Disg Seminar Series - PAOLO PIRAS
Understanding heart function is a central topic in both research and clinical practice. Geometric Morphometrics (GM) is a modern shape analysis tracing back to seminal papers by Kendall and allows the statistical comparison of different shapes identified by homologous landmarks. One of the most efficient ways to align such configurations is the Generalized Procrustes Analysis (GPA). Very often GPA is followed by a Principal Component Analysis (PCA) in order to find axes of maximal variations. Using a technique called “linear shift” it is possible to observe the sole deformations among individuals thus partialling out inter-individual shape variation. GPA+PCA performed on shifted data better illustrates actual deformations occurring among different subjects. Once assessed a proper morphospace for studying shape deformation, it is possible to study the shape of the trajectories themselves and test if they differ among healthy and pathological subjects. Together with its shape, both the orientation and the size of a trajectory constitutes fundamental attributes of this physical representation. Using both static shape and trajectory-based analyses, it is possible to assess if healthy subject are set apart from pathological individuals.