Engineering Commons^™

Reduced Diaphyseal Strength Associated With High Intracortical Vascular Porosity Within Long Bones Of Children With Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Osteogenesis imperfecta is a genetic disorder resulting in bone fragility. The mechanisms behind this fragility are not well understood. In addition to characteristic bone mass deficiencies, research suggests that bone material properties are compromised in individuals with this disorder. However, little data exists regarding bone properties beyond the microstructural scale in individuals with this disorder.

Specimens were obtained from long bone diaphyses of nine children with osteogenesis imperfecta during routine osteotomy procedures. Small rectangular beams, oriented longitudinally and transversely to the diaphyseal axis, were machined from these specimens and elastic modulus, yield strength, and maximum strength were measured in three-point …

Generalized Approach Of Stator Shifting In Interior Permanent-Magnet Machines Equipped With Fractional-Slot Concentrated Windings, Patel B. Reddy, Kum-Kang Huh, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Electrical drive systems, which include electrical machines and power electronics, are a key enabling technology for advanced vehicle propulsion systems that reduce the petroleum dependence of the ground transportation sector. To have significant effect, electric drive technologies must be economical in terms of cost, weight, and size while meeting performance and reliability expectations. Interior permanent magnet machines with fractional-slot concentrated windings have been shown to be good candidates for hybrid traction applications. One of the key challenges is the additional stator magnetomotive force sub- and superharmonic components that lead to higher losses in the rotor as well as saturation effects. …

Entrepreneurship In Capstone Design: Has The Pendulum Swung Too Far?, Jay R. Goldberg

Biomedical Engineering Faculty Research and Publications

The author supports entrepreneurial education for all interested students, but not at the expense of design education. He thinks we should develop business literacy among all of our students to prepare them for work in start-ups and established medical device companies, and provide opportunities for interested students to add entrepreneurial literacy to better prepare them to create new companies, either upon graduation or later in their careers. Capstone design courses should focus on helping students develop solid design skills and providing opportunities to apply the analytical tools learned in previous courses. Students should be encouraged, not required, to consider commercializing …

Multi-Objective Tradeoffs In The Design Optimization Of A Brushless Permanent-Magnet Machine With Fractional-Slot Concentrated Windings, Peng Zhang, Gennadi Y. Sizov, Muyang Li, Dan M. Ionel, Nabeel Demerdash, Steven J. Stretz, Alan W. Yeadon

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a robust parametric model of a brushless permanent magnet machine with fractional-slot concentrated windings, which was developed for automated design optimization is presented. A computationally efficient finite-element analysis method was employed to estimate the dq-axes inductances, the induced voltage and torque ripple waveforms, and losses of the machine. A method for minimum effort calculation of the torque angle corresponding to the maximum torque per ampere load condition was developed. A differential evolution algorithm was implemented for the global design optimization with two concurrent objectives of minimum losses and minimum material cost. An engineering decision process based on …

Comparative Assessment Of Diverse Strategies For Malaria Vector Population Control Based On Measured Rates At Which Mosquitoes Utilize Targeted Resource Subsets, Gerry F. Killeen, Samson Sifael Kiware, Aklilu Seyoum, John E. Gimnig, George Corliss, Jennifer Stevenson, Christopher J. Drakeley, Nakul Chitnis

Electrical and Computer Engineering Faculty Research and Publications

Background

Eliminating malaria requires vector control interventions that dramatically reduce adult mosquito population densities and survival rates. Indoor applications of insecticidal nets and sprays are effective against an important minority of mosquito species that rely heavily upon human blood and habitations for survival. However, complementary approaches are needed to tackle a broader diversity of less human-specialized vectors by killing them at other resource targets.

Methods

Impacts of strategies that target insecticides to humans or animals can be rationalized in terms of biological coverage of blood resources, quantified as proportional coverage of all blood resources mosquito vectors utilize. Here, this concept …

Therapeutic Potential Of Haptic Theradrive: An Affordable Robot/Computer System For Motivating Stroke Rehabilitation, Andrew Theriualt, Mark L. Nagurka, Michelle J. Johnson

Mechanical Engineering Faculty Research and Publications

There is a need for increased opportunities for effective neurorehabilitation services for stroke survivors outside the hospital environment. Efforts to develop low-cost robot/computer therapy solutions able to be deployed in home and community rehabilitation settings have been growing. Our long-term goal is to develop a very low-cost system for stroke rehabilitation that can use commercial gaming technology and support rehabilitation with stroke survivors at all functioning levels. This paper reports the results of experiments comparing the old and new TheraDrive systems in terms of ability to assist/resist subjects and the root-mean-square (RMS) trajectory tracking error. Data demonstrate that the new …

