Biomechanical Engineering Commons^™

A Real-Time, 3-D Musculoskeletal Model For Dynamic Simulation Of Arm Movements, Edward K. Chadwick, Dimitra Blana, Antonie J. Van Den Bogert, Robert F. Kirsch

Mechanical Engineering Faculty Publications

Neuroprostheses can be used to restore movement of the upper limb in individuals with high-level spinal cord injury. Development and evaluation of command and control schemes for such devices typically require real-time, ldquopatient-in-the-looprdquo experimentation. A real-time, 3-D, musculoskeletal model of the upper limb has been developed for use in a simulation environment to allow such testing to be carried out noninvasively. The model provides real-time feedback of human arm dynamics that can be displayed to the user in a virtual reality environment. The model has a 3-DOF glenohumeral joint as well as elbow flexion/extension and pronation/supination and contains 22 muscles …

Simulating The Growth Of Articular Cartilage Explants In A Permeation Bioreactor To Aid In Experimental Protocol Design, Timothy P. Ficklin, Andrew Davol, Stephen M. Klisch

Mechanical Engineering

Recently a cartilage growth finite element model (CGFEM) was developed to solve nonhomogeneous and time-dependent growth boundary-value problems (Davol et al., 2008, “A Nonlinear Finite Element Model of Cartilage Growth,” Biomech. Model. Mechanobiol., 7, pp. 295–307). The CGFEM allows distinct stress constitutive equations and growth laws for the major components of the solid matrix, collagens and proteoglycans. The objective of the current work was to simulate in vitro growth of articular cartilage explants in a steady-state permeation bioreactor in order to obtain results that aid experimental design. The steady-state permeation protocol induces different types of mechanical stimuli. When the specimen …

An Inverse Method For Predicting Tissue-Level Mechanics From Cellular Mechanical Input, Wangdo Kim, Derek C. Tretheway, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Extracellular matrix (ECM) provides a dynamic three-dimensional structure which translates mechanical stimuli to cells. This local mechanical stimulation may direct biological function including tissue development. Theories describing the role of mechanical regulators hypothesize the cellular response to variations in the external mechanical forces on the ECM. The exact ECM mechanical stimulation required to generate a specific pattern of localized cellular displacement is still unknown. The cell to tissue inverse problem offers an alternative approach to clarify this relationship. Developed for structural dynamics, the inverse dynamics problem translates measurements of local state variables (at the cell level) into an unknown or …

Application Of The Actor-Critic Architecture To Functional Electrical Stimulation Control Of A Human Arm, Philip Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik

Mechanical Engineering Faculty Publications

Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of the actor-critic architecture, with neural networks for the both the actor and the critic, as a controller that can adapt to these changing dynamics of a human arm. Development and tests were done in simulation using a planar arm model and Hill-based muscle dynamics. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant changes to the dynamics of …

Concurrent Simulation Of Neuromuscular Control And Tissue Deformation Is Possible By Adaptive Surrogate Modeling, Jason P. Halloran, Ahmet Erdemir, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

No abstract provided.

Adaptive Surrogate Modeling For Efficient Coupling Of Musculoskeletal Control And Tissue Deformation Models, Jason P. Halloran, Ahmet Erdemir, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background

Finite element (FE) modeling and multibody dynamics have traditionally been applied separately to the domains of tissue mechanics and musculoskeletal movements, respectively. Simultaneous simulation of both domains is needed when interactions between tissue and movement are of interest, but this has remained largely impractical due to high computational cost.

Method of Approach

Here we present a method for concurrent simulation of tissue and movement, in which state of the art methods are used in each domain, and communication occurs via a surrogate modeling system based on locally weighted regression. The surrogate model only performs FE simulations when regression from …

Design And Characterization Of A Shock And Vibration Mitigation Seat System, George Samaan Ladkany

UNLV Theses, Dissertations, Professional Papers, and Capstones

Extensive research has been conducted into the development of pneumatic seatbladder systems for shock and vibration mitigation for use in current U.S military vehicle envelopes. This research expands on the previous work through an elaborate experimental characterization of four prototype air bladder seat cushion systems. The experimental characterization conducted included shock testing, continuous vibration, and internal dynamic pressure measured during the shock event.

