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Full-Text Articles in Biomedical Engineering and Bioengineering

Enabling Daily Tracking Of Individual’S Cognitive State With Eyewear, Soha Rostaminia Oct 2022

Enabling Daily Tracking Of Individual’S Cognitive State With Eyewear, Soha Rostaminia

Doctoral Dissertations

Research studies show that sleep deprivation causes severe fatigue, impairs attention and decision making, and affects our emotional interpretation of events, which makes it a big threat to public safety, and mental and physical well-being. Hence, it would be most desired if we could continuously measure one’s drowsiness and fatigue level, their emotion while making decisions, and assess their sleep quality in order to provide personalized feedback or actionable behavioral suggestions to modulate sleep pattern and alertness levels with the aim of enhancing performance, well-being, and quality of life. While there have been decades of studies on wearable devices, we …


Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian Oct 2022

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …


A Generalized Method For Predictive Simulation-Based Lower Limb Prosthesis Design, Mark Price Apr 2021

A Generalized Method For Predictive Simulation-Based Lower Limb Prosthesis Design, Mark Price

Doctoral Dissertations

Lower limb prostheses are designed to replace the functions and form of the missing biological anatomy. These functions are hypothesized to improve user outcome measures which are negatively affected by receiving an amputation – such as metabolic cost of transport, preferred walking speed, and perceived discomfort during walking. However, the effect of these design functions on the targeted outcome measures is highly variable, suggesting that these relationships are not fully understood. Biomechanics simulation and modeling tools are increasingly capable of analyzing the effects of a design on the resulting user gait. In this work, prothesis-aided gait is optimized in simulation …


Design And Biomechanical Evaluation Of A Clutch-Based Energy Storage And Release Assistive Knee Brace, Ericber Jimenez Francisco Feb 2021

Design And Biomechanical Evaluation Of A Clutch-Based Energy Storage And Release Assistive Knee Brace, Ericber Jimenez Francisco

Doctoral Dissertations

Knee osteoarthritis (OA) is a serious degenerative disease affecting over 240 million people around the world. The most disabling symptoms are joint pain, joint stiffness, and reduction in joint functionality. Medial compartment knee OA is the most common case of unicompartmental knee OA, and pain and progression have been associated with tibiofemoral alignment in early to moderate knee OA patients, mainly due to its association with knee loading as measured by knee adduction moment (KAM) and tibiofemoral contact forces (KCF). Valgization knee braces have been developed to correct the malalignment at the tibiofemoral joint, but they have no direct effect …


Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel Nov 2017

Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel

Doctoral Dissertations

A uniform dispersion of reactants is necessary to achieve a complete reaction involving multi-components, especially for the crosslinking of rigid high-performance materials. In these reactions, miscibility is crucial for curing efficiency. This miscibility is typically enhanced by adding a third component, a plasticizer. For the reaction of the highly crystalline crosslinking agent hexamethylenetetramine (HMTA) with a strongly hydrogen-bonded phenol formaldehyde resin, furfural has been traditionally used as the plasticizer. However, the reason for its effectiveness is not clear. In this doctoral thesis work, miscibility and crosslinking efficiency of plasticizers in phenolic curing reactions are studied by thermal analysis and spectroscopic …


A Magnetic Resonance Compatible Knee Extension Ergometer, Youssef Jaber Jul 2017

A Magnetic Resonance Compatible Knee Extension Ergometer, Youssef Jaber

Masters Theses

The product of this thesis aims to enable the study of the biochemical and physical dynamics of the lower limbs at high levels of muscle tension and fast contraction speeds. This is accomplished in part by a magnetic resonance (MR) compatible ergometer designed to apply a load as a torque of up to 420 Nm acting against knee extension at speeds as high as 4.7 rad/s. The system can also be adapted to apply the load as a force of up to 1200 N acting against full leg extension. The ergometer is designed to enable the use of magnetic resonance …


Multi-Classifier Fusion Strategy For Activity And Intent Recognition Of Torso Movements, Abhijit Kadrolkar Nov 2016

Multi-Classifier Fusion Strategy For Activity And Intent Recognition Of Torso Movements, Abhijit Kadrolkar

Doctoral Dissertations

As assistive, wearable robotic devices are being developed to physically assist their users, it has become crucial to develop safe, reliable methods to coordinate the device with the intentions and motions of the wearer. This dissertation investigates the recognition of user intent during flexion and extension of the human torso in the sagittal plane to be used for control of an assistive exoskeleton for the human torso. A multi-sensor intent recognition approach is developed that combines information from surface electromyogram (sEMG) signals from the user’s muscles and inertial sensors mounted on the user’s body. Intent recognition is implemented by following …


Development Of A Portable Cmos Time-Domain Fluorescence Lifetime Imager, Hongtao Wang Jul 2016

