Biomedical Engineering and Bioengineering Commons^™

Activity And Function Of The Endothelial Sodium Channel Is Regulated By The Effector Domain Of Marcks-Like Protein 1 In Mouse Aortic Endothelial Cells, Ling Yu, Niharika Bala, Van-Anh L. Nguyen, Leah Kessler, John F. Ladisa Jr., Abdel A. Alli

Biomedical Engineering Faculty Research and Publications

Enhanced endothelial sodium channel (EnNaC) functioning causes an increase in vessel stiffness. Here, we investigated the regulation of EnNaC in mouse aortic endothelial cells (mAoECs) by the actin cytoskeleton and lipid raft association protein myristoylated alanine-rich C-kinase substrate-like protein 1 (MLP1). We hypothesized that mutation of specific amino acid residues within the effector domain of MLP1 or loss of association between MLP1 and the anionic phospholipid phosphate PIP2 would significantly alter membrane association and EnNaC activity in mAoECs. mAoECs transiently transfected with a mutant MLP1 construct (three serine residues in the effector domain replaced with aspartate residues) showed a significant …

Computational Model Of Coarctation Of The Aorta In Rabbits Suggests Persistent Ascending Aortic Remodeling Post-Correction, Ashley A. Hiebing, Matthew A. Culver, John F. Ladisa, Colleen M. Witzenburg

Biomedical Engineering Faculty Research and Publications

Coarctation of the aorta (CoA) is a common congenital cardiovascular lesion that presents as a localized narrowing of the proximal descending aorta. While improvements in surgical and catheter-based techniques have increased short-term survival, there is a high long-term risk of hypertension and a reduced average lifespan despite correction. Computational models can be used to estimate aortic remodeling and peripheral vascular compensation, potentially serving as key tools in developing a mechanistic understanding of the interplay between pre-treatment dynamics, post-treatment recovery, and long-term hypertension risk. In this study, we developed a lumped-parameter model of the heart and circulation to simulate CoA. After …

Connecting Developed Pressure – Preload Relationship In Ex-Vivo Beating Heart With Cellular Sarcomere Length – Tension Relationship, Lei Fan, Vahid Ziaei-Rad, Jason Bazil, Lik Chuan Lee

Biomedical Engineering Faculty Research and Publications

The heart’s developed pressure (DP) in Langendorff heart experiments increases with preload via the Frank-Starling mechanism up to a critical transition point at which DP starts to decrease with preload. A similar behavior is found at the cellular level, where the tension developed by skinned cardiac fibers or myocytes in isometric tension test increases with sarcomere length up to a transition point beyond which, the tension decreases. This cellular-level behavior is termed myofilament length dependent activation. While these two behaviors are similar, they occur at vastly different scales. Specifically, the DP – preload and sarcomere length – tension relationships occur, …

Increased Visual Response Delay Impact On Sensorimotor Control In Persons With Multiple Sclerosis, Julie C. Wagner, Frankie M. Ingram, Vincenzo Daniele Boccia, Matilde Inglese, Maura Casadio, Camilla Pierella, Andrea Canessa, Robert A. Scheidt, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Multiple Sclerosis negatively affects hand function in 60% of cases. Upper extremity dysfunction in persons with Multiple Sclerosis (PwMS) has previously been linked to slower, more variable movement, increased visual response delays (T_v), and neuroimaging evidence of altered brain activity; yet no one knows how these aspects relate to each other. This work combines clinical, kinematic, sensorimotor control, and neural imaging techniques to gain a more complete understanding of how upper extremity dysfunction arises in PwMS. Twenty PwMS and 20 Controls completed a reach and hold task with simultaneous electroencephalography recorded to determine if increased T_v in …

Lung Uptake Of Two Spect Markers Identifies Sensitivity To Hyperoxia-Induced Acute Respiratory Distress Syndrome In Rats, Anne V. Clough, Taheri Pardis, Guru P. Sharma, Ming Zhao, Elizabeth R. Jacobs, Said H. Audi

Biomedical Engineering Faculty Research and Publications

Introduction: Exposure of adult rats to hyperoxia is a well-established model of human Acute Respiratory Distress Syndrome (ARDS). Although rats exposed to 100% O₂ display clinical evidence of lung injury after ∼40 h and death by 72 h, rats exposed to 60% O₂ for up to 7 days show little sign of injury. However, when subsequently exposed to hyperoxia, these pre-exposed rats become more susceptible to ARDS. The objective of this study is to evaluate the ability of imaging biomarkers to track this hyperoxia susceptibility and to elucidate underlying mechanisms.

