Biomedical Engineering and Bioengineering Commons^™

Development Of A Heart Rate Variability Measurement System Using Embedded Electronics, Naresh Kumar Velmurugan

Graduate Theses and Dissertations

Recent advances in embedded electronics have a remarkable influence on the health care system. One of the most important applications is to monitor the health care of the patients at anytime and anyplace. In the last two decades, many researchers have focused mainly on heart rate variability (HRV) measurements. Patient's heart rate variability should be continuously monitored to help them in case of emergency. Under these circumstances, patients are required to have a HRV measuring kit for a constant observation.

The proposed project focuses on the development of a heart rate variability measurement system with the use of embedded electronics. …

A Highly Adaptive And Cost Effective Second Generation Incubator (Sgi) Towards Educational, Research And Clinical Processes, Yassir H. Al-Sayagh

Department of Biological Systems Engineering: Dissertations and Theses

Today´s rising demand for more reliable and affordable alternatives to organ transplant has led to a growing market for in vitro tissue culture systems. The main objective of tissue engineering as a whole is to employ human tissue equivalents for commercial use. The state-of-the-art processes for producing these so called tissue models are still very expensive, difficult to produce and time-consuming.

To engineer tissues, in vitro, a three-dimensional support structure commonly termed scaffold is needed. Stem cells are then added to the scaffold. In order for tissue to materialize, the scaffold and the cells must be incubated (cultured) at a …

Fabrication, Testing And Analysis Of A Fatigue Sensor For Structural Health Monitoring, Subash Gokanakonda

Dissertations

A novel fatigue monitoring sensor (FMS) is designed, fabricated and tested for detecting and monitoring the fatigue damage and estimating the remaining life of structures and components subjected to cyclic loads. The concept is based on the characteristics of stress / strain life cycle relationship of engineering materials. Sensor consists of alternate slots and strips having different strain magnification factor with respect to the nominal strain. The sensor is designed in such a way that the strips will experience the strain which closely resemble the actual strain distribution in the notch or critical area of the component. The sensor can …

The Effect Of Artery Bifurcation Angles On Fluid Flow And Wall Shear Stress In The Middle Cerebral Artery, Zachary Ramey Jones

Master's Theses

Saccular aneurysms are the abnormal plastic deformation of veins and arteries that can lead to lethal thrombus genesis or internal hemorrhaging. Medication and surgery greatly reduce the mortality rates, but treatment is limited by predicting who will develop aneurysms. A common location for saccular aneurysm genesis is at the main middle cerebral artery (MCA) bifurcation. The main MCA bifurcation is comprised of the M1 MCA segment, parent artery, and two M2 segments, daughter arteries. Studies have found that the lateral angle (LA) ratio of the MCA bifurcation is correlated with aneurysm formation. The LA ratio is defined as the angle …

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

Fabrication And Characterization Of Antioxidant Loaded Liposomes., Brian Gettler

Electronic Theses and Dissertations

Radiation exposure is both a major obstacle in space exploration and an occupational hazard for various careers causing DNA damage and ROS. In order to reduce the effects of radiation, the primary and most explored approach has been focused around mitigation in terms of exposure duration, exposure intensity, and shielding usage. In some situations none of these reduction strategies were viable and so the use of antioxidants is being explored as an alternate strategy for therapeutic purposes. One such antioxidant is curcumin, otherwise known as diferuloylmethane, is a component of turmeric with both antioxidant properties and anti-inflammatory properties. Another antioxidant …

Comparative Analysis Of Clavicular Tunnel Confìguration For Coracoclavicular Ligament Reconstruction, Mark Omwansa

Masters Theses

A number of coracoclavicular ligament reconstructions are carried out each year and post surgical fractures of the clavicle have been reported. The primary objective of this research is to develop a comparative metrics that compares clavicular tunnel configurations used in coracoclavicular reconstruction techniques. The goal of this comparison is to reduce post surgical failures due to clavicle fractures. The present analysis compared two techniques { a single 3 mm clavicular tunnel and the other double 6 mm tunnels { experimentally, using Four-point bending testing and Finite Element Analysis (FEA). A unique method, slicing, was used to create an FE clavicle …

A Low-Power Approach For Front End Biological Signal Conditioning, Logan Smith Taylor

Masters Theses

In a lab-on-a-chip (LOC) application, the measurement of small analog signals such as local temperature variation often involves detection of very low-level signals in a noisy micro-scale environment. This is true for other biomedical monitoring systems as well. These systems observe various physiological parameters or electrochemical reactions that need to be tracked electrically. For temperature measurement pyroelectric transducers represent an efficient solution in terms of speed, sensitivity, and scale of integration, especially when prompt and accurate temperature monitoring is desired.

