Artificial
Joint Manufacturing
Custom
Systems
Aerotech
designs and manufactures custom systems to your specifications.
•
Available
in ball-screw-driven (ATS) or linear motor drive (ALS)
•
Optimized
cable management systems
•
Complete
engineering support
•
Variety
of feedback and control options to meet
your
needs
Aerotech’s
custom five-axis
system
used in the production of a
hip
joint Ňshaving” instrument.
shaping
instrument detailed above. A five-axis system
Acetabular
Joint Forming
consisting
of three linear axes and two rotary axes is used to
Hip
implant surgery involves replacing the acetabulum and
position
the hemisphere-shaped instrument for cutting with a
femoral
head that comprise the hip joint with a synthetic
laser.
The shape of the cutting edges of the instrument are
device.
As there is a wide variation in bone structure among
complex
in form and creation of the motion program is
replacement
patients, the joint must be shaped or formed to
further
complicated as these shapes must be projected onto a
accept
the profile of the mating replacement socket. This
spherical
surface. A third-party 3D CAD/CAM program was
shaping
is accomplished by Ňshaving” bone material from
used
to generate the desired tool path along the surface of the
the
socket area (acetabulum). To provide a consistent form
hemisphere.
The A3200's
ability to execute standard G-code-
on
the mating-bone surface, joint replacement manufacturers
type
programs provides a ready-made interface to accept the
supply
a hemispherical Ňshaving” device whose diameter is
tool
path output from CAD/CAM programs. For this
consistent
with that of the synthetic acetabulum to be
application
the A3200 operated in ŇInverse Time” mode,
implanted.
This instrument has a series of projected cutting
which
provides a means of ensuring a constant surface speed
edges
that are placed in a
when
executing the complex geometry on the surface of the
spiral
fashion along the
hemisphere.
In ŇInverse Time” mode the CAD/CAM
surface.
These cutting
program
calculates the path distance for each block and
edges
have some degree
encodes
this information on the G-code program line. This
of
overlap so that bone
distance
is then used by the A3200 controller to calculate a
material
is removed
constant
surface speed along the programmed path ensuring
around
the entire surface
consistent
results on all regions of the part.
of
the mating socket as the
device
is rotated. After the
A
combination of direct drive and screw-driven stages were
instrument
has been used
used
within the system. ALS5000
linear motor stages were
to
shape the bone, the
A
hemisperical Ňshaving”
chosen
for the X and Y axes due to their high stiffness,
socket
is ready to accept
device
is used to shape the hip
throughput,
and load carrying capability. Screw-driven axes
the
insertion of the
socket
prior to insertion of the
were
used for the rotary and vertical axes to counteract
synthetic
replacement
synthetic
replacement joint.
forces
induced by gravity and offset fixtures. Special
joint.
shrouding
was applied to the cable management of the X and
Y
axes to provide protection from the debris generated as a
Aerotech
has provided motion equipment to joint
byproduct
of the cutting process.
replacement
suppliers to manufacture the acetabulum-