Methods: Sprague-Dawley rats were exposed to either room …

Virtual Reality-Based Training To Augment Recovery Of Hand Dexterity After Surgery For Degenerative Cervical Myelopathy, Viprav B. Raju, Roxanne Hauer, Mohammad Ghassemi, Anjishnu Banerjee, Derek Kamper, Brian D. Schmit, Aditya Vedantam

Biomedical Engineering Faculty Research and Publications

Degenerative cervical myelopathy (DCM), the leading cause of non-traumatic spinal cord injury, frequently results in impaired hand dexterity. While surgical decompression is the primary treatment, over 40% of patients report residual hand disability after surgery. There are no therapies to restore hand function after surgery for DCM. In this single-arm clinical trial, post-surgical DCM participants (within 12 months after surgery) underwent a 4-week VR training protocol using the Virtual Keyboard system, which promotes practice of finger individuation. Assessments of hand dexterity were performed at baseline (at week 1), post-training (at week 6) and follow-up (at week 10). The primary outcome …

Scoping Review Of Machine Learning Techniques In Marker-Based Clinical Gait Analysis, Kevin N. Dibbern, Maddalena G. Krzak, Alejandro Olivas, Mark V. Albert, Joseph J. Krzak, Karen M. Kruger

Biomedical Engineering Faculty Research and Publications

The recent proliferation of novel machine learning techniques in quantitative marker-based 3D gait analysis (3DGA) has shown promise for improving interpretations of clinical gait analysis. The objective of this study was to characterize the state of the literature on using machine learning in the analysis of marker-based 3D gait analysis to provide clinical insights that may be used to improve clinical analysis and care. Methods: A scoping review of the literature was conducted using the PubMed and Web of Science databases. Search terms from eight relevant articles were identified by the authors and added to by experts in clinical gait …

Eigenbin Compression For Reducing Photon-Counting Ct Data Size, Taly Gilat Schmidt, Zhye Yin, Jingwu Yao, Jiahua Fan

Biomedical Engineering Faculty Research and Publications

Background

Photon-counting CT (PCCT) systems acquire multiple spectral measurements at high spatial resolution, providing numerous image quality benefits while also increasing the amount of data that must be transferred through the gantry slip ring.

Purpose

This study proposes a lossy method to compress photon-counting CT data using eigenvector analysis, with the goal of providing image quality sufficient for applications that require a rapid initial reconstruction, such as to confirm anatomical coverage, scan quality, and to support automated advanced applications. The eigenbin compression method was experimentally evaluated on a clinical silicon PCCT prototype system.

Methods

The proposed eigenbin method performs principal …

Seasonal Variation In Atp-Induced Retinal Damage In The Cone-Dominant 13-Lined Ground Squirrel, Owen R. Bowie, Hannah M. Follett, Ching Tzu Yu, Chloe Guillaume, Phyllis M. Summerfelt, Nicole Manfredonia, Jenna Grieshop, Dana K. Merriman, Sergey Tarima, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To examine whether time of year (relative to hibernation emergence) influences the retinal degenerative effects of intravitreal injection of adenosine triphosphate (ATP) in the 13-lined ground squirrel (13-LGS).

