Engineering Commons^™

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 …

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 …

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 …

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 …

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

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 …}

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

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 …

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 …

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 …

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 …

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. …

Integrating Meal And Exercise Into Personalized Glucoregulation Models: Metabolic Dynamics And Diabetic Athletes, Sofie Schunk

Master's Theses (2009 -)

Diabetes affects nearly 26 million Americans, according to the American Diabetes Association, with as many as three million Americans who have Type 1 Diabetes (ADA, 2015). Type 1 Diabetes (T1D) is autoimmune and characterized by little to no insulin production whereas Type 2 Diabetes (T2D) concerns insulin resistance and inability to use produced insulin. Factors contributing to current diabetes management and regulation include exercise type, daily movement activities, and distinct tissue compartment metabolism, each challenging to model in a robust and comprehensive manner. Past models are highly limited in regard to exercise and varying glucose fluctuations dependent on type, intensity, …

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 …

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 …

Real-Time Topic And Sentiment Analysis In Human-Robot Conversation, Elise Russell

Master's Theses (2009 -)

Socially interactive robots, especially those designed for entertainment and companionship, must be able to hold conversations with users that feel natural and engaging for humans. Two important components of such conversations include adherence to the topic of conversation and inclusion of affective expressions. Most previous approaches have concentrated on topic detection or sentiment analysis alone, and approaches that attempt to address both are limited by domain and by type of reply. This thesis presents a new approach, implemented on a humanoid robot interface, that detects the topic and sentiment of a user’s utterances from text-transcribed speech. It also generates domain-independent, …

Bidirectional Ac-Dc Converter For Vehicle-To-Grid (V2g) Applications, Arjun Raj Prabu Andhra Sridhar

Master's Theses (2009 -)

Electric vehicles are growing at a rapid pace in the internal combustion engine dominated transportation sector, and bring environmental and economic benefits to society. Electric vehicles produce nearly zero carbon emission, provided that they are charged through renewable energy sources. Electric vehicles reduce our dependency on foreign oil and also offer additional benefits like Vehicle-to-grid (V2G). V2G is a technology that allows electric energy stored in the electric vehicle batteries to be returned to the grid during peak demand. V2G can also provide voltage regulation, voltage shaving, reactive power compensation and distributed generation. This necessitates that an electric vehicle battery …

Noninvasive Assessment Of Photoreceptor Structure And Function In The Human Retina, Robert Francis Cooper

Dissertations (1934 -)

The human photoreceptor mosaic underlies the first steps of vision; thus, even subtle defects in the mosaic can result in severe vision loss. The retina can be examined directly using clinical tools; however these devices lack the resolution necessary to visualize the photoreceptor mosaic. The primary limiting factor of these devices is the optical aberrations of the human eye. These aberrations are surmountable with the incorporation of adaptive optics (AO) to ophthalmoscopes, enabling imaging of the photoreceptor mosaic with cellular resolution. Despite the potential of AO imaging, much work remains before this technology can be translated to the clinic. Metrics …

Anaerobic Membrane Bioreactors To Treat Municipal Wastewater At Ambient Temperatures, Matthew D. Seib

Dissertations (1934 -)

Anaerobic biotechnology is viewed as a sustainable alternative to aerobic biotechnology for municipal wastewater recovery. However, anaerobic processes have not been successful in cold climates. Past examples have not been able to meet low organic effluent concentrations, or have failed due to biomass washout resulting from low temperature operation and short hydraulic residence time. Recently, the anaerobic membrane bioreactor (AnMBR) has been shown to achieve low effluent organic concentrations and maintain stable anaerobic biomass. However, shortcomings have included high energy demands for membrane operation and poor understanding of microbial community structures within AnMBRs. This dissertation describes efforts to improve AnMBRs …

Health Condition Monitoring And Fault-Tolerant Operation Of Adjustable Speed Drives, Jiangbiao He

Dissertations (1934 -)

Adjustable speed drives (ASDs) have been extensively used in industrial applications over the past few decades because of their benefits of energy saving and control flexibilities. However, the wider penetration of ASD systems into industrial applications is hindered by the lack of health monitoring and fault-tolerant operation techniques, especially in safety-critical applications. In this dissertation, a comprehensive portfolio of health condition monitoring and fault-tolerant operation strategies is developed and implemented for multilevel neutral-point-clamped (NPC) power converters in ASDs. Simulations and experiments show that these techniques can improve power cycling lifetime of power transistors, on-line diagnosis of switch faults, and fault-tolerant …

A Semantics-Based Approach To Construction Cost Estimating, Mehrdad Niknam

Dissertations (1934 -)

A construction project requires collaboration of different organizations such as owner, designer, contractor, and resource suppliers. These organizations need to exchange information to improve their teamwork. Understanding the information created in other organizations requires specialized human resources. Construction cost estimating is one of the processes that requires information collected from several sources including a building information model (BIM) created by designers, estimating assembly and work item information maintained by contractors, and construction resource cost information provided by resource suppliers. Currently, it is not easy for computers to integrate the information for construction cost estimating over the Internet. This study discusses …

Biomechanical Characerization And Evaluation Of Conservative Clubfoot Correction, Tamara Loren Cohen

Dissertations (1934 -)

Congential talipes equinovarus, or clubfoot, affects approximately 200,000 newborns worldwide each year and presents with equinovarus of the hindfoot, as well as cavus and adduction of the midfoot. In addition to bone malformation and displacement, soft tissue contractures encapsulate the medial and posterior aspects of the affected foot. The Ponseti method is a conservative treatment that progressively repositions the clubfoot through weekly casting, followed by bracing. Concerns exist regarding the variability in outcomes, resistance to treatment, and risk of relapse, which occur in approximately 10% of the population. Potential factors contributing to variability and resistant clubfoot include cast material performance, …

Computational Approaches For Remote Monitoring Of Symptoms And Activities, Ferdaus Kawsar

Dissertations (1934 -)

We now have a unique phenomenon where significant computational power, storage, connectivity, and built-in sensors are carried by many people willingly as part of their life style; two billion people now use smart phones. Unique and innovative solutions using smart phones are motivated by rising health care cost in both the developed and developing worlds. In this work, development of a methodology for building a remote symptom monitoring system for rural people in developing countries has been explored. Design, development, deployment, and evaluation of e-ESAS is described. The system’s performance was studied by analyzing feedback from users. A smart phone …