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Full-Text Articles in Mechanical Engineering

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil Aug 2019

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil

Sarah A. Bentil

Traumatic brain injuries (TBI) affect millions of people each year. While research has been dedicated to determining the mechanical properties of the uninjured brain, there has been a lack of investigation on the mechanical properties of the brain after experiencing a primary blast-induced TBI. In this paper, whole porcine brains were exposed to a shock wave to simulate blast-induced TBI. First, ten (10) brains were subjected to unconfined compression experiments immediately following shock wave exposure. In addition, 22 brains exposed to a shock wave were placed in saline solution and refrigerated between 30 minutes and 6.0 hours before undergoing ...


Computational Cardiovascular Flow Analysis With The Variational Multiscale Methods, Kenji Takizawa, Yuri Bazilevs, Tayfun E. Tezduyar, Ming-Chen Hsu Jul 2019

Computational Cardiovascular Flow Analysis With The Variational Multiscale Methods, Kenji Takizawa, Yuri Bazilevs, Tayfun E. Tezduyar, Ming-Chen Hsu

Ming-Chen Hsu

Computational cardiovascular flow analysis can provide valuable information to medical doctors in a wide range of patientspecific cases, including cerebral aneurysms, aortas and heart valves. The computational challenges faced in this class of flow analyses also have a wide range. They include unsteady flows, complex cardiovascular geometries, moving boundaries and interfaces, such as the motion of the heart valve leaflets, contact between moving solid surfaces, such as the contact between the leaflets, and the fluid–structure interaction between the blood and the cardiovascular structure. Many of these challenges have been or are being addressed by the Space–Time Variational Multiscale ...


On-Chip Development Of Hydrogel Microfibers From Round To Square/Ribbon Shape, Zhenhua Bai, Janet M. Mendoza Reyes, Reza Montazami, Nicole Nastaran Hashemi Nov 2018

On-Chip Development Of Hydrogel Microfibers From Round To Square/Ribbon Shape, Zhenhua Bai, Janet M. Mendoza Reyes, Reza Montazami, Nicole Nastaran Hashemi

Nicole N. Hashemi

We use a microfluidic approach to fabricate gelatin fibers with controlled sizes and cross-sections. Uniform gelatin microfibers with various morphologies and cross-sections (round and square) are fabricated by increasing the gelatin concentration of the core solution from 8% to 12%. Moreover, the increase of gelatin concentration greatly improves the mechanical properties of gelatin fibers; the Young's modulus and tensile stress at break of gelatin (12%) fibers are raised about 2.2 and 1.9 times as those of gelatin (8%) fibers. The COMSOL simulations indicate that the sizes and cross-sections of the gelatin fibers can be tuned by using ...


Agonabadietal_2018_Eduexoemgdelaytutorial_13.Pdf, Arash Mohammadzadeh Gonabadi, Philippe Malcolm Jul 2018

Agonabadietal_2018_Eduexoemgdelaytutorial_13.Pdf, Arash Mohammadzadeh Gonabadi, Philippe Malcolm

Philippe Malcolm

No abstract provided.


Real-Time Simulation Of Three-Dimensional Shoulder Girdle And Arm Dynamics, Edward K. Chadwick, Dimitra Blana, Robert F. Kirsch, Antonie J. Van Den Bogert May 2018

Real-Time Simulation Of Three-Dimensional Shoulder Girdle And Arm Dynamics, Edward K. Chadwick, Dimitra Blana, Robert F. Kirsch, Antonie J. Van Den Bogert

Antonie J. van den Bogert

Electrical stimulation is a promising technology for the restoration of arm function in paralyzed individuals. Control of the paralyzed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability tomodel the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate the ...


