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Biomedical Engineering and Bioengineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Virginia Commonwealth University

2013

Articles 1 - 16 of 16

Full-Text Articles in Biomedical Engineering and Bioengineering

The Design And Validation Of A Computational Rigid Body Model For Study Of The Radial Head, Cassandra Woodcock Dec 2013

The Design And Validation Of A Computational Rigid Body Model For Study Of The Radial Head, Cassandra Woodcock

Theses and Dissertations

Rigid body modeling has historically been used to study various features of the elbow joint including both physical and computational models. Computational modeling provides an inexpensive, easily customizable, and effective method by which to predict and investigate the response of a physiological system to in vivo stresses and applied perturbations. Utilizing computer topography scans of a cadaveric elbow, a virtual representation of the joint was created using the commercially available MIMICS(TM) and SolidWorks(TM) software packages. Accurate 3D articular surfaces, ligamentous constraints, and joint contact parameters dictated motion. The model was validated against two cadaveric studies performed by Chanlalit et al. …

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Localization Of Auditory Spatial Targets In Sighted And Blind Subjects, Richard Nuckols Dec 2013

Localization Of Auditory Spatial Targets In Sighted And Blind Subjects, Richard Nuckols

Theses and Dissertations

This research was designed to investigate the fundamental nature in which blind people utilize audible cues to attend to their surroundings. Knowledge on how blind people respond to external spatial stimuli is expected to assist in development of better tools for helping people with visual disabilities navigate their environment. There was also interest in determining how blind people compare to sighted people in auditory localization tasks. The ability of sighted individuals, blindfolded individuals, and blind individuals in localizing spatial auditory targets was assessed. An acoustic display board allowed the researcher to provide multiple sound presentations to the subjects. The subjects’ …

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Examination Of The Effect Of Different Training Metrics On Performance Of A Minimally Invasive Surgery Transfer Task, Cristofer Madera Dec 2013

Examination Of The Effect Of Different Training Metrics On Performance Of A Minimally Invasive Surgery Transfer Task, Cristofer Madera

Theses and Dissertations

The purpose of this experiment was to determine if there existed techniques to more efficiently train prospective surgeons the skills necessary to capably perform minimally invasive surgical procedures. Also, we wanted to know if trainees could be pushed to cognitively define a laparoscopic environment with a novel hand-eye relationship. To explore these questions, a simulation was setup wherein subjects would perform a laparoscopic transfer task and receive active feedback during training. Different subjects would receive different metrics as feedback and a comparison would be made between subjects with respect to standard metrics. Results of this experiment show that all subjects …

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Patient-Specific Modeling Of Adult Acquired Flatfoot Deformity Before And After Surgery, Edward Meade Spratley Dec 2013

Patient-Specific Modeling Of Adult Acquired Flatfoot Deformity Before And After Surgery, Edward Meade Spratley

Theses and Dissertations

The use of computational modeling is an increasingly commonplace technique for the investigation of biomechanics in intact and pathological musculoskeletal systems. Moreover, given the robust and repeatable nature of computer simulation and the prevalence of software techniques for accurate 3-D reconstructions of tissues, the predictive power of these models has increased dramatically. However, there are no patient-specific kinematic models whose function is dictated solely by physiologic soft-tissue constraints, articular shape and contact, and without idealized joint approximations. Moreover, very few models have attempted to predict surgical effects combined with postoperative validation of those predictions. Given this, it is not surprising …

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Spectral Analysis Of Nonstationary Heart Rate Of Neonates Receiving Therapeutic Hypothermia Treatment, Tareq Al-Shargabi Nov 2013

Spectral Analysis Of Nonstationary Heart Rate Of Neonates Receiving Therapeutic Hypothermia Treatment, Tareq Al-Shargabi

Theses and Dissertations

We studied Heart Rate Variability (HRV) evolution during therapeutic hypothermia in newborns with hypoxic ischemic encephalopathy (HIE) using spectral analysis. We hypothesized that HRV measures are predictive of neurological outcome in babies with HIE. Non-stationarity in the data causes inaccurate quantification of the spectral power. A modification was proposed to power spectral analysis approach to mitigate the effect of non-stationarity. The modified and the standard approaches were applied to cardiac beat-to-beat intervals of newborns receiving hypothermia treatment. The performance of the approaches in distinguishing the RRi dynamics of two groups of newborns was assessed using area under the receiver operating …

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The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter Aug 2013