Methods: Eighteen (9 male, 9 female) 13-LGS in three experimental cohorts (early season, mid-season, late season) (n = 6 each) underwent baseline imaging using scanning light ophthalmoscopy (SLO) and optical coherence tomography (OCT). Animals then received a 10-µL intravitreal injection of 0.723 M ATP, followed by OCT and SLO imaging at 3, 10, and 21 days. Adaptive optics SLO (AOSLO) was performed in animals without retinal damage after the 21-day …

Expanded Combined Loading Injury Criterion For The Human Lumbar Spine Under Dynamic Compression, Maria Ortiz-Paparoni, Joost Op't Eynde, Christopher Eckersley, Concetta Morino, Mitchell Abrams, Derek Pang, Jason Kait, Frank A. Pintar, Narayan Yoganandan, Jason Moore, David Barnes, Kathryn Loftis, Cameron R. Bass

Biomedical Engineering Faculty Research and Publications

Contemporary injury tolerance of the lumbar spine for under-body blast references axial compression and bending moments in a limited range. Since injuries often occur in a wider range of flexion and extension with increased moment contribution, this study expands a previously proposed combined loading injury criterion for the lumbar spine. Fifteen cadaveric lumbar spine failure tests with greater magnitudes of eccentric loading were incorporated into an existing injury criterion to augment its applicability and a combined loading injury risk model was proposed by means of survival analysis. A loglogistic distribution was the most representative of injury risk, resulting in optimized …

Mesenchymal-Type Genetic Mutations Are Likely Prerequisite For Glioblastoma Multiforme To Metastasize Outside The Central Nervous System: An Original Case Series And Systematic Review Of The Literature, Bryce J. Laurin, Randall Treffy, Jennifer M. Connelly, Michael Straza, Wade Mueller, Max O. Krucoff

Biomedical Engineering Faculty Research and Publications

Background

Glioblastoma Multiforme (GBM) is the most aggressive and prevalent type of malignant brain tumor, yet it metastasizes outside the central nervous system (CNS) in only 0.4% of cases. Little is known about what enables this subset of GBMs to take root outside the CNS, but genetic mutations likely play a role.

Methods

We conducted a PRISMA-compliant systematic review of metastatic GBM wherein we reviewed 3579 search results and 1080 abstracts, analyzing data from 139 studies and 211 unique patients. In addition, we describe 4 cases of patients with pathologically confirmed GBM metastases outside the CNS treated at our institution. …

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. …

Talar And Calcaneal Coordinate Axes Definitions Across Foot Pathologies, Kassidy Knutson, Erika 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 …

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 …

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 …

Behind Armor Blunt Trauma: Liver Injuries Using A Live Animal Model, Narayan Yoganandan, Alok Shah, Brian D. Stemper, Lewis Somber, Valeta Carol Chancey, Joseph Mcentire

Biomedical Engineering Faculty Research and Publications

Introduction

While the 44-mm clay penetration criterion was developed in the 1970s for soft body armor applications, and the researchers acknowledged the need to conduct additional tests, the same behind the armor blunt trauma displacement limit is used for both soft and hard body armor evaluations and design considerations. Because the human thoraco-abdominal contents are heterogeneous, have different skeletal coverage, and have different functional requirements, the same level of penetration limit does not imply the same level of protection. It is important to determine the regional responses of different thoraco-abdominal organs to better describe human tolerance and improve the current …

The Shriners Children's Standard Gait Model (Scgm), Karen M. Kruger, Patrick Fischer, Sam Augsburger, Jing Feng, Jean-Francois Girouard, Daniel L. Gregory, Logan Johnson, Bruce A. Macwilliams, Mark L. Mcmulkin, Bradley Nelson, Spencer Warshauer, Prabhav Saraswat, Ross S. Chafetz

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Altered Cortical Activity During A Finger Tap In People With Stroke, Priya Balasubramanian, Roxanne P. Deleon, Dylan B. Snyder, Scott A. Beardsley, Allison S. Hyngstrom, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

This study describes electroencephalography (EEG) measurements during a simple finger movement in people with stroke to understand how temporal patterns of cortical activation and network connectivity align with prolonged muscle contraction at the end of a task. We investigated changes in the EEG temporal patterns in the beta band (13–26 Hz) of people with chronic stroke (N = 10, 7 F/3 M) and controls (N = 10, 7 F/3 M), during and after a cued movement of the index finger. We quantified the change in beta band EEG power relative to baseline as activation at each electrode and …

