Robust tracking of dexterous continuum robots: Fusing FBG shape sensing and stereo vision

Abstract

Robust and efficient tracking of continuum robots is important for improving patient safety during space-confined minimally invasive surgery, however, it has been a particularly challenging task for researchers. In this paper, we present a novel tracking scheme by fusing fiber Bragg grating (FBG) shape sensing and stereo vision to estimate the position of continuum robots. Previous visual tracking easily suffers from the lack of robustness and leads to failure, while the FBG shape sensor can only reconstruct the local shape with integral cumulative error. The proposed fusion is anticipated to compensate for their shortcomings and improve the tracking accuracy. To verify its effectiveness, the robots' centerline is recognized by morphology operation and reconstructed by stereo matching algorithm. The shape obtained by FBG sensor is transformed into distal tip position with respect to the camera coordinate system through previously calibrated registration matrices. An experimental platform was set up and repeated tracking experiments were carried out. The accuracy estimated by averaging the absolute positioning errors between shape sensing and stereo vision is 0.67±0.65 mm, 0.41±0.25 mm, 0.72±0.43 mm for x, y and z, respectively. Results indicate that the proposed fusion is feasible and can be used for closed-loop control of continuum robots.

Robust Catheter Tracking by Fusing Electromagnetic Tracking, Fiber Bragg Grating and Sparse Fluoroscopic Images

“…The B-spline tube model in the 2D image Ω can thus be defined by a set of knot points sampling from the estimated shape from FBG followed by projecting to the 2D image plane. Then, the corresponding control points can be calculated by (14) and interpolated via ( 13) to obtain a B-spline representation of the shape projected in the image plane. Currently, the estimated shape of the catheter in the image plane is represented by B-spline center-line model.…”

“…While interesting Azizian's and Alambeigi's methods only focus on tracking the tip of the catheter where the entire shape is of interest in clinical applications. Zhang et al proposed to fuse FBG shape sensing with stereo vision [14]. Although an excellent accuracy was reported in Zhang's work (absolute position error of 0.67±0.07 mm) stereo vision is typically not available in cardiovascular applications.…”

Robust Catheter Tracking by Fusing Electromagnetic Tracking, Fiber Bragg Grating and Sparse Fluoroscopic Images

“…While interesting Azizian's and Alambeigi's methods only focus on tracking the tip of the catheter where the entire shape is of interest in clinical applications. Zhang et al proposed to fuse FBG shape sensing with stereo vision [18]. Although excellent accuracy was reported in Zhang's work (absolute position error of 0.67±0.07 mm) stereo vision is typically not available in cardiovascular applications.…”