The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter

Theses and Dissertations

Graphical information presented as pictures, graphs, maps, and the like are an important media for relaying knowledge and are a fundamental means of education rarely experienced by people who are blind or have a severe visual impairment. This thesis presents the design, development and testing of a multiple finger, haptic matrix dynamic display device capable of relaying graphical information through simulated textures. The design is based on user perception studies that determined which hand constraints provided the best tradeoff between simplicity of design, accuracy and time to answer. The best design was one that incorporated multiple fingers in close proximity …

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Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu Jul 2013

Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu

Theses and Dissertations

Common therapy for diabetes mellitus is subcutaneous administration of insulin that is subject to serious disadvantages, such as patient noncompliance and occasional hypoglycemia. Hence, oral administration of insulin could be more convenient and serve as a desired route. However, oral administration of insulin is severely limited by the low bioavailability of insulin through the gastrointestinal tract. In this study, a semi-interpenetrating network gelatin fiber scaffold (sIPN GF) was fabricated for oral mucosal delivery of insulin as an alternative route. This sIPN GF was engineered from an electrospun gelatin fiber scaffold (GF), which was further crosslinked with polyethylene glycol diacrylate (PEG-DA) …

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The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov Jul 2013

The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov

Theses and Dissertations

This thesis investigated the effect of visuomotor and working memory 1) task difficulty and 2) multitasking on dynamic functional connectivity in the brain. Studies have only recently begun to investigate functional connectivity within the scope of concurrent dual task or varying task difficulty conditions (Cocchi, Zalesky, et al. 2011; Rietschel et al. 2012). A series of EEG recordings were conducted during execution of visuomotor or working memory tasks within a novel paradigm using BCI2VR custom MATLAB toolbox. Functional connectivity was correlated with task-related coherence (TRCoh) analysis between two task conditions involving either variation in task difficulty or concurrent execution during …

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Modernization Of The Mock Circulatory Loop: Advanced Physical Modeling, High Performance Hardware, And Incorporation Of Anatomical Models, Charles Taylor May 2013

Modernization Of The Mock Circulatory Loop: Advanced Physical Modeling, High Performance Hardware, And Incorporation Of Anatomical Models, Charles Taylor

Theses and Dissertations

A systemic mock circulatory loop plays a pivotal role as the in vitro assessment tool for left heart medical devices. The standard design employed by many research groups dates to the early 1970's, and lacks the acuity needed for the advanced device designs currently being explored. The necessity to update the architecture of this in vitro tool has become apparent as the historical design fails to deliver the performance needed to simulate conditions and events that have been clinically identified as challenges for future device designs. In order to appropriately deliver the testing solution needed, a comprehensive evaluation of the …

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Automatic Segmentation Of Pressure Images Acquired In A Clinical Setting, Anathea Pepperl May 2013

Automatic Segmentation Of Pressure Images Acquired In A Clinical Setting, Anathea Pepperl

Theses and Dissertations

One of the major obstacles to pressure ulcer research is the difficulty in accurately measuring mechanical loading of specific anatomical sites. A human motion analysis system capable of automatically segmenting a patient's body into high-risk areas can greatly improve the ability of researchers and clinicians to understand how pressure ulcers develop in a hospital environment. This project has developed automated computational methods and algorithms to analyze pressure images acquired in a hospital setting. The algorithm achieved 99% overall accuracy for the classification of pressure images into three pose classes (left lateral, supine, and right lateral). An applied kinematic model estimated …

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The Design And Validation Of A Computational Model Of The Human Wrist Joint, Afsarul Mir May 2013

The Design And Validation Of A Computational Model Of The Human Wrist Joint, Afsarul Mir

Theses and Dissertations

Advancements in computational capabilities have allowed researchers to turn towards modeling as an efficient tool to replicate and predict outcomes of complex systems. Computational models of the musculoskeletal system have gone through various iterations with early versions employing dramatic simplifications. In this work, a three-dimensional computational model of the wrist joint was developed. It accurately recreated the skeletal structures of the hand and wrist and represented the constraints imposed by soft tissue structures like ligaments, tendons, and other surrounding tissues. It was developed to function as a tool to investigate the biomechanical contributions of structures and the kinematic response of …

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Tissue Engineering Composite Biomimetic Gelatin Sponges For Bone Regeneration, Isaac Rodriguez May 2013

Tissue Engineering Composite Biomimetic Gelatin Sponges For Bone Regeneration, Isaac Rodriguez

Theses and Dissertations

The field of tissue engineering aims to develop viable substitutes with the ability to repair and regenerate the functions of damaged tissue. Common practices to supplement bone regeneration in larger defects include bone graft biomaterials such as autografts, allografts, xenografts, and synthetic biomaterials. Autologous bone grafting is the current gold-standard procedure used to replace missing or damaged bone. However, these grafts have disadvantages such as donor site morbidity, limited availability, and the need for a secondary surgery. The focus of this study is to tissue engineer a lyophilized gelatin composite sponge composed of hydroxyapatite (HA), chitin whiskers (CW), and preparations …