F Wave Analysis Based On The Compound Muscle Action Potential Scan, Xiaoyan Li, Maoqi Chen, Paul E. Barkhaus, Sanjeev D. Nandedkar, Brian D. Schmit, Ping Zhou

Biomedical Engineering Faculty Research and Publications

Introduction/Aims

Conventional F wave analysis involves a relatively uniform physiological environment induced by supramaximal stimulations. The F wave characteristics in a dynamic physiological condition, however, are rarely investigated. This study aimed to improve understanding of F wave properties in the more dynamic process by introducing a novel method to analyze F waves based on the compound muscle action potential (CMAP) scan technique.

Methods

Twenty four healthy subjects participated in the study. The CMAP scan was applied to record muscle responses in the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles, respectively. F wave characteristics including mean F wave …

Mitochondrial Function In Lungs Of Rats With Different Susceptibilities To Hyperoxia-Induced Acute Lung Injury, Pardis Taheri, Devanshi D. Dave, Ranjan K. Dash, Guru P. Sharma, Anne V. Clough, Elizabeth R. Jacobs, Said H. Audi

Biomedical Engineering Faculty Research and Publications

Adult rats exposed to hyperoxia (>95% O₂) die from respiratory failure in 60–72 h. However, rats preconditioned with >95% O₂ for 48 h followed by 24 h in room air acquire tolerance of hyperoxia (H-T), whereas rats preconditioned with 60% O₂ for 7 days become more susceptible (H-S). Our objective was to evaluate lung tissue mitochondrial bioenergetics in H-T and H-S rats. Bioenergetics was assessed in mitochondria isolated from lung tissue of H-T, H-S, and control rats. Expressions of complexes involved in oxidative phosphorylation (OxPhos) were measured in lung tissue homogenate. Pulmonary endothelial filtration coefficient …

Penetration Thresholds Of Porcine Limbs For Low Sectional Density Projectiles In High-Rate Impact, Joseph Lesueur, Jared Michael Koser, Carolyn E. Hampton, Michael Kleinberger, Frank A. Pintar

Biomedical Engineering Faculty Research and Publications

Introduction

With similar prevalence to injuries from fires, stings, and natural disasters, soft tissue injuries may occur from fireworks, industrial accidents, or other explosives. Surgeons are less familiar with treating high-velocity penetration from small debris, which may increase the chance of infection and subsequent fatality. Penetration risk curves have been developed to predict V₅₀, the velocity with 50% probability of penetration, for various sized projectiles. However, there has been limited research using nonmetallic materials to achieve lower density projectiles less than 1 g cm−2, such as sand or rocks.

Material and Methods

To emulate the size and density …

Recommendation Of Minimal Distal Tibial Length For Long Axis Coordinate System Definitions, Erika P. Muhlrad, Andrew C. Peterson, Abigail M. Anderson, Katelyn C. Aragon, Rich J. Lisonbee, Bruce A. Macwilliams, Karen M. Kruger, Amy L. Lenz

Biomedical Engineering Faculty Research and Publications

Accurate anatomical coordinate systems for the foot and ankle are critical for interpreting their complex biomechanics. The tibial superior-inferior axis is crucial for analyzing joint kinematics, influencing bone motion analysis during gait using CT imaging and biplane fluoroscopy. However, the lack of consensus on how to define the tibial axis has led to variability in research, hindering generalizability. Even as advanced imaging techniques evolve, including biplane fluoroscopy and weightbearing CT, there exist limitations to imaging the entire foot together with the full length of the tibia. These limitations highlight the need to refine axis definitions. This study investigated various superior-inferior …

Cervical Spinal Cord Angiography And Vessel-Selective Perfusion Imaging In The Rat, Seongtaek Lee, Brian Schmit, Shekar N. Kurpad, Matthew D. Budde

