Biomedical Engineering and Bioengineering Commons^™

Analysis Of 26" And 29" Wheel Mountain Bikes, Jacob Publicover, David Wang, Alex Warring

Mechanical Engineering

There are two major mountain bike diameter wheel sizes on the market today, but with two different options, one would naturally wonder, “Which one is best?” During the course of this project, 26 and 29 inch wheel mountain bikes were analyzed quantitatively and qualitatively, using a variety of test methods, from heart rate monitoring to serial data acquisition to computer simulated analyses; static, dynamic, theoretical, and subjective tests were administered.

Comparison Of Microwave And Conventionally Sintered Yttria-Doped Zirconia Ceramics, Colin J. Reidy, Thomas J. Fleming, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper reports on improvement of the physical and mechanical properties of Y₂O₃-ZrO₂ ceramics through compositional optimization, the use of nanograined powders and utilization of microwave sintering. ZrO₂ with 2-5 mol% Y₂O₃, prepared from nanopowders, was sintered in both conventional and microwave furnaces under exactly the same heating schedule. It was found that microwave sintering improves physical and mechanical properties of Y₂O₃-ZrO₂ ceramics compared with conventional sintering. Compositions containing 2 mol% Y₂O₃ exhibit the greatest improvement due to retention of tetragonal ZrO …

Effect Of Sensory Feedback From The Proximal Upper Limb On Voluntary Isometric Finger Flexion And Extension In Hemiparetic Stroke Subjects, Gilles Hoffmann, Brian D. Schmit, Jennifer H. Kahn, Derek G. Kamper

Biomedical Engineering Faculty Research and Publications

This study investigated the potential influence of proximal sensory feedback on voluntary distal motor activity in the paretic upper limb of hemiparetic stroke survivors and the potential effect of voluntary distal motor activity on proximal muscle activity. Ten stroke subjects and 10 neurologically intact control subjects performed maximum voluntary isometric flexion and extension, respectively, at the metacarpophalangeal (MCP) joints of the fingers in two static arm postures and under three conditions of electrical stimulation of the arm. The tasks were quantified in terms of maximum MCP torque [MCP flexion (MCP_flex) or MCP extension (MCP_ext)] and activity …

Patterns Of Hypermetria And Terminal Cocontraction During Point-To-Point Movements Demonstrate Independent Action Of Trajectory And Postural Controllers, Robert A. Scheidt, Claude Ghez, Supriya Asnani

Biomedical Engineering Faculty Research and Publications

We examined elbow muscle activities and movement kinematics to determine how subjects combine elementary control actions in performing movements with one and two trajectory segments. In reaching, subjects made a rapid elbow flexion to a visual target before stabilizing the limb with either a low or a higher level of elbow flexor/extensor coactivity (CoA), which was cued by target diameter. Cursor diameter provided real-time biofeedback of actual muscle CoA. In reversing, the limb was to reverse direction within the target and return to the origin with minimal CoA. We previously reported that subjects overshoot the goal when attempting a reversal …

Sensing With The Motor Cortex, Nicholas G. Hatsopoulos, Aaron J. Suminski

Biomedical Engineering Faculty Research and Publications

The primary motor cortex is a critical node in the network of brain regions responsible for voluntary motor behavior. It has been less appreciated, however, that the motor cortex exhibits sensory responses in a variety of modalities including vision and somatosensation. We review current work that emphasizes the heterogeneity in sensorimotor responses in the motor cortex and focus on its implications for cortical control of movement as well as for brain-machine interface development.

Design, Fabrication, And Implementation Of A Wireless, Passive Implantable Pressure Sensor Based On Magnetic Higher-Order Harmonic Fields, Ee Lim Tan, Andrew Derouin, Brandon D. Pereles, Keat Ghee Ong

Michigan Tech Publications, Part 1

A passive and wireless sensor was developed for monitoring pressure in vivo. Structurally, the pressure sensor, referred to as the magneto-harmonic pressure sensor, is an airtight chamber sealed with an elastic pressure membrane. A strip of magnetically-soft material is attached to the bottom of the chamber and a permanent magnet strip is embedded inside the membrane. Under the excitation of an externally applied AC magnetic field, the magnetically-soft strip produces a higher-order magnetic signature that can be remotely detected with an external receiving coil. As ambient pressure varies, the pressure membrane deflects, altering the separation distance between the magnetically-soft strip …

Predictive Mathematical Model For Polyhydroxybutyrate Synthesis In Escherichia Coli, Angela Dixon

Engineering Datasets

Polyhydroxybutyrate has been studied as a potential biodegradable replacement for petrochemical plastics. Polyhydroxybutyrate synthesis is not native to Escherichia coli, but the genes have successfully been inserted through plasmids. However, polyhydroxybutyrate production needs to be more cost-effective before it can be commercially produced. A mathematical model for polyhydroxybutyrate synthesis was developed to identify genes that could be altered to increase polyhydroxybutyrate production. The major metabolic pathways included in the model were glycolysis, acetyl coenzyme-A synthesis, tricarboxylic acid cycle, glyoxylate bypass, and polyhydroxybutyrate synthesis. Reactions were modeled using kinetic mechanisms identified for each enzyme. The transcriptional network was incorporated into the …

Role Of Ammonia In The Activiation Of Methanol Dehydrogenase/Cytochrome C(L) Enzyme, Ancy Kunjumon

Doctoral Dissertations

Recent advancement in enzyme catalysis has opened ways to design efficient biocatalysts, bio-sensors and bio-fuel cells. An in-depth knowledge about the mechanism of the reaction taking place within the enzymes is of great importance to achieve these goals. In this dissertation, various computation methods are applied to investigate the mechanism behind enzyme catalysis in the presence of compounds called activators.

