Engineering Commons^™

Eeg Functional Connectivity In Infants At Elevated Familial Likelihood For Autism Spectrum Disorder, Christian O'Reilly, Scott Huberty, Stefon Van Noordt, James Desjardins, Nicky Wright, Julie Scorah, Sara Jane Webb, Mayada Elsabbagh, Basis Team

Publications

Background

Many studies have reported that autism spectrum disorder (ASD) is associated with atypical structural and functional connectivity. However, we know relatively little about the development of these differences in infancy.

Methods

We used a high-density electroencephalogram (EEG) dataset pooled from two independent infant sibling cohorts, to characterize such neurodevelopmental deviations during the first years of life. EEG was recorded at 6 and 12 months of age in infants at typical (N = 92) or elevated likelihood for ASD (N = 90), determined by the presence of an older sibling with ASD. We computed the functional connectivity between …

Validation Of A Biomechanical Injury And Disease Assessment Platform Applying An Inertial-Based Biosensor And Axis Vector Computation, Wangdo Kim, Emir A. Vela, Sean S. Kohles, Victor Huayamave

Publications

Inertial kinetics and kinematics have substantial influences on human biomechanical function. A new algorithm for Inertial Measurement Unit (IMU)-based motion tracking is presented in this work. The primary aims of this paper are to combine recent developments in improved biosensor technology with mainstream motion-tracking hardware to measure the overall performance of human movement based on joint axis-angle representations of limb rotation. This work describes an alternative approach to representing three-dimensional rotations using a normalized vector around which an identified joint angle defines the overall rotation, rather than a traditional Euler angle approach. Furthermore, IMUs allow for the direct measurement of …

Predicting Corrosion Damage In The Human Body Using Artificial Intelligence: In Vitro Progress And Future Applications Applications, Michael A. Kurtz, Ruoyu Yang, Mohan S. R. Elapolu, Audrey C. Wessinger, William Nelson, Kazzandra Alaniz, Rahul Rai, Jeremy L. Gilbert

Publications

Artificial intelligence (AI) is used in the clinic to improve patient care. While the successes illustrate the impact AI can have, few studies have led to improved clinical outcomes. A gap in translational studies, beginning at the basic science level, exists. In this review, we focus on how AI models implemented in non-orthopedic fields of corrosion science may apply to the study of orthopedic alloys. We first define and introduce fundamental AI concepts and models, as well as physiologically relevant corrosion damage modes. We then systematically review the corrosion/AI literature. Finally, we identify several AI models that may be Preprint …

A Protocol For Coupling Volumetrically Dynamic In Vitro Experiments To Numerical Physiology Simulation For A Hybrid Cardiovascular Model, Abraham Umo, Ethan Kung

Publications

Objective: The Physiology Simulation Coupled Experiment (PSCOPE) is a hybrid modeling framework that enables a physical fluid experiment to operate in the context of a closed-loop computational simulation of cardiovascular physiology. Previous PSCOPE methods coupled rigid experiments to a lumped parameter network (LPN) of physiology but are incompatible with volumetrically dynamic experiments where fluid volume varies periodically. We address this limitation by introducing a method capable of coupling rigid, multi-branch, and volumetrically dynamic in-vitro experiments to an LPN. Methods: Our proposed method utilizes an iterative weighted-averaging algorithm to identify the unique solution waveforms for a given PSCOPE model. We confirm …

Tunable Blood Shunt For Neonates With Complex Congenital Heart Defects, Ellen Garver, Christopher B. Rodell, Kristen Shema, Krianthan Govender, Samantha E. Cassel, Bryan Ferrick, Gabriella Kupsho, Ethan Kung, Kara L. Spiller, Randy Stevens, Amy L. Throckmorton

Publications

Despite advancements in procedures and patient care, mortality rates for neonatal recipients of the Norwood procedure, a palliation for single ventricle congenital malformations, remain high due to the use of a fixed-diameter blood shunt. In this study, a new geometrically tunable blood shunt was investigated to address limitations of the current treatment paradigm (e.g., Modified Blalock-Taussig Shunt) by allowing for controlled modulation of blood flow through the shunt to accommodate physiological changes due to the patient’s growth. First, mathematical and computational cardiovascular models were established to investigate the hemodynamic requirements of growing neonatal patients with shunts and to inform design …