Relationship Between Jump Landing Kinematics And Peak Acl Force During A Jump In Downhill Skiing: A Simulation Study, D. Heinrich, Antonie J. Van Den Bogert, W. Nachbauer May 2018

Relationship Between Jump Landing Kinematics And Peak Acl Force During A Jump In Downhill Skiing: A Simulation Study, D. Heinrich, Antonie J. Van Den Bogert, W. Nachbauer

Antonie J. van den Bogert

Recent data highlight that competitive skiers face a high risk of injuries especially during off-balance jump landing maneuvers in downhill skiing. The purpose of the present study was to develop a musculo-skeletal modeling and simulation approach to investigate the cause-and-effect relationship between a perturbed landing position, i.e., joint angles and trunk orientation, and the peak force in the anterior cruciate ligament (ACL) during jump landing. A two-dimensional musculo-skeletal model was developed and a baseline simulation was obtained reproducing measurement data of a reference landing movement. Based on the baseline simulation, a series of perturbed landing simulations (n=1000) was ...


An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert May 2018

An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert

Antonie J. van den Bogert

Here we share a rich gait data set collected from fifteen subjects walking at three speeds on an instrumented treadmill. Each trial consists of 120 s of normal walking and 480 s of walking while being longitudinally perturbed during each stance phase with pseudo-random fluctuations in the speed of the treadmill belt. A total of approximately 1.5 h of normal walking (>5000 gait cycles) and 6 h of perturbed walking (>20,000 gait cycles) is included in the data set. We provide full body marker trajectories and ground reaction loads in addition to a presentation of processed data that ...


An Analytical Model For Rotator Cuff Repairs, A. Aurora, Jorge E. Gatica, Antonie J. Van Den Bogert, J. A. Mccarron, Kathleen A. Derwin May 2018

An Analytical Model For Rotator Cuff Repairs, A. Aurora, Jorge E. Gatica, Antonie J. Van Den Bogert, J. A. Mccarron, Kathleen A. Derwin

Jorge E. Gatica

Background

Currently, natural and synthetic scaffolds are being explored as augmentation devices for rotator cuff repair. When used in this manner, these devices are believed to offer some degree of load sharing; however, no studies have quantified this effect. Furthermore, the manner in which loads on an augmented rotator cuff repair are distributed among the various components of the repair is not known, nor is the relative biomechanical importance of each component. The objectives of this study are to (1) develop quasi-static analytical models of simplified rotator cuff repairs, (2) validate the models, and (3) predict the degree of load ...


A Paper Based Graphene-Nanocauliflower Hybrid Composite For Point Of Care Biosensing, S. L. Burrs, R. Sidhu, M. Bhargava, J. Kieman-Lewis, N. Schwalb, Y. Rong, Carmen Gomes, Jonathan C. Claussen, D. C. Vanegas, E. S. Mclamore Mar 2018

A Paper Based Graphene-Nanocauliflower Hybrid Composite For Point Of Care Biosensing, S. L. Burrs, R. Sidhu, M. Bhargava, J. Kieman-Lewis, N. Schwalb, Y. Rong, Carmen Gomes, Jonathan C. Claussen, D. C. Vanegas, E. S. Mclamore

Jonathan C. Claussen

Graphene paper has diverse applications in printed circuit board electronics, bioassays, 3D cell culture, and biosensing. Although development of nanometal-graphene hybrid composites is commonplace in the sensing literature, to date there are only a few examples of nanometal-decorated graphene paper for use in biosensing. In this manuscript, we demonstrate the synthesis and application of Pt nano cauliflower-functionalized graphene paper for use in electrochemical biosensing of small molecules (glucose, acetone, methanol) or detection of pathogenic bacteria (Escherichia coli O157:H7). Raman spectroscopy, scanning electron microscopy and energy dispersive spectroscopy were used to show that graphene oxide deposited on nanocellulose crystals was ...


Application Of Pca To Cardiac Optical Mapping, Louis Woodhams Aug 2017

Application Of Pca To Cardiac Optical Mapping, Louis Woodhams

Louis Woodhams

Structural remodeling of the heart due to pathologies such as hypertension and myocardial infarction leads to the appearance of myofibroblasts, a phenotype largely absent in physiologic myocardium. While myofibroblasts are responsible for wound healing and structural repair of damaged myocardium, they are thought to have deleterious effects on electrical and mechanical properties of the heart. Understanding these effects is critical to developing effective treatments, and has motivated the development of a series of in vitro engineered heart tissues and cardiomyocyte-myofibroblast co-cultures whose mechanical and electrophysiological function can be deduced from video analysis. Electrophysiological properties are evident from changes in intensity ...


