Newswise — NORMAN – Geometry is often referenced for matters of the heart. Marriage has been described as “two parallel lines,” and others have compared love to an “irrational equation” or as unending as “pi.” But when it comes to the medical matters of the heart, geometry can be a lonely and dangerous affair.

“The shape and size of a heart is not the same for every person, and a diseased heart, such as ischemia heart failure, is different than a healthy heart,” explains Dr. Chung-Hao Lee, an assistant professor in the Biomechanics and Biomaterials Design Laboratory in the University of Oklahoma’s School of Aerospace and Mechanical Engineering. “So, when it is necessary to do surgery on the heart, it important to map out the individual’s particular geometry to know how it will respond to different surgical treatment options.”

Lee’s recent research is focused on a predictive surgery for a serious heart condition called Functional Tricuspid Regurgitation, which affects approximately 1.6 million Americans. FTR is typically caused when the left side of the heart fails, causing the right side to expand and a geometric distortion of the heart. The distortion can lead to reverse blood flow, poor functioning of the heart valves, or worse, heart failure on the right side.

Long-term surgical outcomes to repair FTR have a 20 percent moderate to severe recurrence rate by 10 years after initial surgery. Also, up to 40 percent of patients who have cardiac surgery require additional surgery within five years due to the individual’s heart characteristics. This results in more open-heart repeat surgeries and significant increases in risk and mortality.

Lee and his team are developing a predictive modeling tool for individual-optimized heart valve surgical repair. The customized analysis will be a surgical planning tool for the treatment of that patient. Lee’s team uses a combination of clinical image data, such as functional magnetic resonance imaging and clinical computed tomography, to reconstruct a 3D computational model of the heart. Lee’s model would guide surgeons on the best approach to repair FTR in a particular patient, reducing the risk of reoccurrence.

“Often, surgeons may have several options on how to repair a heart,” Lee said. “They may try to manipulate the geometry of the heart or valves or change the size of each individual apparatus. We can simulate those surgical scenarios, one by one, to know the individual-optimized therapeutic option.” The right approach can improve the durability of the repair.

“We are now entering a level of knowledge and technical capability where computational modeling can deliver precision medicine,” Lee said. “If we can predict how a distinct heart will function under different surgical scenarios, we can help surgeon select the best approach to the surgery.”

 

The intersection of science, computational science, clinical research and the heart make a healthy affair.

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The Gallogly College of Engineering at the University of Oklahoma challenges students to solve the world’s toughest problems through a powerful combination of education, entrepreneurship, research, community service and student competitions. Research is focused on both basic and applied topics of societal significance, including biomedical engineering, energy, engineering education, civil infrastructure, nanotechnology and weather technology.

The programs within the college’s eight areas of study are consistently ranked in the top third of engineering programs in the United States. The college faculty has achieved research expenditures of more than $22 million and created 12 start-up companies.


Source: https://www.newswise.com/articles/ou-researchers-uses-geometry-for-affairs-of-the-heart

 

 

Professor Subramanyam Gollahalli, Lesch Centennial Chair at the University of Oklahoma (OU) School of Aerospace and Mechanical Engineering (AME), retired and transitioned to emeritus status in May 2017, after 41 years of service at OU (52 years including his tenure at the Indian Institute of Science, India and the University of Waterloo, Canada). His service included eight years of directorship at AME.

His distinguished career was marked by many awards from various professional organizations and many recognitions from OU, including the Regents Superior Teaching Award and Regents Professional Service Award. A few of the awards bestowed upon Professor Gollahalli are the Westinghouse Gold Medal, the Energy Systems Award, the Ralph James Award, the Ralph Teetor Award, the Samuel Collier Award and the Sustained Service Award.

Professor Gollahalli’s research in energy and combustion involved many experimental studies. He founded the internationally-recognized Combustion Laboratory, where he mentored over 100 graduate students (M.S. and Ph.D.) and post-doctoral associates and produced nearly 300 publications. He involved many undergraduate students in his laboratory research as well.

Professor Gollahalli strongly believes that “hands-on experimental experience” is an essential component of engineering education to prepare well-rounded engineers. He was the founding chair of the AME Laboratory Committee (1989), in which capacity he served until retirement (with a break during his directorship). He was the author of the “AME Lab Plan” required by the accreditation agency, which provides guidelines for various laboratories (two required labs and five elective labs). It deals with coordination, safety aspects and general guidelines for funding and conducting laboratory courses. During his tenure as the chair, he raised funds and arranged allocation of funds through the Lab Committee to modernize the lab education to keep pace with technological innovations.