Pediatric Cardiac Devices: Recent Progress And Remaining Problems, Kyle Crawford, Martine Leberge, Dan Simionescu, Naren Vyavahare

Publications

Pediatric cardiology is a field that largely relies on translation of innovation in its adult counterpart in order to improve patient outcomes and introduce new technology to the field. Few FDA-approved pediatric cardiac devices are available for clinical use, thus leading to widespread off-label use within the field. Nonetheless, adaption of devices and technology from the adult field has proven to improve patient outcomes and overall wellness. However, the diversity of congenital heart disease, in terms of basic anatomy and treatment response, continues to complicate results. The combination of diversity of anatomy and small population size make it difficult for …

Systematic Review And Regression Modeling Of The Effects Of Age, Body Size, And Exercise On Cardiovascular Parameters In Healthy Adults, Aseem Pradhan, John Scaringi, Patrick Gerard, Ross Arena, Jonathan Myers, Leonard A. Kaminsky, Ethan Kung

Publications

Purpose

Blood pressure, cardiac output, and ventricular volumes correlate to various subject features such as age, body size, and exercise intensity. The purpose of this study is to quantify this correlation through regression modeling.

Methods

We conducted a systematic review to compile reference data of healthy subjects for several cardiovascular parameters and subject features. Regression algorithms used these aggregate data to formulate predictive models for the outputs—systolic and diastolic blood pressure, ventricular volumes, cardiac output, and heart rate—against the features—age, height, weight, and exercise intensity. A simulation-based procedure generated data of virtual subjects to test whether these regression models built …

Plaque Contact Surface Area And Flow Lumen Volume Predict Stroke Risk In Extracranial Carotid Artery Stenosis, Ryan Gendey, Ethan Kung, Veena Mehta, Adam Brown, Matthew Bridges, Ravi Veeraswamy

Publications

The standard indication for intervention in asymptomatic disease is currently percent stenosis in the internal carotid artery as measured by the NASCET method, which remains limited in discriminating power. CT angiography (CTA) is widely used to calculate NASCET stenosis but also offers the opportunity to analyze carotid artery plaques from a morphological perspective that has not been widely utilized. We aim to improve stroke risk stratification of patients with carotid artery stenosis using plaque 3D modeling and image analysis. Patients with CTAs appropriate for 3D reconstruction were identified from an NIH designated stroke center database, and carotid arteries were segmented …

Hemodynamic Response To Device Titration In The Shunted Single Ventricle Circulation - A Patient Cohort Modeling Study, Chet Villa, Farha Zafar, Angela Lorts, Ethan Kung

Publications

Clinical outcomes of ventricular assist device (VAD) support for shunted single ventricle patients trail the larger population due in part to the challenges in optimizing VAD support and balancing systemic and pulmonary circulations. We sought to understand the response to VAD titration in the shunted circulation using a lumped-parameter network modeling six patient-specific clinical cases. Hemodynamic data from six patients (mean body surface area = 0.30 m²) with a systemic-to-pulmonary shunt was used to construct simulated cases of heart failure and hemodynamic response to increasing VAD flow from 5 to 10 L/min/m². With increasing VAD flow, …

Biomechanics Of Trail Running Performance: Quantification Of Spatio-Temporal Parameters By Using Low Cost Sensors In Ecological Conditions, Noé Perrotin, Nicolas Gardan, Arnaud Lesprillier, Clément Le Goff, Jean-Marc Seigneur, Ellie Abdi, Borja Sanudo, Redha Taiar

Publications

The recent popularity of trail running and the use of portable sensors capable of measuring many performance results have led to the growth of new fields in sports science experimentation. Trail running is a challenging sport; it usually involves running uphill, which is physically demanding and therefore requires adaptation to the running style. The main objectives of this study were initially to use three “low-cost” sensors. These low-cost sensors can be acquired by most sports practitioners or trainers. In the second step, measurements were taken in ecological conditions orderly to expose the runners to a real trail course. Furthermore, to …

