Percutaneous medical procedures, using surgical needles, are among the least invasive approaches to accessing deep internal structures of organs without damaging surrounding tissues. Today, many surgical procedures rely on the use of needles allowing for complex interventions such as curie-therapies or thermoablations of tumors (cryoablation, radio frequencies). Unlike traditional open surgery, these approaches only affect a localized area around the needle reducing this way trauma and risks of complications. These treatments also offer new solutions for tumors or for metastases for which traditional methods may be contraindicated due to the age of the patient and the extent or location of the disease.
Although they provide very good results, these interventions significantly increase the level of expertise required for practitioners. Thermoablation can be extremely complex to achieve since the effectiveness of the treatment will mainly depend on the accuracy of needle’s positioning, limited by the fact that needles are manipulated from outside of the patient using intraoperative images offering poor visibility of internal structures. Medical robotics has the potential to assist surgical gesture, overcome limitations due to human factors and increase the accuracy of tools positioning. Many research projects and commercial products aim to develop surgical robots for needle insertion assistance. However, the deformation of the organs remains, an open problem limiting the development of these robots for wide use in the operating room.In this project, we want to develop new solutions for the control of medical robots interacting with soft tissues.
This work is motivated by recent advances in the field of medical simulation achieving a sufficient level of realism to help surgeons during the operation. These simulations are now used for training of surgeons, and even for visual assistance during the operation thanks to augmented reality. The maturity of these techniques now suggests the ability to use a simulation intraoperatively to control the motion of a robotic system for needle insertion. This is really a challenge, because in general, very few information can be extracted in real time from images during an intervention. We believe that even minimal knowledge of the mechanical behavior of structures, associated with the use of images can make it possible and allow a robot to reach a pre-identified target during a planning stage, without human intervention.
The originality of our approach lies in the fact that we will address the problem of deformation using inverse real-time finite element simulations in the control loop of the robot. This represents important scientific obstacles that will be addressed in this project. In particular, we will need to achieve an optimal compromise between the accuracy and speed of models to predict the interaction of soft tissues and needles. These works will be implemented on a dedicated hardware platform. This consists of a collaborative robot equipped with a previously designed needle manipulation tool, which will allow the validation of the method in realistic applications. A strong motivation is to bring our research results to an experimental prototype allowing for qualitative and quantitative evaluation of our method.