Non-Common Path Aberration Correction In An Adaptive Optics Scanning Ophthalmoscope, Yusufu N. Sulai, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

The correction of non-common path aberrations (NCPAs) between the imaging and wavefront sensing channel in a confocal scanning adaptive optics ophthalmoscope is demonstrated. NCPA correction is achieved by maximizing an image sharpness metric while the confocal detection aperture is temporarily removed, effectively minimizing the monochromatic aberrations in the illumination path of the imaging channel. Comparison of NCPA estimated using zonal and modal orthogonal wavefront corrector bases provided wavefronts that differ by ~λ/20 in root-mean-squared (~λ/30 standard deviation). Sequential insertion of a cylindrical lens in the illumination and light collection paths of the imaging channel was used to compare image resolution …

The Reliability Of Parafoveal Cone Density Measurements, Benjamin S. Liu, Sergey Tarima, Alexis D. Visotcky, Alex Pechauer, Robert F. Cooper, Leah Landsem, Melissa A. Wilk, Pooja Godara, Vikram Makhijani, Yusufu N. Sulai, Najia Syed, Galen Yasumura, Anupam K. Garg, Mark E. Pennesi, Brandon J. Lujan, Alfredo Dubra, Jacque L. Duncan, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Background Adaptive optics scanning light ophthalmoscopy (AOSLO) enables direct visualisation of the cone mosaic, with metrics such as cone density and cell spacing used to assess the integrity or health of the mosaic. Here we examined the interobserver and inter-instrument reliability of cone density measurements.

Methods For the interobserver reliability study, 30 subjects with no vision-limiting pathology were imaged. Three image sequences were acquired at a single parafoveal location and aligned to ensure that the three images were from the same retinal location. Ten observers used a semiautomated algorithm to identify the cones in each image, and this was repeated …

Upper Extremity Biomechanics Of Children With Spinal Cord Injury During Wheelchair Mobility, Alyssa J. Schnorenberg, Brooke A. Slavens, Adam Graf, Joseph J. Krzak, Lawrence C. Vogel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

While much work is being done evaluating the upper extremity joint dynamics of adult manual wheelchair propulsion, limited work has examined the pediatric population of manual wheelchair users. Our group used a custom pediatric biomechanical model to characterize the upper extremity joint dynamics of 12 children and adolescents with spinal cord injury (SCI) during wheelchair propulsion. Results show that loading appears to agree with that of adult manual wheelchair users, with the highest loading primarily seen at the glenohumeral joint. This is concerning due to the increased time of wheelchair use in the pediatric population and the impact of this …

Deterministic And Stochastic Resilience Analysis Of Minimum-Time-Controlled Discrete-Time Systems, Jennifer L. Bonniwell, Susan C. Schneider Phd, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

The resilience of discrete-time systems subject to minimum-time control is analysed for both deterministic and stochastic control gain perturbations. Lyapunov analysis is used to determine a tight upper bound on the control gain perturbations to maintain asymptotic stability.

Panel I: Connecting 2nd Law Analysis With Economics, Ecology And Energy Policy, Richard Gaggioli, Mauro Reini

Mechanical Engineering Faculty Research and Publications

The present paper is a review of several papers from the Proceedings of the Joint European Thermodynamics Conference, held in Brescia, Italy, 1–5 July 2013, namely papers introduced by their authors at Panel I of the conference. Panel I was devoted to applications of the Second Law of Thermodynamics to social issues—economics, ecology, sustainability, and energy policy. The concept called Available Energy which goes back to mid-nineteenth century work of Kelvin, Rankine, Maxwell and Gibbs, is relevant to all of the papers. Various names have been applied to the concept when interactions between the system of interest and an environment …

Failure Mechanisms And Key Parameters Of Frp Debonding From Cracked Concrete Beams, Tayyebeh Mohammadi

Dissertations (1934 -)

Intermediate crack (IC) induced debonding failure of Fiber Reinforced Polymer (FRP)-strengthened reinforced concrete beams starts at the tip of flexural/shear cracks within the shear span and propagates towards the FRP plate termination. In this study, experimental and numerical programs are performed to characterize and predict the failure mechanisms of IC debonding failure, and identify the key parameters affecting such failure. It is found that the bond-slip relation obtained from the pullout test does not represent the bond-slip relation of the FRP/concrete interface in the FRP-strengthened concrete beams, and it cannot be directly used for predicting the load capacity of the …

