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Articles 121 - 150 of 386

Full-Text Articles in Biomedical Engineering and Bioengineering

Derivation Of The Respiratory Rate Signal From A Single Lead Ecg, Murtaza M. Lakdawala May 2008

Derivation Of The Respiratory Rate Signal From A Single Lead Ecg, Murtaza M. Lakdawala

Theses

It has been long established that respiration has an influence on heart rate, and this effect is called respiratory sinus arrhythmia. As a result, two inferences can be postulated: first respiration information can be derived from cardiac activity, and second this effect offers the potential of removing the respiration effect that suppresses cardiac information which is of clinical significance. As a result of research performed at NJIT, there is a significant amount of data on exercise and heart rate recovery, but not the associated respiration signal. The motivation of this research was to compare and implement an optimal ECG derived …


The Synergistic Effect Of Pulsed Electromagnetic Fields And Demineralized Bone Matrix On The Osteogenic Differentiation Of Mesenchymal Stem Cells, John Manocchio May 2008

The Synergistic Effect Of Pulsed Electromagnetic Fields And Demineralized Bone Matrix On The Osteogenic Differentiation Of Mesenchymal Stem Cells, John Manocchio

Theses

Orthopaedic bone grafting continues to be a mainstay in the treatment of non unions and other difficult to heal bone defects. Tissue engineering strategies have focused on providing bone graft materials that are osteoconductive, osteoinductive and osteogenic in order to achieve optimal bone healing. Furthermore, electrical stimulation technologies such as pulsed electromagnetic fields (PEMF) have been used to enhance the effectiveness of bone graft materials. PEMP has been shown to have a synergistic effect with BMP-2 and it was hypothesized that PEMF would have the same effect with demineralized bone matrix (DBM). In the present study human mesenchymal stem cells …


A Comparative Study Of Common Crosslinking Agents For Electrospun Collagen Scaffolds, Pallavi Masih May 2008

A Comparative Study Of Common Crosslinking Agents For Electrospun Collagen Scaffolds, Pallavi Masih

Theses

Cartilage injury is one of the leading causes of knee pain in the world. Over two million Americans suffer from cartilage injury every year, resulting in swelling, pain or joint impairment, causing it difficult to maintain an active life style. Synthetic grafts are used extensively to restore tissue functions. The major drawback limiting successful incorporation of synthetic grafts in body is their lower ability to integrate to natural tissue, poor biocompatibility which often results in triggering immunogenic responses, causing graft rejection. Collagen is thus studied and used excessively as a successful implantable material. The reason being that it is natural …


Interactions Between Adult Human Mesenchymal Stem Cells And Nanofibrous Scaffolds Of Different Compositions, Lisamarie Moore May 2008

Interactions Between Adult Human Mesenchymal Stem Cells And Nanofibrous Scaffolds Of Different Compositions, Lisamarie Moore

Theses

Stem cells have become increasingly important in the biomedical field because they have the potential to invade and regenerate damaged tissue. In particular, the bone marrow contains meesenchymal stem cells (MSCs) that have the capacity to differentiate into many cell lineages. The incorporation of MSCs within a multidimensional biomaterial provides a delivery vehicle to areas of injury. Natural and synthetic biomaterials can be made into scaffolds to represent different types of tissues. The ratio of synthetic to natural biomaterials in the scaffold influences the interaction with MSCs. This thesis created two different nanofibrous scaffolds by a process of electrospinning. The …


Process-Structure-Property Relationships Of Resorbable Desamino Tyrosine Derived Polymers : Effect Of Backbone Chemistry And Assembly On Drug Delivery, Pinar Nebol May 2008

Process-Structure-Property Relationships Of Resorbable Desamino Tyrosine Derived Polymers : Effect Of Backbone Chemistry And Assembly On Drug Delivery, Pinar Nebol

Theses

The selection the correct biomaterial for a specific medical application plays an important role for the success of both application and the device. Since different applications require different properties, investigation and improvement of biomaterials with different properties are very important. L-tyrosine derived polymers enable the manipulation of the properties of the material by changing backbone or pendent chain structure. L-tyrosine derived polyarylate is one of the class of these materials.

