Biomedical Engineering and Bioengineering Commons^™

A Fractal-Based Mathematical Model For Cancellous Bone Growth Considering The Hierarchical Nature Of Bone, Stephanie Marie Suhr

Browse all Theses and Dissertations

The hierarchical structure of bone alone is not comprehensive enough to provide morphological explanation of how the size and arrangement of the trabeculae within cancellous bone affect load distribution, particularly concerning deterioration of bone in elderly patients. The collagen network and hydroxyapatite play a large role in defining the shape of trabeculae in cancellous bone despite that the arrangement and size is seemingly random. The growth of plates and rods in cancellous bone is mainly due to loading and stress lines within the bone, but mathematical predictive models can be developed using fractal analysis to show how bone may grow …

Early Assessment Of Burn Severity In Human Tissue With Multi-Wavelength Spatial Frequency Domain Imaging, Chien Sing Poon

Browse all Theses and Dissertations

Burn injuries such as thermal burns, which are caused by contact with flames, hot liquids, hot surfaces, and other sources of high heat as well as chemical burns and electrical burns, affects at least 500,000 people in the United States, to which 45,000 of them require medical treatment and 3,500 of them result in death. It has also been reported that in the United States alone, fire results in a death approximately every three hours and an injury every 33 minutes. Early knowledge about burn severity can lead to improved outcome for patients. In this study, the changes in optical …

Optical Redox Imaging Of Metabolic Activity, Syed Anwar Hyder Zaidi

Browse all Theses and Dissertations

Fluorescence imaging can be used to determine tissue metabolism, which is an indication of the cellular functionality. Metabolic contrast is useful for the early detection of several medical conditions such as cancer, diabetes, lung diseases etc. This study aims to use fluorescence imaging to quantify NADH and FAD, which are cellular metabolic indicators. A parameter known as Redox ratio, can be used to study metabolic state of several tissue types and disease states. To quantify the Redox ratio, three fluorescence imaging systems were optimized to measure the fluorescence signal from NADH and FAD. The first system was a camera based …

Measuring Pulse Rate Variability During Motion Artifact With A Non-Contact, Multi-Imager Photoplethysmography System, Zachary Adam Kiehl

Browse all Theses and Dissertations

Non-contact imaging photoplethysmography is an exciting new field based on the principles of traditional photoplethysmography where viable signals can now be acquired without the use of contact equipment. Recent advances regarding non-contact imaging photoplethysmography have permitted a wide range of new possibilities focused on sensing the cardiopulmonary system. Physiological metrics such as pulse rate, respiration rate, and pulse rate variability can be obtained by current photoplethysmographic imaging methods. Although previous systems were challenged by head-motion artifacts, the mitigation of rigid head-motion artifacts has been demonstrated with a multi-imager design. This study investigated the feasibility and accuracy of pulse rate variability …

Left Ventricle Volume Reconstruction To Minimize Scanning Time: Slice-Fitting Method, Prateek Kalra

Browse all Theses and Dissertations

Assessment of left ventricle volume is usually done for diagnosis and prognosis of heart diseases. Slice-summation method is a standard method used to compute left ventricle volume where region of interest from several short axis (SA) slices are added. There are some limitations to this method, however. It requires short-axis slices to be taken parallel to the mitral valve plane from the base to apex. Moreover, scanning several short-axis slices is a tedious and time consuming process especially for studies that require several hundreds datasets. There are some existing methods to reconstruct left ventricle volume but most of them depend …

Reducing Error Rates In Intelligence, Surveillance, And Reconnaissance (Isr) Anomaly Detection Via Information Presentation Optimization, Donald Glen Church

Browse all Theses and Dissertations

In the ISR domain, time-critical decision-making and dealing with multiple information feeds places high demands on the human. When designing aids and tools, the decision maker must be taken into account. This research looks toward designing a decision aid based the personality type of the operator. The BFI is used to determine the impact of personality and decision aid type (graphical vs. textual) on performance. Results show Openness and Agreeableness to be the strongest single factors for decision aid impact on performance. A model was also developed to show how the human takes the information and relates it to a …

