Author's Name:
Sasidhar Uppuganti
Advisor's Name: Juay
Seng Tan
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Sasidhar
Uppuganti
Title: In-Vitro
Biomechanical Stability of Trans-Sacral L5-S1 Fusion
Abstract:
Background: The axial trans-sacral screw for L5-S1 fusion is a recently
introduced least invasive surgical procedure. Clinical outcomes have not
been satisfactory despite favorable outcome from sponsored biomechanical
studies. The purpose of this biomechanical study was to independently
assess the multi-directional stability of trans-sacral L5-S1 fixation.
Methods: Flexibility tests in flexion-extension (FE), lateral bending (LB) and
axial rotation (AR) were carried out on 8 L3-S1 human cadaveric
specimens. The specimens were tested 1) intact, 2) with L5-S1 discectomy,
3) with pedicle screws alone, 4) with combined pedicles screws and trans-sacral
screw, and 5) with trans-sacral screw alone. Range of motion (ROM) and
neutral zone (NZ) was compared using repeated measures ANOVA with
α=0.05. Adjacent level effects across L3-L4 and L4-L5 were
analyzed using the hybrid protocol. Results: Trans-sacral
fixation alone did not result in reduced L5-S1 ROM in FE (104%?27% of intact),
LB (100%?24%) or AR (96%?23%) (all p>0.05). Comparatively, pedicle
screws fixation alone resulted in significantly lower ROM in FE (58%?34% of
intact, p=0.0007), LB (41%?34%, p=0.0001) and AR (73%?24%, p=0.045).
Adjacent level effect was not observed with trans-sacral fixation.
Conclusion: The current biomechanical study determined that stand-alone
trans-sacral fixation did not result in enhanced multi-directional stability
across L5-S1.
Author's Name:
Nagmesh Kumar
Advisor's Name: Dr.
Juay Seng Tan
Presentation Type:
research
Invention Disclosure Rights:
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Nagmesh
Kumar
Title: In-Vitro
Biomechanical Analysis of Cervical Open Door Laminoplasty
Abstract:
Background: Current surgical techniques of cervical open door
laminoplasty (ODL) involve resection of posterior ligaments and spinous
processes across C3-C7. The purpose of this study was to compare the
effects of resection of posterior ligaments and lamina on stability and range
of motion (ROM) of the cervical spine. Methods: Multidirectional flexibility
tests were carried out on 9 C2-T1 cadaveric specimens. The specimens were
tested intact and after each surgical procedure of 1) ODL alone, 2) ODL with
resection of terminal ligaments, 3) ODL with removal of all ligaments, and 4)
total laminectomy. Repeated measures ANOVA at α=0.05 determined
differences between surgical procedures. Results: ROM in flexion-extension
(FE), normalized against intact, was 95%?7% for ODL alone, 100%?10% for ODL
without terminal ligaments, and 102%?10% for ODL without all ligaments.
There was no significant difference between ODL techniques in FE, with similar
trend in lateral bending. Total laminectomy resulted in significantly
higher FE ROM (120%?18% of intact, p<0.0001). ODL resulted in 27% to
39% increase in axial rotation ROM (p=0.008). Conclusion: The less
disruptive ODL is no different from the disruptive procedures in terms of
overall cervical motion. The cervical spine is unstable in axial rotation
after ODL surgery.
Author's Name: Mary
Beth Wade
Advisor's Name:
Kimberly Sloan Stakleff, PhD
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Mary Beth
Wade
Title: Mechanically
Enhanced, Peptide Cross-linked Poly(ester ureas) for Critical Bone Defect
Repair
Abstract:
Critical-sized bone defects are injuries to bones that create a gap in the
range of 10 to 30 cm. The goal of the current research is to develop a
bioactive (PEU) scaffold that will promote bone healing across large bone
defects. Incorporation of bone growth factors will stimulate the migration and
synthesis of new bone. Creation of a biodegradable scaffold with the porosity
and strength of bone will provide enough support to bear weight while
effectively inducing bone to grow into it as it slowly degrades over
time. The objective of the first phase of these studies was to
demonstrate biocompatibility of the polymers. The initial polymer derivatives
that were tested included PEU crosslinked with Phenylalanine (PHE) or with
Leucine (LEU). Additionally, each was tethered with the active region of
Osteogenic Growth Peptide (OGP) at either 0.5% or 1% (w/w) concentration. PLLA
was used as a control. All polymers were melt-pressed and cut into 1 cm wide
discs. The polymers were placed in the subcutaneous space and maintained in
vivo for 4 and 12 weeks. Histological analyses of the surrounding subcutaneous
tissue were performed to determine whether the polymers elicit an inflammatory
response, integration of new bone or neovascularization.
