Engineering Commons^™

Material And Structural Aspects Of Bone In Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Bone fragility is a fundamental problem in individuals with osteogenesis imperfecta (OI). The mechanisms behind this fragility, however, are not yet well understood. Multiple factors appear to contribute to the increased fracture risk in OI. At the structural level, bone mass deficiency can result in increased stress levels within bones. The underlying mineral and collagen abnormalities that define OI are also believed to result in compromised material-level properties. The variability of collagen biochemical irregularities causing OI and the corresponding heterogeneity of disease severity result in abnormalities that are not easily generalized within the OI population.

The aims of this chapter …

Motion Analysis Strategy Appropriate For 3d Kinematic Assessment Of Children And Adults With Osteogenesis Imperfecta, Jeffrey D. Kertis, Jessica M. Fritz, Sergey Tarima, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Human motion analysis provides a quantitative means of assessing whole body and segmental motion of subjects with musculoskeletal pathologies. This chapter describes a low cost motion analysis appropriate for complete three-dimensional (3D) assessment of upper and lower extremity kinematics. The system has been designed to support lower cost outreach efforts that require accuracy and resolution on the order of classical fixed lot systems such as Vicon. The focus of this work addresses the assessment needs typically seen in adults and children with osteogenesis imperfect (OI) experiencing ambulatory and upper extremity challenges.

Lessons Learned From A 10-Year Collaboration Between Engineering And Industrial Design Students In Capstone Design Projects, Jay R. Goldberg, Pascal Malassigné

Biomedical Engineering Faculty Research and Publications

Engineers and industrial designers have different approaches to problem solving. Both place heavy emphasis on identification of customer needs, manufacturing methods, and prototyping. Industrial designers focus on aesthetics, ergonomics, ease of use, and the user’s experience. They tend to be more visual and more concerned with the interaction between users and products. Engineers focus on functionality, performance requirements, analytical modeling, and design verification and validation. They tend to be more analytical and more concerned with the design of internal components and product performance. Engineers and industrial designers often work together on project teams in industry. Collaboration between the two groups …

Smartphone Microendoscopy For High Resolution Fluorescence Imaging, Xiangqian Hong, Vivek K. Nagarajan, Dale H. Mugler, Bing Yu

Biomedical Engineering Faculty Research and Publications

High resolution optical endoscopes arc increasingly used in diagnosis of various medical conditions of internal organs, such as the cervix and gastrointestinal (GI) tracts, but they are too expensive for use in resource-poor settings. On the other hand, smartphones with high resolution cameras and Internet access have become more affordable, enabling them to diffuse into most rural areas and developing countries in the past decade. In this paper, we describe a smartphone microendoscope that can take fluorescence images with a spatial resolution of 3.1 μm. Images collected from ex vivo, in vitro and in vivo samples using the device …

Robust Multi-Criteria Optimal Fuzzy Control Of Discrete-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a novel fuzzy control design of discrete-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with an inherent stability property together with a dissipativity type of disturbance reduction. The Takagi–Sugeno-type fuzzy model is used in our control system design. By solving a linear matrix inequality at each time step, the optimal control solution can be found to satisfy mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the …

A Computationally Efficient Method For Calculation Of Strand Eddy Current Losses In Electric Machines, Alireza Fatemi, Dan M. Ionel, Nabeel Demerdash, Dave A. Staton, Rafal Wrobel, Yew Chuan Chong

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a fast finite element (FE)-based method for the calculation of eddy current losses in the stator windings of randomly wound electric machines with a focus on fractional slot concentrated winding (FSCW) permanent magnet (PM) machines will be presented. The method is particularly suitable for implementation in large-scale design optimization algorithms where a qualitative characterization of such losses at higher speeds is most beneficial for identification of the design solutions which exhibit the lowest overall losses including the ac losses in the stator windings. Unlike the common practice of assuming a constant slot fill factor, sf, for all …

Sensor-Based Estimation Of Btex Concentrations In Water Samples Using Recursive Least Squares And Kalman Filter Techniques, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco

Electrical and Computer Engineering Faculty Research and Publications

This work investigates sensor signal processing approaches that can be used with a sensor system for direct on-site monitoring of groundwater, enabling detection and quantification of BTEX (benzene, toluene, ethylbenzene and xylene) compounds at μg/L (ppb) concentrations in the presence of interferents commonly found in groundwater. A model for the sensor response to water samples containing multiple analytes was first formulated based on experimental results. The first signal processing approach utilizes only RLSE (recursive least squares estimation) whereas the second, a two-step processing technique, utilizes both RLSE and bank of Kalman filters for the estimation process. The estimation techniques were …