An Improved Adaptive Filtering Approach For Removing Artifact From The Electroencephalogram, Justin Ronald Estepp

Browse all Theses and Dissertations

The biophysics of volume conduction that enable electrophysiological data acquisition also result in the mixing of data sources including possible, undesirable noise sources at the electrode interface. This work specifically focuses on improving the performance of the recursive least-squares (RLS) adaptive filtering method for removing eye movement artifact from the electroencephalogram. In biophysically-inspired simulated data, the RLS algorithm is verified to produce results that are inferior to extended infomax independent component analysis (ICA), the most widely used artifact correction approach in this problem space, due to its non-linear filter phase response and the presence of bidirectional contamination, or cross-talk, resultant …

Evaluating Warehouse Strategies For Two-Product Class Distribution Planning, Bradley R. Guthrie

Browse all Theses and Dissertations

Distribution networks often manage products with varying life-cycles, where demand for some products is relatively stable throughout the year (basic products) and the demand for others is short-lived (fashion products). Beyond the coordination of inventory and transportation decisions, decisions at the warehouse must be considered as its resources are frequently shared by both product classes simultaneously. For this two-product class distribution planning problem, we focus on characterizing three real-world distribution strategies observed in industry and evaluating them based on total distribution cost and warehouse measures (e.g., workforce plan and workload variation) against a benchmark ILS-based heuristic. Experimental results suggest that …

Design Of A Low-Cost Wireless Nirs System With Embedded Linux And A Smartphone Interface, Diogo Da Silva Dias

Browse all Theses and Dissertations

Wireless near-infrared spectroscopy (NIRS) systems can help to reduce movement artifacts, and distraction due cables. Utilizing Embedded Linux (EL) can reduce size, development time, cost of a project and allow portability. The goal of this project is to develop a low-cost wireless small-sized NIRS system using EL and a Smartphone as the interface. This was achieved using a BeagleBone Black (BBB) with a deployed custom EL that: (1) controls two sources, (2) receives data from photodetectors (PDs), (3) processes, stores and transmits data via Bluetooth to an Android Smartphone. This device was implemented in under US$150 and its dimension was …

Neural Correlates Of Convergence Eye Movements In Convergence Insufficiency Patients Vs Normal Binocular Vision Controls: An Fmri Study, Chirag Bharatkumar Limbachia

Browse all Theses and Dissertations

Convergence Insufficiency is a binocular vision disorder, characterized by reduced ability of performing convergence eye movements. Absence of convergence causes, eye strain, blurred vision, doubled vision, headaches, and difficulty reading due frequent loss of place. These symptoms commonly occur during near work. The purpose of this study was to quantify neural correlates associated with convergence eye movements in convergence insufficient (CI) patients vs. normal binocular vision (NBV) controls, and to examine statistical differences between them. Functional magnetic resonance imaging (fMRI) scans were collected using a 3T Siemens scanner. A disparity-driven convergence task was designed using a standard block design approach, …

Measuring Brain Activation Through Functional Magnetic Resonance Imaging (Fmri) During Visual Task Learning, Mohd Saif Usmani

Browse all Theses and Dissertations

The purpose of this study is to understand the brain activity associated with learning a visual task by utilizing the applications of functional magnetic resonance imaging in cognitive neuroscience. The study was performed using two visual tasks referred to as aircraft and control, respectively. We compared the brain activation of these two visual tasks to understand the learning process of the participants. Fifteen young adults, ten males and five females, ranging in age from 19 to 35 years, participated in a ten-week study. Eight participants dropped out either voluntarily or were excluded for different reasons. The data analysis was completed …

Evaluation Of Functional Near Infrared Spectroscopy (Fnirs) For Assessment Of The Visual And Motor Cortices In Adults, Brenna Giacherio

Browse all Theses and Dissertations

Introduction: Functional near-infrared spectroscopy (fNIRS) is a relatively young technique in the field of medical imaging. As such, it has yet to be widely implemented for clinical use, despite its promising advantages. However, unlike fMRI-its much bulkier and costly counterpart-fNIRS has yet to be proven as a standalone imaging tool within a clinical setting, particularly that of ophthalmology or physical therapy.

