Authors:
Ana Costa
1
;
Daniel Rodrigues
2
;
Marina Castro
2
;
Sofia Assis
2
and
Hélder P. Oliveira
3
;
4
Affiliations:
1
Faculty of Engineering of the University of Porto, Portugal
;
2
Adapttech, Porto, Portugal
;
3
Faculty of Sciences of the University of Porto, Portugal
;
4
INESC-TEC, Porto, Portugal
Keyword(s):
Principal Component Analysis, Point Cloud Registration, Statistical Shape Models, Lower Limb Sockets, 3D Scanning.
Abstract:
Lower limb amputation is a condition affecting millions of people worldwide. Patients are often prescribed
with lower limb prostheses to aid their mobility, but these prostheses require frequent adjustments through an
iterative and manual process, which heavily depends on patient feedback and on the prosthetist’s experience.
New computer-aided design and manufacturing technologies have been emerging as a way to improve the
fitting process by creating virtual socket models. Statistical Shape modelling was used to create 3D models
of transtibial (TT) and transfemoral (TF) sockets. Their generalization errors were, respectively, 6.8 ± 1.8
mm and 10.5 ± 1.6 mm, while specificity errors were 9.7 ± 0.6 mm and 9.8 ± 0.2 mm. In both models, a
visual analysis showed that biomechanically meaningful features were captured: the largest variations found
for both types were in the length of the residual limb and in the perimeter variation along the limb. The results
obtained proved that statistica
l shape modelling methods can be applied to TF and TT sockets, with several
potential applications in the orthoprosthetic field: generation of new plausible shapes and on-demand socket
design adjustments.
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