An End-To-End Convolutional Selective Autoencoder Approach To Soybean Cyst Nematode Eggs Detection, Adedotun Akintayo, Nigel Lee, Vikas Chawla, Mark P. Mullaney, Christopher C. Marett, Asheesh K. Singh, Arti Singh, Gregory L. Tylka, Baskar Ganapathysubramanian, Soumik Sarkar Jun 2017

An End-To-End Convolutional Selective Autoencoder Approach To Soybean Cyst Nematode Eggs Detection, Adedotun Akintayo, Nigel Lee, Vikas Chawla, Mark P. Mullaney, Christopher C. Marett, Asheesh K. Singh, Arti Singh, Gregory L. Tylka, Baskar Ganapathysubramanian, Soumik Sarkar

Baskar Ganapathysubramanian

Soybean cyst nematodes (SCNs), Heterodera glycines, are unwanted micro-organisms that reduce yields of a major source of food–soybeans. In the United States alone, approximately $1 billion is lost per annum due to cyst nematode infections on soybean plants. Experts have conceived methods of mitigating the losses through phenotyping techniques via SCN eggs density estimation, and then applying the right control measures. Currently, they rely on labor intensive and time-consuming identification of SCN eggs in soil samples processed onto microscopic frames. However, phenotyping a vast array of fields requires automated high-throughput techniques. From an automation perspective, detection of rarely occurring ...


Cellulose–Hemicellulose And Cellulose–Lignin Interactions During Fast Pyrolysis, Jing Zhang, Yong S. Choi, Chang G. Yoo, Tae H. Kim, Robert C. Brown, Brent H. Shanks Jun 2017

Cellulose–Hemicellulose And Cellulose–Lignin Interactions During Fast Pyrolysis, Jing Zhang, Yong S. Choi, Chang G. Yoo, Tae H. Kim, Robert C. Brown, Brent H. Shanks

Brent H. Shanks

Previously, the primary product distribution resulting from fast pyrolysis of cellulose, hemicellulose, and lignin was quantified. This study extends the analysis to the examinations of interactions between cellulose–hemicellulose and cellulose–lignin, which were determined by comparing the pyrolysis products from their native mixture, physical mixture, and superposition of individual components. Negligible interactions were found for both binary physical mixtures. For the native cellulose–hemicellulose mixture, no significant interaction was identified either. In the case of the native cellulose–lignin mixture, herbaceous biomass exhibited an apparent interaction, represented by diminished yield of levoglucosan and enhanced yield of low molecular weight ...


Rapid And Label-Free Detection Of Interferon Gamma Via An Electrochemical Aptasensor Comprising A Ternary Surface Monolayer On A Gold Interdigitated Electrode Array, Shaowei Ding, Curtis L. Mosher, Xian Y. Lee, Suprem R. Das, Allison A. Cargill, Xiaohui Tang, Bolin Chen, Eric S. Mclamore, Carmen Gomes, Jesse M. Hostetter, Jonathan C. Claussen Mar 2017

Rapid And Label-Free Detection Of Interferon Gamma Via An Electrochemical Aptasensor Comprising A Ternary Surface Monolayer On A Gold Interdigitated Electrode Array, Shaowei Ding, Curtis L. Mosher, Xian Y. Lee, Suprem R. Das, Allison A. Cargill, Xiaohui Tang, Bolin Chen, Eric S. Mclamore, Carmen Gomes, Jesse M. Hostetter, Jonathan C. Claussen

Jonathan C. Claussen

A label-free electrochemical impedance spectroscopy (EIS) aptasensor for rapid detection (<35 >min) of interferon-gamma (IFN-γ) was fabricated by immobilizing a RNA aptamer capture probe (ACP), selective to IFN-γ, on a gold interdigitated electrode array (Au IDE). The ACP was modified with a thiol group at the 5′ terminal end and subsequently co-immobilized with 1,6-hexanedithiol (HDT) and 6-mercapto-1-hexanolphosphate (MCH) to the gold surface through thiol–gold interactions. This ACP/HDT-MCH ternary surface monolayer facilitates efficient hybridization with IFN-γ and displays high resistance to nonspecific adsorption of nontarget proteins [i.e., fetal bovine serum (FBS) and bovine serum albumin (BSA)]. The Au ...