Methods: Ten healthy young adults (23.8 ± 4.8 years) participated in the study. Activation of the visual cortex was achieved utilizing various reversing checkerboard stimuli across three data collection sessions for each participant. Further, activation of the motor cortex …

Segmentation And Analysis Of Mris Of Infants With Dysphagia, Irfaan A. Dar

Browse all Theses and Dissertations

Neonates are at a rapid stage of development from birth throughout childhood. Impairments to certain cortical areas can result in long lasting neuro-cognitive dysfunctions. Disorders to the swallowing neural pathways can have detrimental effects throughout life course since methods to provide nutrition can be comprised. Dysphagia, or the inability to swallow, can be caused by a multitude of reasons, chiefly neurological, but the underlying disruptions to the neural pathways are not defined. In this study we investigated the growth of multiple cortical areas involved in the swallowing pathway and categorized feeding outcomes with neural growth. Results showed that infants that …

Finite Element Simulation Of Skull Fracture Evoked By Fall Injuries, Anthony Vicini

Browse all Theses and Dissertations

This study presents novel predictive equations for von Mises stresses and deflection of bones in the frontal and lateral regions of the skull. The equations were developed based on results of a finite element model developed here. The model was validated for frontal and lateral loading conditions with input values mimetic to fall scenarios. Using neural network processing of the information derived from the model achieved R2 values of 0.9990 for both the stress and deflection. Based on the outcome of the fall victims, a threshold von Mises stress of 40.9 to 46.6 MPa was found to indicate skull fracture …

An Investigation Of Thermal Imaging To Detect Physiological Indicators Of Stress In Humans, Carl Brady Cross

Browse all Theses and Dissertations

Real-time, stand-off sensing of humans to detect emotional state would be valuable in many defense, security and medical scenarios. Using a multimodal sensor platform that incorporates high-resolution visible-wavelength and mid-wave infrared cameras and a millimeter-wave (mmW) radar system, the detection of physiological indicators of psychological stress is tested through laboratory experiments. Our approach focuses on thermal imaging to measure temperature patterns in distinct facial regions representative of underlying hemodynamic patterns. Experiments were designed to: 1) determine the ability of thermal imaging to detect high levels of psychological stress and assess responses to physical versus psychological stressors; 2) evaluate the fidelity …

Mobile Computing For Trauma And Surgical Care Continuous Education, Muhammad Y. Alamoud

Browse all Theses and Dissertations

In medical domain, mobile computing has proven to be convenient, effective, and productive. With varying screen sizes, there is a challenge to present the right information in the right format such that medical practitioners can access information quickly. In this thesis, we discuss how mobile computing can be used as a way of continuous education for medical practitioners in the field of trauma and surgical care, and provide design guidelines on how to effectively present information on different mobile form factors. The focus is on three screen sizes- 4.7, 7 and 10.1 in., and three interaction methods - dropdown, slide, …

Investigation Of The Utility Of Center Frequency In Electroencephalographic Classification Of Cognitive Workload Transitions, Jones Melissa

Browse all Theses and Dissertations

Successful classification of human cognitive workload is a vital component in identifying and avoiding potential performance deficits resulting from operator work overload. Previous research suggests that electroencephalogram (EEG) derived features, including center frequency, provide a robust signal which may be used to obtain highly accurate workload classification. The purpose of this work is to investigate evidence of physiological hysteresis and determine if center frequency improves a classifier's ability to correctly identify workload level. Results confirmed that including spectral data creates the most robust feature sets, while center frequency across all bands is equally reliable for classifying workload in the case …

Utility Of A Volume-Regulated Drive System For Direct Mechanical Ventricular Actuation, Benjamin A. Schmitt

Browse all Theses and Dissertations

Direct Mechanical Ventricular Actuation (DMVA) is a non-blood contacting cardiac assist device that augments ventricular function. The purpose of this study was to determine if a volume-regulated "hand pump" drive system and a pressure-regulated "switch tank" drive system provide equivalent levels of cardiac support. Canine (n=2) and swine (n=4) were instrumented for hemodynamic monitoring and intravascular echocardiography. DMVA support was assessed during both severe heart failure and fibrillation. Pump function was evaluated using hemodynamic measures to calculate stroke work. Myocardial function was assessed using echocardiographic speckle tracking to quantify strain rate. Results were compared between groups using paired t-tests. There …