Author's Name:
Samuel Dwomoh
Advisor's Name: Juay
Seng Tan, PhD
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Samuel
Dwomoh
Title: Biomechanical
Evaluation of Annular Closure with Polyisobutylene Cyanoacrylate 1Samuel Dwomoh
B.E., 3Ryan Gasser M.D., 2Gabor Erdodi Ph.D., 2Joseph Kennedy Ph.D.,
1Juay Seng Tan Ph.D. 1Department
Abstract:
Background: No gold standard exists to repair torn annulus in herniated
discs. A novel biocompatible polyisobutylene cyanoacrylate ?(PIB-CA)3
glue is proposed as an annular sealant. This study was carried out to
determine if the repaired disc could withstand physiologic intradiscal
pressure. Method: A 9 mm wide and 20 mm deep posterolateral annular
defect was created in the disc of 18 bovine lumbar specimens. Twelve
defects were repaired with ?(PIB-CA)3 while 6 were repaired with cyanoacrylate
(control). Static intradiscal pressurization up to 3.4 MPa was applied
and the maximum pressure sustained without leakage was noted. In
surviving specimens, cyclic intradiscal pressurization between 2.0 to 3.4 MPa
was applied for 20 cycles. Results: Two specimens repaired with ?(PIB-CA)3
leaked at 0 MPa, while 9 out of the remaining 10 specimens withstood 3.4 MPa of
intradiscal pressure without leakage. In contrast, only 1 out of 6
specimens repaired with cyanoacrylate withstood 3.4 MPa of pressure.
Cyclic loading resulted in leakage in 2 of 9 remaining ?(PIB-CA)3 repaired
specimens. Conclusion: Our novel ?(PIB-CA)3 glue provided
sufficient repair strength to the annular defect to withstand intradiscal
pressure beyond physiological levels. Optimal injection volume and
delivery protocol remains to be established to achieve higher success rates.
Author's Name:
Kushal Shah
Advisor's Name: John
Elias
Presentation Type:
research
Invention Disclosure Rights: private
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Kushal
Shah
Title:
All-Epiphyseal ACL Reconstruction Improves Tibiofemoral Contact
Abstract: An
all-epiphyseal approach to ACL reconstruction is performed in pediatric
patients to restore knee stability without disturbing the physis. We
hypothesized that all-epiphyseal ACL reconstruction would shift contact
anteriorly on the tibia, as compared to the ACL-deficient knee. Ten
cadaver knees were tested with the ACL cut and with an all-epiphyseal
reconstruction. The knees were fixed at multiple flexion angles (0?, 15?,
30?, and 45?) and loaded through a combination of quadriceps (600 N) and
hamstrings (200 N) forces. Sensors under the menisci characterized the
center of force on the tibia. Paired t-tests were used to identify
significant (p < 0.05) differences between the reconstructed and cut
conditions at all flexion angles. On the medial plateau, the average
center of force was at least 2 mm more anterior for the reconstructed condition
than for the ACL cut, with the difference significant at all angles. On
the lateral plateau, the anterior shift in the center of force from the ACL cut
to reconstructed condition was significant for all angles except 0?, with an
average difference of approximately 2 mm for all significant differences.
The data indicates that all-epiphyseal ACL reconstruction can improve stability
while minimizing the risk of iatrogenic physeal injury.
Author's Name:
Caroline Frampton
Advisor's Name: John
Elias
Presentation Type:
innovation
Invention Disclosure Rights: private
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Caroline
Frampton
Title: A System for
Characterization of In Vivo Patellofemoral Motion
Abstract: No
consensus exists on optimal surgical treatment for recurrent patellofemoral
instability. Representing symptomatic knees with in vitro models or
computational simulations is complicated by the unstable condition of the knee,
as well as the dysplasia that frequently contributes to instability. We
are developing a technique to reconstruct in vivo patellofemoral motion through
a combination of diagnostic imaging and computational modeling. The
system will be used to characterize function in patients before and after
surgical treatment. Subjects perform a knee extension during a dynamic CT
scan. The CT data is used to reconstruct representations of the patella,
femur and tibia at multiple positions of extension. Patellofemoral and
tibiofemoral kinematics are characterized by digitizing landmarks on the three
bones to create local coordinate systems and characterizing the motion of the
patella and tibia with respect to the femur based on the floating axis
convention. The method has been used to evaluate three patients in the
pre-operative condition to date. Lateral malalignment was identified,
with the average patellar lateral tilt and shift larger than 15 and
6 mm, respectively, from 40 of flexion to full extension.