Estimation Of The Centre Of Mass From Motion Capture And Force Plate Recordings: A Study On The Elderly, Sebastien Cotton, Michele Vanoncini, Philippe Fraisse, Nacim Ramdani, Emel Demircan, Andrew P. Murray, Thierry Keller Feb 2017

Estimation Of The Centre Of Mass From Motion Capture And Force Plate Recordings: A Study On The Elderly, Sebastien Cotton, Michele Vanoncini, Philippe Fraisse, Nacim Ramdani, Emel Demircan, Andrew P. Murray, Thierry Keller

Andrew P. Murray

The estimation of the centre of mass position in humans is usually based on biomechanical models developed from anthropometric tables. This method can potentially introduce errors in studies involving elderly people, since the ageing process is typically associated with a modification of the distribution of the body mass. In this paper, an alternative technique is proposed, and evaluated with an experimental study on 9 elderly volunteers. The technique is based on a virtual chain, identified from experimental data and locating the subject's centre of mass. Its configuration defines the location of the centre of mass, and is a function ...


Impedance Biosensor For The Rapid Detection Of Listeria Spp. Based On Aptamer Functionalized Pt-Interdigitated Microelectrodes Array, R. Sidhu, Y. Rong, D. C. Vanegas, Jonathan Claussen, E. S. Mclamore, Carmen L. Gomes May 2016

Impedance Biosensor For The Rapid Detection Of Listeria Spp. Based On Aptamer Functionalized Pt-Interdigitated Microelectrodes Array, R. Sidhu, Y. Rong, D. C. Vanegas, Jonathan Claussen, E. S. Mclamore, Carmen L. Gomes

Jonathan C. Claussen

Listeria monocytogenes is one of the most common causes of food illness deaths worldwide, with multiple outbreaks in the United States alone. Current methods to detect foodborne pathogens are laborious and can take several hours to days to produce results. Thus, faster techniques are needed to detect bacteria within the same reliability level as traditional techniques. This study reports on a rapid, accurate, and sensitive aptamer biosensor device for Listeria spp. detection based on platinum interdigitated array microelectrodes (Pt-IDEs). Pt-IDEs with different geometric electrode gaps were fabricated by lithographic techniques and characterized by cyclic voltammetric (CV), electrochemical impedance spectroscopy (EIS ...


Bio-Inspired Patterned Networks (Bips) For Development Of Wearable/ Disposable Biosensors, E. S. Mclamore, M. Convertino, John Hondred, Suprem Das, Jonathan C. Claussen, Carmen L. Gomes Dec 2015

Bio-Inspired Patterned Networks (Bips) For Development Of Wearable/ Disposable Biosensors, E. S. Mclamore, M. Convertino, John Hondred, Suprem Das, Jonathan C. Claussen, Carmen L. Gomes

Jonathan C. Claussen

Here we demonstrate a novel approach for fabricating point of care (POC) wearable electrochemical biosensors
based on 3D patterning of bionanocomposite networks. To create Bio-Inspired Patterned network (BIPS) electrodes, we first generate fractal network in silico models that optimize transport of network fluxes according to an energy function. Network patterns are then inkjet printed onto flexible substrate using conductive graphene ink. We then deposit fractal nanometal structures onto the graphene to create a 3D nanocomposite network. Finally, we biofunctionalize the surface with biorecognition agents using covalent bonding. In this paper, BIPS are used to
develop high efficiency, low cost biosensors ...


Real-World Industry Collaboration Within A Mechatronics Class, Vidya Nandikolla, Susan Shadle, Patricia Pyke, John Gardner, Robert Grover, Suhas Pharkute Dec 2015

Real-World Industry Collaboration Within A Mechatronics Class, Vidya Nandikolla, Susan Shadle, Patricia Pyke, John Gardner, Robert Grover, Suhas Pharkute

John Gardner

This paper describes the implementation and assessment of an innovative senior/graduate level mechatronics (robotics) module that integrated structured and unstructured learning experiences, in collaboration with an industry partner. With real-world constraints and expectations, students designed and delivered a product as the final project. In fall 2007, the corporate partner provided state-of-the-art, programmable robotic kits with a user-friendly programming environment. The assigned project was to design a biomedical robot to work in a hospital intensive care unit (ICU) to perform tasks such as transporting supplies or delivering paperwork. Students with diverse skills and majors were grouped in ten teams, two ...


