Biomedical Engineering and Bioengineering Commons^™

A Dynamic Supine Stander For Subjects With Disabilities Leading To Prolonged Immobility, Luis Alberto Espina

Theses

Bone tissue needs to be exposed to loading in order to stimulate the osteogenic response of the body. Disabilities that lead to prolonged immobility will result in a decrease of the osteogenic processes and an increase in resorption of bone by osteoclast cells. This disuse modeling can lead to osteopenia, osteoporosis, and subsequent non-traumatic fractures. These disabilities are varied in nature and duration, and can include load bearing bone fracture, excessive obesity, spinal cord injury, and cerebral palsy.

The following describes the concept and design of a novel dynamic supine stander that will provide loads simulating ambulation to the lower …

Multi-Degree Of Freedom Telemanipulation In An Unstructured Environment, Diego Ramirez

Theses

Two approaches to 6-degrees-of-freedom telemanipulation that will accommodate different needs and skills of potential users with congenital amputation, arthrogryposis, muscular dystrophy and cerebral palsy were developed. One method uses scalable movements (i.e. position and orientation), and the second employs isometric forces and torques without movement. The scalable position approach employs a 6-degress-of-freedom electromechanical stylus whose joint orientations are used by the controlling computer to determine the position and orientation of the robot's end effector via inverse kinematics or by one-to-one matching of the stylus joint angles with those of the manipulator. The isometric method uses the measured forces and torques …

Implementation Of Stereo Correspondence Algorithms For Multi-Baseline Vision System, Navaneetha Shivram

Theses

The purpose of this study is to determine the impact of varying camera baselines on correspondence and depth estimation. As the baseline increases the resolution of depth increases but finding correspondences is very tedious. On the other hand when cameras are placed close to each other and thereby reducing the baseline distance points in the images are easily matched however depth resolution deteriorates. This problem is solved by using a multi-camera system is used in which the cameras are spaced close to each other along a straight line. Calculating the correspondence along successive camera pairs is relatively easy. These respondences …

Inverse Dynamic Modeling For Characterization Of Spasticity, Katharine Markel Swift

Theses

Spasticity affects subjects with cerebral palsy, stroke, multiple sclerosis, and traumatic brain injury. The need to develop a deeper understanding of spasticity is driven by the existing limited understanding and the lack of satisfactory interventions for this disabling phenomenon.

An inverse model is implemented to describe the motion in the pendulum knee drop test. Inverse kinematic modeling is implemented to investigate the pathophysiology of spasticity.

Using the equilibrium point hypothesis as a conceptual framework to explain disabled and non-disabled neuromuscular control, it has been demonstrated that the equilibrium point of the passive knee is dynamic and exhibits a pseudo-exponential trajectory …

Characterization Of Hypertension Through Multivariate Analysis Utilizing Linear And Nonlinear Methods, Diane L. Donnelly

Dissertations

Analysis of blood pressure by nonlinear methods is vastly underutilized in current research. As such, 24-hour ambulatory blood pressure data from a small cohort of borderline hypertensive and normotensive subjects were analyzed using linear and nonlinear methods. Data were collected and provided by researchers from Columbia University. The cohort size was twelve subjects, consisting of two groups of six each. Although disease state was known, group membership for individual subjects was not. Therefore, one aspect of this research was to separate the cohort, a-priori, into two distinct, evenly sized groups, based solely on analysis results. Separation was accomplished by the …

Individual Cell Pressure Control In An Air Mattress For The Prevention Of The Pressure Sores, Kapilchandra Anand

Theses

Many kinds of pressure-relieving mattresses have been developed to prevent pressure sores in patients with spinal cord injuries (SCIs) and obesity. Current technology uses alternating air pressure mattress, foam and low pressure mattress for reducing the incidence of pressure sores in SCI and obesity patients. These mattresses do not have control of pressure in individual air chambers. They are open loop system and they do not receive any feedback from the system. They have at the most control of two different pressures. The purpose of this study is to improve the current assistive technology in reducing pressure sores and to …

In-Vitro Characterization Of Boronized Titanium Alloy By Means Of Corrosion And Electrochemical Impedance Spectroscopy Methods In Simulated Body Fluids, David Anthony Panus

Theses

Titanium and titanium alloys are becoming the backbone of medical implants and prosthetics. Titanium alloys are used because of its high biocompatibility and similarity to bone. However, titanium and titanium alloys have a low wear resistance. Titanium and titanium alloys are susceptible to particle erosion, which can cause inflammation, infection, and even implant rejection. Boronizing titanium alloy improves titanium's wear resistance and also improves corrosion resistance.

