Biomechanical Engineering Commons^™

Hybrid Fes-Exoskeleton Control: Using Mpc To Distribute Actuation For Elbow And Wrist Movements, Nathan Dunkelberger, Jeffrey Berning, Eric M. Schearer, Marcia K. O'Malley

Mechanical Engineering Faculty Publications

Introduction: Individuals who have suffered a cervical spinal cord injury prioritize the recovery of upper limb function for completing activities of daily living. Hybrid FES-exoskeleton systems have the potential to assist this population by providing a portable, powered, and wearable device; however, realization of this combination of technologies has been challenging. In particular, it has been difficult to show generalizability across motions, and to define optimal distribution of actuation, given the complex nature of the combined dynamic system. Methods: In this paper, we present a hybrid controller using a model predictive control (MPC) formulation that combines the actuation of both …

Using Statistics, Computational Modelling And Artificial Intelligence Methods To Study And Strengthen The Link Between Kinematic Impacts And Mtbis, Andrew Luke Mcconnell Patterson

Electronic Thesis and Dissertation Repository

Mild traumatic brain injuries (mTBIs) are frequently occurring, yet poorly understood, injuries in sports (e.g., ice hockey) and other physical recreation activities where head impacts occur. Helmets are essential pieces of equipment used to protect participants’ heads from mTBIs. Evaluating the performance of helmets to prevent mTBIs using simulations on anatomically accurate computational head finite element models is critically important for advancing the development of safer helmets. Advancing the level of detail in, and access to, such models, and their continued validation through state-of-the-art brain imaging methods and traditional head injury assessment procedures, is also essential to improve safety. The …

Design And Validation Of A Variable, Speed-Dependent Resistance Training Method For Muscle Hypertrophy, Alvaro Andres Aracena Alvial

Honors Undergraduate Theses

Muscle disorders and induced muscle atrophy impose critical risks to the well-being of an individual, limiting normal activities of daily living. Several resistance training methods have effectively reversed the progression of muscle atrophy. Weightlifting and hydrotherapy are the two widely practiced schemes for resistance training; however, there is the potential risk of excessive loads exerted on the muscles during weightlifting, and limited accessibility and cost are barriers to hydrotherapy. An alternative is using a resistance band. Some limitations include engaging multiple muscles/joints while only unidirectional resistance is feasible. To address these limitations, a VAriable Resistance Suit (VARS) was designed to …

Variational Autoencoder And Sensor Fusion For Robust Myoelectric Controls, Keith A. Currier

Honors Undergraduate Theses

Myoelectric control schemes aim to utilize the surface electromyography (EMG) signals which are the electric potentials directly measured from skeletal muscles to control wearable robots such as exoskeletons and prostheses. The main challenge of myoelectric controls is to increase and preserve the signal quality by minimizing the effect of confounding factors such as muscle fatigue or electrode shift. Current research in myoelectric control schemes are developed to work in ideal laboratory conditions, but there is a persistent need to have these control schemes be more robust and work in real-world environments. Following the manifold hypothesis, complexity in the world can …

Audible And Subaudible Components Of The First And Second Heart Sounds Using Phonocardiography And Seismocardiography, Daniella King

Honors Undergraduate Theses

Cardiovascular disease continues to be a leading cause of death in the United States, and a source of financial strain on the healthcare system. This prompts the need for new methods of low-cost, noninvasive technologies for cardiac monitoring to improve patient health and reduce healthcare costs. While the first and second heart sounds are common references that are listened to during auscultation of heart, seismocardiography (SCG) is a technology that detects chest sound vibrations with an accelerometer and may offer more information beyond the audible heart sounds. There is currently limited information regarding both the relationship between audible heart sounds …

Investigation Of Endothelial Mechanics On Primary Cell Functions: Endothelium Permeability And Wound Healing, Sean Beverung

Electronic Theses and Dissertations, 2020-

The endothelium composes the inner lining of blood vessels, the heart, and lymphatic vessels. Within the cardiovascular system, it is an extremely important structure, aiding in the regulation of blood pressure with the vascular tone, recruiting immune response, regulating the transfer of material in and out of the bloodstream, and the creation of new blood vessels through angiogenesis. The endothelium is composed entirely of endothelial cells. These cells lay in a flat squamous formation and are in direct contact with blood and aid in the regulation and transfer of material in and out of the bloodstream via active and passive …

Effects Of Exciting And Relaxing Music On Heart Rate Variability, Pratik S. Mahajan

Honors Undergraduate Theses

Heart rate variability (HRV) and music have been demonstrated to have a relationship in previous literature. The primary objective of this study is to further investigate that relationship by observing HRV during periods of listening to relaxing and exciting music and comparing the results to a baseline as well as the other condition. The secondary objective of this study is to investigate the efficacy and potential usage of the Polar H10 chest strap monitor in measuring HRV parameters. The results of the Polar H10 will be compared to the iWorx TA-220 and iWorx-ECG12, the existing gold standard in HRV and …