On The Analytical Formulation Of Excess Noise In Avalanche Photodiodes With Dead Space, Erum Jamil, Jeng Shiuh Cheong, J.P.R. David, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

Simple, approximate formulas are developed to calculate the mean gain and excess noise factor for avalanche photodiodes using the dead-space multiplication theory in the regime of small multiplication width and high applied electric field. The accuracy of the approximation is investigated by comparing it to the exact numerical method using recursive coupled integral equations and it is found that it works for dead spaces up to 15% of the multiplication width, which is substantial. The approximation is also tested for real materials such as GaAs, InP and Si for various multiplication widths, and the results found are accurate within ∼ …

Effect Of Tendon Vibration On Hemiparetic Arm Stability In Unstable Workspaces, Megan O. Conrad, Bani Gadhoke, Robert A. Scheidt, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Sensory stimulation of wrist musculature can enhance stability in the proximal arm and may be a useful therapy aimed at improving arm control post-stroke. Specifically, our prior research indicates tendon vibration can enhance stability during point-to-point arm movements and in tracking tasks. The goal of the present study was to investigate the influence of forearm tendon vibration on endpoint stability, measured at the hand, immediately following forward arm movements in an unstable environment. Both proximal and distal workspaces were tested. Ten hemiparetic stroke subjects and 5 healthy controls made forward arm movements while grasping the handle of a two-joint robotic …

Plasmonic Field Confinement For Separate Absorption-Multiplication In Ingaas Nanopillar Avalanche Photodiodes, Alan C. Farrell, Pradeep Senanayake, Chung-Hong Hung, George El-Howayek, Abhejit Rajagopal, Marc Currie, Majeed M. Hayat, Diana L. Huffaker

Electrical and Computer Engineering Faculty Research and Publications

Avalanche photodiodes (APDs) are essential components in quantum key distribution systems and active imaging systems requiring both ultrafast response time to measure photon time of flight and high gain to detect low photon flux. The internal gain of an APD can improve system signal-to-noise ratio (SNR). Excess noise is typically kept low through the selection of material with intrinsically low excess noise, using separate-absorption-multiplication (SAM) heterostructures, or taking advantage of the dead-space effect using thin multiplication regions. In this work we demonstrate the first measurement of excess noise and gain-bandwidth product in III–V nanopillars exhibiting substantially lower excess noise factors …

Comments On “The Principal Axes Decomposition Of Spatial Stiffness Matrices”, Shuguang Huang, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

A significant amount of research has been directed toward developing a more intuitive appreciation of spatial elastic behavior. Results of these analyses have been described in terms of behavior decompositions and in terms of behavior centers. In a recent paper entitled “The Principal Axes Decomposition of Spatial Stiffness Matrices” by Chen et al. (IEEE Trans. Robot., vol. 31, no. 1, pp. 191-207), a decomposition of spatial stiffness was presented, and centers of stiffness and compliance were identified. The results presented in the paper have substantial overlap with previously published results and redefine previously used terms. The objective of this communication …

Ecohydrological Controls On Grass And Shrub Above-Ground Net Primary Productivity In A Seasonally Dry Climate, Anthony J. Parolari, Michael L. Goulden, Rafael L. Bras

Civil and Environmental Engineering Faculty Research and Publications

Seasonally dry, water‐limited regions are often co‐dominated by distinct herbaceous and woody plant communities with contrasting ecohydrological properties. We investigated the shape of the above‐ground net primary productivity (ANPP) response to annual precipitation (P_a) for adjacent grassland and shrubland ecosystems in Southern California, with the goal of understanding the role of these ecohydrological properties on ecosystem function. Our synthesis of observations and modelling demonstrates grassland and shrubland exhibit distinct ANPP‐P_a responses that correspond with characteristics of the long‐term P_a distribution and mean water balance fluxes. For annual grassland, no ANPP occurs below a ‘precipitation …

Biochar From Pyrolysis Of Biosolids For Nutrient Adsorption And Turfgrass Cultivation, Daniel Elliott Carey, Patrick J. Mcnamara, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

At water resource recovery facilities, nutrient removal is often required and energy recovery is an ever-increasing goal. Pyrolysis may be a sustainable process for handling wastewater biosolids because energy can be recovered in the py-gas and py-oil. Additionally, the biochar produced has value as a soil conditioner. The objective of this work was to determine if biochar could be used to adsorb ammonia from biosolids filtrate and subsequently be applied as a soil conditioner to improve grass growth. The maximum carrying capacity of base modified biochar for NH₃−N was 5.3 mg/g. Biochar containing adsorbed ammonium and potassium was …

Increased Lower Limb Spasticity But Not Strength Or Function Following A Single-Dose Serotonin Reuptake Inhibitor In Chronic Stroke, Krishnaj Gourab, Brian D. Schmit, T. George Hornby

Biomedical Engineering Faculty Research and Publications

Objective: To investigate the effects of single doses of a selective serotonin reuptake inhibitor (SSRI) on lower limb voluntary and reflex function in individuals with chronic stroke.