Application Of The Human-Machine Interaction Model To Multiple Attribute Task Battery (Matb): Task Component Interaction And The Strategy Paradigm, Craig M. Walters

Browse all Theses and Dissertations

The Multiple-Attribute Task Battery (MATB) is composed of four simultaneously running components to which a human operator responds. A prior report has quantified information content as a machine input baud rate using the Hick-Hyman and Fitt's Laws for three of the four components and defines a strategy function. This report covers methods to quantify information content of the fourth component, creating a single metric which describes overall task complexity and evaluates human performance and strategy. Six MATB task-scenarios (combinations of two, three, or all four MATB components) each at two input baud rates are evaluated. Subjects were also provided with …

Optimization Of Wsu Total Ankle Replacement Systems, Bradley Jay Elliott

Browse all Theses and Dissertations

Total ankle arthroplasty (TAR) is performed in order to reduce the pain and loss of ambulation in patients with various forms of arthritis and trauma. Although replacement devices fail by a number of mechanisms, wear in the polyethylene liner constitutes one of the dominating failure modes. This leads to instability and loosening of the implant. Mechanisms that contribute to wear in the liners are high contact and subsurface stresses that break down the material over time. Therefore, it is important to understand the gait that generates these stresses. Methods to characterize and decrease wear in Ohio TARs have been performed …

System Optimization And Patient Translational Motion Correction For Reduction Of Artifacts In A Fan-Beam Ct Scanner, Zachary Gordon Lee Wise

Browse all Theses and Dissertations

In computed tomography (CT) systems, many different artifacts may be present in the reconstructed image. These artifacts can greatly reduce image quality. For our laboratory prototype CT system, a fan-beam/cone-beam focal high-resolution computed tomography (fHRCT) scanner, the major artifacts that affect image quality are distortions due to errors in the reconstruction algorithm's geometric parameters, ring artifacts caused by uncalibrated detectors, cupping and streaking created by beam hardening, and patient-based motion artifacts. Optimization of the system was required to reduce the effects of the first three artifact types, and an algorithm for correction of translational motion was developed for the last. …

Evaluation Of Interpolation And Registration Techniques In Magnetic Resonance Image For Orthogonal Plane Super Resolution Reconstruction, Amir Pasha Mahmoudzadeh

Browse all Theses and Dissertations

Super resolution reconstruction (SRR) combines several perspectives of an image (typically low resolution) in order to reconstruct a more complete and comprehensive (higher resolution) image. The aim is to use this concept on magnetic resonance imaging (MRI) data, for which the standard is to scan in several-plane orientation in a 2D fashion. As a result, clinical MRI, functional MRI (FMRI), diffusion weighted imaging (DWI)/diffusion tensor imaging (DTI), and MR angiography (MRA) tend to have high in- plane resolution but low resolution in the slice-select direction. By combining the 2 scans of the orthogonal plane, new 3D images can be reconstructed. …

Influence Of Design Parameters On Cup-Stem Orientations For Impingement Free Range Of Motion In Hip Implants, Dishita Prakashbhai Patel

Browse all Theses and Dissertations

The objective of this investigation is to determine the optimum positions of the prosthesis in total hip arthroplasty that produce least amount of impingement. Theoretical ranges of six basic hip motions were determined under walking, stumbling, internal rotation at 90 flexion and external rotation at 0 extension with 15 abduction, using mathematical models and validated for impingement using finite element analysis. A generalized approach, where impingement does not occur, was developed in this study to understand influence of design parameters such as head-neck ratio, neck-shaft angle, oscillation angle, and stem offset on cup-stem orientations such as cup inclination, cup anteversion, …

A Validation Of A Prototype Dry Electrode System For Electroencephalography, Jason Monnin

