Day 1 :
University of Toledo, USA
Time : 10:05-10:35
Mohamed Samir Hefzy is currently serving as Associate Dean of Graduate Studies and Research Administration of the College of Engineering and Professor of Mechanical, Industrial and Manufacturing Engineering at The University of Toledo (UT), Toledo, Ohio. He has been on the faculty of The UT since 1987. He graduated from Cairo University, Egypt, with a B.E. in Civil Engineering in 1972, and a B.Sc. in Mathematics from Ain-Shams University in 1974. He earned his M.S. in Aerospace Engineering in 1977 and his Ph.D. in Applied Mechanics in 1981, both from The University of Cincinnati. He then received training as a Postdoctoral Research Associate for two years in the Department of Orthopedic Surgery at The University of Cincinnati’s College of Medicine. In December 2003, Dr. Hefzy was elevated to the Grade of American Society of Mechanical Engineers (ASME) Fellow. He is the recipient of many awards, including the 2011 Distinguished Service Award from the ASME.
A person with quadriceps weakness has limited ability to perform knee extension. A knee-ankle-foot orthosis (KAFO) is a common prescription for such disability. Several types of KAFOs are currently available in the market: passive KAFOs, stance-control KAFOs and dynamic KAFOs. In passive KAFOs, the knee joint is kept locked during standing and walking. However the associated uncomfortable walking gait with high energy consumption makes these devices abandoned by patients. Stance control KAFOs block knee motion for weight bearing and allows free rotation in swing phase. However abnormal gait pattern still exists because of the locked knee joint in the stance phase. Dynamic KAFOs are developed to control both stance and swing phases. But those presently available are inconvenient to use and have complex control systems. This research is directed at using superelastic alloys to develop a biologically inspired dynamic knee actuator that can be mounted on a traditional passive KAFO. The actuator stiffness can match that of a normal knee joint during the walking gait cycle. Two superelastic actuators are used for this purpose. They are activated independently. Each actuator is developed by combining a superelastic rod and a rotary spring in series. When neither actuator is engaged, the knee joint is allowed to rotate freely. The stance actuator works only in the stance phase and the swing actuator is active for the swing phase. The conceptual design of the knee actuator was verified using numerical simulation and a prototype is being developed through additive manufacturing for confirming the concept.
Wayne State University, USA
Time : 10:35-11:05
Michele J Grimm earned her BS in Biomedical Engineering and Engineering Mechanics from Johns Hopkins and her PhD in Bioengineering from the University of Pennsylvania. She joined Wayne State in 1994 and had the opportunity to work with world leaders in injury biomechanics. In 1997, she began collaborating with an obstetrician on a model of shoulder dystocia and NBPP. She has since become a recognized expert in this area and was the only engineer on the American College of Obstetricians & Gynecologists working group on NBPP. She is a Fellow of ASME and a past chair of the Bioengineering Division of ASME.
Approximately 1 in 1000 infants is noted to have a brachial plexus palsy at the time of birth – resulting in paralysis of the arm. About 10% of these injuries are “permanent” – with residual paralysis after 1 year-of-age. For over 100 years, efforts have been made to understand the mechanism of neonatal brachial plexus palsy (NBPP) and reduce its incidence. Due to the relatively rare nature of the injury, and the sensitivity of studies involving pregnant women and infants, typical experimental methods in injury biomechanics have not been appropriate for NBPP. In the past 15 years, modeling techniques – both computer physical models – have been developed to gain greater insight into NBPP injury mechanisms. But the development of models that cannot be fully validated presents its own challenges. Both computer and physical models have demonstrated that significant stretch of the brachial plexus occurs both as a result of the natural, maternal forces of delivery (uterine contractions and maternal pushing) and any assistive traction applied by the clinician. Available data indicates that stretch due to maternal forces alone is sufficient to cause permanent NBPP in some infants. Currently, there is no way to characterize clinically which individuals will be more susceptible to nerve injury than others. This presentation will review the current state of the art with respect to models of NBPP, with particular focus on the development of computer models, in addition to the current data regarding nerve injury thresholds. The gaps in knowledge that deserve to be addressed will be identified.
OrthoKinetic Technologies, LLC, USA
Keynote: Innovative biomaterials and surface technologies for medical devices: Observations of mechanotransduction and biologic induction
Time : 11:25-11:55
Dr. Lisa Ferrara has been faculty at two prestigious academic medical centers and served as the director of the musculoskeletal research facilities. She has received numerous accolades, was involved with the Medical Device Advisory Committee to the FDA, and has provided consulting services about spinal disorders for ABC News. Dr. Ferrara is widely published, provides frequent lectures, serves on multiple scientific and medical advisory boards, and has recently been appointed as a board member to the Advisory Committee for Biotechnology in Southeastern North Carolina.\\r\\n\\r\\nDr. Ferrara previously served as the Director of the Spine Research Laboratory in the Department of Neurosurgery and Orthopedics at The Cleveland Clinic with a research focus on musculoskeletal biomechanics and the development of implantable MEMS sensors for various biomedical applications. She was awarded the Who’s Who Award in Technology in 1999, the NASS Award for Outstanding Research in 1995, and is the recent recipient of the Healthcare Entrepreneur of the Year Award for Coastal North Carolina. \\r\\n
Over multiple decades, orthopedic medical devices have been fabricated from various materials including metals, polymers, ceramics, and allograft tissue. Each material has intrinsic properties that possess certain mechanical characteristics designed for specific anatomical regions and biomechanical parameters. Numerous challenges still exist with the long-term success of many orthopedic devices, yet as innovation continues to progress rapidly, novel materials and surface geometries offer the potential to optimize interface mechanics for improved osseointegration and performance. Therefore, medical devices must be designed with an understanding of the biological and biomechanical principles at the macro, micro, and nano level to offer improved design and implant function. Optimized surface geometries and novel biomaterials have the potential to improve mechanotransduction, while providing greater biological compatibility and biomechanical synergy for long term implantation. These new technologies potentially possess antibiotic/anti-infective properties, micro/nano-surface technologies for improved osseointegration, and controlled surface structures for directed cellular differentiation. Surface geometries and multidimensional load bearing scaffolds have been incorporated into orthopedic implant designs to provide greater contact surface areas at the tissue and bone interface and contribute to improved performance for long term stabilization and immobilization of the tissue. Additionally, the advent of new manufacturing technologies can develop intricate structural scaffolds and nanosurfaces that provide controlled and predictable mechanical stimuli to the cell, where mechanotransduction can be optimized to improve implant function. Therefore, the objective of this work will be to present an overview of a few of these novel technologies, and to present the effects of these novel biomaterials, surface technologies, and structural designs on mechanotransduction and tissue healing.