“Dr. Gollahalli is a truly dedicated professor, he inspires his students to solve problems and make a difference,” said Sai Gundavelli, AME alum.

His passion for giving students hands-on experience resulted in the modernization of the AME machine shop with numerically controlled equipment. During his directorship, he gave priority to funding labs and the machine shop in which students were given the opportunity to work by themselves under the supervision of machine shop staff.

The capstone design project program, which involves industrial projects, saw a major growth in size and increase in funding during his directorship. The AME Capstone Project Poster Fair, where students exhibit their hands-on developed creations and win awards at the conclusion of judging by the industry personnel, became an annual popular event during his term as the director.

During his tenure as the director, he encouraged and supported the student competition activities, such as Sooner Racing Team, Human-Powered Vehicle Team, Robotics Team and Design-Build-Fly Team. The teams facilitated direct student involvement in designing, manufacturing and competing in national events. He personally attended some of the competitions to encourage students. He took great pleasure and felt proud when the teams achieved high national rankings.

When Professor Gollahalli stepped down from the directorship after eight years, the AME Board of Advisors started a fund to honor his legacy, which was intended to support the undergraduate laboratories. Now, after his retirement, to mark his passion and belief in providing valuable laboratory hands-on experience to students, Professor Gollahalli’s family decided to make a significant contribution to this fund to make it a permanent endowment, which will serve as a source of funding for this cause.

“I am grateful to the AME Board of Advisors for establishing Gollahalli Legacy Fund to support instructional labs. I thank my wonderful students and friends for their generous donation for this cause, which will facilitate production of well-rounded future AME engineers,” said Professor Gollahalli.

The School of AME requests your contributions to this fund to mark your name and help fulfill Professor Gollahalli’s long-standing desire. To contribute to the Gollahalli Legacy Fund please visit: https://giving.oufoundation.org/OnlineGivingWeb/Giving/OnlineGiving/Gollahalli

mentored-research-fellowship-ame-2017

From Left to Right: Samuel Jett, Devin Laurence, Octavio Serrano, McKenzie Makovec, Dr. Chung-Hao Lee, Robert Kunkel

The Mentored Research Fellowship (MRF) award, sponsored by the Office of Undergraduate Research (O.U.R.), was given to five of Dr. Chung-Hao Lee’s undergraduate students. Each award is in the amount of $1000 for conducting undergraduate research projects in the Biomechanics and Biomaterials Design lab (BBDL).

The awardees are chosen based on the intellectual merit of the student’s submitted proposal (research project). The five students awarded from Dr. Lee’s research group are:

  • Devin Laurence (ME Senior under accelerated BS/MS program)
  • Robert Kunkel  (ME Senior under accelerated BS/MS program)
  • Samuel Jett  (ME Senior under accelerated BS/MS program)
  • Octavio Serrano  (ME Senior)
  • McKenzie Makovec  (ChemE Senior)

Dr. Lee’s BBDL research lab focuses on the following research areas:

  • Multiscale Biomechanical Modeling of the Cardiovascular Systems – Heart Valves
  • Characterization of Structural and Mechanical Properties of Soft Biological Tissues
  • Patient-Specific Modeling for Improved Diagnosis and Prophylactic Disease Management
  • Cell Mechanics and Mechanobiology Linking with Collagen Biosynthesis and Tissue Growth & Remodeling (G&R)
  • Advanced Finite Element and Meshfree Methods for Image-Based Computational Biomechanics

The following profiles expand on each award winner’s current research projects and backgrounds:

devin-laurence-profile-pic-description-239dwwyrobert-kunkel-profile-pic-description-13z62dosamuel-jett-profile-pic-description-1twi5hdoctavio-serrano-profile-pic-description-25foqwdmckenzie-makovec-profile-pic-description

According to the MRF website, the Mentored Research Fellowship is a program to cultivate and support student-mentor relationships while working on a research or creative project. This is part of the Office of Undergraduate Research’s commitment to empowering students’ exploration. MRF is open to all University of Oklahoma-Norman Campus undergraduate students.

Congratulations!