Methanol dehydrogenase (MDH) is a well-known bio-catalyst that can oxidize excess of methanol from the environment to formaldehyde. The enzyme works well within the bacterial environment, but under in vitro, it loses activity. Ammonia is used as an activator …

Passive Micromixers And Organic Electrochemical Transistors For Biosensor Applications, Senaka Krishna Kanakamedala

Doctoral Dissertations

Fluid handling at the microscale has greatly affected different fields such as biomedical, pharmaceutical, biochemical engineering and environmental monitoring due to its reduced reagent consumption, portability, high throughput, lower hardware cost and shorter analysis time compared to large devices. The challenges associated with mixing of fluids in microscale enabled us in designing, simulating, fabricating and characterizing various micromixers on silicon and flexible polyester substrates. The mixing efficiency was evaluated by injecting the fluids through the two inlets and collecting the sample at outlet. The images collected from the microscope were analyzed, and the absorbance of the color product at the …

Revised Reference Curves For Bone Mineral Content And Areal Bone Mineral Density According To Age And Sex For Black And Non-Black Children: Results Of The Bone Mineral Density In Childhood Study, Babette S. Zemel, Heidi J. Kalkwarf, Vicente Gilsanz, Joan M. Lappe, Sharon Oberfield, John A. Shepherd, Margaret M. Frederick, Xangke Huang, Ming Lu, Soroosh Mahboubi, Thomas N. Hangartner, Karen K. Winer

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Context: Deficits in bone acquisition during growth may increase fracture risk. Assessment of bone health during childhood requires appropriate reference values relative to age, sex, and population ancestry to identify bone deficits.

Objective: The objective of this study was to provide revised and extended reference curves for bone mineral content (BMC) and areal bone mineral density (aBMD) in children.

Design: The Bone Mineral Density in Childhood Study was a multicenter longitudinal study with annual assessments for up to 7 yr.

Setting: The study was conducted at five clinical centers in the United States.

Participants: Two thousand fourteen healthy children (992 …

Improving Cardiovascular Stent Design Using Patient-Specific Models And Shape Optimization, Timothy J. Gundert

Master's Theses (2009 -)

Stent geometry influences local hemodynamic alterations (i.e. the forces moving blood through the cardiovascular system) associated with adverse clinical outcomes. Computational fluid dynamics (CFD) is frequently used to quantify stent-induced hemodynamic disturbances, but previous CFD studies have relied on simplified device or vascular representations. Additionally, efforts to minimize stent-induced hemodynamic disturbances using CFD models often only compare a small number of possible stent geometries. This thesis describes methods for modeling commercial stents in patient-specific vessels along with computational techniques for determining optimal stent geometries that address the limitations of previous studies.

An efficient and robust method was developed for virtually …

Effectiveness Of Group Kickboxing As A Means To Improve Gait And Balance In Individuals With Ms, Kurt Jackson, Kimberly Edginton Bigelow, Christina Cooper, Harold L. Merriman

Mechanical and Aerospace Engineering Faculty Publications

In recent years, there has been a particular emphasis on identifying and delivering appropriate therapeutic interventions that address the significant balance and gait impairments that affect individuals with multiple sclerosis (MS). Group interventions implemented in community settings have been especially of interest, including tai chi classes. Recently, the authors conducted a preliminary study to examine whether group kick-boxing, which requires more vigorous movements, might be a feasible intervention. Initial findings showed promise and led the authors to pursue a more rigorous follow-up study, with the objective of determining whether a 5-week group kickboxing class improved clinical measures of balance and …

Comparison Of An Ankle-Foot-Orthosis And Neuroprosthesis During Level And Non-Level Walking For Individuals Post-Stroke, Michelle Beverly Gallagher

Master's Theses (2009 -)

This study used gait analysis to compare the efficacy of the two foot drop treatments (ankle-foot-orthosis and neuroprosthesis) and to contrast the stimulation control of the two different neuroprosthesis sensors during level and non-level ambulation of post-stroke individuals.