This study investigates the behavior of the tyrosine derived polyarylates under in vitro conditions. The change of structure caused by incubation in phosphate buffer solution and the effect on the …


Design And Construction Of A Novel Transpalpebral Ophthalmic Tonometer, Philippe R. Moinot May 2008

Design And Construction Of A Novel Transpalpebral Ophthalmic Tonometer, Philippe R. Moinot

Theses

Glaucoma -- a degeneration of the optic nerve- is a leading cause of blindness which is primarily caused by large fluctuations in intraocular pressure (lOP) known as diurnal variations. Because these peak in the early morning dropping off rapidly, a self administrable and inexpensive lOP home testing procedure is highly desirable. The approach contained herein -- unlike traditional Goldman applanation tonometry which requires the use of ophthalmic anesthetics and complex diagnostic equipment- describes a novel lOP measurement method consisting of concavation of the cornea or sclera through the palpebra superior by the spherical tip of an optoelectronic photodetector suspended in …


A Virtual Training Environment For Wheelchair Mounted Robot, Elizabeth Leichtnam May 2008

A Virtual Training Environment For Wheelchair Mounted Robot, Elizabeth Leichtnam

Theses

A model of a robotic manipulator designed to respond to different inputs from users with different skills or conditions is presented. This model can be adapted to different input variables and converted into joint angles which relate to movement in space of the manipulator's links. The algorithm allows for real time response and the features of the virtual environments (i.e., 3D design, stereoscopic vision) gives the designers the opportunity to use this model for training and usability evaluation according to the skills and different conditions that users could present.

Two types of virtual environments were created aiming to be used …


Cortical Location Of Saccadic And Vergence Oculomotor Learning Using Fmri, Yelda Alkan Jan 2008

Cortical Location Of Saccadic And Vergence Oculomotor Learning Using Fmri, Yelda Alkan

Theses

Motor learning is critical to the survival of a species and changes throughout life via neuroplasticity. The brain receives most of its information about the external world via the visual system. Eye movements are used to direct the visual information of interest to the fovea, the area of the retina which has the highest density of photoreceptors, and the largest amount of cortical area. This research will study how two of the five eye movement systems utilize oculomotor learning. Saccadic eye movements are used to quickly shift the fovea to objects using conjugate movements typically used during reading. The vergence …


The Use Of Instrumented Measures To Describe Lower Extremity Joint Mechanics, Steven Thomas Kaufman Jan 2008

The Use Of Instrumented Measures To Describe Lower Extremity Joint Mechanics, Steven Thomas Kaufman

Theses

Currently, various biomechanical assessments are used in clinical settings that offer diagnostic information about the studied joint. These assessments, however, are based on the judgment and experience of the therapist conducting the test and have a high degree of inter and intra rater variability, decreasing the strength of the observation. A set of instrumented measures consisting of a force/torque sensor and an angle sensor was created to quantitatively assess the mechanics of the lower extremity joints as a possible solution to the low repeatability of commonly used clinical tests.

It was shown through the use of instrumentation that the torques …


Design Of Three-Dimensional Axon Stretch Growth Device, Fayekah Assanah Jan 2008

Design Of Three-Dimensional Axon Stretch Growth Device, Fayekah Assanah

Theses

Spinal Cord Injury (SCI) causes destruction and degeneration of axons in the white matter of the spinal cord, resulting in functional loss and paralysis. A successful treatment of SCI requires axons to regenerate across damaged regions. Current studies focus on identifying mechanisms to promote axon regeneration in lesions and have yet to be successful in preventing nerve degeneration due to scar tissue formation. Establishing axonal bridges over long distances of SCI lesions remains a challenge, resulting in poor functional recovery. Instead of relying on promoting axon regeneration into lesions, Pfister et al. has developed a transplantable nervous tissue construct spanned …


Pattern Recognition Of Brain Fmri Images For Various Physiological States, Priyanka Bhatt Jan 2008

Pattern Recognition Of Brain Fmri Images For Various Physiological States, Priyanka Bhatt

Theses

The development of fMRI (functional Magnetic Resonance Imaging) has led many researchers to localize brain functions using different stimuli. The use of pattern recognition techniques have made it possible to predict the stimuli being presented from the corresponding brain images and activation patterns. The primary objective of the present study was to use pattern recognition methods to develop a model using available fMRJ images and then to use the model to identify the stimulus presented from a large number of unknown images. Two different experimental conditions were used involving both binary and multi-class classification. Bilateral finger tapping data which had …


Fracture Healing : The Effects Of Local Insulin Delivery Via Calcium Sulfate And Tricalcium Phosphate, Sarah Elizabeth Buchala Jan 2008

Fracture Healing : The Effects Of Local Insulin Delivery Via Calcium Sulfate And Tricalcium Phosphate, Sarah Elizabeth Buchala

Theses

Previous studies have documented the major role played by insulin in osseous healing. This is the first study to examine local intramedullary insulin delivery to the fracture site and its effect upon the normal fracture healing process. Preceding results show that when administered at the fracture site of the impaired fracture healing model of the diabetic BB Wistar rat, insulin will regulate early cellular proliferation and chondrogenesis and late mineralized tissue, cartilage content and mechanical strength.