 

aiaa-asme-ame-symposium-2017AME faculty, graduate, and undergraduate students attended the 37th Oklahoma AIAA/ASME Symposium at Oral Roberts University in Tulsa, Oklahoma on April 15, 2017. AME students contributed 15 technical presentations to the symposium. AME faculty, Drs. Chung-Hao Lee and Yingtao Liu, served as session chairs and led technical discussions in their session.

The Oklahoma AIAA/ASME Symposium is an annual student conference in the State of Oklahoma. Students majoring in mechanical and aerospace engineering from the University of Oklahoma, Oklahoma State University, and University of Tulsa present their research at this conference. This is a prestigious opportunity for OU AME students to publicize their research and prepare for their academic / industrial careers.

 

andrea-lafflitto-a-mathematical-perspective-on-flight-dynamics-and-control-book

 

Dr. Andrea L’Afflitto has recently published a new book titled A Mathematical Perspective on Flight Dynamics and Control. The book provides a mathematically rigorous description of flight dynamics complementing those presented from a physical perspective.

About this Book

This brief presents several aspects of flight dynamics, which are usually omitted or briefly mentioned in textbooks, in a concise, self-contained, and rigorous manner. The kinematic and dynamic equations of an aircraft are derived starting from the notion of the derivative of a vector and then thoroughly analyzed, interpreting their deep meaning from a mathematical standpoint and without relying on physical intuition. Moreover, some classic and advanced control design techniques are presented and illustrated with meaningful examples.

Distinguishing features that characterize this brief include a definition of angular velocity, which leaves no room for ambiguities, an improvement on traditional definitions based on infinitesimal variations. Quaternion algebra, Euler parameters, and their role in capturing the dynamics of an aircraft are discussed in great detail. After having analyzed the longitudinal- and lateral-directional modes of an aircraft, the linear-quadratic regulator, the linear-quadratic Gaussian regulator, a state-feedback H-infinity optimal control scheme, and model reference adaptive control law are applied to aircraft control problems. To complete the brief, an appendix provides a compendium of the mathematical tools needed to comprehend the material presented in this brief and presents several advanced topics, such as the notion of semistability, the Smith–McMillan form of a transfer function, and the differentiation of complex functions: advanced control-theoretic ideas helpful in the analysis presented in the body of the brief.

A Mathematical Perspective on Flight Dynamics and Control will give researchers and graduate students in aerospace control an alternative, mathematically rigorous means of approaching their subject.

About the Author:

The author is an assistant professor at the School of Aerospace and Mechanical Engineering of The University of Oklahoma and is presently teaching a graduate course in flight control. Dr. L’Afflitto holds a B.S., M.S., and Ph.D. degree in aerospace engineering and an M.S. degree in Mathematics and his research is currently focused on optimal control theory and differential games theory with applications to aerospace control problems, such as fuel-optimal path planning and formation flying.

 

To purchase or learn more about this book, please visit: http://www.springer.com/us/book/9783319474663

A group of students from Dr. Andrea L’afflitto’s Flight Controls class created the following video:

According to Dr. L’afflitto, this project consisted of designing an autopilot for a quadrotor using some modern, very aggressive control techniques. The purpose of this video is to show the results achieved graphically, however, the mathematical models, the control design problem and the numerical simulations have very deep roots.

“I am extremely proud of their work because these are all undergraduate students, but the quality and the mathematical complexity is the one of a graduate project,” said Dr. L’afflitto. “We all can imagine the impact of the development of such technology, considering the growing attention that OU is putting on the UAS technology.”

Video Transcript:

This video shows the result of a students’’ project developed as part of the AME 4513/5513 “Flight Controls” course at the University of Oklahoma in Fall 2016. A DJI F450 will inspect some buildings of OU’s main campus. The drone’s autopilot implements an algorithm based on Model Reference Adaptive Control.

An important feature of this simulation is that the quadrotor dynamics is not captured by a set of nonlinear differential equations, but it is deduced from a SimMechanics model of a DJI F450. This guarantees high accuracy of the results presented.

The adaptive control technology allows precise, aggressive maneuvers in the vicinity of obstacles, such as buildings.

[VIDEO]

Next, we compare the performance of a quadrotor (in white) implementing an adaptive control law and a quadrotor (in black) implementing a classic PID controller.

[VIDEO]

Created by: Blake Anderson

Riley Cotter

Jordan Logue

Kevin Murray Jr.

michael-zavlanos-dream-course

Dr. Michael Zavlanos visited AME on February 2, 2017 as part of Dr. Andrea L’Afflitto’s Dream Course, Modern Control Theory and Applications.

