Biomedical Engineering and Bioengineering Commons^™

An Algorithm For Extracting The Ppg Baseline Drift In Real-Time, Tuan Ngoc Nguyen

Theses: Doctorates and Masters

Photoplethysmography is an optical technique for measuring the perfusion of blood in skin and tissue arterial vessels. Due to its simplicity, accessibility and abundance of information on an individual’s cardiovascular system, it has been a pervasive topic of research within recent years. With these benefits however there are many challenges concerning the processing and conditioning of the signal in order to allow information to be extracted. One such challenge is removing the baseline drift of the signal, which is caused by respiratory rate, muscle tremor and physiological changes within the body as a response to various stimuli.

Over the years …

A Flexible Pet-Based Wearable Sensor For Arterial Pulse Waveform Measurement, Dan Wang, Dean Krusienski, Zhili Hao

Mechanical & Aerospace Engineering Faculty Publications

In light of the need of health monitoring, the paper presents a flexible polyethylene terephthalate (PET)-based wearable sensor for arterial pulse waveform measurement. The sensor encompasses a polydimethylsiloxane (PDMS) microstructure embedded with an electrolyte-enabled 5×1 transducer array, which spans 6mm and has a spatial resolution of 1.5mm. A pulse signal exerts a deflection on the microstructure and is recorded as a resistance change by a transducer at the site of the pulse. An untrained individual can easily align the sensor on a targeted artery with a negligible margin and then acquire the arterial pulse waveform continuously and non-invasively. This sensor …

Automated Solid-Substrate Cultivation Of The Anaerobic Bacterium Clostridium Thermocellum, Mathew J. Ruwaya

Theses and Dissertations--Biosystems and Agricultural Engineering

The organism Clostridium thermocellum grows on cellulosic substrates and produces ethanol, acetate, lactate, formic acid, and CO₂. The organic acids produced alter the growth environment in which the bacteria grows and ultimately inhibit bacterial growth. One method which has been used successfully to maintain the system at acceptable growth conditions is to intermittently flush out the spent media and metabolic products and replace with new fermentation media. Our goal was to design and build an automated system that will automatically flush the spent media from the growing culture and resupply new media without manual intervention. An automated control …

A New Technique To Improve The Operation Of Prosthetic Limbs During Muscle Fatigue, H. Albunashee, G. Rasool, K. Iqbal, G. White

Journal of the Arkansas Academy of Science

Prosthetic limbs hold a promise to renew the quality of life for the amputee. Neural commands are decoded via a classifier to generate control signals for the prosthetic devices. In the literature, many challenges and limitations have been identified that affect the prosthesis operation. One such drawback is muscle fatigue which degrades the surface electromyogram (sEMG) signals, and consequently, the performance of the deployed classification algorithm declines from 90% to 50% of average accuracy. We used a new technique using the Linear Discrimination Analysis (LDA) algorithm and the muscle synergy-based task discrimination (MSD) algorithm to improve the classification accuracy. In …

Radio-Frequency Plasma Polymerized Biodegradable Carrier For In Vivo Release Of Cis-Platinum, Sudhir Bhatt, Fatemeh Valamanesh, Jerome Pulpytel, Rea Lo Dico, Aliby Baiyukha, Iman Al-Dybiat, Marc Pocard, Farzaneh Arefi-Khonsari, Massoud Mirshahi

Bioelectrics Publications

A low pressure plasma process based on plasma deposition has been used to develop a drug delivery strategy. In this study, a drug delivery system based on different layers of plasma co-polymerized Poly ε-caprolactone-Polyethylene glycol (PCL-PEG) co-polymers was deposited on biocompatible substrates. Cis-platinum (118 μgm/cm²) was used as an anti-cancer drug and incorporated for local delivery of the chemotherapeutic agent. The co-polymer layers and their interaction with cancer cells were analyzed by scanning electron microscopy. Our study showed that the plasma-PCL-PEG coated cellophane membranes, in which the drug, was included did not modify the flexibility and appearance of …

Automated Detection And Analysis Of Depolarization Events In Human Cardiomyocytes Using Madec, Agnieszka F. Szymanska, Christopher M. Heylman, Rupsa Datta, Enrico Gratton