Detailed Computational Modeling Of Laminar And Turbulent Sooting Flames, Adhiraj Dasgupta, Somesh Roy, Daniel C. Haworth

Mechanical Engineering Faculty Research and Publications

This study reports development and validation of two parallel flame solvers with soot models based on the open-source computation fluid dynamics (CFD) toolbox code OpenF0AM. First, a laminar flame solver is developed and validated against experimental data. A semi-empirical two-equation soot model and a detailed soot model using a method of moments with interpolative closure (MOMIC) are implemented in the laminar flame solver. An optically thin radiation model including gray soot radiation is also implemented. Preliminary results using these models show good agreement with experimental data for the laminar axisymmetric diffusion flame studied. Second, a turbulent flame solver is developed …

Determination Of A Predictive Stiffness Model For A 1 Dof Human Inspired Robotic Joint, Michael Boyarsky

Master's Theses (2009 -)

In order to facilitate more natural and intuitive interaction for human users, robots need to move in a more human-like manner as compared to current robots. This change would enable humans to better anticipate robot movements (which would allow humans to better avoid collisions if necessary) and also improve safety in the context of a collision between a robot and a human. The goal of this thesis was to analyze experimental data of human motion to gain an understanding of how human motion and robot motion differ. From this understanding, a neuro-motor model (NMM) of a human elbow (previously established …

Seismic Response Of A Tall Building To Recorded And Simulated Ground Motions, Nenad Bijelic, Ting Lin, Gregory Deierlein

Civil and Environmental Engineering Faculty Research and Publications

Seismological modeling technologies are advancing to the stage of enabling fundamental simulation of earthquake fault ruptures, which offer new opportunities to simulate extreme ground motions for collapse safety assessment and earthquake scenarios for community resilience studies. With the goal toward establishing the reliability of simulated ground motions for performance-based engineering, this paper examines the response of a 20-story concrete moment frame building analyzed by nonlinear dynamic analysis under corresponding sets of recorded and simulated ground motions. The simulated ground motions were obtained through a larger validation study via the Southern California Earthquake Center (SCEC) Broadband Platform (BBP) that simulates magnitude …

Automated Selection Of The Optimal Cardiac Phase For Single-Beat Coronary Ct Angiography Reconstruction, Daniel Stassi

Master's Theses (2009 -)

This thesis investigates an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. Reconstructing a low-motion cardiac phase improves coronary artery visualization in coronary CT angiography (CCTA) exams. Currently, standard end-systole and/or mid-diastole default phases are prescribed or alternatively, quiescent phases are determined by the user. As manual selection may be time-consuming and standard locations may be suboptimal due to patient variability, an automated method is investigated. An automated algorithm was developed to select the optimal phase based on quantitative image quality (IQ) metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated …

An Experimental Fatigue And Finite Element Study Of A Welded Joint Of A Snowplow Blade, George Ernest Selburg

Master's Theses (2009 -)

This study describes a method to evaluate the fatigue life of a welded joint of a snowplow. Fatigue specimens were then fabricated, which simulated the joint and its loading characteristics. The joint in the specimens were characterized by measuring the geometry of the weld and the hardness of the parent material, weld material, and heat affected zone. It was determined that the fatigue crack that developed in the joint was exposed to mode I fracture forces in the normal plane of the crack. The specimens were then tested in a hydraulic closed looped system to determine the mechanism of fatigue …

Design Of A Passive Ankle Prosthesis With Powered Push-Off Using A Cam Timing Mechanism, Jacob J. Rice

Master's Theses (2009 -)

This thesis presents the design and simulation results of the CamWalk, a novel passive prosthetic ankle that has mechanical behavior similar to that for a natural ankle. The CamWalk uses a compression spring network that allows coupling between two degrees of freedom; one for translation along the leg and another for rotation about the ankle joint. When walking, potential energy from the person's weight is stored in the spring network in deflection along the leg. The energy is released by the network as rotation of the foot. The amount of translational work that is converted to rotational work about the …

Analysis Of Sensor Signals And Quantification Of Analytes Based On Estimation Theory, Karthick Sothivelr

Master's Theses (2009 -)