Post-operative reevaluation will show how surgical treatment influences
patellofemoral alignment during function.
Author's Name: Greg
Gould
Advisor's Name:
Tarun Goswami
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Greg Gould
Title: Research at
Wright State's Biomechanical Lab
Abstract: Many
orthopedic devices are currently available on the market. The biomechanics lab
at Wright State uses synthetic and cadaver specimens to test these devices and
make the outcome relevant in the clinical aspect. It is not only important to know
the orthopedic devices materialistic properties and how the device withstands
forces independently but also when fixated with bones. The lab not only test
devices currently on the market, but is also used to test prototype designs
from Wright State graduate students, Professors, and medical students.
Orthopedic surgeons, engineers, and students work together to design projects
and testing procedures for the orthopedic device and then create resulting
articles to be published.
Author's Name:
Michael Lawrenchuk
Advisor's Name:
Presentation Type:
innovation
Invention Disclosure Rights: private
Funding Provided By:
Conflict of Interest: no
Registration:
attendee
Name Tag: Michael
Lawrenchuk
Title: Innovations
in medical image processing for the design of custom medical devices and
implants
Abstract: There is a
growing trend towards personalization of medical care, as evidenced by the
latest developments in multislice CT imaging and ultra-fast MR imaging,
personalized treatment planning in a variety of surgical disciplines and the
development of more suitable implantable devices. To support this trend, the
role of the biomedical engineer becomes increasingly important, as the
operating theater becomes more and more a technical environment. Hospitals need
multidisciplinary teams for the development of diagnostic tools, implants and
tissue engineered materials, computer assisted surgery and rapid product
development & virtual process simulation processes. Here, we
will describe the use of 3D medical image information of individual patients as
well as selected patient populations, combined with CAE tools and processes, in
the rapid product development of custom and standard implantable devices. The
combination of medical image information with methods such as CAD, RP,
and FEA allows the engineer to develop implantable devices faster and better,
with optimized designs tailored to the anthropometry of the targeted patient
(population), using virtual instead of mechanical prototype
testing. Case studies from leading biomedical research institutes
as well as medical device manufacturers will be demonstrated with a focus on
orthopedic applications of this innovative technology.
Author's Name: J. Adam Hamilton, John Dundon
Advisor's Name: Michael Herbenick
Presentation Type: innovation
Invention Disclosure Rights: private
Funding Provided By:
Conflict of Interest: no
Registration: student
Name Tag: John Dundon, MD
Title: The Cannulated Screw Core: Improving the Mechanical properties of Cannulated Screws
Abstract:
Introduction: Cannulated screws are commonly used orthopedic implants.
While cannulated screws can be easier to insert, studies have demonstrated a
decrease in fatigue strength.[i] The purpose of this study is to test a
novel cannulated screw, as designed by Hamilton, that has a so called
?cannulated screw core? insert that may allow it to have similar mechanical
properties to a solid core screw. Methods: Five separate groups of 4.5mm screws
were tested with six samples per group. These groups included: a Synthes
solid core, a Synthes cannulated, a solid core prototype, a cannulated
prototype, and a cannulated with core prototype screws. Each sample was
subjected to 3-point bending at a constant rate. Maximum load to failure
and flexural strength were determined from stress strain graphs.
Results: The mean 3-poin flexural strength of the solid core, cannulated, and
cannulated with core prototypes were 2414 (SD 70.8), 1775 (SD 50.6), and 2166
(SD 72.9) N, respectively. Discussion: Testing of the Synthes
screws confirmed that solid core screws are generally stronger than cannulated
screws. Although other testing like cyclical loading will have to be
done, this study suggests that a cannulated screw core makes a cannulated screw
behave similarly to a solid core screw.
Author's Name: Amy
Yousefi
Advisor's Name:
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
attendee
Name Tag: Amy
Yousefi, Ph.D.
