Simultaneous catheter and environment modeling for Trans-catheter Aortic Valve Implantation

This paper proposes a new vasculature reconstruction and catheter modeling scheme based on data fusion from intravascular ultrasound (IVUS) imaging, electromagnetic (EM) tracking and shape sensing for trans-femoral Transcatheter Aortic Valve Implantation (TAVI). The system is suitable for obtaining inner cross sectional images of the aorta with an IVUS probe, reconstructing its 3D virtual model using sensor fusion of the corresponding pose information of IVUS probe from an electromagnetic (EM) sensor, as well as reconstructing the catheter shape based on optical fibers with Fiber Bragg Grating (FBG) sensors. A hybrid probe consisting of an IVUS sensor, an EM sensor and an optical shape sensor has been created and tested on in-vitro silicone aortic phantoms. A practical image processing method based on the gradient vector flow (GVF) snake has been proposed, followed by fusion with pose information from an EM sensor for the anatomical model reconstruction. Demonstration of the proposed method was performed on two aortic phantoms. Preliminary results show how the catheter shape reconstruction is realized by the shape sensor. The proposed method could facilitate intra-operative surgical guidance for valve alignment, improve the precision for positioning, reduce the time of the TAVI procedure, minimize the use of contrast agent, and assess the status of the deployed valve after surgery.