High Aspect Ratio Carbon Nanotube Membranes Decorated With Pt Nanoparticle Urchins For Micro Underwater Vehicle Propulsion Via H2o2 Decomposition, Kevin Marr, Bolin Chen, Eric J. Mootz, Jason Geder, Marius Pruessner, Brian J. Melde, Richard R. Vanfleet, Igor L. Medintz, Brian D. Iverson, Jonathan C. Claussen Sep 2015

High Aspect Ratio Carbon Nanotube Membranes Decorated With Pt Nanoparticle Urchins For Micro Underwater Vehicle Propulsion Via H2o2 Decomposition, Kevin Marr, Bolin Chen, Eric J. Mootz, Jason Geder, Marius Pruessner, Brian J. Melde, Richard R. Vanfleet, Igor L. Medintz, Brian D. Iverson, Jonathan C. Claussen

Jonathan C. Claussen

The utility of unmanned micro underwater vehicles (MUVs) is paramount for exploring confined spaces, but their spatial agility is often impaired when maneuvers require burst-propulsion. Herein we develop high-aspect ratio (150:1), multiwalled carbon nanotube microarray membranes (CNT-MMs) for propulsive, MUV thrust generation by the decomposition of hydrogen peroxide (H2O2). The CNT-MMs are grown via chemical vapor deposition with diamond shaped pores (nominal diagonal dimensions of 4.5 × 9.0 μm) and subsequently decorated with urchin-like, platinum (Pt) nanoparticles via a facile, electroless, chemical deposition process. The Pt-CNT-MMs display robust, high catalytic ability with an effective activation energy of 26 ...


Characterization Of Biochars Produced From Cornstovers For Soil Amendment, James W. Leeq, Michelle Kidder, Barbara R. Evans, Sokwon Paik, A.C. Buchanan Iii, Charles T. Garten, Robert C. Brown Sep 2015

Characterization Of Biochars Produced From Cornstovers For Soil Amendment, James W. Leeq, Michelle Kidder, Barbara R. Evans, Sokwon Paik, A.C. Buchanan Iii, Charles T. Garten, Robert C. Brown

Robert C. Brown

Through cation exchange capacity assay, nitrogen adsorption−desorption surface area measurements, scanning electron microscopic imaging, infrared spectra and elemental analyses, we characterized biochar materials produced from cornstover under two different pyrolysis conditions, fast pyrolysis at 450 °C and gasification at 700 °C. Our experimental results showed that the cation exchange capacity (CEC) of the fast-pyrolytic char is about twice as high as that of the gasification char as well as that of a standard soil sample. The CEC values correlate well with the increase in the ratios of the oxygen atoms to the carbon atoms (O:C ratios) in the ...


Mitigating Visually Induced Motion Sickness: A Virtual Hand-Eye Coordination Task, Michael K. Curtis, Kayla Dawson, Kelli Jackson, Liat Litwin, Chase Meusel, Michael C. Dorneich, Stephen B. Gilbert, Jonathan W. Kelly, Richard T. Stone Aug 2015

Mitigating Visually Induced Motion Sickness: A Virtual Hand-Eye Coordination Task, Michael K. Curtis, Kayla Dawson, Kelli Jackson, Liat Litwin, Chase Meusel, Michael C. Dorneich, Stephen B. Gilbert, Jonathan W. Kelly, Richard T. Stone

Richard T. Stone

Virtual reality has grown rapidly over the past decade, yet visually induced motion sickness (VIMS), continues to affect the usability of this technology. Aside from medicine, physical hand-eye-coordination tasks have been found to be effective in mitigating symptoms of VIMS, however the need for equipment outside of virtual reality limits the usefulness of these mitigation techniques. In this study, 21 participants were sickened via a virtual obstacle course and used one of two mitigation techniques. The first, natural decay, is simply waiting outside the virtual environment (VE) for symptoms to subside; the other was a virtual peg-in-hole task, performed in ...