The target of this research was to characterize the corrosion characteristics of both unboronized and boronized titanium using both electrochemical corrosion methods and Electrochemical Impedance Spectroscopy (ELS) in simulated body fluid. Using electrochemical methods …

Fabrication Of Hydroxyapatite-Biodegradable Polymer Scaffolds By Electrospinning For Potential Bone Tissue Application, Satomi Suzuki

Theses

The purpose of this study is to determine the potential of combining hydroxyapatite (HA) and polymers to form synthetic composite materials used for bone tissue engineering applications. In this study, ceramic-biodegradable polymer composites are fabricated by electrospinning method. The biodegradable polymers used are poly(L-lactic acid) (PLLA), and poly(lactide-co-glycolide) (PLGA). Two types of HA-polymer solutions are first prepared to achieve HA weight percentage of 0, 10, and 25%of the total combined weight of HA and PLLA, and HA and PLGA. The solutions are electrospun to form nanofibrous mats incorporated with HA powder. A biomimetic process was also conducted as a …

Fabrication Of Aligned Nanofiber Yarns, Mats And Isolation Of Single Nanofiber In Electrospinning, Venkatesh T. Nathilvar

Theses

Electrospinning has been extensively used as an effective technique for the fabrication of submicron and nanometer scale polymeric fibers. In spite of technological advances in electrospinning, creating a highly aligned fiber structure is a tough target to be achieved because of the chaotic motion of the electrospinning jet. In this study, two different techniques have been adopted to form a highly aligned nanofibrous scaffolds. Using these methods highly aligned fiber yams and mats are produced from Cellulose Acetate (CA) in a mixed solvent of acetone and water. In both the techniques the nanofibers suspend over the gap in a highly …

Osteogenic Differentiation Of Human Mesenchymal Stem Cells On Thin Film Tyrosine Derived Polycarbonates, Tamunotoyne Briggs

Theses

Mesenchymal stem cells, harvested from adult bone marrow, are promising in the field of regenerative medicine because of the vast differentiation potential into various cell lines such as: osteoblasts, chondrocytes, adipocytes, and neurons. Osteogenic differentiation of human mesenchymal stem cells (hMSC) could be an important tool in the treatment of orthopedic deficiencies such as bone defects. The extent of in vitro human mesenchymal stem cell growth, adhesion, motility and differentiation into osteoblasts is a function of the material surface chemistry which is mediated by protein adsorption onto the surface. A library of tyrosine derived polycarbonates allows the tailoring of material …

Auto Detection In Autism, Gayathri Chandar

Theses

Autism is a neurobiological disorder in which, certain regions of the brain are affected. The main features of autism are impairment in communication, social interaction, language and deficit in imitation and theory of mind. Using Functional Magnetic Resonance Imaging (fMRI), haemodynamic responses during a bilateral finger tapping task are analyzed for both autistic subjects and normal control subjects. fMRI is a noninvasive technique to image the activity of the brain related to a specific task. Generally, the active voxels in the IMRI images are detected using parametric or non-parametric statistical methods in which the fMRI response is assumed to have …

The Complex Behavior Of Poly(Dte) Carbonate And Its Blend Properties, Christopher George Elvin

Theses

Over the years a number of different polymers have been studied for bone applications. Polyesters such as the poly lactic acids (PLA), poly glycolic acids (PGA), and their copolymers have been studied intensely for bone regeneration purposes. Poly(DTE)carbonate has been found useful for bone regenerative purposes and is under review by the U.S. Food and Drug Administration.

