title: Real-time localization of articulated surgical instruments in retinal microsurgery.
abstract: Real-time visual tracking of a surgical instrument holds great potential for improving the outcome of retinal microsurgery by enabling new possibilities for computer-aided techniques such as augmented reality and automatic assessment of instrument manipulation. Due to high magnification and illumination variations, retinal microsurgery images usually entail a high level of noise and appearance changes. As a result, real-time tracking of the surgical instrument remains challenging in in-vivo sequences. To overcome these problems, we present a method that builds on random forests and addresses the task by modelling the instrument as an articulated object. A multi-template tracker reduces the region of interest to a rectangular area around the instrument tip by relating the movement of the instrument to the induced changes on the image intensities. Within this bounding box, a gradient-based pose estimation infers the location of the instrument parts from image features. In this way, the algorithm does not only provide the location of instrument, but also the positions of the tool tips in real-time. Various experiments on a novel dataset comprising 18 in-vivo retinal microsurgery sequences demonstrate the robustness and generalizability of our method. The comparison on two publicly available datasets indicates that the algorithm can outperform current state-of-the art.
authors.affiliation: Computer Aided Medical Procedures, Technische Universität München, Germany. Electronic address: nicola.rieke@tum.de.
authors.forename: Nicola
authors.initials: N
authors.lastname: Rieke
authors.affiliation: Computer Aided Medical Procedures, Technische Universität München, Germany.
authors.forename: David Joseph
authors.initials: DJ
authors.lastname: Tan
authors.affiliation: Computer Aided Medical Procedures, Technische Universität München, Germany; Carl Zeiss Meditec AG, München, Germany.
authors.forename: Chiara
authors.initials: C
authors.lastname: Amat di San Filippo
authors.affiliation: Computer Aided Medical Procedures, Technische Universität München, Germany; DISI, University of Bologna, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Tombari
authors.affiliation: Computer Aided Medical Procedures, Technische Universität München, Germany.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alsheakhali
authors.affiliation: Visual Geometry Group, Department of Engineering Science, University of Oxford, Great Britain.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Belagiannis
authors.affiliation: Carl Zeiss Meditec AG, München, Germany.
authors.forename: Abouzar
authors.initials: A
authors.lastname: Eslami
authors.affiliation: Computer Aided Medical Procedures, Technische Universität München, Germany.
authors.forename: Nassir
authors.initials: N
authors.lastname: Navab
mesh_terms: D000465:Algorithms; D006801:Humans; D008866:Microsurgery / Q000379:methods*; D012160:Retina / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013525:Surgical Instruments
keywords: Pose estimation; Retinal microsurgery; Visual tracking