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The Mechanotransduction Of Primary Cilia In Tumor Progression Of Lung Adenocarcinoma, Sagar Patel Apr 2013

The Mechanotransduction Of Primary Cilia In Tumor Progression Of Lung Adenocarcinoma, Sagar Patel

Theses and Dissertations

The objective of this study was to investigate primary cilia and their mechanotransduction role in lung adenocarcinoma tumor progression. The main focus investigated the effect of primary cilia on cell cycle progression, survival, adhesion and migration analysis of these cells and the role of sonic hedgehog signaling pathway in mechanotransduction. Human Non-Small Cell Lung Cancer (NSCLC) adenocarcinoma biopsies contain more primary cilia than non-tumor lung sections. To observe the effects of primary cilia presence in lung cancer cells in-vitro, formation of primary cilia is inhibited using small interfering RNA. A549 cells with intact primary cilia observe less cell cycle progression …

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A Hierarchical Method For Removal Of Baseline Drift From Biomedical Signals: Application In Ecg Analysis, Yurong Luo, Rosalyn H. Hargraves, Ashwin Belle, Ou Bai, Xuguang Qi, Kevin R. Ward, Michael Paul Pfaffenberger, Kayvan Najarian Jan 2013

A Hierarchical Method For Removal Of Baseline Drift From Biomedical Signals: Application In Ecg Analysis, Yurong Luo, Rosalyn H. Hargraves, Ashwin Belle, Ou Bai, Xuguang Qi, Kevin R. Ward, Michael Paul Pfaffenberger, Kayvan Najarian

Computer Science Publications

Noise can compromise the extraction of some fundamental and important features from biomedical signals and hence prohibit accurate analysis of these signals. Baseline wander in electrocardiogram (ECG) signals is one such example, which can be caused by factors such as respiration, variations in electrode impedance, and excessive body movements. Unless baseline wander is effectively removed, the accuracy of any feature extracted from the ECG, such as timing and duration of the ST-segment, is compromised. This paper approaches this filtering task from a novel standpoint by assuming that the ECG baseline wander comes from an independent and unknown source. The technique …

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Amelogenin Peptide Extract Increases Differentiation And Angiogenic And Local Factor Production And Inhibits Apoptosis In Human Osteoblasts, Rene Olivares-Navarrete, Sharon L. Hyzy, Argelia Almaguer-Flores, Corinna Mauth, Anja C. Gemperli, Barbara D. Boyan, Zvi Schwartz Jan 2013

Amelogenin Peptide Extract Increases Differentiation And Angiogenic And Local Factor Production And Inhibits Apoptosis In Human Osteoblasts, Rene Olivares-Navarrete, Sharon L. Hyzy, Argelia Almaguer-Flores, Corinna Mauth, Anja C. Gemperli, Barbara D. Boyan, Zvi Schwartz

Biomedical Engineering Publications

Enamel matrix derivative (EMD), a decellularized porcine extracellular matrix (ECM), is used clinically in periodontal tissue regeneration. Amelogenin, EMD’s principal component, spontaneously assembles into nanospheres in vivo, forming an ECM complex that releases proteolytically cleaved peptides. However, the role of amelogenin or amelogenin peptides in mediating osteoblast response to EMD is not clear. Human MG63 osteoblast-like cells or normal human osteoblasts were treated with recombinant human amelogenin or a 5 kDa tyrosine-rich amelogenin peptide (TRAP) isolated from EMD and the effect on osteogenesis, local factor production, and apoptosis assessed. Treated MG63 cells increased alkaline phosphatase specific activity and levels of …

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Automated Detection Of Incomplete Exhalation As An Indirect Detection Of Auto-Peep On Mechanically Ventilated Adults, Nyimas Arief Jan 2013

Automated Detection Of Incomplete Exhalation As An Indirect Detection Of Auto-Peep On Mechanically Ventilated Adults, Nyimas Arief

Theses and Dissertations

Auto-PEEP is auto positive end-expiratory pressure due to excessive amounts of alveolar gas produced by sustained recurrent incomplete exhalation. Incomplete exhalation occurs when the exhaled breath never reaches a flow rate of 0 L/min. The objective of this dissertation is to develop an automated detection system of auto-PEEP through incomplete exhalation as revealed by ventilator graphics for mechanically ventilated adults. Auto-PEEP can cause adverse effects if allowed to linger and if not quickly identified. An automated detection system will be instrumental in helping to quickly identify auto-PEEP. A computerized algorithm was developed to detect incomplete exhalation based on the following …

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