Design: Double-blind, randomized, placebo-controlled crossover trial.

Setting: Outpatient research setting.

Participants: Individuals (N=10; 7 men; mean age ± SD, 57±10y) with poststroke hemiplegia of >1 year duration who completed all assessments.

Interventions: Patients were assessed before and 5 hours after single-dose, overencapsulated 10-mg doses of escitalopram (SSRI) or placebo, with 1 week between conditions.

Main Outcome Measures: Primary assessments included maximal ankle and knee isometric strength, and velocity-dependent (30°/s–120°/s) plantarflexor stretch reflexes under …

Retinal Architecture In ​Rgs9- And ​R9ap-Associated Retinal Dysfunction (Bradyopsia), Rupert W. Strauss, Adam M. Dubis, Robert F. Cooper, Rola Ba-Abbad, Anthony T. Moore, Andrew R. Webster, Alfredo Dubra, Joseph Carroll, Michel Michaelides

Biomedical Engineering Faculty Research and Publications

Purpose

To characterize photoreceptor structure and mosaic integrity in subjects with RGS9- and R9AP-associated retinal dysfunction (bradyopsia) and compare to previous observations in other cone dysfunction disorders such as oligocone trichromacy.

Design

Observational case series.

Methods

setting: Moorfields Eye Hospital (United Kingdom) and Medical College Wisconsin (USA). study population: Six eyes of 3 subjects with disease-causing variants in RGS9 or R9AP. main outcome measures: Detailed retinal imaging using spectral-domain optical coherence tomography and confocal adaptive-optics scanning light ophthalmoscopy.

Results

Cone density at 100 μm from foveal center ranged from 123 132 cones/mm²to 140 013 cones/mm^{2 …}

Toward Higher-Order Mass Detection: Influence Of An Adsorbate’S Rotational Inertia And Eccentricity On The Resonant Response Of A Bernoulli-Euler Cantilever Beam, Stephen M. Heinrich, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

In this paper a new theoretical model is derived, the results of which permit a detailed examination of how the resonant characteristics of a cantilever are influenced by a particle (adsorbate) attached at an arbitrary position along the beam’s length. Unlike most previous work, the particle need not be small in mass or dimension relative to the beam, and the adsorbate’s geometric characteristics are incorporated into the model via its rotational inertia and eccentricity relative to the beam axis. For the special case in which the adsorbate’s (translational) mass is indeed small, an analytical solution is obtained for the particle-induced …

Stochastic Rainfall-Runoff Model With Explicit Soil Moisture Dynamics, Mark Bartlett, E. Daly, Jeffrey Mcdonnell, Anthony J. Parolari, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Stream runoff is perhaps the most poorly represented process in ecohydrological stochastic soil moisture models. Here we present a rainfall-runoff model with a new stochastic description of runoff linked to soil moisture dynamics. We describe the rainfall-runoff system as the joint probability density function (PDF) of rainfall, soil moisture and runoff forced by random, instantaneous jumps of rainfall. We develop a master equation for the soil moisture PDF that accounts explicitly for a general state-dependent rainfall-runoff transformation. This framework is then used to derive the joint rainfall-runoff and soil moisture-runoff PDFs. Runoff is initiated by a soil moisture threshold and …

Ion Exchange-Precipitation For Nutrient Recovery From Dilute Wastewater, A. T. Williams, Daniel Zitomer, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Regulated phosphorus (P) and nitrogen (N) discharges and the cost of fertilizer provide economic drivers for nutrient removal and recovery from wastewater. This study used ion exchange (IX) in dilute (domestic) wastewater to concentrate nutrients with subsequent recovery by struvite precipitation. This is the first tertiary wastewater treatment study directly comparing P removal using a range of Fe, Cu, and Al-based media followed by clinoptilolite IX columns for N removal and precipitation using the combined regenerants. Phosphate removal prior to breakthrough was 0.5–2.0 g P L_media⁻¹, providing effluent concentrations −1 PO₄-P and −1 NH_{4 …}

Computational Replication Of The Patient-Specific Stenting Procedure For Coronary Artery Bifurcations: From Oct And Ct Imaging To Structural And Hemodynamics Analyses, Claudio Chiastra, Wei Wu, Benjamin Dickerhoff, Ali Aleiou, Gabriele Dubini, Hiromasa Otake, Francesco Migliavacca, John F. Ladisa Jr.

