Goal:  The objective of this paper is to introduce a probabilistic filtering approach to estimate the pose and internal shape of a highly flexible surgical snake robot during minimally invasive surgery.   Methods:  Our approach renders a depiction of the robot that is registered to preoperatively reconstructed organ models to produce a 3-D visualization that can be used for surgical feedback. Our filtering method estimates the robot shape using an extended Kalman filter that fuses magnetic tracker data with kinematic models that define the motion of the robot. Using Lie derivative analysis, we show that this estimation problem is observable, and thus, the shape and configuration of the robot can be successfully recovered with a sufficient number of magnetic tracker measurements.  Results:  We validate this study with benchtop and  in-vivo  image-guidance experiments in which the surgical robot was driven along the epicardial surface of a porcine heart.  Conclusion:  This paper introduces a filtering approach for shape estimation that can be used for image guidance during minimally invasive surgery.  Significance:  The methods being introduced in this paper enable informative image guidance for highly articulated surgical robots, which benefits the advancement of robotic surgery.
['Stephen Tully', 'Howie Choset']
A Filtering Approach for Image-Guided Surgery With a Highly Articulated Surgical Snake Robot