Biomedical Engineering and Bioengineering Commons^™

An Adaptive Neuro-Fuzzy Inference System For Modeling Mechanical Properties Of Tapioca Starch-Poly(Lactic Acid) Nanocomposite Foams, Siew-Yoong Lee, Milford Hanna, David D. Jones

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Tapioca starch, poly(lactic acid) and Cloisite 30B nanocomposites foams, with clay contents of 1, 3, 5 and 7% (w/w), were prepared by a meltintercalation method. Multiple inputs single output models were developed to predict radial expansion ratio, unit density, bulk compressibility and spring index of the nanocomposite foams. An individual ANFIS model was developed for each mechanical property using clay content, temperature, pressure and torque as input parameters. All models preformed well with R² values > 0.71. All models had very low root mean squared error values.

Force Measurement And Evaluation For Surgical Cutting Applications: Development Of An Effective Characterisation Testbed, Dean Callaghan

Conference Papers

Sensorized instruments that cater for accurate measurement of the interaction forces (between biological tissue and instrument end-effector) during surgical procedures offer surgeons a greater sense of immersion during minimally invasive robotic surgery (MIRS). There is much ongoing research into force measurement/evaluation involving surgical graspers. However, comparatively little corresponding effort has been expended in the measurement and subsequent evaluation of forces between scissor blades and tissue. This paper presents the design and development of a force/strain measurement test apparatus, which will ultimately serve as an effective sensor characterisation and evaluation platform. Data acquired from the testing platform can be used to …

An Effect Of Relative Motion On Trajectory Discrimination, Scott A. Beardsley, Lucia M. Vaina

Biomedical Engineering Faculty Research and Publications

Psychophysical studies point to the existence of specialized mechanisms sensitive to the relative motion between an object and its background. Such mechanisms would seem ideal for the motion-based segmentation of objects; however, their properties and role in processing the visual scene remain unclear. Here we examine the contribution of relative motion mechanisms to the processing of object trajectory. In a series of four psychophysical experiments we examine systematically the effects of relative direction and speed differences on the perceived trajectory of an object against a moving background. We show that background motion systematically influences the discrimination of object direction. …

Spatial Variations In Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nutrient and microbial transport by runoff may vary at different locations within a beef cattle feedlot. If the areas making the largest contributions to nutrient and microbial transport can be identified, it may be possible to institute site‐specific management practices to reduce runoff nutrient and microbial transport. The objectives of this study were to: (1) measure selected feedlot soil properties and nutrient and microbial transport in runoff from various feedlot locations, (2) compare the effects of unconsolidated surface materials (USM) (loose manure pack) and consolidated subsurface materials (CSM) (compacted manure and underlying layers) on nutrient and microbial transport, and (3) …

Leg Sympathetic Response To Noxious Skin Stimuli Is Similar In High And Low Level Human Spinal Cord Injury, M. Kevin Garrison, Alexander V. Ng, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Objective

To determine if sympathetically mediated vasoconstriction in the lower extremities is injury level dependent. Although sympathetic responses have been measured in the limbs of people with high and low level SCI using blood flow measurements, including Doppler ultrasound and venous plethysmography, a direct comparison between injury levels has not been made.

Methods

Volunteers with chronic SCI were grouped according to injury level. Above T6: high level (HL, n = 7), and T6 and below: low level (LL, n = 6). All subjects had complete motor and sensory loss. Leg arterial flows were recorded by venous occlusion plethysmography, and continuous …

Mineral Trioxide Aggregate Material Use In Endodontic Treatment: A Review Of The Literature, Howard W. Roberts, Jeffrey M. Toth, David W. Berzins, David G. Charlton

Biomedical Engineering Faculty Research and Publications

Objective

The purpose of this paper was to review the composition, properties, biocompatibility, and the clinical results involving the use of mineral trioxide aggregate (MTA) materials in endodontic treatment.

Methods

Electronic search of scientific papers from January 1990 to August 2006 was accomplished using PubMed and Scopus search engines (search terms: MTA, GMTA, WMTA, mineral AND trioxide AND aggregate).

Results

Selected exclusion criteria resulted in 156 citations from the scientific, peer-reviewed dental literature. MTA materials are derived from a Portland cement parent compound and have been demonstrated to be biocompatible endodontic repair materials, with its biocompatible nature strongly suggested by …

The Role Of Sr²⁺ On The Structure And Reactivity Of Sro-Cao-Zno-Sio2 Ionomer Glasses, Daniel Boyd, Mark R. Towler, Sally Watts, Robert G. Hill, Anthony W. Wren, Owen M. Clarkin

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Polyalkenoate Cements (GPCs) for use in orthopaedics is retarded by the presence in the glass phase of aluminum, a neurotoxin. Unfortunately, the aluminum ion plays an integral role in the setting process of GPCs and its absence is likely to hinder cement formation. However, the authors have previously shown that aluminum free GPCs may be formulated based on calcium zinc silicate glasses and these novel materials exhibit significant potential as hard tissue biomaterials. To further improve their potential and given that Strontium (Sr) based drugs have had success in the treatment of osteoporosis, the authors have …