Biomedical Engineering

Optical imaging-based methods for assessing the membrane electrophysiology of in vitro human cardiac cells allow for non-invasive temporal assessment of the effect of drugs and other stimuli. Automated methods for detecting and analyzing the depolarization events (DEs) in image-based data allow quantitative assessment of these different treatments. In this study, we use 2-photon microscopy of fluorescent voltage-sensitive dyes (VSDs) to capture the membrane voltage of actively beating human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs). We built a custom and freely available Matlab software, called MaDEC, to detect, quantify, and compare DEs of hiPS-CMs treated with the β-adrenergic drugs, propranolol and …

Label-Free Imaging Of Metabolism And Oxidative Stress In Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes, Rupsa Datta, Christopher M. Heylman, Steven C. George, Enrico Gratton

Biomedical Engineering

In this work we demonstrate a label-free optical imaging technique to assess metabolic status and oxidative stress in human induced pluripotent stem cell-derived cardiomyocytes by two-photon fluorescence lifetime imaging of endogenous fluorophores. Our results show the sensitivity of this method to detect shifts in metabolism and oxidative stress in the cardiomyocytes upon pathological stimuli of hypoxia and cardiotoxic drugs. This non-invasive imaging technique could prove beneficial for drug development and screening, especially for in vitro cardiac models created from stem cell-derived cardiomyocytes and to study the pathogenesis of cardiac diseases and therapy.

Enhancing Osseointegration Of Orthopaedic Implants With Titania Nanotube Surfaces, Erin A. Baker

Dissertations, Master's Theses and Master's Reports

Introduction: As joint arthroplasty surgical procedures increase annually, the development of new strategies, including novel materials and surface modifications, to attain solid bone-implant fixation are needed to increase implant terms of service. In this study, we evaluate two morphologies of titania nanotubes in both in vitro and in vivo experiments to quantify osseointegrative potential and material-level biocompatibility.

Materials and Methods: Samples were prepared via an electrochemical etching process. Two different titania nanotube (TiNT) morphologies were produced, Aligned and Trabecular. For the in vitro experiment, Sprague Dawley (SD) rat marrow-derived bone marrow cells (BMC) were seeded on samples. Alkaline phosphatase (ALP) …

Knee Internal Forces In Moderate Squat Exercise, Dumitru I. Caruntu, Jose Mario Salinas

Mechanical Engineering Faculty Publications

This paper deals with internal forces of human knee during moderate squat exercise. The moderate squat exercise consists of a descending phase from standing to the lowest position (largest flexion angle) in which no significant contact between thigh and calf occurs, and an ascending phase back to standing position. This research predicts the internal forces such as muscle forces, contact forces, and ligamentous forces. The ligamentous structures in this research consist of Anterior Cruciate Ligament (ACL), Posterior Cruciate Ligament (PCL), Lateral Collateral Ligament (LCL), and Medial Collateral Ligament (MCL). The ligaments are modeled as nonlinear elastic strips (they do not …

Impairment Of Continuous Insulin Delivery Therapy And Analysis From Graeco-Latin Square Design Model, Norou Diawara, Ayodeji Demuren, Eric Gyuricsko

Mathematics & Statistics Faculty Publications

The desire to deliver measured amount of insulin continuously to patients with type I diabetes, for glycemic control, has attracted a lot of attention. Continuous subcutaneous insulin infusion has seen some success in recent years. However, occlusion of insulin delivery may prevent the patient from receiving the prescribed dosage, with adverse consequence. An in vitro study of insulin delivery is performed, using different insulin pumps, insulin analogs and operating conditions. The aim is to identify incidences of occlusion due to bubble formation in the infusion line. A detailed statistical analysis was performed on the data collected to determine any significant …

The Smart Hard Hat, Darcy Fyffe, Connor Langenderfer, Charlton Johns

Williams Honors College, Honors Research Projects

In a wide variety of manual labor industries, workers are often unaware that they are approaching dangerous vital thresholds until they have already overexerted themselves. According to a 2012 white paper by the Occupational Safety and Health Administration (OSHA), over 4,500 workers lose their lives, and more than 4 million are seriously injured each year. There is an immediate need to improve the safety and monitoring of manual workers to reduce the number of workplace injuries and fatalities. Millions of laborers around the globe go to work every day relying on basic safety devices, such as harnesses and steel toed …

Reducing Fretting Corrosion At The Femoral Neck To Taper Junction In Total Hip Arthroplasty, Andrea M. Carly, Nicholas S. Moyer, Abel S. Pietros