The ability to perform laboratory operations on a small scale using miniaturized LOC devices is a promising biosensing technique. The …

Protective Effects Of Milk Phospholipids Against Uv-Induced Dna Damage In Human Skin Cells, Lan-Anh Nguyen

Master's Theses

Skin cancer is the most common type of cancer in the US. The American Academy of Dermatology estimated that more than 3.5 million new cases of skin cancer are diagnosed in the US each year and 1 in 5 Americans will likely to develop skin cancer in their life time. Most cases of skin cancer are caused by exposure to ultraviolet (UV) radiation from the sun. Some of the most common sunscreen ingredients are unstable and can form harmful radicals upon exposure to UV radiation. There is a strong clinical need for a more stable and effective sunscreen ingredient such …

Vascular Reactivity In Newly-Formed And Mature Arterialized Collateral Capillaries, Sara K. Hellstrom

Master's Theses

Peripheral arterial occlusive disease (PAOD) is a globally-prevalent cardiovascular disease in which atherosclerotic plaques narrow arterial lumen diameters and restrict blood flow to downstream tissues. The impact of these occlusions can be mitigated by collateral vessels that connect parallel arterial branches and act as natural bypasses to maintain perfusion. In animal models that lack collateral arterioles, capillaries that connect terminal arteriolar segments can arterialize and form functional collaterals following an ischemic event; however, in the early stages of development, vasodilation is impaired. We explored the mechanism of impaired vasodilation in arterialized collateral capillaries (ACCs) and pre-existing collaterals (PECs) by evaluating …

Ultrasound-Guided Mechatronic System For Targeted Delivery Of Cell-Based Cancer Vaccine Immunotherapy In Preclinical Models, Adem Nadjib Hadj Boussaad

Electronic Thesis and Dissertation Repository

Injection of dendritic cell (DC) vaccines into lymph nodes (LN) is a promising strategy for eliciting immune responses against cancer, but these injections in mouse cancer models are challenging due to the small target scale (~ 1 mm × 2 mm). Direct manual intranodal injection is difficult and can cause architectural damage to the LN, potentially disrupting crucial interactions between DC and T cells. Therefore, a second-generation ultrasound-guided mechatronic device has been developed to perform this intervention. A targeting accuracy of < 500 μm will enable targeted delivery of the DCs specifically to a LN subcapsular space. The device was redesigned from its original CT-guided edition, which used a remote centre of motion architecture, to be easily integrated onto a commercially available VisualSonics imaging rail system. Subtle modifications were made to ensure simple workflow that allows for live-animal interventions that fall within the knockout periods stated in study protocols. Several calibration and registration techniques were developed in order to achieve an overall targeting accuracy appropriate for the intended application. A variety of methods to quantify the positioning accuracy of the device were investigated. The method chosen involved validating a guided injection into a tissue-mimicking phantom using ultrasound imaging post-operatively to localize the end-point position of the needle tip in the track left behind by the needle. Ultrasound-guided injections into a tissue-mimicking phantom revealed a targeting accuracy of 285 ± 94 μm for the developed robot compared to 508 ± 166 μm for a commercial-available manually-actuated injection device from VisuailSonics. The utility of the robot was also demonstrated by performing in vivo injections into the lymph nodes of mice.

The Discovery And Study Of Fluvirucin B1 Polyketide Synthase, Tsung-Yi Lin

Doctoral Dissertations

Rapidly decreasing numbers of viable therapeutic leads in the pharmaceutical pipeline demand new, sustainable methods for improved drug discovery and development. Despite vast improvements in de novo drug design and target recognition, Nature remains the richest source of small molecule therapeutics. Among many natural products, polyketides are not only the most promising ones for developing new antibiotic leads, but also exhibit unusually high therapeutic value ranging from clinical use as anticancer, antiviral, and immunosuppressant drugs. Modular polyketide synthases (PKSs) are dedicated nano-machinery that can be manipulated to produce a structurally diverse library for drug discovery programs. The ability to manipulate …