Title: Biomimetic
Constructs for Cartilage Regeneration and Cartilage Replacement
Abstract: The
biological basis of joint problems is the deterioration of articular cartilage
and subchondral bone at the joint surface. Current treatments have
limited success in terms of their efficiency or have unacceptable side
effects. Tissue engineering approach using polymeric scaffolds is a novel
alternative to conventional repair techniques with the goal of restoring tissue
functionality. In our previous studies, poly(L-lactic acid)(PLLA) and
poly(L-lactic-co-glycolic acid)(PLGA) were used to produce tissue-engineering
scaffolds by a combination of 3D-plotting and porogen-leaching techniques.
These constructs, designed to mimic cartilage and seeded with chondrocytes,
improved the cell viability under dynamic loading inside a mechanically-loaded
bioreactor. The in vivo results in a canine model demonstrated that the
implanted scaffolds were favorably contributing to the repair process as
compared to the empty control lesions. While our current focus is on tissue
engineering approach, this work will also present our recent results on
designing hydrogel-based biomaterials for cartilage replacement. Polyvinyl
alcohol/polyvinylpyrrolidone (PVA/PVP) hydrogels were prepared by successive
freeze-thaw cycles. Adjusting the polymer concentration, PVP/PVA ratio, number
of freeze-thaw cycles , and thawing rate provided insight into designing
constructs with desired wear resistance and target storage and loss moduli (E?
and E?) matching those of cartilage.
Author's Name: Lei
Kerr and Huiying Jia
Advisor's Name: Lei
Kerr
Presentation Type:
innovation
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
attendee
Name Tag: Dr. Lei
Kerr, Associate Professor, Miami Universit
Title: Anodized TiO2
Nanotube Film for Controllable Drug Delivery in the Implant
Abstract: To control
drug delivery is to administer the necessary amount of drug safely and
effectively to specific sites in the human body and to regulate the temporal
drug profile for maximum therapeutic benefits. Drug therapy regiments are
now required by most of medical implant procedures in order to decrease
inflammation, control infection and prevent clotting. However, when the
antibiotic is given orally, it is not effective for preventing bacterial
infection around the implant. This is because most antibiotic will travel
through the whole body as well as be absorbed by the liver, intestine, kidneys,
or lung. As a result the drug cannot reach the infection site in the implant
surface with effective concentration. Increasing drug doses cannot solve
this problem because it will lead to organ toxicity. Thus, delivery of drugs
locally from an implant surface has become a commonly used option to prevent
infection. In this study, we develop a method for controllable drug release
using an innovative hybrid biodegradable polymer/TiO2 nanotube structure.
The TiO2 nanotube with various morphologies is synthesized via the anodization
method.
Author's Name: David
Kirschman
Advisor's Name: n/a
Presentation Type:
innovation
Invention Disclosure Rights: private
Funding Provided By:
Conflict of Interest: no
Registration:
attendee
Name Tag: David
Kirschman
Title: In vivo and
In vitro biomechanical performance of a novel pedicle screw system: A two-year
retrospective analysis.
Abstract: Objective.
To perform a review of the in vivo and in vitro biomechanical performance of a
novel rotary locking polyaxial pedicle screw system. Methods. Operative and
postoperative data on all patients treated at single center with lumbar
rotary-locking pedicle screw fixation between January and December of
2007 were reviewed using standard operative data. Additionally, the screw
system was tested using internationally accepted biomechanical testing
methodologies. Results.Of the implantations performed, no patients required
re-operation due to hardware complications and 1 patient required re-operation
due to infection (2.4%), and 1 patient required non-surgical treatment for
superficial wound infection (2.4%). Additionally, rotary locking pedicle screw
systems underwent in vitro polyaxial yield testing, screw pullout testing,
axial slip testing, compressive static yield testing and compressive fatigue
testing per ASTM F1717 and F1798 guidelines. Conclusion. The Capless
pedicle screw system is a viable alternative to currently used pedicle screw
systems, demonstrating effective biomechanical performance in vitro and in
vivo.
