Biplane Shape Sensing

Modeling and Sensing

Building off our initial work in (Lawson et al., 2023), we wanted to leverage biplane fluoroscopy to not only capture the pose of the bending plane, but also the bending shape and axial “roll” of the catheter. We leveraged the radiopacity of marker bands typically placed in the catheter tip, and placed these markers in a patterned shape along the distal segment of the catheter.

The radiopaque marker band of an off-the-shelf catheter. From (Lawson et al., 2025).
The radiopaque marker bands placed patterned around a radiolucent catheter. From (Lawson et al., 2025).

This combination of markers are segmented in each plane and reconstructed in 3D to serve as the basis for solving the shape and orientation of the catheter segment.

Workflow of shape estimation for the slim catheter prototype. From (Lawson et al., 2025).

We then deployed this approach under fluoroscopy for many static shape configurations, and even during a catheter insertion in a phantom model.

Estimated shape overlaid on fluoroscopic images. From (Lawson et al., 2025).

References

2025

  1. RAL
    Fluoroscopic Shape and Pose Tracking of Catheters With Custom Radiopaque Markers
    Jared Lawson, Rohan Chitale, and Nabil Simaan
    IEEE Robotics and Automation Letters, 2025

2023

  1. ICRA
    Model-Based Pose Estimation of Steerable Catheters under Bi-Plane Image Feedback
    Jared Lawson, Rohan Chitale, and Nabil Simaan
    In 2023 IEEE International Conference on Robotics and Automation (ICRA), 2023