Modeling and process design of a new type of catheter for special endovascular treatments of abdominal aortic aneurysms

A consortium of laboratories named MATEO (directed by Professor Frank Boudghene) has been created in response to a national call in Health Technologies, and we have focused our project on the risks related to the endoluminal method (endovascular) stent placement in aorta with a flexible catheter. In order to improve the actual surgical method, it is necesary to dispose a catheter with an actuated distal part. In this paper, we define the mechanical design and the modeling of a new actuator based on the deformation of three cylindrical nickel bellows due to internal hydraulic pressure of physiological water. This device produces bending movement as an elastic continuum without the need for an additional skeletal structure. Two actuators are implemented in the distal part of the catheter, one into the tip and one just before the part where is localized the endoprosthesis. The first actuator allows a control to open the way through the vessels and the second actuator allows a control of the orientation of the distal part just before the dropping phase of the endoprosthesis. The geometrical constraints due to a severe reduction are satisfied and a real scale prototype has been carried out (fig.1).