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Facilities
- Micro-Computed
Tomography (µCT)
- Mechanical Testing
- Bone Densitometry
- Joint kinematics
- Sports Medicine
- Specimen Preparation
- Biomaterials/Biochemistry
- Computing
- Machine Shop
Micro-computed
Tomography (µCT)
Micro-computed tomography is a new and emerging technique for the
nondestructive assessment and analysis of the three-dimensional
trabecular bone structure. A compact micro-tomographic system has
recently been developed by Rüegsegger et al.
(Calcif. Tiss. Int., 1996, 58:24-29). This miniature CT-scanner, also
referred to as desk-top µCT, allows for noninvasive imaging and
quantitative morphometry of bone specimens of various sizes.
The µCT imaging system is used to non-destructively image and
quantify specimen micro-structure three-dimensionally. It is likely that
this new technique will allow for the characterization of the effects of
disease processes and therapeutic agents on trabecular bone architecture
in human bone and a variety of animal models. Trabecular bone consists
of a complicated three-dimensional network of plates and rods, arranged
in a lattice-like network. Aging, disease process, and therapeutic
agents can influence the number of elements in this network, their
dimensions and connectivity, thereby causing dramatic changes in bone
strength. To date, information about these structural parameters of
trabecular bone are only available by histomorphometry, a destructive
procedure limited to two-dimensional analysis. More information on the
capabilities and system specifications of the compact micro-tomographic
system at the OBL
µCT page.
In addition, you'll find relevant information with respect to
collaborative imaging and analysis studies in the
OBL
µCT page.
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Mechanical Testing
The mechanical testing facilities allows for evaluation,
simulation and testing of cadaveric and manufactured specimens. The
testing room is fully equipped with a large and small Instron testing
machine, as well as an Interlaken machine and a hydraulic pendulum
impact simulator. Each piece of equipment is instrumented to a computer
for data acquisition.
For mechanical testing, an Instron 1331 load frame with an Interlaken
Series 3200 controller is used for standardized tests such as
tension, compression and bending. As with all instruments in the
Mechanical Testing room, the equipment is interfaced to a PC for data
acquisition and analysis (mostly using LabView as the interface). Funded
by an NIH Shared Instrumentation Grant, our laboratory has acquired an
Interlaken Series 3300 Axialtorsion load frame with a Interlaken
DDC 4000 digital controller. The multi-axial system allows us
to investigate material and structural properties of tissue under
combined loading, which more closely approximates physiologic
conditions. A sixaxis load cell and fully equipped strain gauging
station are available for experimental stress analysis and system
validation. A high capacity, automated impact testing system is
available for mechanical testing at high loading rates. In addition, we
have a portable Instron Model 8511 (image 3) which is dedicated for
fatigue and is designed for both low force, cyclic fatigue applications
and for tensile/compression testing. Within the facility, there is also
a Fall Impact Simulator, which is a high impact pendulum, and has been
used to simulate falls with a surrogate human pelvis to test hip pads,
as well as other impact related experiments.
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Bone Densitometry
The OBL has extensive facilities for
noninvasive assessment of bone density and geometry, including
dualenergy xray absorptiometry (DXA), peripheral quantitative computed
tomography (pQCT), and quantitative ultrasound (QUS). With these systems
skeletal status may be assessed in vivo or in vitro, with specimens
spanning the size range from small
animals
to humans.
The OBL has a Hologic QDR2000+ (Hologic, Inc, Waltham, MA) bone
densitometer that measures bone mineral content (in grams) and
bone mineral density (in g/cm2) for selected regions of interest. In
addition to the standard algorithms (a/p spine, wrist, and proximal
femur), we also have algorithms for high resolution scanning of small
specimens, rat whole body, metal removal, and lateral imaging. Within
the OBL there is a Norland/Stratec XCT960A (Norland Corp, Fort Atkinson,
WI) device for quantitative computed tomography scanning of
various specimens. The device can be used in vivo or in vitro on
specimens ranging in size from approximately 3 to 60 mm in diameter. The
resolution of the image is a function of the size of the region scanned.
The device can be used to measure bone density (in g/mm3) and crosssectional geometry, such as cross sectional area and
moments of inertia. We have three ultrasound systems designed to assess
skeletal status noninvasively: two waterbased systems for
assessing ultrasound velocity and broadband ultrasound attenuation
through the heel (UBA575+, Hologic, Inc, Waltham, MA and a custom-built
device), and a contact ultrasound system for assessing ultrasound
velocity at the midtibia (SS2000, Myriad Ultrasound Systems,
Rehovot, Israel). Mechanical testing and ashing facilities are also
available at the Orthopedic Biomechanics Laboratory, providing a
complete set of tools for assessing skeletal status in a variety of
animal models and/or human cadaveric specimens.