Author's Name: John
Cotton
Advisor's Name:
Presentation Type:
research
Invention Disclosure Rights:
Funding Provided By:
Conflict of Interest: no
Registration:
attendee
Name Tag: John
Cotton
Title: Mechanical
modeling of the porcine temporomandibular joint
Abstract:
Temporomandiular joint (TMJ) disorders affect up to 25 percent of the
population, leading to pain disfunction and arthritis. The pig is an
excellent model for examining human TMJ mechanics due to its low cost and
relative similarity. My lab at Ohio University uses the pig TMJ to
examine both porcine and human TMJ mechanics. We created a FE
model of a pig TMJ as follows. From a Hanford pig CT scan, we segmented
the mandibular and temporal bone proximal to the joint. Soft tissues
representing the fibrocartilage disc, and both TMJ and retrodiscal ligaments
were added based on the CT image and anatomic dissections. The model was
meshed, and bone and ligaments given appropriate linear elastic or hyperelastic
material properties. We applied muscle and reaction loads representing
mastication taken from the literature. We see a stress distribution
pattern in the disc similar to published qualitative
estimations. In a related work, we have microCT scanned the
mandibular condyle from six Handford pigs to determine microscale properties of
the underlying bone. As trabecular bone adapts both its density and
orientation in response to the magnitude and directionality of stress, we
examine the use of trabecular bone structure to validate the FE model.
Author's Name: Rinki
Goswami
Advisor's Name: Dr.
James Bartsch
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Rinki
Goswami
Title:
Characterizing the Effects of Bromelain on the Mechanical Properties of Bovine
Articular Cartilage
Abstract: The
effects of an enzymatic environment on the mechanical properties of bovine
cartilage was examined. Additionally, the effects of varying bromelain
concentrations (BR1 ? 2.3 GDU/gram vs. BR2 ? 10 GDU/gram) on cartilage are
characterized, and the effects of immersion time on the properties of cartilage
are noted. Cartilage samples were tested under compression, relaxation,
and cyclic loading. The average strain energy tended to be higher in PBS
samples compared to bromelain samples for both 1 week and 24 hour samples. The
Young?s modulus was greater in BR1 samples. Neither of the analyses showed
solution sensitive results. The Young?s modulus data showed definite decrease
after increased immersion time sensitivity. From the relaxation data, the
average relaxation time was not particularly descriptive. For the samples
submerged for 24 hours, the time constant was the largest in PBS, a value that
was lower than the one in BR1, but larger than the one in BR2. This
latter decreasing trend was reversed with an increase in the length of the submersions,
with the time constant for the submersion in the order of BR1, PBS, BR2.
From analysis of the cyclic loading data, the average hysteresis and degree of
plasticity tended to be higher in PBS samples than in samples that were
immersed in bromelain (47.3% and 13.2% respectively). Increased bromelain
concentrations resulted in an increase on the hysteresis and degree of
elasticity of cartilage samples (13.27% and 12.9% respectively).
Author's Name:
S.Hueston, I.Mabe, M.Makola
Advisor's Name: Tarun
Goswami, D.Sc
Presentation Type:
research
Invention Disclosure Rights:
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Susan
Hueston, Isaac Mabe, Mbulelo Makola
Title: Morphometry
Analysis and Kinematic Response of the Cervical Spine
Abstract: In medical
device development it is important to understand the anatomy of the human body,
of particular interest for this group and this investigation is the cervical
spine. In order to aid in the understanding of the cervical spine an analysis
of differences in the morphometry based on demographics of the patient was
investigated. Investigation into the change in the dimensional anatomy of
the cervical spine vertebras based off gender, race, and age was
accomplished. From the same CT scans three-dimensional anatomical models
were constructed of the cervical spine. Static load conditions are used to for
model validation to determine the accuracy of the 3D model. While static
analysis is good, in vivo situations are dynamic so this study will also
examine the relationship between static and dynamic loading and the differences
there in. While complete physiological loads are difficult to replicate a
dynamic load response is key to investigating the kinematic response of the
cervical vertebra to applied injurious loading conditions. The results of
this will further assist in more accurate device development, understanding of
risk, and a better understanding of the functionality of the cervical spine.
Author's Name:
Dishita Patel
Advisor's Name:
Dr.Tarun Goswami
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Dishita
Patel
Title: Influence of
Design Parameters on Cup-Stem Orientations for Impingement free RoM in Hip
Implants
Abstract: This study
was conducted to study the influence of design parameters namely the head/neck
ratio, neck-shaft angle , oscillation angle and stem offset on cup-stem
orientations namely the cup inclination, cup anteversion and stem antetorsion.
