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Biomedical Engineering and Bioengineering Commons™
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- Keyword
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- Biological sciences (7)
- Applied sciences (6)
- Health and environmental sciences (3)
- AMPK (1)
- Aerial robotics (1)
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- Ankle moment (1)
- Biologically-inspired robots (1)
- Cartilage injury (1)
- Chondrocytes (1)
- Compliant joint/mechanism (1)
- Damage mechanisms (1)
- Data logging (1)
- Elastography (1)
- FAK (1)
- High-capacity (1)
- Joint moment (1)
- Kolsky bar (1)
- Legged (1)
- Magnetic resonance imaging (1)
- Mechanotransduction (1)
- Medial collateral ligament (1)
- MicroSD (1)
- Phase contrast imaging (1)
- Post-traumatic osteoarthritis (1)
- Rate sensitivity (1)
- Relaxivity (1)
- Running (1)
- SRC (1)
- Slip (1)
- Stability (1)
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Articles 1 - 15 of 15
Full-Text Articles in Biomedical Engineering and Bioengineering
The Role Of Mechanical Loading In Chondrocyte Signaling Pathways, Qiaoqiao Wan
The Role Of Mechanical Loading In Chondrocyte Signaling Pathways, Qiaoqiao Wan
Open Access Dissertations
Chondrocytes are a predominant cell type present in articular cartilage, whose integrity is jeopardized in joint degenerative diseases such as osteoarthritis (OA). In the chondrocytes of patients with OA, the elevated levels of inflammatory cytokines such as interleukin 1β (IL1β) and tumor necrosis factor α (TNFα) have been reported. These cytokines contribute to degradation of cartilage matrix by increasing activities of proteolytic enzymes. In addition to their contribution to proteolytic enzymes, these cytokines adversely affect anabolic activity of chondrocytes by inhibiting the production of proteoglycans and type II collagen. Therefore, blocking the action of these cytokines is a potential strategy …
A Three Constituent Mixture Theory Model Of Cutaneous And Subcutaneous Tissue In The Context Of Neonatal Pressure Ulcer Etiology And Prevention, Anne Dye Zakrajsek
A Three Constituent Mixture Theory Model Of Cutaneous And Subcutaneous Tissue In The Context Of Neonatal Pressure Ulcer Etiology And Prevention, Anne Dye Zakrajsek
Open Access Dissertations
Localized ischemia, impaired interstitial fluid flow, and sustained mechanical loading of cells have all been hypothesized as mechanisms of pressure ulcer (PrU) etiology. Time-varying loading has experimentally been shown to increase fluid flow in human skin in vivo. Towards the design of prophylactic protocols and treatment modalities for PrU management there is a need for an analytical model to investigate the local fluid flow characteristics of skin tissue under time-varying loading. In this study, a triphasic mixture theory model with constituents of extracellular matrix, interstitial fluid, and blood was calibrated and validated and used to investigate stress and fluid velocity …
Characterization And Evaluation Of Head Impact Sensors And Varsity Football Helmets, Brian R. Cummiskey
Characterization And Evaluation Of Head Impact Sensors And Varsity Football Helmets, Brian R. Cummiskey
Open Access Theses
An increased understanding of the effects of brain injury in recent years has led to greater attention being given to the topic. A desire to investigate the causal agents of these injuries in athletes has led to the development and use of several devices that track head impacts as well as improving helmet technology to protect players from said impacts. In order to determine which devices are able to best measure head impacts, a Hybrid III headform was used to quantify the accuracy for translational and angular accelerations. Testing was performed by means of administering impacts to a helmet on …
Measurement, Characterization, And Effects Of Head Impacts In Women's Soccer, Emily C. Mccuen
Measurement, Characterization, And Effects Of Head Impacts In Women's Soccer, Emily C. Mccuen
Open Access Theses
The potential for long term neurological deficits resulting from repetitive head trauma is a major concern for collision sport athletes. Research conducted on football played has found neurophysiologic changes in the absence of concussion in athletes as early as high school age. Given that female soccer players show the highest rate of concussion for female athletes and a higher rate of concussion than their male counterparts, it is important to characterize the types of impacts female soccer athletes receive and assess female soccer athletes for neurophysiologic changes due to these impacts. This work paired head impact sensors with functional MRI …
Magnetic Manipulation And Multimodal Imaging For Single Cell Direct Mechanosensing, Robert L. Wilson