Williams Honors College, Honors Research Projects

Fretting corrosion due to micromotion between the femoral head and neck of hip implants is a growing concern of surgeons and patients. Debris from corrosion can lead to severe adverse effects for patients of total hip arthroplasty and reduce the lifespan of the product. Previous studies conducted by Zimmer Biomet show a connection between higher impaction force and reduced fretting corrosion and debris. This design project explored this issue and developed a training device using a current technology, a dynamic force sensor, and data analysis software for surgeons to obtain muscle memory of a 4kN strike on the head impactor, …

Pediatric Electrical Stimulation For Limb Lengthening: A Non-Invasive Approach, Corey J. Schurko, Sofia Chinchilla, Amanda E. Pinheiro, Jacob A. Brock

Williams Honors College, Honors Research Projects

Leg Length Discrepancy (LLD) is a problematic ailment for children as the differences in limb lengths can lead to scoliosis, hip, knee, and ankle problems, and back pain. If LLD is untreated, the symptoms will worsen as the child matures. Today LLD is corrected by using the Ilizarov Method, which uses pins that are externally attached to the broken bone for extension over time using a fixator or by using internal plates that do not require externalization. In our project we aim to use external electrical stimulation to correct the limb discrepancies. Several companies, such as Zimmer Biomet, have created …

Characterization Of Peripheral Lung Lesions By Statistical Image Processing Of Endobronchial Ultrasound Images, Aaron T. Madaris

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This thesis introduces the concept of implementing greyscale analysis, also known as intensity analysis, on endobronchial ultrasound (EBUS) images for the purposes of diagnosing peripheral lung tumors. The statistical methodology of using greyscale and histogram analysis allows the characterization of lung tissue in EBUS images. Regions of interest (ROI) will be analyzed in MATLAB and a feature vector will be created. A feature vector of first-order, second-order and histogram greyscale analysis will be created and used for the classification of malignant vs benign peripheral lung tumors. The tools that were implemented were MedCalc for the initial statistical analysis of receiver …

Emlighten, Emily Mulvany

Williams Honors College, Honors Research Projects

This project is focused on creating a system to increase patient satisfaction in hospitals. My senior design team has been working hand in hand with the emergency department of Akron General to design this system called EMlighten. The goal is to create an experience for patients where they exit the hospital feeling more satisfied than they currently are. Patient satisfaction is a key performance indicator used by many hospitals to determine how much additional funding each hospital department is granted. If patients feel more satisfied, not only is that indicative of better care, but departments will receive extra funding. EMlighten …

Improving Anomaly Detection Through Identification Of Physiological Signatures Of Unconscious Awareness, Alyssa Marie Piasecki

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Missed anomalies have the potential to cause detrimental effects in the Intelligence, Surveillance, and Reconnaissance (ISR) domain. One possible cause of these missed anomalies is that cognitive processing may not reach conscious awareness and may only be perceived by the unconscious mind. Identification of correlates of these unconscious processes could provide an insight into potential missed targets. The present study explored missed anomalies in a visual search task and the possibility of unconscious awareness. Eye metrics were recorded and a "Detection Threshold Model" was created and validated with a nominal logistic regression model, in order to characterize the search patterns …

Β-Aminopropionitrile-Induced Reduction In Enzymatic Crosslinking Causes In Vitro Changes In Collagen Morphology And Molecular Composition, Silvia P. Canelón, Joseph M. Wallace

Weldon School of Biomedical Engineering Graduate Student Publications

Type I collagen morphology can be characterized using fibril D-spacing, a metric which describes the periodicity of repeating bands of gap and overlap regions of collagen molecules arranged into collagen fibrils. This fibrillar structure is stabilized by enzymatic crosslinks initiated by lysyl oxidase (LOX), a step which can be disrupted using β-aminopropionitrile (BAPN). Murine in vivo studies have confirmed effects of BAPN on collagen nanostructure and the objective of this study was to evaluate the mechanism of these effects in vitro by measuring D-spacing, evaluating the ratio of mature to immature crosslinks, and quantifying gene expression of type I collagen …

Hydroband: The Continuous Hydration Monitoring System, Karina E. Atkinson, Catherine P. Benedict