Movement Effects On The Flow Physics And Nutrient Delivery In Engineered Valvular Tissues, Manuel Salinas

FIU Electronic Theses and Dissertations

Mechanical conditioning has been shown to promote tissue formation in a wide variety of tissue engineering efforts. However the underlying mechanisms by which external mechanical stimuli regulate cells and tissues are not known. This is particularly relevant in the area of heart valve tissue engineering (HVTE) owing to the intense hemodynamic environments that surround native valves. Some studies suggest that oscillatory shear stress (OSS) caused by steady flow and scaffold flexure play a critical role in engineered tissue formation derived from bone marrow derived stem cells (BMSCs). In addition, scaffold flexure may enhance nutrient (e.g. oxygen, glucose) transport. In this …

Neuromuscular Changes In Older Adults During The Lateral Step Task, Tatiana Bejarano

FIU Electronic Theses and Dissertations

Older adults may have trouble when performing activities of daily living due to decrease in physical strength and degradation of neuromotor and musculoskeletal function. Motor activation patterns during Lateral Step Down and Step Up from 4-inch and 8-inch step heights was assessed in younger (n=8, 24.4 years) and older adults (n=8, 58.9 years) using joint angle kinematics and electromyography of lower extremity muscles. Ground reaction forces were used to ascertain the loading, stabilization and unloading phases of the tasks. Older adults had an altered muscle activation sequence and significantly longer muscle bursts during loading for the tibialis anterior, gastrocnemius, vastus …

Design Of A Passive Exoskeleton Spine, Haohan Zhang

Masters Theses

In this thesis, a passive exoskeleton spine was designed and evaluated by a series of biomechanics simulations. The design objectives were to reduce the human operator’s back muscle efforts and the intervertebral reaction torques during a full range sagittal plane spine flexion/extension. The biomechanics simulations were performed using the OpenSim modeling environment. To manipulate the simulations, a full body musculoskeletal model was created based on the OpenSim gait2354 and “lumbar spine” models. To support flexion and extension of the torso a “push-pull” strategy was proposed by applying external pushing and pulling forces on different locations on the torso. The external …

Were Neandertal Humeri Adapted For Spear Thrusting Or Throwing? A Finite Element Study, Michael Anthony Berthaume

Masters Theses

An ongoing debate concerning Neandertal ecology is whether or not they utilized long range weaponry. The anteroposteriorly expanded cross-section of Neandertal humeri have led some to argue they thrusted their weapons, while the rounder cross-section of Late Upper Paleolithic modern human humeri suggests they threw their weapons. We test the hypothesis that Neandertal humeri were built to resist strains engendered by thrusting rather than throwing using finite element models of one Neandertal, one Early Upper Paleolithic (EUP) human and three recent human humeri, representing a range of cross-sectional shapes and sizes. Electromyography and kinematic data and articulated skeletons were used …

Quantification Of Protein Adhesion Strength To Surface Attached Poly (N- Isopropylacrylamide) Networks By Hydrodynamic Detachment Shear Stresses, Gulnur Sanden

USF Tampa Graduate Theses and Dissertations

Stimuli responsive coatings offer a versatile method by which to manipulate interfacial interactions of proteins in a desired way. However, there exists little guidance as to how the structure of a responsive polymer coating influences adsorption of proteins. In this dissertation, the adsorption behavior of immuglobulin G (IgG) on poly (N-isopropylacryamide) (PNIPAAm) hydrogel coatings was investigated as a function of film thickness. PNIPAAm exhibits a hydrophilic to hydrophobic transition above a critical temperature of ~32°C in aqueous solutions. In this research, through the use of quartz crystal microbalance with dissipation (QCM-D) it was observed that the adsorption was thickness dependent …

Increasing Label-Free Stem Cell Sorting Capacity To Reach Transplantation-Scale Throughput, Melinda Simon, Ying Li, Janahan Arulmoli, Lisa Mcdonnell, Adnan Akil, Jamison Nourse, Abraham Lee, Lisa Flanagan

Faculty Publications

Dielectrophoresis (DEP) has proven an invaluable tool for the enrichment of populations of stem and progenitor cells owing to its ability to sort cells in a label-free manner and its biological safety. However, DEP separation devices have suffered from a low throughput preventing researchers from undertaking studies requiring large numbers of cells, such as needed for cell transplantation. We developed a microfluidic device designed for the enrichment of stem and progenitor cell populations that sorts cells at a rate of 150,000 cells/h, corresponding to an improvement in the throughput achieved with our previous device designs by over an order of …

