The cause of pectus excavatum (PE) is unknown and little research has been done to assess the material properties of the
PE costal cartilage. One source reported, after studying ex vivo various properties of the costal cartilage in cases of PE
that the biomechanical stability of PE cartilage is decreased when compared to that of normals. Building on this idea, it
would be beneficial to measure the biomechanical properties of the costal cartilages in vivo to further determine the
differences between PE subjects and normals. An approach to doing this would be to use a modified FARO arm, which
can read applied loads and resulting deflections. These values can be used to establish a finite element model of the chest
area of a person with PE. So far, a validated technique for the registration between a CT based 3D model of the ribcage
and a skin surface scan in case of PE has been addressed.
On the basis of the data gathered from 10 subjects with normal chests using a robot arm, stylus and 3D laser scanner, we
tried to evaluate the influence of inter-measurement respiration of a subject on results accuracy and the possibility of
using the stylus for deflection measurement. In addition, we established the best strategy for taking measurements.