Biomedical Engineering Faculty Research and Publications

Arterial spin labeling (ASL) has been widely used to evaluate arterial blood and perfusion dynamics, particularly in the brain, but its application to the spinal cord has been limited. The purpose of this study was to optimize vessel-selective pseudocontinuous arterial spin labeling (pCASL) for angiographic and perfusion imaging of the rat cervical spinal cord. A pCASL preparation module was combined with a train of gradient echoes for dynamic angiography. The effects of the echo train flip angle, label duration, and a Cartesian or radial readout were compared to examine their effects on visualizing the segmental arteries and anterior spinal artery …

Intervisit Reproducibility Of Foveal Cone Density Metrics, Iniya Adhan, Emma Warr, Jenna Grieshop, Joseph Kreis, Danica Nikezic, Ashleigh Walesa, Katherine Hemsworth, Robert F. Cooper, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To assess longitudinal reproducibility of metrics of foveal density (peak cone density [PCD], cone density centroid [CDC], and 80th percentile centroid area) in participants with normal vision.

Methods: Participants (n = 19; five male and 14 female) were imaged at two time points (average interval of 3.2 years) using an adaptive optics scanning light ophthalmoscope (AOSLO). Foveally centered regions of interest (ROIs) were extracted from AOSLO montages. Cone coordinate matrices were semiautomatically derived for each ROI, and cone mosaic metrics were calculated.

Results: On average, there were no significant changes in cone mosaic metrics between visits. The average …

Quantifying Image Quality In Aoslo Images Of Photoreceptors, Brea D. Brennan, Heather Heitkotter, Joseph Carroll, Sergey Tarima, Robert F. Cooper

Biomedical Engineering Faculty Research and Publications

The use of “quality” to describe the usefulness of an image is ubiquitous but is often subject to domain specific constraints. Despite its continued use as an imaging modality, adaptive optics scanning light ophthalmoscopy (AOSLO) lacks a dedicated metric for quantifying the quality of an image of photoreceptors. Here, we present an approach to evaluating image quality that extracts an estimate of the signal to noise ratio. We evaluated its performance in 528 images of photoreceptors from two AOSLOs, two modalities, and healthy or diseased retinas. The algorithm was compared to expert graders’ ratings of the images and previously published …

Spatial Correspondence Of Cortical Activity Measured With Whole Head Fnirs And Fmri Toward Clinical Use Within Subject, Anthony Zinos, Julie C. Wagner, Scott A. Beardsley, Wei-Liang Chen, Lisa Conant, Marsha Malloy, Joseph Heffernan, Brendan Quirk, Robert W. Prost, Mohit Maheshwari, Jeffrey Sugar, Harry T. Whelan

Biomedical Engineering Faculty Research and Publications

Functional near infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI) both measure the hemodynamic response, and so both imaging modalities are expected to have a strong correspondence in regions of cortex adjacent to the scalp. To assess whether fNIRS can be used clinically in a manner similar to fMRI, 22 healthy adult participants underwent same-day fMRI and whole-head fNIRS testing while they performed separate motor (finger tapping) and visual (flashing checkerboard) tasks. Analyses were conducted within and across subjects for each imaging approach, and regions of significant task-related activity were compared on the cortical surface. The spatial correspondence between …

Longitudinal Changes In Diffusion Tensor Imaging In Hemodialysis Patients, Wesley T. Richerson, Brian D. Schmit, Dawn F. Wolfgram

Biomedical Engineering Faculty Research and Publications

Introduction

Hemodialysis patients have increased white matter and gray matter pathology in the brain relative to controls based on MRI. Diffusion tensor imaging is useful in detecting differences between hemodialysis and controls but has not identified the expected longitudinal decline in hemodialysis patients. In this study we implemented specialized post-processing techniques to reduce noise to detect longitudinal changes in diffusion tensor imaging parameters and evaluated for any association with changes in cognition.

Methods

We collected anatomical and diffusion MRIs as well as cognitive testing from in-center hemodialysis patients at baseline and 1 year later. Gray matter thickness, white matter volume, …