Compact sensor systems for on-site monitoring of groundwater for trace organic compounds are currently under development. To permit near real-time analysis of samples containing multiple analytes, the present work investigates a sensor signal processing approach based on estimation theory, specifically using Kalman Filter and Extended Kalman Filter. As a first step towards the analysis of groundwater samples containing multiple compounds, the approach presented in this work permits estimation of analyte concentration(s) in binary mixtures and single analyte samples on-line, before the sensor response reaches steady-state. Sensor signals from binary mixtures and single analyte samples of BTEX compounds (benzene, toluene, ethylbenzene, …

Modeling, Analysis, And Verification Of A Weld-Breaking Mechanism For Automatic Circuit Recloser Applications, Brian Korves

Master's Theses (2009 -)

The automatic circuit recloser (ACR) is responsible for protecting electrical distribution grids in the event that high voltage power lines come in contact with ground. In order to prevent damage, ACRs break the electrical continuity of the circuit through the use of a vacuum interrupter and a weld breaking mechanism. Vacuum interrupters consist of two metallic contacts in an air-tight ceramic housing. Due to the electrical interactions that take place during the interruption process, unintended welds are formed between the contacts. These welds have the ability to impede or completely stop the interruption process, thus rendering the ACR inoperable. In …

The Effects Of Organ-Based Tube Current Modulation On Radiation Dose And Image Quality In Computed Tomography Imaging, Diksha Gandhi

Master's Theses (2009 -)

The purpose of this thesis was to quantify dose and noise performance of organ-dose-based tube current modulation (ODM) through experimental studies with an anthropomorphic phantom and simulations with a voxelized phantom library. Tube current modulation is a dose reduction technique that modulates radiation dose in angular and/or slice directions based on patient attenuation. ODM technique proposed by GE Healthcare further reduces tube current for anterior source positions, without increasing current for posterior positions. Axial CT scans at 120 kV were performed on head and chest phantoms (Rando Alderson Research Laboratories, Stanford, CA) on an ODM-equipped scanner (Optima CT660, GE Healthcare, …

Analysis Of The Detection Of Organophosphate Pesticides In Aqueous Solutions Using Polymer-Coated Single Idt Sensors, Michael J. Mccarthy

Master's Theses (2009 -)

The single interdigital transducer (IDT) device was investigated as a micro-chemical sensor for the detection of organophosphates compounds in aqueous solutions. The compounds of interest are: parathion, parathion-methyl, and paraoxon. The polymers used as a partially-selective coating for the direct detection of these compounds are 2,2'-diallylbisphenol A- 1,1,3,3,5,5-hexamethyltrisiloxane (BPA-HMTS) and polyepichlorohydrin (PECH). BPA-HMTS is synthesized here at Marquette University. The measurement of interest for the single IDT is the change radiation resistance. The radiation resistance represents the energy stored in the propagating acoustic wave. As analyte absorbs into the polymer coating, changes in the film's properties will undergo resulting in …

Design And Verification Of A Compact Variable Stiffness Actuator With A Very Large Range Of Stiffness, Daniel Garces

Master's Theses (2009 -)

Current conventional robots require high stiffness joints to provide absolute positioning accuracy in free space which also causes problems when operating in constrained space. To circumvent these problems, Variable Stiffness Actuators (VSAs) can be used to vary their stiffness to suit the task being performed. A new VSA was designed to provide a very large range of stiffness in a compact size. The Arched Flexure VSA uses a cantilevered beam acting as the flexure with a variable point of contact. It allows the joint to have continuous variable stiffness, have zero stiffness for a small range of motion, and rapid …

Measuring Tumor Cycling Hypoxia And Angiogenesis Using A Side-Firing Fiber Optic Probe, Bing Yu, Amy Shah, Bingqing Wang, Narasimhan Rajaram, Quanli Wang, Nirmala Ramanujam, Gregory M. Palmer, Mark W. Dewhirst

Biomedical Engineering Faculty Research and Publications

Hypoxia and angiogenesis can significantly influence the efficacy of cancer therapy and the behavior of surviving tumor cells. There is a growing demand for technologies to measure tumor hypoxia and angiogenesis temporally in vivo to enable advances in drug development and optimization. This paper reports the use of frequency-domain photon migration with a side-firing probe to quantify tumor oxygenation and hemoglobin concentrations in nude rats bearing human head/neck tumors administered with carbogen gas, cycling hypoxic gas or just room air. Significant increase (with carbogen gas breathing) or decrease (with hypoxic gas breathing) in tumor oxygenation was observed. The trend in …

Relationship Between Foveal Cone Specialization And Pit Morphology In Albinism, Melissa A. Wilk, John T. Mcallister, Robert F. Cooper, Adam M. Dubis, Teresa N. Patitucci, Phyllis Summerfelt, Jennifer L. Anderson, Deborah M. Costakos, Thomas B. Connor Jr., William J. Wirostko, Pei-Wen Chiang, Alfredo Dubra, Christine A. Curcio, Murray H. Briliant, C. Gail Summers, Joseph Carroll, Jennifer L. Anderson

Biomedical Engineering Faculty Research and Publications

Purpose. Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism.