Target Flow-Pressure Operating Range For Designing A Failing Fontan Cavopulmonary Support Device, Masoud Farahmand, Minoo N. Kavarana, Phillip M. Trusty, Ethan Kung

Publications

Fontan operation as the current standard of care for the palliation of single ventricle defects results in significant late complications. Using a mechanical circulatory device for the right circulation to serve the function of the missing subpulmonary ventricle could potentially stabilize the failing Fontan circulation. This study aims to elucidate the hydraulic operating regions that should be targeted for designing cavopulmonary blood pumps. By integrating numerical analysis and available clinical information, the interaction of the cavopulmonary support via the IVC and full assist configurations with a wide range of simulated adult failing scenarios was investigated; with IVC and full assist …

Risks And Benefits Of Using A Commercially Available Ventricular Assist Device For Failing Fontan Cavopulmonary Support: A Modeling Investigation, Masoud Farahmand, Minoo N. Kavarana, Ethan Kung

Publications

Fontan patients often develop circulatory failure and are in desperate need of a therapeutic solution. A blood pump surgically placed in the cavopulmonary pathway can substitute the function of the absent sub-pulmonary ventricle by generating a mild pressure boost. However, there is currently no commercially available device designed for the cavopulmonary application; and the risks and benefits of implanting a ventricular assist device (VAD), originally designed for the left ventricular application, on the right circulation of failing Fontan patients is not yet clear. Moreover, further research is needed to compare the hemodynamics between the two clinically-considered surgical configurations for cavopulmonary …

An Algorithm For Coupling Multibranch In Vitro Experiment To Numerical Physiology Simulation For A Hybrid Cardiovascular Model, Ehsan Mirzaei, Masoud Farahmand, Ethan Kung

Publications

The hybrid cardiovascular modeling approach integrates an in vitro experiment with a computational lumped‐parameter simulation, enabling direct physical testing of medical devices in the context of closed‐loop physiology. The interface between the in vitro and computational domains is essential for properly capturing the dynamic interactions of the two. To this end, we developed an iterative algorithm capable of coupling an in vitro experiment containing multiple branches to a lumped‐parameter physiology simulation. This algorithm identifies the unique flow waveform solution for each branch of the experiment using an iterative Broyden's approach. For the purpose of algorithm testing, we first used mathematical …

Factors Affecting Cardiovascular Physiology In Cardiothoracic Surgery: Implications For Lumped-Parameter Modeling, Joshua Kaufmann, Ethan Kung

Publications

Cardiothoracic surgeries are complex procedures during which the patient cardiovascular physiology is constantly changing due to various factors. Physiological changes begin with the induction of anesthesia, whose effects remain active into the postoperative period. Depending on the surgery, patients may require the use of cardiopulmonary bypass and cardioplegia, both of which affect postoperative physiology such as cardiac index and vascular resistance. Complications may arise due to adverse reactions to the surgery, causing hemodynamic instability. In response, fluid resuscitation and/or vasoactive agents with varying effects may be used in the intraoperative or postoperative periods to improve patient hemodynamics. These factors have …

A Hybrid Experimental‐Computational Modeling Framework For Cardiovascular Device Testing, Ethan Kung, Masoud Farahmand, Akash Gupta

Publications

Significant advances in biomedical science often leverage powerful computational and experimental modeling platforms. We present a framework named physiology simulation coupled experiment (“PSCOPE”) that can capitalize on the strengths of both types of platforms in a single hybrid model. PSCOPE uses an iterative method to couple an in vitro mock circuit to a lumped-parameter numerical simulation of physiology, obtaining closed-loop feedback between the two. We first compared the results of Fontan graft obstruction scenarios modeled using both PSCOPE and an established multiscale computational fluid dynamics method; the normalized root-mean-square error values of important physiologic parameters were between 0.1% and 2.1%, …

