, B. Tucker Woodson, Guilherme J.M. Garcia

Biomedical Engineering Faculty Research and Publications

Objective

The biomechanics of upper airway collapse in obstructive sleep apnea (OSA) remains poorly understood. The goal of this study is to compare the area-pressure relationship (tube law) of the velopharynx at peak inspiration and peak expiration.

Study Design

Cross-sectional.

Setting

Academic tertiary medical center.

Methods

The velopharyngeal tube law was quantified in a convenience sample of 20 OSA patients via step reductions in nasal mask pressure during drug induced sleep endoscopy (DISE). The velopharyngeal airspace cross-sectional area was estimated from endoscopy while luminal pressure was recorded with a catheter. The tube law was quantified for nasal mask pressures from …

Morphology Of The Normative Human Cone Photoreceptor Mosaic And A Publicly Available Adaptive Optics Montage Repository, Robert F. Cooper, Snega Kalaparambath, Geoffrey K. Aguirre, Jessica I. W. Morgan

Biomedical Engineering Faculty Research and Publications

Adaptive optics ophthalmoscopy has enabled visualization of the in vivo human photoreceptor mosaic in health, disease and its treatment. Despite this, the clinical utility of the imaging technology has been limited by a lack of automated analysis techniques capable of accurately quantifying photoreceptor structure and a lack of an available normative image database. Here, we present a fully automated algorithm for estimating cone spacing and density over a complete adaptive optics montage along with a database of normative images and cone densities. We imaged the cone mosaics surrounding the fovea and along the horizontal and vertical meridians of fifty normal-sighted …

Assessing The Impact Of Femur Morphological Variations On Pediatric Hip Joint Biomechanics Using Statistical Shape Modeling, Tamara Chambers

Doctoral Dissertations and Master's Theses

This dissertation aimed to (1) quantify morphological variations in the pediatric hip joint and (2) evaluate the sensitivity of an infant musculoskeletal model (MSM) to these variations, considering hip joint center estimation errors. A shape statistical model (SSM) of decedent infant femurs from the Ortolani collection was created using ShapeWorks, capturing key morphological features, such as variations in the femoral neck-shaft and anteversion angles. Seven synthetic femurs were generated from the SSM to create SSM-informed MSMs, which were systematically evaluated through kinematics and kinetics analyses in OpenSim. Incorporating the SSM led to slight changes in the pediatric MSMs’ kinematics but …

The Accurate Conversion Of Biological Experiments From Cesium Irradiation To X-Ray Irradiation: The Significance, Problems, And The Future Of Experimental Radiation Research, Gretchen Carpenter

Dartmouth College Master’s Theses

Preclinical small animal irradiation studies, once conducted on Cesium irradiators, are increasingly being performed with X-ray-based irradiators. The transition stems from concerns regarding national security risks, making X-ray irradiators which are compact and easy to operate an enticing alternative. However, questions regarding the relative biological effectiveness between the two sources have revealed a lack of adequate dosimetric characterization of X-ray beams, standardized protocol for dose calibration, and thorough understanding of experimental biological parameters. A literature review conducted on orthovoltage irradiators has revealed that there are over 54 different types of beam structures used, a dramatic departure from the one uniform …

Roles Of The His-Purkinje System In Long Qt Syndrome Mediated Arrhythmias, Anthony Owusu-Mensah

Biomedical Engineering Theses & Dissertations

Long QT syndrome (LQTS) is a genetic or drug-induced electrophysiological disorder in the heart that prolongs the QT interval on the electrocardiogram. LQTS is present in considerable proportions (1:3000 to 1:5000) of the general population. LQTS has a high incidence of malignant ventricular arrhythmias during physical and emotional stress and is a significant cause of sudden death in younger subjects. This poses a substantial medical burden on the healthcare system in terms of morbidity, mortality, and finances. Despite extensive genetic research into LQTS, the mechanisms underlying spontaneous initiation and maintenance of arrhythmias are not fully understood. Beta-blockers are the standard …