Williams Honors College, Honors Research Projects

Dehydration is defined as a mild, moderate, or extreme loss of water in the body. It can result in fever, muscle cramps, headaches, dizziness, or heat stroke in athletes. Ways to determine hydration levels include analysis of the urine, blood, or sweat, body weight changes, skin elasticity tests, and increases in core temperature. Patent search, research journals, and outside studies in the health and fitness market showed that a convenient and continuous hydration monitoring system was not available. Changes in core body temperature proved to be the quickest way to measure hydration levels. The HydroBand system is geared towards athletes …

Biomechanics Of Retinal Venous Pulsations As Indicators Of Intracranial Pressure, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

The origin of retinal venous pulsations remains an open problem in physiology and medicine; so too, their exact relationship to intracranial pressure. This study takes a mathematical modeling approach to explore details of blood flow through the eye to reveal the mechanism of pulsations. The intravaginal, intraneural, and intraocular segments of the retinal arteries and veins are modeled as connected resistive-capacitive segments. The analysis incorporates two critical mechanical properties of these small blood vessels, not heretofore studied, which become significant under conditions of negative transmural pressures: (1) dramatically reduced compliance during flattening and (2) cross-sectional shape change as internal volume …

A Potential New Technique To Estimate The Origins Of Focal Atrial Tachycardias From 12-Lead Electrocardiograms, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Background: This brief report presents a potential new technique for locating the sites of origin of focal atrial tachycardias from standard 12-lead electrocardiograms. Methods: Estimated P wave vector coordinates are derived from leads I, aVF, V1 and V2, and mapped to a three dimensional coordinate system in space. A simple graphical method is used to find the back projection of the P wave vector onto the surface of atrial muscle to estimate the most likely site of origin of the tachycardia. Results: Graphical back projection correctly identified foci of atrial tachycardias in 19 of 19 cases described in the most …

Development Of Carbon Based Neural Interface For Neural Stimulation/Recording And Neurotransmitter Detection, Wenwen Yi

Wayne State University Dissertations

Electrical stimulation and recording of neural cells have been widely used in basic neuroscience studies, neural prostheses, and clinical therapies. Stable neural interfaces that effectively communicate with the nervous system via electrodes are of great significance. Recently, flexible neural interfaces that combine carbon nanotubes (CNTs) and soft polymer substrates have generated tremendous interests. CNT based microelectrode arrays (MEAs) have shown enhanced electrochemical properties compared to commonly used electrode materials such as tungsten, platinum or titanium nitride. On the other hand, the soft polymer substrate can overcome the mechanical mismatch between the traditional rigid electrodes (or silicon shank) and the soft …

Antibacterial Properties Of Poly (Octanediol Citrate)/Gallium-Containing Bioglass Composite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses may function as antimicrobial delivery systems through the incorporation and subsequent release of therapeutic ions. The aim of this study was to evaluate the antimicrobial properties of a series of composite scaffolds composed of poly (octanediol citrate) with increased loads of a bioactive glass that releases zinc (Zn²⁺) and gallium (Ga³⁺) ions in a controlled manner. The antibacterial activity of these scaffolds was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The ability of the scaffolds to release ions and the subsequent ingress of these ions into hard tissue was evaluated …

Inorganic Hemostats: The State-Of-The-Art And Recent Advances, Sara Pourshahrestani, Ehsan Zeimaran, Ivan Djordjevic, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hemorrhage is the most common cause of death both in hospitals and on the battlefield. The need for an effective hemostatic agent remains, since all injuries are not amenable to tourniquet use. There are many topical hemostatic agents and dressings available to control severe bleeding. This article reviews the most commonly used inorganic hemostats, subcategorized as zeolite and clay-based hemostats. Their hemostatic functions as well as their structural properties that are believed to induce hemostasis are discussed. The most important findings from in vitro and in vivo experiments are also covered.

Polyethylene Oxide Nanofiber Production By Electrospinning, H. E. Schneider, J. G. Steuber, W. Du, M. Mortazavi, D. W. Bullock

Journal of the Arkansas Academy of Science

Electrospinning is an inexpensive technique that is used to produce nanofibers for a variety of applications. In electrospinning, a polymer solution is dispensed from a hypodermic-like syringe where an intense electric field attracts the solution to a collector while drawing the polymer into a very thin fiber. The diameter of the fiber can be controlled by tuning the process parameters such as the applied electric field, solution flow rate, distance between syringe tip and collector, and the collector geometry. In this paper we describe results from electrospinning poly(ethylene oxide) (PEO), a likely candidate for applications involving scaffolding for tissue engineering. …