This study attempted to answer following assumptions whether a) implants with
higher H-N ratio can achieve higher oscillations and higher stem anterosion, b)
stems with higher neck shaft angle can achieve higher cup anteversion with lower
stem offset and stem antetorsion, c) stem with higher offsets can achieve lower
cup anteversion with higher stem antetorsion, and d) lower cup anteversion can
be achieved when stem antetorsion is higher, e)maximum stress occurs on
acetabular cup or femoral stem during gait cycle, f) how critical is the
interaction between ball-stem to predict impingement for dislocation. A
theoretical and a finite element method was implemented to anaylze range of
motion until impingement between cup and neck occurred. Multivariate prediction
models were developed to predict optimal cup-stem orientations for the chosen
design parameters of 12 hip implants. This study aims to enhance the
understanding of cup-stem orientation for pre-surgical planning to
achieve optimal component placement as well as designing better components for
a successful Total Hip Arthroplasty.
Author's Name:
Matthew Coombs
Advisor's Name:
Donita Bylski-Austrow
Presentation Type:
research
Invention Disclosure Rights: private
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Matthew
Coombs incl. Donita Bylski-Austrow & D
Title: Spinal
Hemiepiphysiodesis: Initial Biomechanical Conditions that Modify Growth
Abstract: With the
goal of preventing juvenile and adolescent spine deformity progression without
arthrodesis, methods of mechanically altering spine growth asymmetrically have
been under investigation. One implant construct has been approved by the FDA for
an early stage clinical study. In previous studies using this device, scoliotic
curvatures were induced in normal porcine spines within 2 months. The
tissue-level mechanism of graduated growth inhibition included decreased
physeal hypertrophic zone and disc heights. Intra-operative bilateral
compressive stresses and in vivo physiological stresses have been reported in
this model. The purpose of these studies was to determine if staple
implantation caused initial biomechanical gradients. Biomechanical
tests were performed in vitro on porcine thoracic spinal motion segments before
and after stapling. Compression tests included custom MEMS sensors placed
bilaterally in the annulus. A finite element model was developed of the segment
and test conditions. FEA well predicted the nonlinear load-displacement curve
before stapling, and overestimated the stiffness of the segment after stapling.
Disc stresses from model and experiment showed stress shielding after stapling.
These studies help define at least one set of biomechanical initial conditions
that have been shown capable of modifying spine growth asymmetrically.
Author's Name: Brian
Yeakley
Advisor's Name: Dr.
Tarun Goswami
Presentation Type:
research
Invention Disclosure Rights:
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Brian
Yeakley - Booz | Allen | Hamilton
Title: Increased
Aircrew Helmet Protection
Abstract: Currently,
there are eight different Air Force aircrew helmets providing 27 different
configurations. The Modular Aircrew Common Helmet program will provide
greater personal protection and replace the eight different helmets with a
single helmet capable of providing the current configurations. When an
aircrew member initiates an aircraft ejection, the added weight of a helmet has
a measurable effect on the cervical spine. The effect is compounded based
on the orientation of the aircrew?s head at the time of ejection
initiation. This analysis focuses on the potential increase in cervical
spine injuries as a result of a heavier helmet. The analysis will also
investigate whether or not the overall increase in personal protection is worth
an increase in cervical spine injuries and fatalities.
Author's Name:
Norman, Timothy
Advisor's Name:
Presentation Type: research
Invention Disclosure Rights:
Funding Provided By:
Conflict of Interest: no
Registration:
Name Tag: Tim Norman
Title: In-Service
Damage Accumulation and Mineralization Heterogeneity in Human Femoral Cortical
Bone
Abstract:
Mineralization heterogeneity may have a role in defining the relationship
between microdamage and mineralization in human cortical bone. Significantly
more cracks exists in interstitial regions of bone perhaps due to increased
mineralization in those regions. However, even though microdamage significantly
increases with age, several studies indicate that average (or bulk)
mineralization in bone decreases with age. It is believed that bone
damageability increases with the elevation or suppression of bone turnover.
Suppression of turnover via bisphosphonates increases local bone mineralization
which theoretically should increase the susceptibility of bone to microcrack
formation. Elevation of bone turnover has also been proposed to increase bone
microdamage through an increase in bone intracortical porosity and local
stresses and strains. This work investigates the relationship between mineral
content and porosity and increase bone in-service damageability. Experimental
measurements of in-vivo diffuse damage area (Df.Dm.Ar, %) and microcrack
density (Cr.Dn) (cracks/mm2) from human cortical bone of the midshaft of the
proximal femur were made from cadavers with an age range of eight decades. In
addition, a semi-empirical micromechanical mineralization model was developed,
to determine the relationship between amount of hypermineralized bone and
average (bulk) mineralization with age. It was hypothesized that although bone
may contain hyper-mineralized regions, that average or bulk mineralization can
decrease with age consistent with experimental data, when undermineralized
regions also exist.