Mechanically Assisted Electrochemical Degradation Of Alumina-Tic Composites, Hetal Umesh Maharaja, Guigen Zhang

Publications

Alumina-TiC composite material is a tough ceramic composite with excellent hardness, wear resistance and oxidation resistance in dry and high-temperature conditions. In aqueous conditions, however, it is likely to be electrochemically active facilitating charge transfer processes due to the conductive nature of TiC. For application as an orthopedic biomaterial, it is crucial to assess the electrochemical behavior of this composite, especially under a combined mechanical and electrochemical environment. In this study, we examined the mechanically assisted electrochemical performance of alumina-TiC composite in an aqueous environment. The spontaneous electrochemical response to brushing abrasion was measured. Changes in the magnitude of electrochemical …

Algal Biofuel: The Future Of Green Jet Fuel In Air Transportation, Rajee Olaganathan

Publications

The aviation industry is one of the major contributors for the greenhouse gases. As air travel has become inevitable in this modern era, and fossil fuel usage is not sustainable, it is essential to produce renewable fuel and commercialize it to reduce the greenhouse gas emissions. In order to produce an alternate aviation biofuel a lot of industrial and academic collaborations have been developed worldwide. The main concern of this collaborative research is to produce aviation biofuel from renewable resources with low environmental impacts, and which is sustainable at an economically viable price. This mini-review briefly discusses the biotechnological approaches …

Cardiovascular Biomechanical Models, Ethan Kung

Publications

Computational and in vitro methods offer powerful means to model the cardiovascular system and investigate biomechanics related to blood flow, cardiovascular tissue, and medical devices. These models can be constructed to directly describe human anatomy and physiology, and can be more highly controlled compared to animal models. Low-order models composed of lumped-parameter elements and simplified descriptions of cardiac function can capture the global physiology, while high-order models exhibiting detailed 3D anatomy and dynamics can provide highly realistic replication of biomechanical interactions in a small region of the circulation. Multiscale models offer the freedom to capture biomechanics in different regions at …

Multiscale Modeling Of Cardiovascular Flows, Alison Marsden, Ethan Kung

Publications

Simulations of blood flow in the cardiovascular system offer investigative and predictive capabilities to augment current clinical tools. Using image-based modeling, the Navier-Stokes equations can be solved to obtain detailed 3-dimensional hemodynamics in patient-specific anatomical models. Relevant parameters such as wall shear stress and particle residence times can then be calculated from the 3D results and correlated with clinical data for treatment planning and device evaluation. Reduced-order models such as open or closed loop 0D lumped-parameter models can simulate the dynamic behavior of the circulatory system using an analogy to electrical circuits. When coupled to 3D simulations as boundary conditions, …

Cancer Cell Redirection Biomarker Discovery Using A Mutual Information Approach, Kimberly Roche, F. Alex Feltus, Jang Pyo Park, Marie-May Coissieux, Chenyan Chang, Vera B.S. Chan, Mohamed Bentires-Alj, Brian W. Booth

Publications

Introducing tumor-derived cells into normal mammary stem cell niches at a sufficiently high ratio of normal to tumorous cells causes those tumor cells to undergo a change to normal mammary phenotype and yield normal mammary progeny. This phenomenon has been termed cancer cell redirection. We have developed an in vitro model that mimics in vivo redirection of cancer cells by the normal mammary microenvironment. Using the RNA profiling data from this cellular model, we examined high-level characteristics of the normal, redirected, and tumor transcriptomes and found the global expression profiles clearly distinguish the three expression states. To identify potential redirection …

Superior Performance Of Continuous Over Pulsatile Flow Ventricular Assist Devices In The Single Ventricle Circulation: A Computational Study, Tyler Schmidt, David Rosenthal, Olaf Reinhartz, Kirk Riemer, Fei He, Tain-Yen Hsia, Alison Marsden, Ethan Kung

