SCEM+: Real-Time Robust Simultaneous Catheter and Environment Modeling for Endovascular Navigation

© 2016 IEEE. Endovascular procedures are characterised by significant challenges mainly due to the complexity in catheter control and navigation. Real-time recovery of the 3-D structure of the vasculature is necessary to visualise the interaction between the catheter and its surrounding environment to facilitate catheter manipulations. State-of-the-art intraoperative vessel reconstruction approaches are increasingly relying on nonionising imaging techniques such as optical coherence tomography (OCT) and intravascular ultrasound (IVUS). To enable accurate recovery of vessel structures and to deal with sensing errors and abrupt catheter motions, this letter presents a robust and real-time vessel reconstruction scheme for endovascular navigation based on IVUS and electromagnetic (EM) tracking. It is formulated as a nonlinear optimisation problem, which considers the uncertainty in both the IVUS contour and the EM pose, as well as vessel morphology provided by preoperative data. Detailed phantom validation is performed and the results demonstrate the potential clinical value of the technique

Registration-free simultaneous catheter and environment modelling

© Springer International Publishing AG 2016. Endovascular procedures are challenging to perform due to the complexity and difficulty in catheter manipulation. The simultaneous recovery of the 3D structure of the vasculature and the catheter position and orientation intra-operatively is necessary in catheter control and navigation. State-of-art Simultaneous Catheter and Environment Modelling provides robust and real-time 3D vessel reconstruction based on real-time intravascular ultrasound (IVUS) imaging and electromagnetic (EM) sensing,but still relies on accurate registration between EM and pre-operative data. In this paper,a registration-free vessel reconstruction method is proposed for endovascular navigation. In the optimisation framework,the EM-CT registration is estimated and updated intra-operatively together with the 3D vessel reconstruction from IVUS,EM and pre-operative data,and thus does not require explicit registration. The proposed algorithm can also deal with global (patient) motion and periodic deformation caused by cardiac motion. Phantom and invivo experiments validate the accuracy of the algorithm and the results demonstrate the potential clinical value of the technique

3D vessel reconstruction based on intra-operative intravascular ultrasound for robotic autonomous catheter navigation

In recent years, robotic technology has improved instrument navigation precision and accuracy, and helped decrease the complexity of minimally invasive surgery. Still, the inherent restricted access to the anatomy of the patients severely complicates many procedures. Interventionists frequently depend on external technologies for visual guidance, usually employing ionizing radiation, due to the limited view upon the surgical scene. In the case of endovascular procedures, fluoroscopy is the common imaging modality used for visualization. This modality is based on X-rays and only offers a two- dimensional (2D) view of the surgical scene. Having a real-time, up-to-date understanding of the surrounding environment of the surgical instruments within the vasculature and not depending on using ionizing radiation would not only be very helpful for interventionists, but also paramount for the navigation of an intraluminal robot. Therefore, the aim of this thesis is to develop an algorithm able to do an intra-operative and real-time three-dimensional (3D) vessel reconstruction. The algorithm is divided into two parts: the reconstruction and the merging. In the first one, it is obtained the 3D vessel reconstruction of a section of the vessel and in the second one, the different sections of 3D vessel reconstruction are combined. A real vessel mesh is used to calculate the fitting errors of the reconstructed vessel which are very smallEn los últimos años, la tecnología robótica ha mejorado la precisión y fiabilidad de la navegación de instrumentos y ha ayudado a disminuir la complejidad de la cirugía mínimamente invasiva. Aún así, el acceso restringido inherente a la anatomía de los pacientes complica gravemente muchos procedimientos. Los intervencionistas dependen con frecuencia de tecnologías externas para la guía visual, generalmente empleando radiación ionizante, debido a la visión limitada de la escena quirúrgica. En el caso de los procedimientos endovasculares, la fluoroscopia es la modalidad de imagen común utilizada para la visualización. Esta modalidad se basa en rayos X y solo ofrece una vista bidimensional (2D) de la escena quirúrgica. Poder saber en tiempo real y de forma actualizada como es el entorno alrededor de los instrumentos quirúrgicos que se encuentran dentro de la vasculatura y no depender del uso de radiación ionizante no solo sería muy útil para los intervencionistas, sino también fundamental para la navegación de un robot intraluminal. Por lo tanto, el objetivo de esta tesis es desarrollar un algoritmo capaz de realizar una reconstrucción tridimensional (3D) del vaso sanguíneo de forma intraoperatoria y en tiempo real. El algoritmo se divide en dos partes: la reconstrucción y la unión. En la primera se obtiene la reconstrucción 3D de una sección del vaso sanguíneo y en el segundo se combinan las diferentes secciones obtenidas de vasos sanguíneos reconstruidos en 3D. Se utiliza una malla de un vaso sanguíneo real para calcular los errores de ajuste del vaso sanguíneo reconstruido, son errores muy pequeñosEn els últims anys, la tecnologia robòtica ha millorat la precisió i la fiabilitat de la navegació dels instruments i ha ajudat a disminuir la complexitat de la cirurgia mínimament invasiva. Tot i així, l'accés restringit inherent a l'anatomia dels pacients complica greument molts procediments. Els intervencionistes sovint depenen de tecnologies externes per a la guia visual, normalment emprant radiacions ionitzants, a causa de la visió limitada de l'escena quirúrgica. En el cas dels procediments endovasculars, la fluoroscòpia és la modalitat d'imatge comuna utilitzada per a la visualització. Aquesta modalitat es basa en raigs X i només ofereix una visió bidimensional (2D) de l'escena quirúrgica. Poder saber en temps real i de forma actualitzada com és l'entorn al voltant dels instruments quirúrgics que es troben dins de la vasculatura i no depèn de l'ús de radiació ionitzant no només seria molt útil per als intervencionistes, sinó també fonamental per a la navegació d'un robot intraluminal. Per tant, l'objectiu d'aquesta tesi és desenvolupar un algorisme capaç de fer una reconstrucció tridimensional (3D) del vas sanguini de forma intraoperatòria i en temps real. L'algorisme es divideix en dues parts: la reconstrucció i la fusió. En la primera s'obté la reconstrucció en 3D d'una secció del vas sanguini i en la segona, es combinen les diferents seccions obtingudes de vasos sanguinis reconstruïts en 3D. S'utilitza una malla d’un vas sanguini real per calcular els errors d'ajust del vas sanguini reconstruït, els errors son molt petit