In this study, two novel delivery vehicles have been evaluated for sustained insulin release in the normal fracture model of the BB Wistar rat. …


Multi Well Uni-Axial Stretch Injury Device, Mridusmita Choudhury Jan 2008

Multi Well Uni-Axial Stretch Injury Device, Mridusmita Choudhury

Theses

Most diffuse brain injury is the result of uni-axial stretch of brain axons in traumatic brain injury. Traumatic injury to axons throughout the brain and is believed to be a major cause for coma, and other complications. Diffuse axonal injury is mostly multi-focal and appears throughout the deep cortical and sub-cortical regions.

Several models have tried to replicate this phenomenon. Previous models, like the Penn model, have lower throughput as they conduct experiments on one well at a time, and it has lower reproducibility as well. The other problem with these models is that they are not very user friendly, …


Creating New Visualization And Human Interface Devices For Theraputic Video Games, Kunal Jayant Doshi Jan 2008

Creating New Visualization And Human Interface Devices For Theraputic Video Games, Kunal Jayant Doshi

Theses

Virtual reality (VR) gaming environment as a tool for rehabilitation of patients with upper extremity disorders is fast gaining momentum. VR based motor training systems provide an engaging, motivating and adaptable environment where the motion of the limb displayed in the virtual world is a replication of the motion produced in the real world by the patient's extremity.

The goal of this thesis was to create a generic gaming system which can be interfaced to a number of different Human interface devices (HID) and produce rich graphics to create a virtual environment which closely resembles the real world. This would …


Comparison Of Linear Parametric Models For Predicting Fmri Response, Parina Gandhi Jan 2008

Comparison Of Linear Parametric Models For Predicting Fmri Response, Parina Gandhi

Theses

In this study, five different linear parametric models including Autoregressive model (ARX), Autoregressive Moving Average Model (ARMAX), Box-Jenkins Model (BJ), Instrument Variable Model (IV) and Prediction Error Model (PEM) were used to predict the fMRI response and their performances compared. Transfer functions were computed for every voxel time series for every subject using all the parametric models. Cross-correlation was subsequently performed between the predicted response and the actual fMRI data to compare the performance of the five models. The consistency of the models and the transfer function was checked by doing a statistical analysis. Among the five models tested, PEM …


Brain Segmentation Using Endogenous Contrast Mechanism Using Breath Holding Fmri Signal For Tissue Characterization, Samata Mukesh Kakkad Jan 2008

Brain Segmentation Using Endogenous Contrast Mechanism Using Breath Holding Fmri Signal For Tissue Characterization, Samata Mukesh Kakkad

Theses

MRL has fast become the modality of choice for the analysis of the complexity of the human brain. MRJ is a non-invasive method and gives high spatial resolution maps of the brain with soft tissue contrast. Conventional MRI technique modified to be used to image the functionality at high temporal resolution is known as fMRI. In fMRI the BOLD signal we measure is the hemodynamic response to neuronal and vascular changes at rest or in response to a stimulus where the various tissue types will have a different response.

While fMRI has been traditionally been used to detect and identify …


A Stereoscopic System Using Knowledge Propagation To Achieve Accurate Depth Calculation, Chaitali Mulay Jan 2008

A Stereoscopic System Using Knowledge Propagation To Achieve Accurate Depth Calculation, Chaitali Mulay

Theses

With the advent of the twenty first century, stereoscopic systems have found a widespread use in the engineering industry. Several biomechanical analyses utilize this concept for efficient information extraction. Some examples of its applications are gait analysis, hand shape recognition, facial surface recognition etc.

The primary goal of this thesis was to optimize the existing stereoscopic system, to increase accuracy and precision of the depth information extracted. The process included redesign of the existing equipment set-up, automation of image acquisition unit and modification of conventionally used correspondence test to achieve higher accuracy. The acquired data was used to estimate depth …


Mapping Inter-Subject And Inter-Regional Brain Connectivity During Free Viewing Of Novel Natural Scenes, Sheela Nagaraj Jan 2008

Mapping Inter-Subject And Inter-Regional Brain Connectivity During Free Viewing Of Novel Natural Scenes, Sheela Nagaraj

Theses

Traditional functional magnetic resonance imaging (fMRI) studies have used controlled tasks such as finger tapping to isolate function in distinct cortical. Recent studies have examined the mechanisms involved during natural conditions by asking subjects to freely view the presentation of a movie. The objective of our study was to further observe the extent to which similarities are present between subjects during natural vision. It was hypothesized that there would be a linear relationship between the percentage of region-specific overlap, which is the percent of the anatomical region of interest which contains spatial activation exhibited by all six subjects, and corresponding …