Browse all Theses and Dissertations

Current physiologically-driven operator cognitive state assessment technology relies primarily on electroencephalographic (EEG) signals. Traditionally, gel-based electrodes have been used; however, the application of gel-based electrodes on the scalp requires expertise and a considerable amount of preparation time. Additionally, discomfort can occur from the abrasion of the scalp during preparation, and the electrolyte will also begin to dry out over extended periods of time. These drawbacks have hindered the transition of operator state assessment technology into an operational environment. QUASAR, Inc., (San Diego, CA) has developed a prototype dry electrode system for electroencephalography that requires minimal preparation. A comparison of the …

A Probabilistic Assessment Of Vertebral Cortical Bone Fracture Of Intraosteonal Structures, Isaac Graham Mabe

Browse all Theses and Dissertations

Cortical bone is a porous structure. The presence of these pores creates the possibility of a local overstressed area that has the likelihood of premature failure. Some failure modes of the vertebral endplates, for example subsidence which occurs at rates as high as 77 percent, can be better predicted with further understanding of failure mechanisms and the ability to predict those mechanisms. A probabilistic assessment of the pore size and its contribution to the fracture toughness has not been investigated in the cortical shell of the vertebral endplates. This research develops a probabilistic model that has the ability to determine …

Anthropometric Analysis Of The Cervical Spine, Susan Hueston

Browse all Theses and Dissertations

An understanding of the dimensional anatomy of the cervical spine is necessary in order to help diagnose disease, deformity, injury, and device development. Previous investigation has been completed utilizing cadavers, X-rays and other imaging techniques. This research utilized computer tomography images from the trauma registry at Miami Valley Hospital in Dayton, Ohio to complete an anthropometric study of the cervical spine. Linear mathematical models were developed to investigate the relationships present in the dimensional anatomy of the cervical spine. New measurements were completed on subjects of both Caucasian and African American descent and of both genders. An approximation of the …

Investigation Of Variability In Cognitive State Assessment Based On Electroencephalogram-Derived Features, Samantha Lokelani Crossen

Browse all Theses and Dissertations

To implement adaptive aiding in modern aviation systems there is a need for accurate and reliable classification of cognitive workload. Using electroencephalogram (EEG)-derived features, it has been reported that an Artificial Neural Network (ANN) can achieve 95% or higher classification accuracy on the same day for an individual operator, but only 70% or less on a different day. To gain a further insight into this discrepancy, data from a previous study was utilized to study the classification variability. The EEG-derived features were first calculated by spectral power estimation. The variability was then analyzed by performing cognitive workload classification in which …

Selective Automatic Image Feature Detection, Aijing Wang

Browse all Theses and Dissertations

To allow automatic assessment of computed tomography (CT) images of long bones, the identification of the location of regions of interest is important. The distance between the distal and proximal styloids may act as reference points for bone length; however, the locations of the distal and proximal growth plates represent further important reference features. The current methods to locate these feature positions are manual. In this project, we attempt to find these feature positions automatically.

A CT data set was split into two subsets, a development set, and a validation set. We first extracted basic information from the stack and …

Predicting Vigilance Performance Under Transcranial Direct Current Stimulation, Nathaniel Reese Bridges

Browse all Theses and Dissertations

A brain stimulation technology called transcranial direct current stimulation (tDCS) may potentially mitigate the vigilance decrement. To practically use such technology, however, a model is necessary that indicates vigilance performance, both when stimulation is being applied and not applied. To address this issue, the author developed models capable of predicting vigilance performance in real and control stimulation conditions using previous tDCS-study data. The "all possible combinations" regression method produced over 200 models, later screened to 10. The model with the best average %error (11.49 ± 0.10) used left hemispheric cerebral blood flow velocity (CBFVL) as its sole input term-accounting for …

Semi-Automated Dental Cast Analysis Software, Mathew Thomas

Browse all Theses and Dissertations

Dental casts have been used extensively to study almost all aspects of the human dentition. These aspects varied from the study of tooth form and morphology, inheritance and genetics, growth and development, occlusion, arch alignment and crowding to mathematical determination of dental arch form.

The aim of this project was to develop a tool to semi-automate the measurement of dental casts that would be precise, accurate and efficient. Measurements include tooth widths, arch lengths and widths, angle of rotation and crown area for each tooth.

The task was divided into two different parts: first, the development of semi-automatic software to …