Biomedical Engineering Faculty Research and Publications

The optimal stenting technique for coronary artery bifurcations is still debated. With additional advances computational simulations can soon be used to compare stent designs or strategies based on verified structural and hemodynamics results in order to identify the optimal solution for each individual’s anatomy. In this study, patient-specific simulations of stent deployment were performed for 2 cases to replicate the complete procedure conducted by interventional cardiologists. Subsequent computational fluid dynamics (CFD) analyses were conducted to quantify hemodynamic quantities linked to restenosis.

Patient-specific pre-operative models of coronary bifurcations were reconstructed from CT angiography and optical coherence tomography (OCT). Plaque location and …

Effect Of Imperceptible Vibratory Noise Applied To Wrist Skin On Fingertip Touch Evoked Potentials – An Eeg Study, Na Jin Seo, Kishor Lakshminarayanan, Leonardo Bonilha, Abigail W. Lauer, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Random vibration applied to skin can change the sense of touch. Specifically, low amplitude white-noise vibration can improve fingertip touch perception. In fact, fingertip touch sensation can improve even when imperceptible random vibration is applied to other remote upper extremity areas such as wrist, dorsum of the hand, or forearm. As such, vibration can be used to manipulate sensory feedback and improve dexterity, particularly during neurological rehabilitation. Nonetheless, the neurological bases for remote vibration enhanced sensory feedback are yet poorly understood. This study examined how imperceptible random vibration applied to the wrist changes cortical activity for fingertip sensation. We measured …

Detection Of Acute Nervous System Injury With Advanced Diffusion-Weighted Mri: A Simulation And Sensitivity Analysis, Nathan P. Skinner, Shekar N. Kurpad, Brian D. Schmit, Matthew D. Budde

Biomedical Engineering Faculty Research and Publications

Diffusion-weighted imaging (DWI) is a powerful tool to investigate the microscopic structure of the central nervous system (CNS). Diffusion tensor imaging (DTI), a common model of the DWI signal, has a demonstrated sensitivity to detect microscopic changes as a result of injury or disease. However, DTI and other similar models have inherent limitations that reduce their specificity for certain pathological features, particularly in tissues with complex fiber arrangements. Methods such as double pulsed field gradient (dPFG) and q-vector magic angle spinning (qMAS) have been proposed to specifically probe the underlying microscopic anisotropy without interference from the macroscopic tissue organization. …

Forecasting Design Day Demand Using Extremal Quantile Regression, David Joseph Kaftan, Jarrett L. Smalley, George F. Corliss, Ronald H. Brown, Richard J. Povinelli

Electrical and Computer Engineering Faculty Research and Publications

Extreme events occur rarely, making them difficult to predict. Extreme cold events strain natural gas systems to their limits. Natural gas distribution companies need to be prepared to satisfy demand on any given day that is at or warmer than an extreme cold threshold. The hypothetical day with temperature at this threshold is called the Design Day. To guarantee Design Day demand is satisfied, distribution companies need to determine the demand that is unlikely to be exceeded on the Design Day.

We approach determining this demand as an extremal quantile regression problem. We review current methods for extremal quantile regression. …

Quantifying Cross-Scatter Contamination In Biplane Fluoroscopy Motion Analysis Systems, Janelle A. Cross, Ben Mchenry, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Biplane fluoroscopy is used for dynamic in vivo three-dimensional motion analysis of various joints of the body. Cross-scatter between the two fluoroscopy systems may limit tracking accuracy. This study measured the magnitude and effects of cross-scatter in biplane fluoroscopic images. Four cylindrical phantoms of 4-, 6-, 8-, and 10-in. diameter were imaged at varying kVp levels to determine the cross-scatter fraction and contrast-to-noise ratio (CNR). Monte Carlo simulations quantified the effect of the gantry angle on the cross-scatter fraction. A cadaver foot with implanted beads was also imaged. The effect of cross-scatter on marker-based tracking accuracy was investigated. Results demonstrated …

Fast Gpu-Based Approach To Branchless Distance-Driven Projection And Back-Projection In Cone Beam Ct, Daniel Edward Schlifske