Data-Driven Dynamic Motion Planning For Practical Fes-Controlled Reaching Motions In Spinal Cord Injury, Derek N.N. Wolf, Antonie J. Van Den Bogert, Eric M. Schearer

Mechanical Engineering Faculty Publications

Functional electrical stimulation (FES) is a promising technology for restoring reaching motions to individuals with upper-limb paralysis caused by a spinal cord injury (SCI). However, the limited muscle capabilities of an individual with SCI have made achieving FES-driven reaching difficult. We developed a novel trajectory optimization method that used experimentally measured muscle capability data to find feasible reaching trajectories. In a simulation based on a real-life individual with SCI, we compared our method to attempting to follow naive direct-to-target paths. We tested our trajectory planner with three control structures that are commonly used in applied FES: feedback, feedforward-feedback, and model …

Multiscale Modeling Of Cardiac Growth And Baroreflex Control, Hossein Sharifi

Theses and Dissertations--Mechanical Engineering

The heart functions within a complex system that adapts its function to any alteration in loading via several mechanisms. For example, the baroreflex is a short-term feedback loop that modulates the heart's function on a beat-to-beat basis to control arterial pressure. On the other hand, cardiac growth is a long-term adaptive response that occurs over weeks or months in response to changes in left ventricular loading. Understanding the mechanisms that drive ventricular growth and biological remodeling is critical to improving patient care. Multiscale models of the cardiovascular system have emerged as effective tools for investigating G&R, offering the ability to …

Optimizing Biomechanical Models: Estimation Of Muscle Tendon Parameters And Ankle Foot Orthosis Stiffness, Sepehr Ramezani

Electronic Theses and Dissertations, 2020-

The complexity of the human musculoskeletal system presents challenges in accurately identifying its characteristics, particularly due to the presence of redundant actuators on a single joint. Non-invasive measures are necessary to overcome these challenges. Optimization algorithms have emerged as a crucial tool to advance subject-specific musculoskeletal modeling allows a more realistic representation of biomechanical behaviors, enhancing our understanding of human movement and enabling better clinical decision-making. Furthermore, optimization algorithms play a vital role in customizing rehabilitation and assistive devices, such as orthoses and prostheses. The current ankle-foot orthosis (AFO) stiffness measurement methods require bulky, complex designs, and often permanent modification …

A Review Of Piezoelectric Footwear Energy Harvesters: Principles, Methods, And Applications, Bingqi Zhao, Feng Qian, Alexander Hatfield, Lei Zuo, Tian-Bing Xu

Mechanical & Aerospace Engineering Faculty Publications

Over the last couple of decades, numerous piezoelectric footwear energy harvesters (PFEHs) have been reported in the literature. This paper reviews the principles, methods, and applications of PFEH technologies. First, the popular piezoelectric materials used and their properties for PEEHs are summarized. Then, the force interaction with the ground and dynamic energy distribution on the footprint as well as accelerations are analyzed and summarized to provide the baseline, constraints, potential, and limitations for PFEH design. Furthermore, the energy flow from human walking to the usable energy by the PFEHs and the methods to improve the energy conversion efficiency are presented. …

Biologically – Plausible Load Feedback From Dynamically Scaled Robotic Model Insect Legs, William Zyhowski

Graduate Theses, Dissertations, and Problem Reports

Researchers have been studying the mechanisms underlying animal motor control for many years using computational models and biomimetic robots. Since testing some theories in animals can be challenging, this approach can enable unique contributions to the field. An example of a system that benefits from this modeling and robotics approach is the campaniform sensillum (CS), a kind of sensory organ used to detect the loads exerted on an insect's legs. The CS on the leg are found in groups on high-stress areas of the exoskeleton and have a major influence on the adaptation of walking behavior. The challenge for studying …

Semi-Robotic Knee Arthroscopy System With Braking Mechanism, Thai Hua

Honors Undergraduate Theses

To alleviate the poor ergonomics which surgeons suffer during knee arthroscopy, a semi-robotic device with braking mechanism is created for intraoperative assistance. A slitted ball joint assembly is developed to transmit the clamping force to the arthroscope inside. Ball deformation and stress at various angles to the vertical and clamping forces is recorded through Abaqus Finite Element Analysis (FEA). Contact forces between the scope and inner surfaces of the ball is also computed in FEA at different clamping forces. The von Mises stress occurring in the ball joint is under the yield stress limit for polyethylene, and there is noticeable …

Computational Investigations Of The Fluid-Structure Interaction During Phonation: The Role Of Vocal Fold Elasticity And Glottal Flow Unsteadiness, Xiaojian Wang

Electronic Theses and Dissertations

Human voice production arises from the biomechanical interaction between vocal fold vibrations and airflow dynamics. Changes in vocal fold stiffness can lead to changes in vocal fold vibration patterns and further changes in voice outcomes. A good knowledge of the cause-and-effect relationship between vocal fold stiffness and voice production can not only deepen the understanding of voice production mechanisms but also benefit the treatment of voice disorders associated with vocal fold stiffness changes. This constitutes the first objective of this dissertation. The second objective of this dissertation is to further examine the range of validity of the quasi-steady assumption of …

Better Tools For Women: Serving Local Gynecologic Cancer Patients, Caitlin Crowley

Purdue Journal of Service-Learning and International Engagement

Introduction: Cervical patients require a mirror to view anatomy between doctor visits. Existing mirrors have inadequate light and magnification, limit available free hands, or require another individual’s assistance.