The shock testing was conducted both at the Army Research Lab as well at UNLV. The shock testing conducted at UNLV was performed on a drop tower designed and constructed during the time of this research. The …

Real-World Industry Collaboration Within A Mechatronics Class, Vidya Nandikolla, Susan Shadle, Patricia Pyke, John Gardner, Robert Grover, Suhas Pharkute

Electrical and Computer Engineering Faculty Publications and Presentations

This paper describes the implementation and assessment of an innovative senior/graduate level mechatronics (robotics) module that integrated structured and unstructured learning experiences, in collaboration with an industry partner. With real-world constraints and expectations, students designed and delivered a product as the final project. In fall 2007, the corporate partner provided state-of-the-art, programmable robotic kits with a user-friendly programming environment. The assigned project was to design a biomedical robot to work in a hospital intensive care unit (ICU) to perform tasks such as transporting supplies or delivering paperwork. Students with diverse skills and majors were grouped in ten teams, two to …

Investigating Isolated Neuromuscular Control Contributions To Non-Contact Anterior Cruciate Ligament Injury Risk Via Computer Simulation Methods, Scott G. Mclean, Xuemei Huang, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background

Despite the ongoing evolution of anterior cruciate ligament injury prevention methods, injury rates and the associated sex-disparity remain. Strategies capable of successfully countering key control parameters existent within the injury mechanism thus remain elusive. Forward dynamics model simulations afford an expedited means to study realistic injury causing scenarios, while controlling all facets of the movement control strategy. Utilizing these methods, the current study examined the potential for perturbations in key initial contact neuromuscular parameters to injure the anterior cruciate ligament during the stance phase of sidestep cutting maneuvers.

Methods

Controlled experiments were performed on optimized and validated subject-specific forward …

Development Of A Technique To Diagnose Subtalar Joint Instability, Ajaya Dhakal

Mechanical & Aerospace Engineering Theses & Dissertations

Most patients escape diagnosis of subtalar joint instability for years before treatment. Therefore, a clinically relevant technique to diagnose subtalar joint instability will improve its management. Towards this goal, a six degree of freedom positioning and loading device was developed to apply physiologic loads to the hindfoot. Because the ideal loading configuration to detect subtalar joint instability is unknown, the device was designed to apply rotational and translational forces simultaneously. Specifically, plantarflexion/dorsiflexion, inversion/eversion, and internal/external rotation can be applied individually or as coupled motions along with an anterior/posterior drawer. Kinematic data were collected from calcaneus, talus and tibia using a …

Experimental Analysis And Modeling Validation Of A Knee Brace In Shock Mitigation, Manish Prakash Dhekane

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental setup simulating the dynamic environment in a high sea state is developed for the lower extremities to study the mitigation of shock impact. A single degree of freedom machine is equipped with six linear induction motors to produce impact acceleration ranging from 0.5G to 4G. The experiments are carried out along the dummy leg by using two configurations, one without a knee brace and one with a knee brace. Force and acceleration data is collected using a data acquisition system.