Multi-Modal, Surface-Focused Anticoagulation Using Poly-2-Methoxyethylacrylate Polymer Grafts And Surface Nitric Oxide Release, Surbhi Gupta, Kagya Amoako, Ahmed Suhaib, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

This study examines platelet adhesion on surfaces that combine coatings to limit protein adsorption along with “anti-platelet” nitric oxide (NO) release. Uncoated and poly-2-methoxyethylacrylate (PMEA) coated, gas permeable polypropylene (PP) membranes were placed in a bioreactor to separate plasma and gas flows. Nitrogen with 100/500/1000 ppm of NO was supplied to the gas side as a proof of concept. On the plasma side, platelet rich plasma (PRP, 1 × 108 cell/mL) was recirculated at low (60)/high (300) flows (mL/min). After 8 hours, adsorbed platelets on PP was quantified via a lactate dehydrogenase assay. Compared to plain PP, the PMEA coating …

Estimating Effective Connectivity From Fmri Data Using Factor-Based Subspace Autoregressive Models, Chee-Ming Ting Phd, Abd-Krim Seghouane Phd, Sh-Hussain Salleh Phd, Alias M. Noor Phd

Chee-Ming Ting

Effect Of Plasticizer On Oxygen Permeability Of Cast Polylactic Acid (Pla) Films Determined Using Dynamic Accumulation Method, Kurniawan Yuniarto, Bruce A. Welt, Aris Purwanto, Hadi Karia Purwadaria, Ayman Abdellatief, Titi C. Sunarti, Setyo Purwanto

Journal of Applied Packaging Research

Polylactic acid (PLA) is becoming an increasingly important biopolymer for packaging applications. PLA brittleness limits its applicability. This study evaluated PLA properties with increasing amounts of added polyethylene glycol (PEG) plasticizer. Oxygen transmission rate (OTR) of cast films was determined using the newly available Dynamic Accumulation (DA) method. Arrhenius temperature sensitivity of OTR and polymer Permeability was also determined. Permeability of neat PLA is 4.848 ml mm (STP)/m² s kPa; hence, 4.84 ml mm (STP)/m² s kPa, 4.07 ml mm (STP)/m² s kPa and 5.42 ml mm (STP)/m² s kPa by adding PEG 1 %, 5% …

Reference Point Indentation Is Not Indicative Of Whole Mouse Bone Measures Of Stress Intensity Fracture Toughness, Alessandra Carriero, Jan L. Bruse, Karla J. Oldknow, José Luis Millán, Colin Farquharson, Sandra J. Shefelbine

Biomedical Engineering and Sciences Faculty Publications

Bone fragility is a concern for aged and diseased bone. Measuring bone toughness and understanding fracture properties of the bone are critical for predicting fracture risk associated with age and disease and for preclinical testing of therapies. A reference point indentation technique (BioDent) has recently been developed to determine bone's resistance to fracture in a minimally invasive way by measuring the indentation distance increase (IDI) between the first and last indentations over cyclic indentations in the same position. In this study, we investigate the relationship between fracture toughness KC and reference point indentation parameters (i.e. IDI, total indentation distance (TID) …

A Novel 2.5d Culture Platform To Investigate The Role Of Stiffness Gradients On Adhesion-Independent Cell Migration, Mark-Phillip Pebworth, Sabrina A. Cismas, Prashanth Asuri

Bioengineering

Current studies investigating the role of biophysical cues on cell migration focus on the use of culture platforms with static material parameters. However, migrating cells in vivo often encounter spatial variations in extracellular matrix stiffness. To better understand the effects of stiffness gradients on cell migration, we developed a 2.5D cell culture platform where cells are sandwiched between stiff tissue culture plastic and soft alginate hydrogel. Under these conditions, we observed migration of cells from the underlying stiff substrate into the alginate matrix. Observation of migration into alginate in the presence of integrin inhibition as well as qualitative microscopic analyses …

Optimization Of Cooling Protocols For Hearts Destined For Transplantation, Abas Abdoli

