Next-Generation Disc Prosthesis Designed in Mathematica
About 15 to 20 percent of all people live with chronic back pain. With the
increasing success of hip and knee joint replacements, researchers hope
to achieve similar results for back ailments with an intervertebral disc
replacement for the spine.
The Eindhoven University of Technology and the Netherlands
Organization for Applied Research have developed new algorithms and a
complete workflow in Mathematica to build customized endplates
for disc prostheses. Proper fixation of the disc to the vertebrae is
of great importance to patient outcomes, but current prostheses are
more or less of a one-size-fits-all design. Imperfect alignment often
leads to complications such as increased pressure on the spinal
column, excessive wear, and other difficulties.
Imaginary balloon inflated
Using modern 3D MRI and CT scans, the exact shape for a customized
disc can be determined without any surgery. This is made possible by a
segmentation technique that is both more accurate and easier to
understand than other methods. Imagine a small balloon being inflated
between two spinal vertebrae until it is perfectly meshed against the
vertebral surfaces. Those contours could then be used to model the
geometry of the needed prosthesis.
Scan images in DICOM format are imported into Mathematica and enhanced as
needed, followed by a three-dimensional fit using a "balloon" algorithm
developed in Mathematica. The results are exported in STL format directly
to a CNC machine, which creates individual conformal endplates that can be
fixed to the vertebral surfaces. Additional research into other aspects of the
prosthesis--such as creating a flexible joint, the endplate material, and
biocompatible coatings--is ongoing.
Researchers eventually hope to make this technique and the specialized,
open-source Mathematica add-on that enables it available to the broader
medical community. Other possible applications of this method include the
segmenting the shape of the brain, ventricles, bones, teeth, or