Abstract: Current robotic systems have the potential to accomplish a previously intractable scope of tasks. Their ever growing capabilities will soon allow them to operate autonomously outside the lab, in remote, unpredictable, and uncertain environments, where the presence of humans is dangerous or even impossible. For this to become possible, a fundamental challenge is to develop new methods that will enable teams of robotic sensors to collaboratively explore unknown environments and extract concise actionable information. In this talk,we present a novel approach to dynamically synthesize optimal controllers for a robotic sensor network tasked with estimating a collection of hidden states. The key idea is to divide the hidden states into clusters and then use dynamic programming to determine optimal trajectories around each hidden state as well as how far along the local optimal trajectories the robot should travel before transitioning to estimating the next hidden state within the cluster. Then, a distributed assignment algorithm is used to dynamically allocate controllers to the robot team from the set of optimal control policies at every cluster. Compared to relevant distributed state estimation methods, our approach scales very well to large teams of mobile robots and hidden vectors. We also present a distributed state estimation method that allows mobile sensor networks to estimate a set of hidden states up to a user-specified accuracy. This is done by formulating a LMI constrained optimization problem to minimize the worst case state uncertainty, which we solve in a distributed way using a new random approximate projections method that is robust to the state disagreement errors that exist among the robots as an Information Consensus Filter (ICF) fuses the collected measurements. To our knowledge, even though the distributed active sensing literature is well-developed, the ability to control worst-case estimation uncertainty in a distributed fashion is new. We present numerical simulations and experimental results that show the efficiency of the reposed methods.

Bio: Michael M. Zavlanos received the Diploma in mechanical engineering from the National Technical University of Athens (NTUA), Athens, Greece, in 2002, and the M.S.E. and Ph.D. degrees in electrical and systems engineering from the University of Pennsylvania, Philadelphia, PA, in 2005 and 2008, respectively. From 2008 to 2009 he was a Post-Doctoral Researcher in the Department of Electrical and Systems Engineering at the University of Pennsylvania, Philadelphia. He then joined the Stevens Institute of Technology, Hoboken, NJ, as an Assistant Professor of Mechanical Engineering, where he remained until 2012. Currently, he is an assistant professor of mechanical engineering and materials science at Duke University, Durham, NC. He also holds a secondary appointment in the department of electrical and computer engineering. His research interests include a wide range of topics in the emerging discipline of networked systems, with applications in robotic, sensor, and communication networks. He is particularly interested in hybrid solution techniques, on the interface of control theory, distributed optimization, estimation, and networking. Dr. Zavlanos is a recipient of the 2014 Office of Naval Research Young Investigator Program (YIP) Award, the 2011 National Science Foundation Faculty Early Career Development (CAREER) Award, as well as Best Student Paper Awards at GlobalSIP 2014 and CDC 2006.

keith-walters-bioDr. Keith Walters was awarded $37,363.00 for his research project titled “Multiphysics Simulations of Multi-Component, Off-Design Aircraft Engine Operation Using Dynamic Hybrid RANS/LES.”

The grant is a subcontract from ATA Engineering, Inc., in collaboration with the Air Force Research Laboratory and Mississippi State University, funded under the Department of Defense High Performance Computing Modernization Program (HPCMP), specifically the HPCMP Applications Software Initiative (HASI) Project. They are working to develop enhanced computational fluid dynamics (CFD) models and algorithms to improve the prediction of flow and combustion in high-speed aircraft propulsion systems. Their focus at OU is the modeling and simulation of fluid turbulence. The team will be implementing newly developed models into the CFD software Loci-CHEM and providing the new tools to their collaborators at ATA and AFRL. This is the first year of a potentially four year project, subject to project progress and funding availability. The research group is hopeful to be awarded Year 2 funding.

jerry-qi-guest-lecture

AME hosted a guest lecture given by Dr. H. Jerry Qui on Monday, October 24, 2016. Dr. Qi presented his research regarding the design of active composites for 4D printing applications.

Recent advances in multimaterial 3D printing allow the precise placement of multiple materials at micrometer resolution with essentially no restrictions on the geometric complexity of the spatial arrangement. Complex 3D solids thus can be created with highly non-regular material distributions in an optimal fashion, enabling the fabrication of devices with unprecedented multifunctional performance. This also enables the emerging concept of 4D printing.