The Role Of E-Cadherin Force In The Maintenance Of Homeostasis In Epithelial Acini, Fnu Vani Narayanan

Theses and Dissertations

Numerous three-dimensional model systems have emerged for emulating the biochemical and physiological states of native tissue. Yet little is known about the effects of mechanical forces on cell behavior in the context of an organized tissue structure in three-dimensional cell-culture. Epithelial cells cultured in a three-dimensional environment comprised of extracellular matrix proteins form spheroids of polarized cells. Cellular responses to mechanical cues, generated from dynamic interactions with the extracellular matrix and neighboring cells, are known to influence cellular behavior to a great extent. Previous studies have shown that tumorigenic progression has been frequently linked to the down regulation of E-cadherin, …

Novel Therapeutic Approach For Regulating The Susceptibility Of Epitheliato Adenovirus Infection, Mahmoud Soliman Salem Alghamri

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Human Adenoviruses (AdVs) are etiologic agents for respiratory tract, digestive tract, heart, and eye infections. Although most AdV infections are self-resolving, some infections progress to acute respiratory disease with up to 50% mortality, particularly in immunosuppressed people. Except for vaccines for serotypes, 4 and 7, serotypes that are prevalent in the military, no vaccines or therapeutics that specifically prevent or treat AdV infection exist. On the other hand, AdV remains the most common vector system used in gene therapy clinical trials worldwide and several AdV vectors show promise in phase III clinical trials. The majority of AdVs use the coxsackievirus …

Modeling Effects Of Diet On Human Gut Microbiota, Richard Thomas Agans

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The human gut microbiota is integrally involved in the metabolism of nutrients contained within the human diet. Studies into human nutrition have primarily been carried out using human and animal models. These studies are extremely important in our understanding of human nutrition, however, suffer from inherent limitations including unique microbial compositions between individuals, compliance in human studies, inability to carry out mechanistic studies, and inability to interrogate proximal regions of the gut without applying invasive techniques. In vitro gut simulator systems circumvent many of these limitations in animal and human models by allowing control of gut environmental conditions, decreasing variability …

A Functional Analysis Of The 3’ Regulatory Region Of The Immunoglobulin Heavy Chain Gene, Andrew David Snyder

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The immunoglobulin heavy chain (IGH) locus is partially responsible for immunoglobulin (Ig) production in B cells. The human IGH locus contains two 3’ regulatory regions (3’IghRR) that each contain three enhancers, which are thought to help drive overall transcription of the locus and also influence class switching to alternative Ig isotypes. The hs1.2 enhancer within the 3’IghRR is polymorphic in humans, containing a 53 bp invariant sequence (IS) that can be repeated up to four times. In vitro, the human hs1.2 enhancer is a sensitive target of exogenous chemicals, particularly 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin), a potent inhibitor of Ig expression …

The Role Of Interleukin-2 In Directing Vascular Smooth Muscle Cell Function And Its Implications For Understanding The Progression Of Atherosclerosis, Prakash Arumugam

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Atherosclerosis is an inflammatory disorder of the vasculature leading to the development of plaques within vessel walls. A critical component of atherosclerosis involves migration and proliferation of vascular smooth muscle cells (VSMCs) into the developing plaque, however, its mechanism is not yet understood. Previous studies have reported that IL-2 is deposited within the vasculature and IL-2 accumulates within atherosclerotic plaques due to secretion by infiltrating Th-1 cells. A limited number of studies suggest that VSMCs express a partial IL-2 receptor, comprising the ß and ¿ subunit. This suggests that IL-2 may elicit a physiological response in VSMCs. Considering IL-2’s proliferative …

Interaction Of Due-B And Treslin During The Initiation Of Dna Replication, Sumeet Poudel

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The initiation of DNA replication is a highly regulated and coordinated process. To ensure that the entire genome is replicated only once per cell cycle, many replication proteins are assembled on the chromatin in a step-wise and cell cycle dependent manner. This process is controlled by interaction of replication proteins, post-translational modifications of the replication factors, control of cellular localization of the proteins, or replication factor degradation after their function terminates. Two kinases, CDK (cyclin dependent kinase) and DDK (Dbf4/Drf1 dependent kinase), play important roles during the initiation stage of DNA replication. The c-myc DNA unwinding element-binding protein (DUE-B) is …