Non-Rigid Surface Matching Technique as a Tool in Scoliosis Deformation Modelling

We present a novel approach for deformation modelling and exploit it on scoliosis monitoring. Despite the extensive use of surface topographies to monitor scoliosis, shape change due to scoliosis deformities has never been satisfactorily resolved. A novel non-rigid surface matching algorithm with nine new parameters has been investigated and developed. This non-rigid matching algorithm has been trialled using models with predictable topographic deformation. There is evidence that surface deformities can be modelled. In addition, to demonstrate the capability of this new non-rigid matching algorithm in scoliosis modelling, we have performed experimental comparison with classical rigid matching algorithm using four different scoliosis data sets. The non-rigid matching algorithm returned r.m.s. values which were improved by at least 10%. The experimental results are very promising, demonstrating that this new non-rigid matching algorithm is able to improve the precision and the accuracy of the matching. Analysis indicates that this new non-rigid matching algorithm has proven to be a very successful tool and is an improvement on the classical approach. Meanwhile the new parameters are able to delineate the possible spatial distribution of surface deformation. 1. Background