Skin lesion size is tracked over time to record advances in healing or disease progression. Current options are inadequate for cutaneous lesion documentation. Parkview Cancer Institute asked me to develop a better self-examination tool for cervical patients. The new device may be used by all women for wellness checks.

Materials and Methods: A hands free illuminated cleanable mirror with magnification was designed after anthropometric and regulatory review.

Device performance was established by …

Hypoxic Incubation Chamber, Simone Lisette Helfrich, Makenzie Nicole Jones

Master's Theses

This paper describes the design, manufacturing, and testing of a novel controllable hypoxic incubator with fully functional oxygen gas control and temperature control in a humid environment. On the current market, a majority of the few hypoxic incubators use pre-mixed gas that does not offer precise control over gas concentration. The objective for this project was to create a chamber that allows the user to set the O2 concentration to varying set points of % O2 while maintaining the chamber at a constant body temperature, CO2 level, humidity, and sterility. To start the project, multiple concepts were developed for the …

3d-Printed Piezoelectric Porous Bioactive Scaffolds And Clinical Ultrasonic Stimulation Can Help In Enhanced Bone Regeneration, Prabaha Sikder, Phaniteja Nagaraju, Harsha P.S. Naganaboyina

Mechanical Engineering Faculty Publications

This paper presents a comprehensive effort to develop and analyze first-of-its-kind design-specific and bioactive piezoelectric scaffolds for treating orthopedic defects. The study has three major highlights. First, this is one of the first studies that utilize extrusion-based 3D printing to develop design-specific macroporous piezoelectric scaffolds for treating bone defects. The scaffolds with controlled pore size and architecture were synthesized based on unique composite formulations containing polycaprolactone (PCL) and micron-sized barium titanate (BaTiO3) particles. Second, the bioactive PCL-BaTiO3 piezoelectric composite formulations were explicitly developed in the form of uniform diameter filaments, which served as feedstock material for the fused filament fabrication …

Development Of A Two-Axis Cyclic Loading Device For Mechanical Testing Of Glenoid Component Fixation, Cintya Tavares

Electronic Thesis and Dissertation Repository

The fundamental mechanism of aseptic glenoid component loosening, the rocking horse phenomenon, is a reaction to glenohumeral articular forces that are not centered on the component. While glenoid component loosening remains a problem, the underlying mechanisms that lead to fixation failure at the bone-component contact remain controversial. Several studies employing the ASTM F2028 technique have successfully recreated the rocking horse effect. However, no obvious strategy to decrease component loosening has been presented. This thesis investigates the behavior of forces that lead to component loosening on cyclically loaded components using three different protocols and testing apparatuses—a Stewart Platform, a cyclic loading …

Computational Simulations Of The Effects Of Gravity On Lymphatic Transport, Huabing Li, Huajian Wei, Timothy P. Padera, James W. Baish, Lance L. Munn

Faculty Journal Articles

Physical forces, including mechanical stretch, fluid pressure, and shear forces alter lymphatic vessel contractions and lymph flow. Gravitational forces can affect these forces, resulting in altered lymphatic transport, but the mechanisms involved have not been studied in detail. Here, we combine a lattice Boltzmann-based fluid dynamics computational model with known lymphatic mechanobiological mechanisms to investigate the movement of fluid through a lymphatic vessel under the effects of gravity that may either oppose or assist flow. Regularly spaced, mechanical bi-leaflet valves in the vessel enforce net positive flow as the vessel walls contract autonomously in response to calcium and nitric oxide …

Atherogenic Potential Of Microgravity Hemodynamics In The Carotid Bifurcation: A Numerical Investigation, Philippe Sucosky, Varun Vinayak Kalaiarasan, Graham B. Quasebarth, Patricia Strack, Jason A. Shar

Faculty Open Access Publishing Fund Collection

Long-duration spaceflight poses multiple hazards to human health, including physiological changes associated with microgravity. The hemodynamic adaptations occurring upon entry into weightlessness have been associated with retrograde stagnant flow conditions and thromboembolic events in the venous vasculature but the impact of microgravity on cerebral arterial hemodynamics and function remains poorly understood. The objective of this study was to quantify the effects of microgravity on hemodynamics and wall shear stress (WSS) characteristics in 16 carotid bifurcation geometries reconstructed from ultrasonography images using computational fluid dynamics modeling. Microgravity resulted in a significant 21% increase in flow stasis index, a 22–23% decrease in …