FIU Electronic Theses and Dissertations

Design and analysis of conceptually different cooling systems for the human heart preservation are numerically investigated. A heart cooling container with required connections was designed for a normal size human heart. A three-dimensional, high resolution human heart geometric model obtained from CT-angio data was used for simulations. Nine different cooling designs are introduced in this research. The first cooling design (Case 1) used a cooling gelatin only outside of the heart. In the second cooling design (Case 2), the internal parts of the heart were cooled via pumping a cooling liquid inside both the heart’s pulmonary and systemic circulation systems. …

Wear Resistant And Biocompatible Coatings For Medical Devices And Method Of Fabrication, Mary Gilliam, Susan Farhat, Ali Zand

Chemical Engineering Patents

Abstract: A method of forming a biocompatible or biologically inert article for use in an application in which the article will make contact with at least one tissue, organ, or fluid within a human or animal body is provided. The method generally comprises providing an article having an external sur face; selecting chemical precursors; using a means to direct one or more chemical precursors towards or to apply such chemical precursors to the ex ternal surface; activating the chemical precursors by exposing said precursors to atmospheric pressure plasma; and grafting and/or cross-linking the chem ical precursors to form a solid …

Covalent Ir820-Peg -Diamine Nanoconjugates For Theranostic Applications In Cancer, Alicia Fernandez-Fernandez, Romila Manchanda, Denny A. Carvajal, Tingjun Lei, Supriya Srinivasan, Anthony J. Mcgoron

Department of Biomedical Engineering Faculty Publications

Near-infrared dyes can be used as theranostic agents in cancer management, based on their optical imaging and localized hyperthermia capabilities. However, their clinical translatability is limited by issues such as photobleaching, short circulation times, and nonspecific biodistribution. Nanoconjugate formulations of cyanine dyes, such as IR820, may be able to overcome some of these limitations. We covalently conjugated IR820 with 6 kDa polyethylene glycol (PEG)-diamine to create a nanoconjugate (IRPDcov) with potential for in vivo applications. The conjugation process resulted in nearly spherical, uniformly distributed nanoparticles of approximately 150 nm diameter and zeta potential -0.4±0.3 mV. The IRPDcov formulation retained the …

Hepatic Carboxylesterase 1 Is Induced By Glucose And Regulates Postprandial Glucose Levels, Jiesi Xu, Liya Yin, Yang Xu, Yuanyuan Li, Munaf Zalzala, Gang Cheng, Yanqiao Zhang

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Metabolic syndrome, characterized by obesity, hyperglycemia, dyslipidemia and hypertension, increases the risks for cardiovascular disease, diabetes and stroke. Carboxylesterase 1 (CES1) is an enzyme that hydrolyzes triglycerides and cholesterol esters, and is important for lipid metabolism. Our previous data show that over-expression of mouse hepatic CES1 lowers plasma glucose levels and improves insulin sensitivity in diabetic ob/ob mice. In the present study, we determined the physiological role of hepatic CES1 in glucose homeostasis. Hepatic CES1 expression was reduced by fasting but increased in diabetic mice. Treatment of mice with glucose induced hepatic CES1 expression. Consistent with the in vivo study, …

A NTh-Order Linear Algorithm For Extracting Diffuse Correlation Spectroscopy Blood Flow Indices In Heterogeneous Tissues, Yu Shang, Guoqiang Yu

Biomedical Engineering Faculty Publications

Conventional semi-infinite analytical solutions of correlation diffusion equation may lead to errors when calculating blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements in tissues with irregular geometries. Very recently, we created an algorithm integrating a Nth-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in homogenous tissues with arbitrary geometries for extraction of BFI (i.e., αD_B ). The purpose of this study is to extend the capability of the Nth-order linear algorithm for extracting BFI in heterogeneous tissues with arbitrary geometries. The previous linear algorithm was modified to extract BFIs …

Wear Characteristics Of Wright State University Total Ankle Replacement Under Shear And Torsion Loads, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Introduction: Total ankle replacement (TAR) involves replacement of the damaged bone with prosthetic components and is usually performed in patients suffering with arthritis to relieve pain and maintain motion. There are several different factors that contribute to failure of TARs but aseptic loosening is the primary method of failure in total ankle replacements. Because of its superior mechanical properties UHMWPE is used as a liner material in TARs. Wear generated from the liner due to high contact stresses during gait causes osteolysis resulting in early loosening of the prostheses.

Most of the earlier studies have focused on wear due to …