Tem Analysis Of Apatite Surface Layers Observed On Zinc Based Glass Polyalkenoate Cements, D. Boyd, Mark R. Towler, A. W. Wren, O. M. Clarkin, D. A. Tanner

Chemical and Biochemical Engineering Faculty Research & Creative Works

The amorphous nature and composition of the surface apatite layers observed on glass polyalkenoate cements based on zinc silicate glasses (Zn-GPCs) after immersion in simulated body fluid (SBF) have been analyzed by the transmission electron microscopy (TEM). TEM was conducted using a JEOL JEM-2011 electron microscope operated at an accelerating voltage of 200 kV. The composition elements of the surface layer indicated the presence of calcium, phosphorous, zinc, and strontium within the amorphous structure. This composition, in particular the inclusion of Zn in the structure, indicates the lack of crystallinity associated with the formation of the apatite layers observed on …

Development Of A Three Dimensional Prolapse Model To Simulate Physiological Haemodynamics In A Stented Coronary Artery, Jonathan Murphy, Fergal Boyle

Conference Papers

Coronary stent implantation can improve blood flow in an artery that has been narrowed by the build up of arterial plaque. However, the haemodynamic effect of stent placement is unclear and may influence arterial restenosis (re-blockage). The degree of tissue prolapse between stent struts may be an important factor in predicting the restenosis rate of a stent due to the haemodynamic influence of the protruding tissue. In this paper a mathematical model has been developed to numerically predict the tissue prolapse for an artery implanted with a coronary stent. The prolapse model has been applied to the Gianturco-Roubin II (GR-II) …

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 …

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 …

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, …

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 …

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

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

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. …

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

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

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 …

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

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 …

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 …

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

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 …

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 …

Evolution Of A Computational Domain For Numerical Analysis Of Fluid Mechanical Disturbance Induced By Coronary Stent Deployment, Jonathan Murphy, Fergal Boyle

Conference Papers

No abstract provided.

Polyelectrolyte Mediated Scalable Synthesis Of Highly Stable Silver Nanocubes In Less Than A Minute Using Microwave Irradiation, Subrata Kundu, Vivek C. Maheshwari, Sanjun Niu, Ravi F. Saraf

Ravi Saraf Publications

Silver nanocubes were synthesized for the first time in large quantities on gold seed in the presence of a polyelectrolyte using microwave heating for 60–120 s. Our experiment indicates that the polyelectrolyte directs the growth of the particle in a specified crystallographic direction resulting in the faceted particle, i.e. a nanocube. The nanocubes are stable for at least 2 months in ambient conditions.

Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 4: Failure Analysis Of 10 Fractured Retaining Screws Retrieved From Three Patients, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino

Biomedical Engineering Faculty Research and Publications

Purpose: The aim of this study was to perform a failure analysis on fractured prosthetic retaining screws after long‐term use in vivo. Additionally, the study addresses the commonly asked question regarding whether complex repeated functional occlusal forces initiate fatigue‐type cracks in prosthetic retaining screws.

Materials and Methods: Ten fractured prosthetic retaining screws retrieved from three patients treated with fixed detachable hybrid prostheses were subjected to a failure analysis. In patients 1 and 2, the middle three retaining screws of the prostheses were found fractured at retrieval time after they had been in service for 20 and 19 months, respectively. In …

Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 3: Preload And Tensile Fracture Load Testing, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino

Biomedical Engineering Faculty Research and Publications

Purpose: The aim of this study was to determine the preload and tensile fracture load values of prosthetic retaining screws after long‐term use in vivo compared to unused screws (controls). Additionally, the investigation addressed whether the preload and fracture load values of prosthetic retaining screws reported by the manufacturer become altered after long‐term use in vivo.

Materials and Methods: For preload testing, 10 new screws (controls) from Nobel Biocare (NB) and 73 used retaining screws [58 from NB and 15 from Sterngold (SG)] were subjected to preload testing. For tensile testing, eight controls from NB and 58 used retaining screws …

Preparation And Characterization Of Tapioca Starch–Poly(Lactic Acid) Nanocomposite Foams By Melt Intercalation Based On Clay Type, Siew-Yoong Lee, Han Chen, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Abstract Tapioca starch (TS), poly(lactic acid) (PLA), and four different organoclays (Cloisite 10A, Cloisite 25A, Cloisite 93A and Cloisite 15A) were used to produce nanocomposite foams by melt-intercalation. Structural, thermal, physical and mechanical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and an Instron universal testing machine, respectively. The first XRD peaks for all four nanocomposite foams, were observed to shift to lower angles, indicating that intercalation occurred. The extent of intercalation depended on the type of organoclay and was exhibited in the sequence of Cloisite 10A > 25A > 93A > 15A. Glass transition temperatures …