To develop the analytical model of the same experimental setup, the knee brace and dummy leg were scanned …

A Cartilage Growth Mixture Model With Collagen Remodeling: Validation Protocols, Stephen M. Klisch, Anna Asanbaeva, Sevan R. Oungoulian, Koichi Masuda, Eugene J.-Ma. Thonar, Andrew Davol, Robert L. Sah

Mechanical Engineering

A cartilage growth mixture (CGM) model is proposed to address limitations of a model used in a previous study. New stress constitutive equations for the solid matrix are derived and collagen (COL) remodeling is incorporated into the CGM model by allowing the intrinsic COL material constants to evolve during growth. An analytical validation protocol based on experimental data from a recent in vitro growth study is developed. Available data included measurements of tissue volume, biochemical composition, and tensile modulus for bovine calf articular cartilage (AC) explants harvested at three depths and incubated for 13 days in 20% fetal borine serum …

Articular Cartilage Tensile Integrity: Modulation By Matrix Depletion Is Maturation-Dependent, Anna Asanbaeva, Johnny Tam, Barbara L. Schumacher, Stephen M. Klisch, Koichi Masuda, Robert L. Sah

Mechanical Engineering

Articular cartilage function depends on the molecular composition and structure of its extracellular matrix (ECM). The collagen network (CN) provides cartilage with tensile integrity, but must also remodel during growth. Such remodeling may depend on matrix molecules interacting with the CN to modulate the tensile behavior of cartilage. The objective of this study was to determine the effects of increasingly selective matrix depletion on tensile properties of immature and mature articular cartilage, and thereby establish a framework for identifying molecules involved in CN remodeling. Depletion of immature cartilage with guanidine, chondroitinase ABC, chondroitinase AC, and Streptomyces hyaluronidase markedly increased tensile …

An Analysis Of The Performance Of Foams Used In Hurling Helmets, Keith Norris, Stephen Tiernan

Conference Papers

Abstract Head injuries can occur in most sporting activities. The seriousness of these injuries can vary greatly depending on the sport. Many sports such as American football, cricket, baseball and hurling try to reduce this risk by designing helmets that are suitable to be worn by the players. The National Standard Authority of Ireland (NSAI) has recently made great strides in this area with the introduction of the first comprehensive standard adopted for the sport I.S. 355:2006, which sets out new testing procedures that all new helmets must meet. The Gaelic Athletic Association (GAA) has also stated its intention to …

The Effect Of Hans Device On Brain Pressure Values In Finite Element Brain Models, Mihir M. Jawale

Mechanical & Aerospace Engineering Theses & Dissertations

A parametric study of behavior of different brain material properties when exposed to a mid-high severity pulse is presented. Few studies have considered brain pressure as a parameter to study the effect of change of brain material properties. Specifically pressure and strain values in the frontal and posterior fossa and occipital region of the brain are investigated for mid-high severity pulse.

The brain model is composed of several parts modeled as hexahedral elements and with different material properties. A parametric study of several material types of brain is conducted using MAthematical DYnamic MOdel (MADYMO). Initially only the finite element (FE) …

A Weighted Least-Squares Method For Inverse Dynamic Analysis, Antonie J. Van Den Bogert, Anne Su

Mechanical Engineering Faculty Publications

Internal forces in the human body can be estimated from measured movements and external forces using inverse dynamic analysis. Here we present a general method of analysis which makes optimal use of all available data, and allows the use of inverse dynamic analysis in cases where external force data is incomplete. The method was evaluated for the analysis of running on a partially instrumented treadmill. It was found that results correlate well with those of a conventional analysis where all external forces are known.

Creating A Reinforcement Learning Controller For Functional Electrical Stimulation Of A Human Arm, Philip S. Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik

Mechanical Engineering Faculty Publications

Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of Reinforcement Learning to create a controller that can adapt to these
changing dynamics of a human arm. Development and tests were done in simulation using a two-dimensional arm model and Hill-based muscle dynamics. An actor-critic architecture is used with artificial neural networks for both the actor and the critic. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant …

Helical Axes Of Skeletal Knee Joint Motion During Running, Antonie J. Van Den Bogert, C. Reinschmidt, A. Lundberg

Mechanical Engineering Faculty Publications

The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase …

The Effect Of Tibiofemoral Loading On Proximal Tibiofibular Joint Motion, Jacob Scott, Ho Lee, Wael Barsoum, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

