Section: Highlights of the Year

Highlights of the Year

Inverse deformable model in real-time by quadratic programming optimization

We have published the formulation of an inverse deformable model that we can compute in real time in the form of quadratic problem under equality and inequality constraints. After the projection of the deformable model in the reduced space of unknown parameters, we get an extremely compact formulation of the problem to be optimized. The quadratic formulation allows to write the problem with the conditions Karush-Kuhn-Tucker (KKT) and thus have certainties about the uniqueness and optimality of a solution. This formulation was used in image registration project for adaptive radiotherapy (study published in the International journal of computer assisted radiology and surgery) and also to calculate the inverse model of a deformable robot (study published in the conference ICRA 2015).

Deformable robots with vertebras

We proposed a for generic modeling method suitable for manipulator arm composed of a successive series of deformable portion (inter-vertebrae) and rigid (vertebrae). This method is very computationally efficient and compatible with real-time. These manipulators have a very large number of degrees of freedom. Our approach is to make a domain decomposition from a FEM model on inter-vertebrae and pre-compute a condensation of the model on the vertebrae to drastically reduce the complexity of the model used online. Condensed models are assembled for the global model of the robot. We have demonstrated in an article published in the ICRA 2015 conference that this model allowed to pilot the flexible robot CBHA developed by Festo. Furthermore, we have used this model to propose a new manipulator arm design called FETCH to the competition website Robotic Toolkits Harvard University. We had the 2nd place ex-aequo with 4 other teams.

SOFA

The work we have done and published around our simulation platform SOFA allowed us to get the price "Dirk Bartz Prize for Visual Computing in Medicine 2015," a biennial competition organized by the Eurographics conference. This award recognizes the significant contributions in computer graphics have an impact in the field of medicine. Parallel to that price, a consortium was created to SOFA (https://www.sofa-framework.org/sofa-consortium/ ) whose objective is to bring the academic community and users of industrial SOFA and also of guide future developments. Defrost is a member of this consortium.

Eurographics Dirk Bartz Prize for Visual Computing in Medicine.