Magnetic Manipulation And Multimodal Imaging For Single Cell Direct Mechanosensing, Robert L. Wilson
Open Access Theses
The study of internal mechanics of single cells is paramount to understand mechanisms of mechanoregulation. External loading and cell-mediated force generation result in changes in cell shape, rheology, and the deformation of subcellular structures such as the nucleus. Moreover, alterations in the processes that regulate these responses have been further correlated to specific pathologies. Cellular deformation is often studied through application of forces in the environment of the cell, relying on strain and stress transfer through focal adhesions and the cytoskeletal system. However, the transfer of these external forces to internal mechanics can introduce uncertainties in the interpretation of subcellular …
Unveiling The Mechanical Behavior Of The Rod-Like Microstructure In The Radular Teeth Of Cryptochiton Stelleri, Enrique Escobar De Obaldia
Unveiling The Mechanical Behavior Of The Rod-Like Microstructure In The Radular Teeth Of Cryptochiton Stelleri, Enrique Escobar De Obaldia
Open Access Dissertations
Natural ceramics provided with high volume fractions of mineralized materials that are surrounded by a weak organic interface combine the stiff mechanical behavior of building blocks, like hydroxyapatite or aragonite, and the compliance of the organic surroundings. Unique mechanical properties (e.g. light density and toughness) distinguish bio-composites from common engineering materials. A key example is the highly mineralized shell of the radular teeth of the Crypochiton stelleri. Nature has provided the radular teeth with a highly oriented rod-like microstructure of nano-scale dimensions embedded in a matrix of chitin sheaths. Compared to other biological materials, the external iron oxide layer of …
Intranuclear Strain Measured By Iterative Warping In Cells Under Mechanical And Osmotic Stress, Jonathan T Henderson
Intranuclear Strain Measured By Iterative Warping In Cells Under Mechanical And Osmotic Stress, Jonathan T Henderson
Open Access Dissertations
The nucleus is a membrane bound organelle and regulation center for gene expression in the cell. Mechanical forces transfer to the nucleus directly and indirectly through specific cellular cytoskeletal structures and pathways. There is increasing evidence that the transferred forces to the nucleus orchestrate gene expression activity. Methods to characterize nuclear mechanics typically study isolated cells or cells embedded in 3D gel matrices. Often report only aspect ratio and volume changes, measures that oversimplify the inherent complexity of internal strain patterns. This presents technical challenges to simultaneously observe small scale nuclear mechanics and gene expression levels inside the nuclei of …
Principle Of Bio-Inspired Insect Wing Rotational Hinge Design, Fan Fei
Principle Of Bio-Inspired Insect Wing Rotational Hinge Design, Fan Fei
Open Access Theses
A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is …
Effects Of Hip And Ankle Moments On Running Stability: Simulation Of A Simplified Model, Rubin C. Cholera
Effects Of Hip And Ankle Moments On Running Stability: Simulation Of A Simplified Model, Rubin C. Cholera
Open Access Theses
In human running, the ankle, knee, and hip moments are known to play different roles to influence the dynamics of locomotion. A recent study of hip moments and several hip-based legged robots have revealed that hip actuation can significantly improve the stability of locomotion, whether controlled or uncontrolled. Ankle moments are expected to also significantly affect running stability, but in a different way than hip moments. Here we seek to advance the current theory of dynamic running and associated legged robots by determining how simple open-loop ankle moments could affect running stability. We simulate a dynamical model, and compare it …
Theory For Diffusional Encounters In Heterogeneous Environments And Multivalent Electrolyte Screening Of Charged Interface, Ran Li
Open Access Dissertations
We develop a theory for encounter rates in a three-dimensional system of connected compartments. The model of connected compartments exhibits the length-scale dependent diffusion that is observed in many heterogeneous environments, such as porous catalysts and biological environments. We discovered a dimensionless number that is the dominant scaling variable and obtained, for the first time, an analytical expression for the encounter rate. The new theory generalizes the classic Smoluchowski diffusion limit to the case of heterogeneous environments. The new theory is tested using Brownian dynamics simulations.^ We also experimentally investigated the behavior of multivalent electrolyte near a charged solid-liquid interface. …