Three-Dimensional Confocal Microscopy Indentation Method For Hydrogel Elasticity Measurement, Donghee Lee, Md Mahmudur Rahman, You Zhou, Sangjin Ryu Aug 2015

Three-Dimensional Confocal Microscopy Indentation Method For Hydrogel Elasticity Measurement, Donghee Lee, Md Mahmudur Rahman, You Zhou, Sangjin Ryu

Md Mahmudur Rahman

No abstract provided.


Expressing The Joint Moments Of Drop Jumps And Sidestep Cutting In Different Reference Frames – Does It Matter?, Eirik Kristianslunda, Tron Krosshauga, Kam-Ming Mok, Scott Mclean, Antonie J. Van Den Bogert Jun 2015

Expressing The Joint Moments Of Drop Jumps And Sidestep Cutting In Different Reference Frames – Does It Matter?, Eirik Kristianslunda, Tron Krosshauga, Kam-Ming Mok, Scott Mclean, Antonie J. Van Den Bogert

Antonie J. van den Bogert

Joint moments help us understand joint loading and muscle function during movement. However, the interpretation depends on the choice of reference frame, but the different reference frames have not been compared in dynamic, high-impact sporting movements. We have compared the magnitude and the resulting ranking of hip and knee joint moments expressed in the laboratory coordinate system, the local system of the distal segment and projected or decomposed to the Joint Coordinate System (JCS) axes. Hip and knee joint moments of drop jumps and sidestep cutting in 70 elite female handball players were calculated based on recordings from an eight-camera ...


Biogeography-Based Optimization For Hydraulic Prosthetic Knee Control, Tim Wilmot, George Thomas, Berney Montavon, Rick Rarick, Antonie J. Van Den Bogert, Steve Szatmary, Daniel J. Simon, William Smith, Sergey Samorezov Jun 2015

Biogeography-Based Optimization For Hydraulic Prosthetic Knee Control, Tim Wilmot, George Thomas, Berney Montavon, Rick Rarick, Antonie J. Van Den Bogert, Steve Szatmary, Daniel J. Simon, William Smith, Sergey Samorezov

Antonie J. van den Bogert

We discuss open-loop control development and simulation results for a newly-developed cyber-physical system (CPS) used as a semi-active, above-knee prosthesis. The control signal of our CPS consists of two hydraulic valve settings that control a linear cylinder actuator and provide torque to the prosthetic knee. We develop open-loop control using biogeography-based optimization (BBO), which is a recently developed evolutionary algorithm. The research contributes to the field of cyber-physical systems by showing that it is possible to find effective open-loop control signals for our newly proposed semi-active hydraulic knee prosthesis through a dual-system optimization process which includes both human and robot ...


Cerebrospinal Fluid Dynamics In The Cervical Spine: Importance Of Fine Anatomical Structures, S. Pahlavian, T. Yiallourou, R. Tubbs, A. Bunck, M. Goodin, Francis Loth, M. Raisee, Bryn Martin Apr 2015

Cerebrospinal Fluid Dynamics In The Cervical Spine: Importance Of Fine Anatomical Structures, S. Pahlavian, T. Yiallourou, R. Tubbs, A. Bunck, M. Goodin, Francis Loth, M. Raisee, Bryn Martin

Dr. Bryn Martin

No abstract provided.


Novel Sensor For Measuring Sodium Concentration For Dialysis Applications, L. Furby, Ajay Mahajan, Jarlen Don, Bradley Schwartz Apr 2015

Novel Sensor For Measuring Sodium Concentration For Dialysis Applications, L. Furby, Ajay Mahajan, Jarlen Don, Bradley Schwartz

Dr. Ajay Mahajan

One of the critical medical problems facing society today is the growing number of patients diagnosed with End-Stage Renal Disease (ESRD). Patients diagnosed with ESRD often face a problem of limited organ transplantation possibilities and time consuming, cumbersome as well as painstaking treatments that affect patients’ quality of life. This study is part of a larger effort to develop new types of dialysis treatments focused on improving the quality of life of ESRD patients. The focus of this paper is the development of a simple, yet reliable sensor that can measure the toxic ion levels in the human body so ...