The human proximal tibiofibular joint (PTFJ) and its relationship to overall knee joint mechanics have been largely unexplored. This study describes force/displacement data from experiments done on four human cadaveric knee specimens and general conclusions obtained with the help of a statistical modeling technique. Specimens were rigidly affixed at the tibia to a force plate and the femur was attached to a custom made device allowing for manual load application. Motion of the fibular head was tracked relative to the tibial plateau by means of reflective markers and a high speed digital camera synchronized with the force plate data stream. …

Shaken Baby Syndrome: Retinal Hemorrhaging. A Biomechanical Approach To Understanding The Mechanism Of Causation, Steven Alex Hans

Mechanical & Aerospace Engineering Theses & Dissertations

Shaken Baby Syndrome (SBS) is a form of abuse where typically an infant, age six months or less, is held and shaken. There may or may not be direct impact associated with this action. Further, there is very little agreement on the actual mechanism of SBS. Clinical studies are limited in showing the exact mechanism of injury and only offer postulations and qualitative descriptions. SBS has received much attention in the media, has resulted in a great deal of litigation and can be the source of unfounded accusations. Therefore, it is necessary to try to quantify the forces that may …

Factors Affecting The Spread Of A Bioterrorist Agent Through A Building, William Cantrell

Mechanical Engineering Undergraduate Honors Theses

Bioterrorism has become a concern for Americans since the 2001 anthrax letters. Many studies have been done regarding the possibilities of biological attacks since, and most deal with possibilities of large scale attacks. However, there is reason to believe that small scale attacks are more likely. Even though studies have been done revolving around the postal system and the spread of bioagents through mail, few if any studies have looked at an attack on a single building. One particular method of attacking a building would be simply releasing an aerosoled contaminant in the building. This purpose of this project is …

Lower Extremity Mechanics During Cutting Tasks In Different Shoe-Turf Combinations, Rafael Garcilazo

McNair Scholars Research Journal

The demands placed on the lower extremity when performing jumping and cutting maneuvers are depending, in part, on the interaction between the playing surface and the athlete's footwear. Higher demands are likely to result in increased incidence of injury, so for safety reasons it is important to quantify how the shoe-turf interface affects joint loads. The purpose of this study is to compare the forces on the lower extremity while landing and side cutting (rapid direction change at approximately 45 degrees) on artificial football turf with different styles of football cleats.

Model-Based Estimation Of Muscle Forces Exerted During Movements, Ahmet Erdemir, Scott Mclean, Walter Herzog, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Estimation of individual muscle forces during human movement can provide insight into neural control and tissue loading and can thus contribute to improved diagnosis and management of both neurological and orthopaedic conditions. Direct measurement of muscle forces is generally not feasible in a clinical setting, and non-invasive methods based on musculoskeletal modeling should therefore be considered. The current state of the art in clinical movement analysis is that resultant joint torques can be reliably estimated from motion data and external forces (inverse dynamic analysis). Static optimization methods to transform joint torques into estimates of individual muscle forces using musculoskeletal models, …

Acl Injuries: Do We Know The Mechanisms?, Antonie J. Van Den Bogert, Scott G. Mclean

Mechanical Engineering Faculty Publications

Injuries of the anterior cruciate ligament (ACL) remain a frequent occurrence in many sports activities. Recent research has identified risk factors, and prevention strategies are being developed based on these findings. There is, however, still a limited understanding of the actual injury mechanisms. In this presentation we will review the current knowledge on ACL injury mechanisms, and identify needs and opportunities for further research.

