Article

Passive-dynamic ankle-foot orthoses (PD-AFOs) constitute a class of ankle braces
that rely on material properties and physical features to establish functional
characteristics such as bending or rotational stiffness. We have developed a
novel framework that combines a fully parameterized PD-AFO computer-aided design
(CAD) model and free-form fabrication to rapidly manufacture customized PD-AFOs.
The three-dimensional locations of select anatomic landmarks serve to fit
customize the PD-AFO CAD model. A virtual orthopedic alignment process and
selection of discrete design parameter values further customize the orthosis,
which is fabricated via selective laser sintering. CAD models were customized and
full-scale orthoses were manufactured for two nondisabled subjects. The surface
of one half-scale CAD model was marked with 3 mm hemispherical dimples, and four
orthoses were manufactured in different build orientations and positions.
Dimensional accuracy was determined by calculating discrepancies between
corresponding CAD and fabricated orthoses interdimple distances. Subjective
evaluations of the full-scale PD-AFOs following use in gait were positive.
Dimension discrepancies were well under a 2 mm tolerance for the four half-scale
orthoses. Mean foot plate, strut, and cuff component discrepancies were 0.31 +/-
0.28, 0.34 +/- 0.08, 0.52 +/- 0.39 mm, respectively, and 0.29 +/- 0.23 mm for the
overall orthosis. Dimensional accuracy of the rapid customization and
manufacturing framework was well within tolerances suggested in the literature.

Langue : ANGLAIS