Full-Field Vibrometry By High-Speed Digital Holography For Middle-Ear Mechanics, Ivo Dobrev Aug 2014

Full-Field Vibrometry By High-Speed Digital Holography For Middle-Ear Mechanics, Ivo Dobrev

Ivo Dobrev

Hearing loss affects approximately 1 in 10 people in the world and this percentage is increasing every year. Some of the most common courses for hearing loss are disorders of the human tympanic membrane (TM or eardrum) and middle-ear. Early detection and diagnosis of hearing loss as well as research and understanding of the hearing process depend on medical and research tools for quantification of the hearing capabilities, including the function of the human TM in the complex acoustic-mechanical transformation of environmental sounds into vibrations of the middle- and the inner-ear. Current ear exams are assessing the state of the ...


Application Of Limited Mixing In The Hele-Shaw Geometry In Fabrication Of Janus Hydrogels, Md Mahmudur Rahman Jul 2014

Application Of Limited Mixing In The Hele-Shaw Geometry In Fabrication Of Janus Hydrogels, Md Mahmudur Rahman

Md Mahmudur Rahman

It is widely accepted that cells behave differently responding to the stiffness of their extracellular matrix (ECM). Such observations were made by culturing cells on hydrogel substrates of tunable stiffness. However, it was recently proposed that cells may sense how strongly they are tethered to ECM, not the local stiffness of ECM. To investigate both hypotheses, we developed a method to fabricate Janus polyacrylamide (PAAM) gels. We squeeze two drops of different concentrations in the Hele-Shaw geometry to generate radial Stokes flow. When the drops coalesce, limited mixing occurs at the interface due to the narrow confinement, and diffusion normal ...


Real-Time Simulation Of Three-Dimensional Shoulder Girdle And Arm Dynamics, Edward K. Chadwick, Dimitra Blana, Robert F. Kirsch, Antonie J. Van Den Bogert Jun 2014

Real-Time Simulation Of Three-Dimensional Shoulder Girdle And Arm Dynamics, Edward K. Chadwick, Dimitra Blana, Robert F. Kirsch, Antonie J. Van Den Bogert

Antonie J. van den Bogert

Electrical stimulation is a promising technology for the restoration of arm function in paralyzed individuals. Control of the paralyzed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability to model the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate ...


Pre-Impact Lower Extremity Posture And Brake Pedal Force Predict Foot And Ankle Forces During An Automobile Collision, Elizabeth C. Hardin, Anne Su, Antonie J. Van Den Bogert Mar 2014

Pre-Impact Lower Extremity Posture And Brake Pedal Force Predict Foot And Ankle Forces During An Automobile Collision, Elizabeth C. Hardin, Anne Su, Antonie J. Van Den Bogert

Anne Su Ph.D.

Background: The purpose of this study was to determine how a driver’s foot and ankle forces during a frontal vehicle collision depend on initial lower extremity posture and brake pedal force. Method of Approach: A 2D musculoskeletal model with seven segments and six right-side muscle groups was used. A simulation of a three-second braking task found 3647 sets of muscle activation levels that resulted in stable braking postures with realistic pedal force. These activation patterns were then used in impact simulations where vehicle deceleration was applied and driver movements and foot and ankle forces were simulated. Peak rearfoot ground ...


A Weighted Least-Squares Method For Inverse Dynamic Analysis, Antonie Van Den Bogert, Anne Su Mar 2014

A Weighted Least-Squares Method For Inverse Dynamic Analysis, Antonie Van Den Bogert, Anne Su

Anne Su Ph.D.

Internal forces in the human body can be estimated from measured movements and external forces using inverse dynamic analysis. Here we present a general method of analysis which makes optimal use of all available data, and allows the use of inverse dynamic analysis in cases where external force data is incomplete. The method was evaluated for the analysis of running on a partially instrumented treadmill. It was found that results correlate well with those of a conventional analysis where all external forces are known.