The purpose of this study was to investigate the properties of poly(DTE)carbonate when PLLA, PLGA, and P(LcoDL)LA was blended with it. The desired outcome was to produce miscible polymer blends or significant phase shift in the blended materials which will make them at …

Automatic Detection Of Qt And Related Intervals, Divya Gowdar

Theses

The objective of this thesis is divided into two main sections: The first section comprises of the development of the algorithm for the detection of the Q wave, Tmax afld the Tend to measure the intervals such as QT, QT corrected (QTc), RT, QT_max and RT_max respectively. The second section deals with the analysis of different variabilities including heart rate variability (HRV), QT, QTc, RT, QT_max and RT_max.

Using the R wave points as reference points, the Q wave was detected by using the Differential Threshold Method (DTH). The Tmax was detected by using a …

Development Of A System To Measure Cardiac Function In The Drosophila Melanogaster Animal Model, Heather Anne Reinhardt

Theses

Previous studies have shown that several genes are evolutionarily conserved from lower organisms to man, where a number of genes have been directly linked to cardiac function and disease. The Drosophila melanogaster (Fruit Fly) has a genome similar to humans and therefore has proven to be an important animal model to study the role of genetics in cardiac function and disease development. Fruit flies are an important basic science model because of the ease with which genes can be manipulated and quickly expressed due to the short lifespan of the fly. Although standard techniques exist to affect the genome of …

Pda Based Ambulatory Pulse Oximeter, Arpita Shah

Theses

The main aim of the research was to develop an ambulatory pulse oximeter which can be used to monitor the SpO₂ heart rate (HR) and plethsymograph (PPG) waveform of a person. To achieve this, an algorithm was developed in LabVIEW 8.0 to extract the HR, SpO₂ and PPG data from a Nonin Xpod device, Nonin Medical, Inc. LabVIEW PDA software was developed to make it compatible with the PDA. LabVIEW software was also developed for sending the data to the PDA via Bluetooth Pulse Oximeter commercialized by Nonin Medical Company.

Using this algorithm, data was collected from three …

Qt Variability Calculation Using A Template Matching Algorithm And Power Spectral Analysis, Theodore Sami Rizkalla

Theses

ECG interval measurement and variability analysis has proven to be a useful tool in investigating autonomic nervous system function. Traditionally, the R to R interval has been the thrust of research conducted in this field. QT variability is another topic on which little research has been done.

This thesis uses an algorithm proposed by Dr. Berger, published in 2003. The algorithm stretches the template in the time domain, and composes a sum-squared error function, which is minimized to find the scaling factor for that beat. These scaling factors are compiled into an array, and an interpolated signal is generated of …

Impact Of Missed Beats On Heart Rate Variability Using Time-Frequency Analysis, Kilbrom T. Hailu

Theses

ECG recordings, especially during an exercise stress test, are exposed to artifacts. The source of artifacts can be due to technical problems, biological events and errors in the automatic detection. As a result missed beats, extra beats and ectopic beats can occur. In this study analysis of missed beats is performed using time-frequency analysis. Some of the patient's data had missed beats.

Fourier spectral analysis was first applied to the missed beats during the resting state. The impact of missed beats using Fourier spectral analysis is significant, especially, when the missed beats are in a row. The Fourier spectral analysis …

Medical Equipment Planning And Construction Of A Interventional Neuroradiology Suite, Furqan Elahi

Theses

New York-Presbyterian Hospital is one of the most comprehensive university hospitals in the world, with leading specialists in every field of medicine. It is composed of two renowned medical centers, New York-Presbyterian Hospital/Columbia University Medical Center and New York-Presbyterian Hospital/Weill Cornell Medical Center. The hospital's strategic planning group identified the need to expand the Interventional Neuroradiology service that the hospital provides. This brought upon the need to form a committee to plan the construction of an Interventional Neuroradiology. The problem statement of this thesis is to prepare a best practices guideline from a clinical engineering perspective on constructing the three …

Non-Invasive Monitoring Of Bone Health Using Ultrasound, Nashit Jahan Meem

Theses

Bone fractures are estimated to afflict everyone at least once in his/her lifetime. Monitoring this becomes crucial especially when it comes to athletes in order for them to safely resume their regular activities as soon as possible. Technologies currently employed are either very expensive or use harmful radiation.