Author's Name:
Shirish Ingawale
Advisor's Name: Dr.
Tarun Goswami
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration: student
Name Tag: Shirish
Ingawale
Title:
Subject-specific Modeling and Finite Element Assessment of Mandible and the TMJ
Implant
Abstract: A subject-specific 3D model of mandible was developed from CT scans of a female. FEA of the model were performed under four loading conditions - balanced loading, unbalanced loading, teeth grinding, and clenching - using bite and muscle forces independently. Three FEA simulations for each loading condition were performed and peak von Mises stresses in condylar fibrocartilage were noted. Also, FEA of the patient-fitted Biomet-Lorenz TMJ implant were performed. The peak von Mises stresses developed in mandibular condylar cartilage during teeth grinding and clenching were found significantly different (p-value <0.0001 at = 0.05) and higher than during balanced loading for bite as well as muscle force simulations. However, the peak stresses in condylar cartilage during unbalanced loading were not significantly different (at = 0.05, p-value = 0.4386 and 0.1967 for bite force and muscle force simulations, respectively) than during balanced loading. Stresses developed in the implant provide insight into structural hot spots of the device; and may help improve the design, treatment efficiency, and durability of the TMJ prostheses.
Author's Name: Kane,
Erik, Pernicano, Leah
Advisor's Name: Tim
Norman
Presentation Type:
research
Invention Disclosure Rights:
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Erik Kane
Title: Three
Dimensional Finite Element Analysis of Intramedullary Nails for Size
Abstract: Missionary
surgeons in third world countries face the challenge of treating many patients
for numerous medical conditions with very limited resources. One specific
surgery they often perform is an intramedullary (IM) nailing to treat a femoral
fracture. The overall goal of this project is to provide a solution to
the problem faced by missionary hospitals, which is the high cost of modern day
medicine. To do this, an existing intramedullary nail
(Russell-Taylor/Smith & Nephew IM nail) used by missionary surgeons was
reverse-engineered. These injuries affect people of many different ages,
heights, and weights; therefore, the missionary surgeons in third world
countries need IM nails of various sizes. The objective of this study was to
investigate the effect of nail size on stresses in the nail, fasteners, and
bone to assess the likelihood of failure. To do this, a 3D finite element model
was created and loaded to simulate single-legged stance and stair-climbing.
Numerical analysis was then performed on these models. Specifically,
nails with diameters of 11, 12, and 13 mm were analyzed and the stresses of the
nail, fasteners, and bone were compared to static and fatigue allowable
stresses. Ultimately, the design will be manufactured and distributed to Tenwek
hospital in Kenya, Africa.
Author's Name:
Bradley Elliott
Advisor's Name: Dr.
Tarun Goswami
Presentation Type:
research
Invention Disclosure Rights: university
Funding Provided By:
Conflict of Interest: no
Registration:
student
Name Tag: Bradley
Elliott
Title: Hip Implant
Micromotion and Resulting Femoral Canal Damage for Several Implant Materials
Abstract:
Interfacial motion between the hip implant stem and the femoral canal in total
hip arthroplasties is one of the primary reasons for a lack of boney ingrowth
for press-fit implants. It has been demonstrated that as much as 40-150
?m (Jasty, Bragdon, Burke, O'Connor, Lowenstein, & Harris, 1997) of motion
at the interface can degrade the likelihood of ingrowth to a point of
non-adherence. Furthermore, the potential for bone damage in the canal
attributed to this motion cannot be readily ignored. Therefore, this
research is aimed at using finite element methods to determine the level of
relative motion between the implant stem and femoral canal and attempt to find
a correlation between this motion and the rate of accumulating damage in the
bone canal. Several implant materials will be tested in order to
determine the role material properties plays in both
phenomena. Reference: Jasty,
M., Bragdon, C., Burke, D., O'Connor, D., Lowenstein, J., & Harris, W. H.
(1997). In Vivo Skeletal Response to Pourous-Surfaced Implants Subjected to
Small Induced Motions. Journal of Bone and Joint Surgery , 707-714.