In his talk, Dr. Qi started with the concept of 4D printing, where he prints a composite in a relatively simple shape; after printing and some thermomechanical programming, the composite can change its shape as a function of time, the 4th dimension of the shape forming process. He further showed different designs to achieve the shape change, such as printed active composites and direct printing shape memory materials. To further enhance the functionality of the 4D printing, Dr. Qi explored the printing of conductive wires that can be used either for electric signal transfer or as heating elements. He investigated how different curing methods of the conductive ink can affect the electric properties as a function of strain.

jerry-qi-guest-lecture-2

Based on the knowledge learned, Dr. Qi can fabricate a stretchable electronic device in a sequential process. He demonstrated a stretchable LED circuit, a heating element for shape memory polymers, and a sensor to detect shape change. This method provides the opportunity to print complex 3D stretchable electronics, which will be integrated with 4D printing for topology transferring devices. Finally, Dr. Qi discussed the challenge and future directions for 4D printing.

Bio: Dr. H. Jerry Qi is Professor and the Woodruff Faculty Fellow in the George W. Woodruff School of Mechanical Engineering at Georgia Institute of Technology. He received his bachelor degrees and graduate degree from Tsinghua University and a ScD degree from Massachusetts Institute of Technology. After one year postdoc at MIT, he joined the University of Colorado Boulder as an assistant professor in 2004, and was promoted to associate professor with tenure in 2010. He joined Georgia Tech in 2014 and was promoted to a full professor in 2016.

Prof. Qi’s research is in the broad field of nonlinear mechanics of soft materials and focuses on developing a fundamental understanding of multi-field properties of soft active materials through experimentation and constitutive modeling then applying these understandings to application designs. He and his collaborators have been working on a range of soft active materials, including shape memory polymers, shape memory elastomeric composites, light activated polymers, covalent adaptable network polymers, for their interesting behaviors such as shape memory, light actuation, surface patterning, surface welding, healing, and reprocessing. Recently, he and his collaborators pioneered the 4D printing concept. Prof. Qi is a recipient of NSF CAREER award (2007). He is a member of Board of Directors for the Society of Engineering Science. In 2015, he was elected to an ASME Fellow.

kevin-bagnall-lecture2016

 

Kevin R. Bagnall visited AME Tuesday, October 4, 2016, to discuss his research on gallium nitride (GaN)-based semiconductor devices. Currently, most electronics use semiconductor devices based on silicon, which cannot meet the demands of many high-performance applications due to its intrinsic material limitations. The goal of his research is to understand and characterize the performance and reliability of GaN-based devices.

According to Bagnall, this work has provided exciting new insights into the fundamental physics of self-heating in this revolutionary technology and has opened new avenues to simultaneously probe thermal, mechanical, and electrical behavior in these devices as never before.

The application of this technology could be used in utility, transportation, and consumer products, such as electric cars or laptops. Although GaN allows for reduction in the size of electronic components, the high dissipated power densities in these devices leads to elevated channel temperatures and degraded lifetime and performance. Using micro-Raman spectroscopy, Bagnall measures the temperature, stress, and electric field distributions to help understand the physics of failure.

“We are very pleased to host Kevin’s visit to the University of Oklahoma. He has been carrying out cutting-edge research at MIT, advancing the science and technology of advanced materials used in semiconductor industry,” said AME Director Cengiz Altan. “It is truly rewarding to see our alumni be so successful and perform world-class research in a highly collaborative environment.”

Kevin Bagnall is a Ph.D. candidate in the Department of Mechanical Engineering at the Massachusetts Institute of Technology (MIT) working under the supervision of Professor Evelyn N. Wang. Kevin is an alumnus of the Department of Aerospace and Mechanical Engineering at OU, having earned a B.S. in Mechanical Engineering in May 2009. He is the recipient of the Rohsenow Graduate Fellowship at MIT and the National Defense Science and Engineering Graduate (NDSEG) Fellowship sponsored by the Department of Defense and Air Force Office of Scientific Research. For the past five years, he has been working on GaN transistor research in a highly collaborative research center at MIT, which includes the involvement of multiple departments and several industrial partners.

“I really appreciate the undergraduate education I received from AME at OU. It has enabled me to pursue graduate research and a career in academia,” said Bagnall. “I will always be proud to be part of the scholarly, warm and caring AME family.”

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