Biomechanical Engineering Commons^™

The Effect Of Mechanics On Migration, Morphology And Matrix Production By Primary Human Corneal Fibroblasts: Long-Term Dynamic Observation, Ramin Zareian

Mechanical Engineering Dissertations

Mechanical load is believed to play a critical role in tissue formation, growth, maintenance, and disease in vertebrate animals. Although many studies have investigated the effect of mechanical stimuli on biological processes, the dynamics of these processes have not been closely explored. Live long-term observation of the collective behavior of Primary Human Corneal Fibroblasts (PHCFs) exposed to mechanical load could provide important insight into the mechanisms used by fibroblasts while they migrate, produce multilayered constructs and manage collagen deposition during the synthesis of organized ExtraCellular Matrix (ECM). Previous studies have shown that PHCFs produce locally organized and aligned ECM similar ...

An Investigation Of Subaxial Cervical Spine Trauma And Surgical Treatment Through Biomechanical Simulation And Kinematic Analysis, Stewart D. Mclachlin

University of Western Ontario - Electronic Thesis and Dissertation Repository

In vitro biomechanical investigations can help to identify changes in subaxial cervical spine (C3-C7) stability following injury, and determine the efficacy of surgical treatments through controlled joint simulation experiments and kinematic analyses. However, with the large spectrum of cervical spine trauma, a large fraction of the potential injuries have not been examined biomechanically. This includes a lack of studies investigating prevalent flexion-distraction injuries. Therefore, the overall objective of this thesis was to investigate the changes in subaxial cervical spine kinematic stability with simulated flexion-distraction injuries and current surgical instrumentation approaches using both established and novel biomechanical techniques.

Three in vitro ...

Mechanics Of Blast Loading On Post-Mortem Human And Surrogate Heads In The Study Of Traumatic Brain Injury (Tbi) Using Experimental And Computational Approaches, Shailesh Govind Ganpule

Engineering Mechanics Dissertations & Theses

Blast induced neurotrauma (BINT) has been designated as the “signature injury” to warfighters in the recent military conflicts. The occurrence of traumatic brain injury (TBI) in blasts is controversial in the medical and scientific communities because the manifesting symptoms occur without visible injuries. Whether the primary blast waves alone can cause mechanical insult that is comparable to existing traumatic brain injury thresholds is still an open question, and this work is aimed to address this issue.

In the first part of this dissertation, mechanics of primary blast loading on Realistic Explosive Dummy (RED) head with and without helmets is studied ...

Stress And Strain Adaptation In Load-Dependent Remodeling Of The Embryonic Left Ventricle, Christine Buffinton

Faculty Journal Articles

Altered pressure in the developing left ventricle (LV) results in altered morphology and tissue material properties. Mechanical stress and strain may play a role in the regulating process. This study showed that confocal microscopy, three-dimensional reconstruction, and finite element analysis can provide a detailed model of stress and strain in the trabeculated embryonic heart. The method was used to test the hypothesis that end-diastolic strains are normalized after altered loading of the LV during the stages of trabecular compaction and chamber formation. Stage-29 chick LVs subjected to pressure overload and underload at stage 21 were reconstructed with full trabecular morphology ...

Optode Based Sensors For Biological Applications, John Dubach

Mechanical Engineering Dissertations

Optode based sensors present a novel approach for the development of new tools to make concentration measurements in biology. Currently measurements of cellular concentrations are performed with fluorescence molecular probes that optically report concentrations from within cells. However, these probes are capable of measuring the concentration of a few ions, which limits the understanding of complete cellular function. Electrophysiology measurements are also used to determine cellular ion channel function, but do not provide specificity of ion activity, requiring the uses chemicals that alter overall cellular function. In other biological measurements, concentration measurements of the blood require blood removal from the ...

Mechano-Regulation Of Mandibular Bone Development And Peri-Implant Osseointegration, Hsuan-Yu Chou

Mechanical Engineering Dissertations

Bone remodeling and bone healing are both complex biological processes that involve well-coordinated cellular activities. Mechanical loading is believed to influence the cellular responses during the development, maintenance, adaptation, and repair of bone. The works contained within this dissertation are aimed to investigate that the role of mechanics plays in the (1) mandibular bone development, (2) bone remodeling around dental implant, and (3) bone healing around dental implant. Regulatory algorithms of bone remodeling and bone healing are implemented in the finite element models.

In the first part of this work, the mandibular bone is shown to be determined by bone ...

Optimal Inertial Sensor Placement And Motion Detection For Epileptic Seizure Patient Monitoring, Babak Kamalizonouzi

Electronic Thesis and Dissertation Repository

Use of inertial sensory systems to monitor and detect seizure episodes in patients suffering from epilepsy is investigated via numerical simulations and experiments. Numerical simulations employ a mathematical model that is able to predict human body dynamic responses during a typical epileptic seizure. An optimized inertial sensor placement procedure is developed to address achievement of highest possible sensing resolution in determining angular accelerations with minimal errors. In addition, a joint torque estimation procedure is formulated to assist in the future development of a possible detection scheme. Experimental motion data obtained from an epileptic seizure patient as well as a healthy ...