Ultrasound can monitor bone fractures in a non-invasive manner, as discussed in United States Patent # 5143069. Three transducers are mounted over the test specimen. A pulse generator excites the transmitting receiver. The second receiver is mounted next to the transmitter and acts as a reference receiver that displays the response across …

Direct Application Of The Least Action Principle To Solve (Human) Movement Dynamics Without Using Differential Equations Of Motion, Amitha Kumar

Theses

This thesis explores the numerical feasibility of solving motion 2-point boundary value problems (BVPs) by direct numerical minimization of the action without using the equations of motion (EOM) as an intermediate step. The proposed direct least action (DLA) approach using the downhill simplex method (DSM) is applied to both the single and double pendulum systems as beginning test problems. The solutions so obtained are compared to numerical solutions of the corresponding Lagrange BOM solved using a first order Euler algorithm for the same mechanical problems. The output path obtained by both of the methods essentially superimpose on each other.

Future …

Quantification Of Long-Range Power Law Correlations Among Healthy And Pathologic Subjects Using Detrended Fluctuation Analysis And Multifractal Detrended Fluctuation Analysis, Hardick Raval

Theses

The healthy heartbeat is traditionally thought to be regulated according to the classical principle of homeostasis whereby physiologic systems operate to reduce variability and achieve an equilibrium-like state. However recent studies reveal that under normal conditions, beat-to-beat fluctuation in heart rate display the kind of long-range correlations typically exhibited by the dynamical system far away from equilibrium. In contrast, heart rate time series from patients with severe congestive heart failure show a breakdown of this long-range correlation behavior. Two different non-linear dynamic methods namely Detrended Fluctuation Analysis (DFA) and Multifractal (MF) DFA are used for the quantification of this correlation …

In Vitro Evaluation Of Human Mesenchymal Stem Cell Neural Differentiation On Tyrsine-Derived Polyarylates And Polycarbonates, Yee-Shuan Lee

Theses

Present spinal cord injury treatments cannot restore motor and sensory functions caused by the injury. These functions can return in the hopes of repairing the neural cells with a tissue engineered designed scaffold complex. The scaffold complex will include cells to repair and replace the damaged cells.

Mesenchymal stem cells (MSC) are multipotent adult stem ells that are capable of differentiating along several lineage pathways. Neural stem cell and MSC differentiating along the neural lineage bave been investigated both in vivo and in vitro depicting its feasibility. MSC for neural differentiation can be achieved by microenvironmental signaling. Substrate surface characteristics …

Haptic Induced Motor Learning And The Extension Of Its Benefits To Stroke Patients, Adrienne M. Coppa

Theses

In this research, the Haptic Master robotic arm and virtual environments are used to induce motor learning in subjects with no known musculoskeletal or neurological disorders. It is found in this research that both perception and performance of the subject are increased through the haptic and visual feedback delivered through the Haptic Master. These system benefits may be extended to enhance therapies for patients with loss of motor skills due to neurological disease or brain injury.

Force and visual feedback were manipulated within virtual environment scenarios to facilitate learning. In one force feedback condition, the subject is required to maneuver …

Growth Behavior Of Fibroblasts Influenced By Small Changes In Polymer Structure, Saraswathi Doddi

Theses

Polymers are a promising class of biomaterials that can be engineered to meet specific end use requirements. The order and processing history of the polymer, which would alter the molecular orientation of the material could have a significant contribution towards cellular attachment and in turn, cell growth on the particular polymer. Surface properties of the material were considered to directly influence the properties of the adherent cells including cellular growth and reorganization. The present study is aimed at comparing cell growth on polyarylates with that of polylactic acid in their original state or by introducing small changes in the surface …

Multifractal Analysis Of Heart Rate Variability Using Wavelet-Transform Modulus-Maxima Method, Chirag Jani

Theses

Physiological signals are complex and carry information of human health. Recent studies reveal that under normal conditions, the heart rate time series shows multifractal behavior. In contrast, HRV in the pathological state such as congestive heart failure exhibits more monofractal-like structure. Recent advances in the assessment of heart rate variability (HRV) uses a nonlinear dynamics approach. In this study, the main objective is to use the wavelet-transform modulus-maxima method for the multifractal analysis of the heart rate time senes.