Master's Theses (2009 -)

Modern CT image reconstruction algorithms rely on projection and back-projection operations to refine an image estimate in iterative image reconstruction. A widely-used state-of-the-art technique is distance-driven projection and back-projection. While the distance-driven technique yields superior image quality in iterative algorithms, it is a computationally demanding process. This has a detrimental effect on the relevance of the algorithms in clinical settings. A few methods have been proposed for enhancing the distance-driven technique in order to take advantage of modern computer hardware. This study explores a two-dimensional extension of the branchless method, which is a technique that does not compromise image quality. …

Towards Mhealth Solutions For Asthma Patients, Nahid Negar

Master's Theses (2009 -)

With the recent, rapid growth in mobile-computing technology, mobile health (mHealth) is becoming a popular research topic. mHealth is one of several examples of how using technology in the health sector is being more advanced every day. mHealth is being applied to the care of a broad spectrum of diseases from acute to chronic, such as the flu, asthma, and cancer. Due to the easy-to-understand and friendly user interfaces, mobility and cost effectiveness; a mobile application can be a powerful tool to collect patient information. Asthma is a common disease around the globe. Collecting the proper symptom, trigger, peak-flow and …

Lpcoms: Towards A Low Power Wireless Smart-Shoe System For Gait Analysis In People With Disabilities, Ishmat Zerin

Master's Theses (2009 -)

Gait analysis using smart sensor technology is an important medical diagnostic process and has many applications in rehabilitation, therapy and exercise training. In this thesis, we present a low power wireless smart-shoe system (LPcomS) to analyze different functional postures and characteristics of gait while walking. We have designed and implemented a smart-shoe with a Bluetooth communication module to unobtrusively collect data using smartphone in any environment. With the design of a shoe insole equipped with four pressure sensors, the foot pressure is been collected, and those data are used to obtain accurate gait pattern of a patient. With our proposed …

Investigation Of Surface Topography Effects On Metal Flow Under Lubricated Hot Compression Of Aluminum, Justin Irvin Kurk

Master's Theses (2009 -)

An investigation was conducted to study the effects of die surface topography, specifically surface roughness and lay, on metal flow and the friction factor under lubricated hot compression. 6061-T6 aluminum rings and square bar stock specimens were compressed on H-13 tool steel platens machined with a unidirectional lay pattern to six different roughnesses between a R 10 and 240 μin. A lab based hydraulic press mounted with an experimental die set was used for all testing. Repeated trials were conducted using high temperature vegetable oil and boron nitride lubricants. Metal flow was quantified as a function of surface roughness, lay …

Optimizing A Hammer Forging Progression For A Large Hand Tool, Edgar Espinoza

Master's Theses (2009 -)

In the forging industry of today the need for United States based companies to reduce cost and maintain or improve the quality of a product has become essential in order to remain competitive. A company such as Green Bay Drop Forge (GBDF), a manufacturer of standard and custom steel forgings, was tasked with improving the forging process of one of their large hand tool products. A large wrench, forged at GBDF was noticed to contain a large amount of flash and excessive amount of hammer blows required to forge the part. The large amounts of flash and excessive hammer blows …

Hockey Skating Kinematics And The Effect Of Skate Design And Technique Training, Rebecca Mae Tidman

Master's Theses (2009 -)

The purpose of this study was to investigate the effects of technique training and hockey skate design on hockey skating performance. Fourteen male subjects, aged 12-16 years, with no recent skate treadmill experience completed ten training sessions on a skating treadmill. Instruction emphasized maximizing stride width by pushing laterally with the skate pointed anteriorly. Subjects were randomly placed into one of two experimental groups based on initial skate type: traditional or Easton Mako. After completion of five sessions, skate type was switched so that skate design effects could be assessed. In contrast to a traditional hockey skate design, the Easton …

Mechanical Characterization Of Carbon Fiber And Thermoplastic Ankle Foot Orthoses, Amanda Wach

Master's Theses (2009 -)

The needs of an increasingly young and active orthotic patient population has led to advancements in ankle foot orthosis (AFO) design and materials to enable higher function. The Intrepid Dynamic Exoskeletal Orthosis (IDEO) is a custom energy-storing carbon fiber AFO that has demonstrated improved clinical function, allowing patients to return to high-intensity activities such as sports and military service. An improved understanding of AFO mechanical function will aid prescription and fitting, as well as assist in design modifications for different patient populations. This study investigated the mechanical properties of AFOs, specifically structural stiffness, rotational motion, and strut deflection, to discern …