Comparison Of The Pull-Out Strengths Of Three Different Screws In Pedicular Screw Revisions: A Biomechanical Study, Irfan Esenkaya, Yurdaer Denizhan, Mehmet Akif Kaygusuz, Mehmet Yetmez, Mehmet Halidun Keleştemur

Faculty Publications - Mechanical Engineering

OBJECTIVES: We investigated the possible effects of three pedicular screws on axial pull-out strength in pedicular revision surgery. METHODS: Two study groups were formed from calf lumbar vertebrae. Initially, Alici pedicular screws with an outer diameter of 6.5 mm were applied (with or without tapping) to all the pedicles. All the pedicles were subjected to axial pull-out testing to induce pedicular insufficiency. Then, Alici pedicular screws with an outer diameter of 7 mm were applied to the left pedicles. The right pedicles in the two study groups were assigned to receive two different types of pedicular screws with an expandable …

Effect Of Gender On Lower Extremity Kinematics During Rapid Direction Changes: An Integrated Analysis Of Three Sports Movements, S. G. Mclean, K. B. Walker, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Anterior cruciate ligament (ACL) injury is a common sports injury, particularly in females. Gender differences in knee kinematics have been observed for specific movements, but there is limited information on how these findings relate to other joints and other movements. Here we present an integrated analysis of hip, knee and ankle kinematics across three movements linked to non-contact ACL injury. It was hypothesised that there are gender differences in lower extremity kinematics, which are consistent across sports movements. Ten female and ten male NCAA basketball players had three-dimensional hip, knee and ankle kinematics quantified during the stance phase of sidestep, …

Association Between Lower Extremity Posture At Contact And Peak Knee Valgus Moment During Sidestepping: Implications For Acl Injury, Scott G. Mclean, Xuemei M. Huang, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background. Knee valgus load during sports movement is viewed as an important predictor of non-contact anterior cruciate ligament injury risk, particularly in females. Formulating movement strategies that can reduce valgus loading during these movements therefore appears pertinent to reducing anterior cruciate ligament injury rates. With this in mind, the current study examined the relationship between peak valgus moment and lower extremity postures at impact during a sidestep cutting task.

Methods. Ten male and ten female NCAA athletes had initial contact three-dimensional hip, knee and ankle angles and subsequent knee valgus moment quantified during the execution of (n=10 trials) …

Letter To The Editor, Scott G. Mclean, Jack T. Andrish, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

No abstract provided.

Evaluation Of A Two Dimensional Analysis Method As A Screening And Evaluation Tool For Anterior Cruciate Ligament Injury, Scott G. Mclean, K. Walker, K. R. Ford, G. D. Myer, T. E. Hewett, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background: Increased knee valgus predicts the risk of anterior cruciate ligament (ACL) injury, particularly in women. Reducing injury rates thus relies on detecting and continually evaluating people with relatively large valgus motions.

Objectives: To examine the potential of a two dimensional (2D) video analysis method for screening for excessive valgus.

Methods: Ten female and 10 male National Collegiate Athletic Association basketball players had three dimensional (3D) knee valgus and two dimensional (2D) frontal plane knee angle quantified during side step, side jump, and shuttle run tasks. 3D valgus was quantified from external marker coordinates using standard techniques, and 2D data …

Biomechanical Measures Of Neuromuscular Control And Valgus Loading Of The Knee Predict Anterior Cruciate Ligament Injury Risk In Female Athletes, Timothy E. Hewett, Gregory D. Myer, Kevin R. Ford, Robert S. Heidt Jr., Angelo J. Colosimo, Scott G. Mclean, Antonie J. Van Den Bogert, Mark V. Paterno, Paul Succop

Mechanical Engineering Faculty Publications

Background: Female athletes participating in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than do male athletes.

Hypothesis: Prescreened female athletes with subsequent anterior cruciate ligament injury will demonstrate decreased neuromuscular control and increased valgus joint loading, predicting anterior cruciate ligament injury risk.

Study Design: Cohort study; Level of evidence, 2.

Methods: There were 205 female athletes in the high-risk sports of soccer, basketball, and volleyball prospectively measured for neuromuscular control using 3-dimensional kinematics (joint angles) and joint loads using kinetics (joint moments) during a jump-landing task. Analysis of variance as well as linear …