The degree of the multifractality is defined by the singularities (a point in time series where a mathematical function is not …

Combined Effects Of Prozac And Hypothalmic Mediated Response On Masseter Muscle Activity In The Cat, Chika P. Nwaorgu

Theses

The present study tested the hypothesis that infusion of Prozac would serve to suppress defensive rage elicited from the medial hypothalamus of the cat. Cats are known to exhibit certain kind of behavior, known as the "defensive rage response" such as unsheathing of the claws, retraction of the ear and vocalization (hissing).

Three adult cats (2 males and 1 female) weighing (2.8 - 3.4 kg) were utilized during the experiments. Cannula-electrodes were implanted into the medial hypothalamus for elicitation of defensive rage behavior. EMG activity was recorded with a bipolar electrode attached to the masseter muscle to establish baseline before …

Wet-Spinning And Thermal Analysis Of Collagen Fibers Incorporating Hydroxyapatite In Mixed And Coated Form, Sandesh Nathaniel Prakash

Theses

The composition of natural bone comprises of collagen (Cg) as organic phase which acts as a matrix and inorganic calcium phosphate, particularly hydroxyapatite (HA), which is used as reinforcement. This study involved the wet-spinning of collagen fibers incorporating HA in mixed and coated form. The weight percent ratio of collagen and HA in the composite fibers was 95 to 5 respectively. HA coating on pure collagen fibers was achieved by immersing them in HA solution formed by mixing HA in water. With Thermomechanical analysis, the highest breaking point temperature was obtained for the composite fibers and the least with pure …

The Creation And Testing Of A Mock Functional Magnetic Resonance Imaging Facility For Pain Patients, Gladstone Vincent Reid

Theses

Unfamiliarity with functional Magnetic Resonance Imaging (fMRI) facilities leads to unwanted stress-related disturbances in the processing of fMRI data. A mock fMRI facility was developed to increase familiarization among subjects participating in fiviRI studies and to alleviate the time and cost of familiarizing each subject in an actual fMRI facility. A decommissioned Magnetic Resonance Imaging (MRI) unit was remodeled to visually and aurally resemble the Siemens Magnetom Allegra 3 Telsa fMRI machine currently used at the University of Medicine and Dentistry of New Jersey (UMDNJ), Newark, New Jersey. Instrumentation was developed using LabVIEW software which presented subjects with recreated sounds …

Quantification Of Regularity In Rr-Interval Time Series Using Approximate Entropy, Sample Entropy, And Multi-Scale Entropy, Nirvish Shah

Theses

Heart rate variability (HRV) has proven to be a useful noninvasive tool to study the neuronal control of the heart. Recently, nonlinear dynamic methods based on chaos theory and fractal dynamics have been developed to uncover the nonlinear fluctuations in heart rate. Approximate Entropy (ApEn), Sample Entropy (SampEn) and Multi-scale Entropy (MSE) are measures based on chaos theory that quantify the regularity in time series. This study has been designed to examine the ability of these measures to distinguish the RR-interval time series of normal subjects (NSR) from subjects with congestive heart failure (CHF). The study was conducted on the …

Characterization Of Mismatch Between Behavioral Stimuli And Frmi Data Using The Kalman Filter, Jason Steffener

Dissertations

The advance of blood oxygen level dependent function magnetic resonance imaging, (BOLD fMRI), allows researchers to non-invasively investigate the functioning human brain. The BOLD fMRI response to brief stimuli is called the hemodynamic response function (HRF), which can vary across brain regions and across subjects.

Models of the HRF are used to increase sensitivity of statistical maps; however, they often don't account for spatial and temporal variance. Physiological effects, such as learning, fatigue or habituation, introduce mismatch between statistical models and the data. Methods that use minimal a priori information and track time varying signals are able to show the …