Publications

This study compares the physiological responses of systemic-to-pulmonary shunted single ventricle patients to pulsatile and continuous flow ventricular assist devices (VADs). Performance differences between pulsatile and continuous flow VADs have been clinically observed, but the underlying mechanism remains poorly understood. Six systemic-to-pulmonary shunted single ventricle patients (mean BSA=0.30 m2) were computationally simulated using a lumped-parameter network tuned to match patient specific clinical data. A first set of simulations compared current clinical implementation of VADs in single ventricle patients. A second set modified pulsatile flow VAD settings with the goal to optimize cardiac output (CO). For all patients, the best-case continuous …

A Real-Time Programmable Pulsatile Flow Pump For In Vitro Cardiovascular Experimentation, Rahul Raj Mechoor, Tyler Schmidt, Ethan Kung

Publications

Benchtop in vitro experiments are valuable tools for investigating the cardiovascular system and testing medical devices. Accurate reproduction of the physiologic flow waveforms at various anatomic locations is an important component of these experimental methods. This study discusses the design, construction, and testing of a low-cost and fully programmable pulsatile flow pump capable of continuously producing unlimited cycles of physiologic waveforms. It consists of a gear pump actuated by an AC servomotor and a feedback algorithm to achieve highly accurate reproduction of flow waveforms for flow rates up to 300 ml/s across a range of loading conditions. The iterative feedback …

Application Of Bioinstrumentation In Developing A Pressure Suit For Suborbital Flight, Pedro Llanos, Erik Seedhouse

Publications

This presentation features Embry-Riddle Aeronautical University's U-2 pressure suit. Built to be light and cost-effective, this suit is comfortable, comes in multiple sizes, operates in pressures up to 5 PSID, has an active airflow-based cooling system, and features bio-instrumentation to measure heart rate, breathing rate, skin temperature and other vitals.

Engineering Xylose Utilization In Yarrowia Lipolytica By Understanding Its Cryptic Xylose Pathway, Gabriel M. Rodriguez, Murtaza Shabbir Hussain, Lauren Gambill, Difeng Gao, Allison Yaguchi, Mark Blenner

Publications

Background

The oleaginous yeast, Yarrowia lipolytica, has been utilized as an industrial host for about 60 years for various applications. Recently, the metabolic engineering of this host has become increasingly popular due to its ability to accumulate lipids as well as improvements made toward developing new genetic tools. Y. lipolytica can robustly metabolize glucose, glycerol, and even different lipid classes. However, little is known about its xylose metabolizing capability. Given the desirability of having a robust xylose utilizing strain of Y. lipolytica, we performed a comprehensive investigation and elucidation of the existing components of its xylose metabolic pathway. …

A Patient-Specific Model Of The Biomechanics Of Hip Reduction For Neonatal Developmental Dysplasia Of The Hip: Investigation Of Strategies For Low To Severe Grades Of Developmental Dysplasia Of The Hip, Victor Huayamave, Christopher Rose, Sheila Serra, Brendan Jones, Eduardo Divo, Faissal Moslehy, Alain J. Kassab, Charles T. Price

Publications

A physics-based computational model of neonatal Developmental Dysplasia of the Hip (DDH) following treatment with the Pavlik Harness (PV) was developed to obtain muscle force contribution in order to elucidate biomechanical factors influencing the reduction of dislocated hips. Clinical observation suggests that reduction occurs in deep sleep involving passive muscle action. Consequently, a set of five (5) adductor muscles were identified as mediators of reduction using the PV. A Fung/Hill-type model was used to characterize muscle response. Four grades (1–4) of dislocation were considered, with one (1) being a low subluxation and four (4) a severe dislocation. A three-dimensional model …

Computational Modeling Of Pathophysiologic Responses To Exercise In Fontan Patients, Ethan Kung, James C. Perry, Christopher Davis, Francesco Migliavacca, Giancarlo Pennati, Alessandro Giardini, Tain-Yen Hsia, Alison Marsden