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Joint kinematics
The joint kinematics facility is used as for the robotic
testing of joint kinematics, especially in relationship to prothetic
implants.
Facility in joint kinematics research facility includes a 6DOF
robotic manipulator (Kawasaki, RZ300), a 6DOF universal force-moment
sensor (JR3, CA). A robotic test system combines the robotic manipulator
and the force-moment sensor. Using sophisticated control algorithm, the
test system has both force and displacement controls in 6 DOF. The
system can be used for biomechanics study of various musculoskeletal
joints. Computer simulation of joint biomechanics is conducted with an
Ultra60 SunWorkstation, that includes 2Gig Ram memory and 40 Gig hard
disk space. Various software for image processing, solid model
reconstruction, rigid body dynamic, and nonlinear finite element
analysis are available.
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Sports Medicine
The sports medicine facility use is primarily used for
surgical testing and training.
For studies of sports medicine, there are four arthroscopic wet lab
systems available. The systems include a wet lab station, suction unit,
specimen stand and 30° Acufex arthroscopic camera and light source with
video monitor. In-flow water is provided by a pressure regulated line
connected to a faucet. A full range of arthroscopic instruments as well
as standard surgical instruments are available. These facilities are
available as part of our surgical training service.
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Specimen Preparation
The OBL is equipped with a specimen preparation facility
consisting of surgical tools, arthroscopy station, and a Faxitron x-ray
machine.
Our Laboratory depends heavily on the use of cadaveric tissue for
investigating the biomechanical behavior of high fracture risk regions
such as the hip, spine and distal radius. Cadaveric tissue is available
from the Harvard Anatomical Gifts Program, and a computerized database
is used to monitor available material. An isolated experimental surgery
suite is equipped with standard surgical instruments as well as an
arthroscopic surgical station. The lab is used for tissue harvesting
(for subsequent testing), device implantation, the development of
experimental procedures and surgical training. The facility is supported
by a Hewlett Packard Faxitron x-ray unit and an automated film
developing system, as well as an OEC Portable C-Arm Fluoroscopy Unit
(OEC, Salt Lake City, UT).
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Biomaterials/Biochemistry
The
biomaterials/biochemistry facilities provides the instrumentation to
perform chemical and specimen preparation for much of the research that is
performed within the OBL. The facilities are equipped with everything from
our own glassware and fume hoods, to diamond cutting saws and an ashing
oven.
This chemistry laboratory is set up with OSHA specifications
including two working fume hoods and appropriate chemical storage
units. The OBL is fully equipped with glassware for condensing and
evaporation, pipettes, beakers, test tubes, mortar and pestles,
separation funnels, filters and desiccators. The lab owns equipment
that provides the capability to perform protein purification and
concentration as well as organic synthesis and polymer procession. Some
of this equipment includes a Labconco lyophilizer, Sorvall centrifuge,
and Buchi evaporator. The biomaterials/biochemistry facilities also include
three low speed diamond saws (Beuhler Isomet), a lasetech wire
saw, a two-station grinder/polisher (Beuhler Tech-Met). There
are three drying ovens, an ashing oven, an ultrasonic cleaner, Metler
scales, centrifuges, and degassing equipment as well.
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Computing
The
Computing center provides the Laboratory with computational, acquisition
and analysis capabilities as well as a number of other resources.
A network of over 40 pentium II and III PC's along with
3
state-of-the-art Sun Microsystems workstations comprise part of the
laboratory's computational facilities. This network allows access to
over 400 GB of on-line disk storage, 8mm tape
backup drive, 4mm 2468 backup drives, a WORM
optical drive, a read/write optical drive, a CD writer, and a scanner.
Output devices include 3 black & white and color laser printers, and 2 film recorders. Software
includes AVS (Image Processing), MSC/Patran, GNOME, and Abaqus (Finite
Element Analysis), Labview for instrumentation, Oracle (Database
Management),
and Statistica (data processing). In addition to the Sun networks there
are 3 Macintosh computers for data acquisition, data
analysis, programming, slide making, and Grant/Personnel tracking.
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Machine shop
A machine shop is available for
prototype development, grip and fixture fabrication and general
maintenance.
The major pieces of equipment
within the facilities include two
lathes, an end mill, two band saws, a bench grinder and two drill presses. A
complete set of hand tools, Dremel tools, various measuring devices,
stock material, and other various tools and supplies available.
Additional resources are available within the institution for more
complex jobs.
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