Finger Joint Impedance Control Applications To Investigate Spasticity, David Naisby Paglia Jan 2008

Finger Joint Impedance Control Applications To Investigate Spasticity, David Naisby Paglia

Theses

In order to investigate how spasticity disrupts the capabilities of the human body, a better understanding of how joint impedance control operates in healthy individuals is necessary. In this investigation, a second order rotary torque model was implemented to investigate the impedances at the metacarpophalangeal (MCP) joint of the index finger. The model was fit to approximately 25 milliseconds of force and displacement data to determine the mechanical impedances at the finger tip. Ranges of damping and stiffness were optimized over a range of mean finger tip force (0-12 N) for extension. The equilibrium-point hypothesis was examined when compared to …


Dexamethasone- And Age-Sensitive Genes In Neonatal Small Intestine, Carla Cerqueira Jan 2008

Dexamethasone- And Age-Sensitive Genes In Neonatal Small Intestine, Carla Cerqueira

Theses

Regulation of GLUT5 is dependent on the presence of its substrate, fructose, but it is also correlated with the developmental (aging) process of the intestine. To identify fructose-responsive genes whose expression also changes with age, intestines of 10 and 20 d old pups were perfused, by Ferraris et al., with fructose and then compared by microarray analysis. From this, a gene clustering analysis revealed that some age- and fructose-specific genes are regulated by corticosterones, which normally increase in pups ≥ 14 d old. Subsequent work indicated that priming the gut with Dexamethasone (Dex, a glucocorticoid analog) allowed fructose to precociously …


Penetration Force Measurements In The Central Nervous System With Silicon Electrodes, Ashwini Arun Nikam Jan 2008

Penetration Force Measurements In The Central Nervous System With Silicon Electrodes, Ashwini Arun Nikam

Theses

One of the major challenges in neural engineering is the tissue damage that occurs during insertion of microelectrodes into the central nervous system. The damage occurs as a result of the dimpling effect that is due to the insertion force. A method which can reduce the penetration force can also reduce dimpling and the resulting tissue damage.

There are two objectives in this thesis. One is to measure the penetration force with Michigan electrodes, which are silicon based electrodes. The second is to reduce the penetration force by using mechanical vibrations.

First, the penetration force was measured in the rat …


Using Wavelet And Template Analysis To Classify Hand Postures In Unsupervised Daily Activities, Soha Hassan Saleh Jan 2008

Using Wavelet And Template Analysis To Classify Hand Postures In Unsupervised Daily Activities, Soha Hassan Saleh

Theses

This project's goal was to identify determinants that characterize different types of activities an individual do in daily life, knowing the quality of hand function is essential to plan more effective rehabilitation therapies and treatments for upper limb movement disorders. The first part of the project was Jebsen-Taylor study where healthy individuals and individuals with brain injury performed seven activities classified as precision grasp, cylindrical grasp, and palmar grasp while metacarpal joint angles were measured in real time. The data from those seven activities was used to determine parameters that characterize each type of activity and which might be used …


The Extraction Of Type 1 Collagen And The Fabrication Of Multi-Filament Embedded Hydrogels For Guided Nerve Regeneration, Mevan Lakmal Siriwardane Jan 2008

The Extraction Of Type 1 Collagen And The Fabrication Of Multi-Filament Embedded Hydrogels For Guided Nerve Regeneration, Mevan Lakmal Siriwardane

Theses

Each year, there are approximately 11,000 new cases of spinal cord injury (SCI) in the United States [2]. There have been some success in pre-clinical studies to induce axonal generation, but the reconnection of axons over large distances remains the greatest challenge. Since the development of nerve conduit to facilitate general axonal regeneration, the primary focus has changed to directing the regeneration of axons while also promoting their outgrowth over very extensive lesions to ensure functional recovery of transected nerves during in vitro experiments by using natural materials such as type I collagen, which is the largest constituent of the …


Orthogonal Cutting Of Bone, Donal Mccrohan Jan 2008

Orthogonal Cutting Of Bone, Donal Mccrohan

Theses

The cutting of bone has been undertaken for many centuries. Research in this area is contnually progressing to achieve an efficient cutting action while reducing recovery time and rauma to the patient.