Publications

Reduced exercise capacity is nearly universal among Fontan patients. Although many factors have emerged as possible contributors, the degree to which each impacts the overall hemodynamics is largely unknown. Computational modeling provides a means to test hypotheses of causes of exercise intolerance via precisely controlled virtual experiments and measurements. We quantified the physiological impacts of commonly encountered, clinically relevant dysfunctions introduced to the exercising Fontan system via a previously developed lumped-parameter model of Fontan exercise. Elevated pulmonary arterial pressure was observed in all cases of dysfunction, correlated with lowered cardiac output (CO), and often mediated by elevated atrial pressure. Pulmonary …

A Simulation Protocol For Exercise Physiology In Fontan Patients Using A Closed Loop Lumped-Parameter Model, Ethan Kung, Giancarlo Pennati, Francesco Migliavacca, Tian-Yen Hsia, Richard Figliola, Alison Marsden, Alessandro Giardini

Publications

Background: Reduced exercise capacity is nearly universal among Fontan patients, though its etiology is not yet fully understood. While previous computational studies have attempted to model Fontan exercise, they did not fully account for global physiologic mechanisms nor directly compare results against clinical and physiologic data. Methods: In this study, we developed a protocol to simulate Fontan lower-body exercise using a closed-loop lumped-parameter model describing the entire circulation. We analyzed clinical exercise data from a cohort of Fontan patients, incorporated previous clinical findings from literature, quantified a comprehensive list of physiological changes during exercise, translated them into a computational model …

In Vitro Validation Of Patient-Specific Hemodynamic Simulations In Coronary Aneurysms Caused By Kawasaki Disease, Ethan Kung, Andrew M. Kahn, Jane C. Burns, Alison Marsden

Publications

To perform experimental validation of computational fluid dynamics (CFD) applied to patient specific coronary aneurysm anatomy of Kawasaki disease. We quantified hemodynamics in a patient-specific coronary artery aneurysm physical phantom under physiologic rest and exercise flow conditions. Using phase contrast MRI (PCMRI), we acquired 3-component flow velocity at two slice locations in the aneurysms. We then performed numerical simulations with the same geometry and inflow conditions, and performed qualitative and quantitative comparisons of velocities between experimental measurements and simulation results. We observed excellent qualitative agreement in flow pattern features. The quantitative spatially and temporally varying differences in velocity between PCMRI …

Differential Effects Of Refractive Blur On Day And Nighttime Driving Performance, Joanne M. Wood, Michael J. Collins, Alex Chaparro, Ralph Marszalek, Trent Carberry, Philippe Lacherez, Byoung Sun Chu

Publications

PURPOSE. To investigate the effect of different levels of refractive blur on real-world driving performance measured under day and nighttime conditions.

METHODS. Participants included 12 visually normal, young adults (mean age = 25.+- 5.2 years) who drove an instrumented research vehicle around a 4 km closed road circuit with three different levels of binocular spherical refractive blur (+0.50 diopter sphere [DS], +1.00 DS, +2.00 DS) compared with a baseline condition. The subjects wore optimal spherocylinder correction and the additional blur lenses were mounted in modified fullfield goggles; the order of testing of the blur conditions was randomized. Driving …

Predictive Modeling Of The Virtual Hemi-Fontan Operation For Second Stage Single Ventricle Palliation: Two Patient-Specific Cases, Ethan Kung, Alessia Baretta, Catriona Baker, Gregory Arbia, Giovanni Biglino, Chiara Corsini, Silvia Schievano, Irene E. Vignon-Clementel, Gabriele Dubini, Giancarlo Pennati, Andrew Taylor, Adam Dorfman, Anthony M. Hlavacek, Alison L. Marsden, Tain-Yen Hsia, Francesco Migliavacca

Publications

Single ventricle hearts are congenital cardiovascular defects in which the heart has only one functional pumping chamber. The treatment for these conditions typically requires a three-staged operative process where Stage 1 is typically achieved by a shunt between the systemic and pulmonary arteries, and Stage 2 by connecting the superior venous return to the pulmonary circulation. Surgically, the Stage 2 circulation can be achieved through a procedure called the Hemi-Fontan, which reconstructs the right atrium and pulmonary artery to allow for an enlarged confluence with the superior vena cava.

Based on pre-operative data obtained from two patients prior to Stage …