Methods. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects …

Microscopic Inner Retinal Hyper-Reflective Phenotypes In Retinal And Neurologic Disease, Drew Scoles, Brian P. Higgins, Robert F. Cooper, Adam M. Dubis, Phyllis Summerfelt, David V. Weinberg, Judy E. Kim, Kimberly E. Stepien, Joseph Carroll, Alfredo Dubra

Biomedical Engineering Faculty Research and Publications

Purpose.

We surveyed inner retinal microscopic features in retinal and neurologic disease using a reflectance confocal adaptive optics scanning light ophthalmoscope (AOSLO).

Methods.

Inner retinal images from 101 subjects affected by one of 38 retinal or neurologic conditions and 11 subjects with no known eye disease were examined for the presence of hyper-reflective features other than vasculature, retinal nerve fiber layer, and foveal pit reflex. The hyper-reflective features in the AOSLO images were grouped based on size, location, and subjective texture. Clinical imaging, including optical coherence tomography (OCT), scanning laser ophthalmoscopy, and fundus photography was analyzed for comparison.

Results.

Seven …

Effect Of Lowest Instrumented Vertebra On Trunk Mobility In Patients With Adolescent Idiopathic Scoliosis Undergoing A Posterior Spinal Fusion, Ubong I. Udoekwere, Joseph Krzak, Adam Graf, Sahar Hassani, Sergey Tarima, Mary Riordan, Peter F. Sturm, Kim W. Hammerberg, Purnendu Gupta, Alireza K. Anissipour, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Study Design

Prospective.

Objectives

The goal of this study was to evaluate the effect of posterior spinal fusion surgery terminating at different lowest instrumented vertebrae (LIV) on trunk mobility in individuals with adolescent idiopathic scoliosis (AIS).

Summary of Background Data

Posterior spinal fusion with instrumentation is the standard surgical technique employed in AIS for correcting spine deformities with Cobb angles exceeding 50°. Surgical correction of curve deformity reduces trunk mobility and range of motion. However, conflicting findings from previous studies investigating the impact of different LIV levels on the reduction in trunk mobility after surgery have been reported.

Methods

The …

Stochastic Analysis Of Cascading-Failure Dynamics In Power Grids, Mahshid Rahnamay-Naeini, Zhuoyao Wang, Nasir Ghani, Andrea Mammoli, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

A scalable and analytically tractable probabilistic model for the cascading failure dynamics in power grids is constructed while retaining key physical attributes and operating characteristics of the power grid. The approach is based upon extracting a reduced abstraction of large-scale power grids using a small number of aggregate state variables while modeling the system dynamics using a continuous-time Markov chain. The aggregate state variables represent critical power-grid attributes, which have been shown, from prior simulation-based and historical-data-based analysis, to strongly influence the cascading behavior. The transition rates among states are formulated in terms of certain parameters that capture grid's operating …

Terahertz Photoacoustic Spectroscopy Using An Mems Cantilever Sensor, Nathan E. Giauvitz, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a microelectromechanical systems cantilever sensor was designed, modeled, and fabricated to measure the photoacoustic (PA) response of gases under very low vacuum conditions. The micromachined devices were fabricated using silicon-on-insulator wafers and then tested in a custom-built, miniature, vacuum chamber during this first-ever demonstration. Terahertz radiation was amplitude modulated to excite the gas under test and perform PA molecular spectroscopy. Experimental data show a predominantly linear response that directly correlates measured cantilever deflection to PA signals. Excellent low pressure (i.e., 2-40 mTorr) methyl cyanide PA spectral data were collected resulting in a system sensitivity of 1.97 × …

Looking For Your Next Disruptive Technology? Try Student Competitions, Jay R. Goldberg, Phil Weilerstein

Biomedical Engineering Faculty Research and Publications

No abstract provided.