Predictive Musculoskeletal Simulation Using Optimal Control: Effects Of Added Limb Mass On Energy Cost And Kinematics Of Walking And Running, Antonie J. Van Den Bogert, Maarten Hupperets, Heiko Schlarb, Berthold Krabbe

Mechanical Engineering Faculty Publications

When designing sports equipment, it is often desirable to predict how certain design parameters will affect human performance. In many instances, this requires a consideration of human musculoskeletal mechanics and adaptive neuromuscular control. Current computational methods do not represent these mechanisms, and design optimization typically requires several iterations of prototyping and human testing. This paper introduces a computational method based on musculoskeletal modeling and optimal control, which has the capability to predict the effect of mechanical equipment properties on human performance. The underlying assumption is that users will adapt their neuromuscular control according to an optimality principle, which balances task ...

Biomechanical Modeling For Lung Tumor Motion Prediction During Brachytherapy And Radiotherapy, Zahra Shirzadi

Electronic Thesis and Dissertation Repository

A novel technique is proposed to develop a biomechanical model for estimating lung’s tumor position as a function of respiration cycle time. Continuous tumor motion is a major challenge in lung cancer treatment techniques where the tumor needs to be targeted; e.g. in external beam radiotherapy and brachytherapy. If not accounted for, this motion leads to areas of radiation over and/or under dosage for normal tissue and tumors. In this thesis, biomechanical models were developed for lung tumor motion predication in two distinct cases of lung brachytherapy and lung external beam radiotherapy. The lung and other relevant ...

Design, Analysis And Testing Of Haptic Feedback System For Laparoscopic Graspers In In Vivo Surgical Robots, Nikhil Salvi

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Laparo-Endoscopic Single Site (LESS) Robotics Surgery is an advanced technology in the field of Minimally Invasive Surgery (MIS). The LESS surgical robots significantly improve the surgeon’s accuracy, dexterity and visualization, and reduce the invasiveness of surgical procedure results in faster recovery time and improved cosmetic results. In a standard robotic endosurgery, the palpation of tissues is performed by laparoscopic graspers located at the end effectors. The master-slave configuration in robotic surgery leads in remote access to the operation site. Therefore, surgeon’s ability to perceive valuable sensory information is severely diminished. Sensory information such as haptics, which is essential ...

Investigation Of In-Vivo Hindfoot And Orthotic Interactions Using Bi-Planar X-Ray Fluoroscopy, Kristen M. Bushey

Electronic Thesis and Dissertation Repository

A markerless RSA method was used to determine the effect of orthotics on the normal, pes planus and pes cavus populations. Computed tomography (CT) was used to create bone models that were imported into the virtual environment. Joint coordinate systems were developed to measure kinematic changes in the hindfoot during weight-bearing gait and quiet standing. The objectives of this thesis were to (1) implement a fluoroscopy-based markerless RSA system on the foot, (2) determine the effect of various orthotics at midstance of fully weight-bearing dynamic gait, and (3) determine the effect of orthotics as measured using three different techniques. Every ...

Prediction Of Articular Cartilage Remodeling During Dynamic Compression With A Finite Element Model, Kevin Akira Yamauchi

Master's Theses and Project Reports

First, an in vitro growth experiment was performed to test the hypothesis that applying dynamic unconfined compression during culture produces het- erogeneous remodeling in newborn bovine articular cartilage explants. Het- erogeneous measures of cartilage microstructure were obtained by biochemical assays and quantified polarized light microscopy. Significant differences were measured between the GAG content in the inner and outer portions of the sam- ples stimulated with dynamic unconfined compression. The COL fiber network was found to be more highly aligned in the inner portion of the sample than in the peripheral region.

Next, a poroelastic finite element model with a remodeling ...

Design And Testing Of A Low Cost Prosthetic Foot, Shalan Ertis, John Kearns, Seija Maniskas

Mechanical Engineering

No abstract provided.

In-Vivo Investigation Of The Medial Longitudinal Arch Of The Foot And Orthotic Interactions Using Bi-Planar Fluoroscopy, Megan E.R. Balsdon

Electronic Thesis and Dissertation Repository

Orthotic devices are a conservative treatment for common disorders of the foot and ankle such as pes planus and pes cavus. It is thought that orthotics change the kinematics of the foot by applying forces and constraint on the plantar surface, which can act to change body biomechanics and correct for malalignment in the legs and trunk. This thesis compares the angle of the medial longitudinal arch (MLA) between three foot types: pes planus (low arch), pes cavus (high arch) and normal arch, during barefoot and shoed walking, and walking with orthotics. In-vivo bi-planar fluoroscopy was used with markerless radiostereometric ...

Hydraulically Driven Mechanical Representation Of A Biological System, Andrea Argouarch, Michael Mceachern, Brandon Parham

Biomedical Eng/General Eng.

No abstract provided.

Viscoelastic Anisotropic Finite Element Mixture Model Of Articular Cartilage Using Viscoelastic Collagen Fibers And Validation With Stress Relaxation Data, Matthew Alexander Griebel

Master's Theses and Project Reports

Experimental results show that collagen fibers exhibit stress relaxation under tension and a highly anisotropic distribution. To further develop the earlier model of Stender [1], the collagen constituent was updated to reflect its intrinsic viscoelasticity and anisotropic distribution, and integrated with an existing mixture model with glycosaminoglycans and ground substance matrix. A two-term Prony series expansion of the quasi-linear viscoelastic model was chosen to model the viscoelastic properties of the collagen fibers. Material parameters were determined by using the simplex method to minimize the sum of squared errors between model results and experimental stress relaxation data of tissue in tension ...