Development Of A Portable Cmos Time-Domain Fluorescence Lifetime Imager, Hongtao Wang

Doctoral Dissertations

Modern laboratory equipments to measure the excited-state lifetime of fluorophores usually include an expensive picosecond pulsed-laser excitation source, a fragile photomultiplier tube, and a large instrument body for optics. A portable and robust device to make fluorescence lifetime measurement in nanosecond scale is of great attraction for chemists and biologists. This dissertation reports the development of a portable LED time-domain fluorimeter from an all-solid-state discrete-component prototype to its advanced CMOS integrated circuit implementation. The motivation of the research is to develop a multiplexed fluorimeter for point-of-care diagnosis. Instruments developed by this novel method have higher fill factor, are more portable, …


A Haptic Surface Robot Interface For Large-Format Touchscreen Displays, Mark Price Jul 2016

A Haptic Surface Robot Interface For Large-Format Touchscreen Displays, Mark Price

Masters Theses

This thesis presents the design for a novel haptic interface for large-format touchscreens. Techniques such as electrovibration, ultrasonic vibration, and external braked devices have been developed by other researchers to deliver haptic feedback to touchscreen users. However, these methods do not address the need for spatial constraints that only restrict user motion in the direction of the constraint. This technology gap contributes to the lack of haptic technology available for touchscreen-based upper-limb rehabilitation, despite the prevalent use of haptics in other forms of robotic rehabilitation. The goal of this thesis is to display kinesthetic haptic constraints to the touchscreen user …


Point Of Care Diagnostics And Health Monitoring Devices, Akshaya Shanmugam Mar 2016

Point Of Care Diagnostics And Health Monitoring Devices, Akshaya Shanmugam

Doctoral Dissertations

Existing disease screening methods mostly rely on symptom based diagnosis. This is mainly because of lack of accessibility and cost associated with the tests. Testing for the presence of the disease after the onset of symptoms has a negative impact on chances of survival and treatment costs. Miniaturized low cost diagnostic devices that can be used outside the hospital setting can provide continuous health monitoring and aid in early diagnosis. This thesis presents techniques to develop such disease screening and health monitoring devices. The techniques presented here focus on medical devices that can benefit from microfluidic devices, fluorescence imaging, and …


A Continous Rotary Actuation Mechanism For A Powered Hip Exoskeleton, Matthew C. Ryder Jul 2015

A Continous Rotary Actuation Mechanism For A Powered Hip Exoskeleton, Matthew C. Ryder

Masters Theses

This thesis presents a new mechanical design for an exoskeleton actuator to power the sagittal plane motion in the human hip. The device uses a DC motor to drive a Scotch yoke mechanism and series elasticity to take advantage of the cyclic nature of human gait and to reduce the maximum power and control requirements of the exoskeleton. The Scotch yoke actuator creates a position-dependent transmission that varies between 4:1 and infinity, with the peak transmission ratio aligned to the peak torque periods of the human gait cycle. Simulation results show that both the peak and average motor torque can …


Nanotechnology Overview Powerpoint, Mark Tuominen Jan 2015

Nanotechnology Overview Powerpoint, Mark Tuominen

Nanotechnology Teacher Summer Institutes

Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications. This PowerPoint gives an overview of the field and introduces the teacher summer institute.


Activity Intent Recognition Of The Torso Based On Surface Electromyography And Inertial Measurement Units, Zhe Zhang Jan 2013

Activity Intent Recognition Of The Torso Based On Surface Electromyography And Inertial Measurement Units, Zhe Zhang

Masters Theses 1911 - February 2014

This thesis presents an activity mode intent recognition approach for safe, robust and reliable control of powered backbone exoskeleton. The thesis presents the background and a concept for a powered backbone exoskeleton that would work in parallel with a user. The necessary prerequisites for the thesis are presented, including the collection and processing of surface electromyography signals and inertial sensor data to recognize the user’s activity. The development of activity mode intent recognizer was described based on decision tree classification in order to leverage its computational efficiency. The intent recognizer is a high-level supervisory controller that belongs to a three-level …


Terahertz Imaging For Cancer Detection, Benjamin A. St. Peter Jan 2012

Terahertz Imaging For Cancer Detection, Benjamin A. St. Peter

Masters Theses 1911 - February 2014

This project evaluates the ability of terahertz (THz) radiation to differentiate cancerous from non-cancerous human breast lumpectomy and mastectomy tissue. This is done by aiming a narrow-band THz beam at medical samples and measuring reflected power. THz images of specimens from Breast Conservation Surgery (BCS) were created using a gas laser source and mechanical scanning. The design and characterization of this system is discussed in detail. The images were correlated with optical histological micrographs of the same specimens and discrimination values of more than 70% were found for five of the six samples using Receiver Operating Characteristic (ROC) analysis.