Orthogonal cutting is defined where the cutting edge of the tool is set in a position that is perpendicular to the direction of relative work or tool motion. The failure mechanisms involved in the cutting of bone, their direct relationships to cutting tool geometry and cutting direction for orthogonal cutting are not accurately defined or quantified. A study of the orthogonal cutting behaviour of bone initiated in the …


Theoretical Framework For Predicting Joint Reaction And Ground Reaction Forces In A Dynamic Pendulum Tree Model Of Human Motion, Peyman Rajai Aug 2007

Theoretical Framework For Predicting Joint Reaction And Ground Reaction Forces In A Dynamic Pendulum Tree Model Of Human Motion, Peyman Rajai

Theses

Lagrangian dynamics and the method of superfluous coordinates are applied to find ground and joint reaction forces on the human body modeled as a general branched 2-D pendulum tree system with arbitrary segments and arbitrarily distributed point masses. A theoretical framework is established for predicting these constraint forces during human motion and consequently their effects on dynamics, dynamic stability, energy efficiency and the potential of these forces to produce joint injury and/or pain. Applications to human walking are initiated. During idealized phases where there is only single point contact of the stance leg with the ground such as just after …


In Vitro Feasibility Testing Of Floating Light-Activated Minroelectrical Stimulators, Ammar Riad Abdo May 2007

In Vitro Feasibility Testing Of Floating Light-Activated Minroelectrical Stimulators, Ammar Riad Abdo

Theses

One of the major challenges of neural stimulation is the mechanical stress and resulting trauma induced on the implanted electrodes by the constant movement of the interconnects. A potential way of eliminating interconnects is to use floating micro-stimulators that can be activated through optical means. As a method of energy transfer to the micro-stimulator, we propose to use a laser beam at near infrared (NIR) wavelengths.

There are two main objectives in this project to test the feasibility of the main approach; investigate the charge injection capacity of titanium nitride (TiN) and iridium oxide (IrOx) as potential contact materials, and …


Adaptable Videogame Platform For Interactive Upper Extremity Rehabilitation, Sally M. Jensen May 2007

Adaptable Videogame Platform For Interactive Upper Extremity Rehabilitation, Sally M. Jensen

Theses

The primary objective of this work is to design a recreational rehabilitation videogame platform for customizing motivating games that interactively encourage purposeful upper extremity gross motor movements. Virtual reality (VR) technology is a popular application for rehabilitation therapies but there is a constant need for more accessible and affordable systems. We have developed a recreational VR game platform can be used as an independent therapy supplement without laboratory equipment and is inexpensive, motivating, and adaptable. The behaviors and interactive features can be easily modified and customized based on players' limitations or progress.

A real-time method of capturing hand movements using …


Automatic Registration And Segmentation Of Abdominal Images And Detection Of Pancreatic Cancer, Girish Kumar Maniprasad May 2007

Automatic Registration And Segmentation Of Abdominal Images And Detection Of Pancreatic Cancer, Girish Kumar Maniprasad

Theses

Localized and detailed analyses of 3D abdominal images obtained through different imaging modalities help greatly in determining the progression of a disease or for postoperative treatment / evaluation. However, such analyses become difficult and sometimes unfeasible due to the effects of patient motion and breathing. This is particularly evident during analysis of the pancreas for cancer, due to its proximity to other intra-abdominal organs. Within subject registration thus becomes imperative for pathological analysis of pancreatic cancer. An intensity-based, global image registration algorithm was developed in the present work, for registration of pancreatic abdominal images. The registration algorithm was automatic and …


Vibrotactile Sensory Substitution For Post-Stroke Rehabilitation, Carlos X. Rosado May 2007

Vibrotactile Sensory Substitution For Post-Stroke Rehabilitation, Carlos X. Rosado

Theses

The aftermath of a stroke leaves people with side effects such as speech and hearing problems, and loss of sensation in one side of their body. Sensory feedback in the hand is used to assess if the individual is using appropriate grip force to hold and use objects; lack of sensory feedback can lead to dropped or damaged objects, and possible hand injury. Existing force biofeedback devices are overly complex and difficult to use in the home. The goal of this project is to provide increased environmental awareness of hand grip force for individuals with reduced hand sensation. Although hand …


A Kinematic Analysis Of Sign Language, Chemuttaai C. Koech Jan 2007

A Kinematic Analysis Of Sign Language, Chemuttaai C. Koech

Theses

Signed languages develop among deaf populations and employ manual communication instead of voiced communication. Stokoe attributes classify individual signs in American Sign Language (ASL) and include handshape, hand location, movement, orientation, and facial expression. Signed and oral languages are not mutually understood, and many deaf individuals live in linguistic isolation. This research addresses computer translation between signing and speech, investigating sign duration in sentence context versus in isolation and identifying kinematic sign markers. To date, there has been little study of continuous signing kinematics; it was previously unknown if kinematic markers existed.

Kinematic data were collected from a proficient signer …