Understanding Preferred Leg Stiffness And Layered Control Strategies For Locomotion, Zhuohua H. Shen
Understanding Preferred Leg Stiffness And Layered Control Strategies For Locomotion, Zhuohua H. Shen
Open Access Dissertations
Despite advancement in the field of robotics, current legged robots still cannot achieve the kind of locomotion stability animals and humans have. In order to develop legged robots with greater stability, we need to better understand general locomotion dynamics and control principles. Here we demonstrate that a mathematical modeling approach could greatly enable the discovery and understanding of general locomotion principles. ^ It is found that animal leg stiffness when scaled by its weight and leg length falls in a narrow region between 7 and 27. Rarely in biology does such a universal preference exist. It is not known completely …
Developing A Hardware Platform For A Low-Power, Low-Cost, Size-Constrained Biomechanical Telemetry System, Aditya Balasubramanian
Developing A Hardware Platform For A Low-Power, Low-Cost, Size-Constrained Biomechanical Telemetry System, Aditya Balasubramanian
Open Access Theses
As sport-related traumatic brain injuries face increasing attention from the media and the general public, the need to be able to detect brain injury quickly, inexpensively and accurately is more important than ever. Commercially-available event-based systems exist that claim to achieve this goal; however, they collect little to no continuous-time data and primarily indicate when a pre-determined acceleration threshold has been exceeded under the unvalidated assumption that a potentially concussive blow has occurred. Recent findings by the Purdue Neurotrauma Group (PNG) have indicated that repeated exposure to both concussive and subconcussive blows can result in cumulative trauma disorder. To track …
Biomechanics And Relaxivity For Functional Imaging Of Articular Cartilage Injury And Degradation, Kateri Elizabeth Fites
Biomechanics And Relaxivity For Functional Imaging Of Articular Cartilage Injury And Degradation, Kateri Elizabeth Fites
Open Access Theses
Osteoarthritis (OA) is a major debilitating health concern and economic burden worldwide, affecting 27 million people in the United States alone. OA often follows tissue injury, and is marked by changes in the structure and biomechanical function of cartilage, including breakdown of extracellular matrix molecules, loss of bulk tissue stiffness, and increase in articular surface friction and wear. Unlike bone and many other tissues, cartilage lacks an intrinsic capacity for regeneration. Advanced OA is typically diagnosed by patient symptoms (e.g. joint pain) and confirmed by radiographic evaluation of joint space narrowing. However, the application of functional imaging to assess cartilage …
Developing An Embedded System Solution For High-Speed, High-Capacity Data Logging For A Size-Constrained, Low-Power Biomechanical Telemetry System And Investigating Components For Optimal Performance, Brandon Blaine Gardner
Developing An Embedded System Solution For High-Speed, High-Capacity Data Logging For A Size-Constrained, Low-Power Biomechanical Telemetry System And Investigating Components For Optimal Performance, Brandon Blaine Gardner
Open Access Theses
The Purdue Neurotrauma Group (PNG) seeks to develop a biomechanical telemetry system capable of monitoring and storing athletes' head motions with the intention of identifying when a player may be at risk of neurophysiological damage, especially brain damage. A number of commercially-available systems exist with a similar goal; however, each of these systems discards information below an acceleration threshold. Research by PNG indicates that any acceleration may contribute to brain damage and that, because of this, an event-based model is insufficient for a proper understanding of an athlete's neurophysiological health. Continuous-time monitoring of head accelerations is therefore necessary. To facilitate …
Characteristics Of Fibrous Tissue At High Rates Of Tensile Loading, Benjamin J. Claus
Characteristics Of Fibrous Tissue At High Rates Of Tensile Loading, Benjamin J. Claus
Open Access Theses
The mechanical behavior of fibrous tissue is generally characterized at very low strain rates. However, many injuries occur at high rates of loading, such as those encountered in sporting events or vehicle accidents. An understanding of injury behavior requires the injury process to be recorded at high strain rates. Even at low rates of loading, the injury/failure within tissues occurs quickly. Furthermore, using conventional imaging systems, the surface of a specimen may be well documented throughout an experiment. However, damage formation does not necessarily begin at the surface of the specimen or even on the surface exposed to a camera. …