Eight subjects completed two gait analysis sessions, once while using a study-provided articulated AFO and the other while using a WalkAide. After four weeks of acclimation to the device, each subject performed two minute walking trials on a level, inclined and declined treadmill. Kinematic and heart rate data were collected for all sessions. Plantar pressure and WalkAide tilt, heel loading, and stimulation …

Motion Analysis Of The Upper Extremities During Lofstrand Crutch-Assisted Gait In Children With Orthopaedic Disabilities, Brooke A. Slavens, Neha Bhagchandani, Mei Wang, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background

This paper presents a review of current state-of-the-art dynamic systems for quantifying the kinematics and kinetics of the joints of the upper extremities during Lofstrand crutch-assisted gait. The reviewed systems focus on the rehabilitation of children and adults with myelomeningocele (MM), cerebral palsy (CP), spinal cord injury (SCI), and osteogenesis imperfecta (OI). Forearm crutch systems have evolved from models with single- to multi-sensor hardware systems that can incorporate an increasing number of segments that are in compliance with the standards of the International Society of Biomechanics (ISB).

Methods

The initial system developed by our group was a single, six-axis, …

A Model For The Evaluation Of Lower Extremity Kinematics With Integrated Multisegmental Foot Motion, Jason T. Long, Mei Wang, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background/Purpose

Current models for assessing lower extremity motion during gait benefit from ease of use in the clinical environment. However, underlying assumptions regarding joint location and distal segment motion limit their effectiveness and accuracy. The aim of this study was to develop a model for lower extremity motion analysis, which integrates functional methods for estimating hip joint center (HJC) location and a multisegmental approach to modeling motion of the foot and ankle. The new model is capable of tracking the motion of six segments (pelvis, bilateral thigh, tibia, hindfoot, forefoot, and hallux) during stance and swing.

Methods

Ten healthy young …

Application Of Engineered Porosity And Modified Effective Moduli To The Design Of Orthopaedic Implants, John Anthony Choren

Dissertations (1934 -)

Commercially available orthopaedic implants have a bending stiffness (flexural rigidity) that is at least 10 times greater than cortical bone. Effects of this stiffness mismatch have been extensively studied relative to total hip arthroplasty (THA). Clinical experience with THA has shown that stiffness mismatch is the primary cause of accelerated bone resorption due to the stress shielding, resulting in sub-optimal bone loading, aseptic loosening and inadequate bone support for a future revision implant.

Attempts to incorporate design features that reduce the flexural rigidity of implants have yielded inconsistent results or failures due to biomaterial incompatibilities and practical manufacturing complications. The …

Quantitative Evaluation Of Redox Processes In Intact Rat Lungs And Endothelial Cells And The Effect Of Hyperoxia, Zhuohui Gan

Dissertations (1934 -)

A common initial treatment of hypoxemia in patients with lung failure secondary to acute lung injury (e.g., adult respiratory distress syndrome) is oxygen (O₂) therapy (hyperoxia). However, prolonged O₂ therapy causes lung O₂ toxicity, which can further impair lung functions. The rat model of lung O₂ toxicity replicates key features of human lung O₂ toxicity. In addition, rats develop tolerance or susceptibility to 100% O₂ by pre-exposing them to 85% O₂ (hyper-85) or 60% O₂ (hyper-60) for 7 days, respectively. Therefore, the long-term objectives of this study are to elucidate mechanisms …

Investigation Of Spatio-Temporal Effects Of Fmri Visual Field Mapping Techniques On V1, John J. Janik

Dissertations (1934 -)

Blood oxygenation level dependent functional magnetic resonance imaging has been used extensively for mapping the representation of the visual field within the human brain. Visual field mapping using fMRI has been used clinically to assess patients with cortical pathology and to plan surgical treatment impacting the visual system. The accuracy of fMRI-based visual field mapping methods needs to be better understood for clinical use. This accuracy can be important for presurgical mapping of brain function near a tumor resection site since inaccurate rendition of the underlying neural function could lead to inappropriate resection of viable brain tissue. The most widely …

Incorporating The Aortic Valve Into Computational Fluid Dynamics Models Using Phase-Contrast Mri And Valve Tracking, David C. Wendell

Dissertations (1934 -)

The American Heart Association states about 2% of the general population have a bicuspid aortic valve (BAV). BAVs exist in 80% of patients with aortic coarctation (CoA) and likely influences flow patterns that contribute to long-term morbidity post-surgically. BAV patients tend to have larger ascending aortic diameters, increased risk of aneurysm formation, and require surgical intervention earlier than patients with a normal aortic valve. Magnetic resonance imaging (MRI) has been used clinically to assess aortic arch morphology and blood flow in these patients. These MRI data have been used in computational fluid dynamics (CFD) studies to investigate potential adverse hemodynamics …

Climate Change Policy Could Make Keystone Xl Obsolete, Adam Liska

Adam Liska Papers

Clearly the Keystone XL pipeline threatens both surface and ground water that sustains the agricultural economy of Nebraska, but the projected profitability of tar sands oil and the pipeline operation are dependent on the future economics of climate change. Three recent scientific studies estimate the total carbon intensity of tar sands-based gasoline from Alberta (from both production and burning of the fuel) at an average of roughly 22 percent higher than U.S. gasoline in 2005, with the range of average carbon intensities for tar sands-gasoline at 16 to 27 percent higher than most other sources.