Contact: Jason Chevrie
Last update: July 2017
This project aims at providing robotic assistance for needle insertion procedures, in which typically long and thin needles need to be steered in soft tissues. Accurate steering of the needle toward a target is difficult to perform because of the complex interaction of the flexible needle with the tissues. Additionally such needles usually have a bevel at their tip to facilitate tissue cutting. This modifies the trajectory of the needle tip, even when the needle is apparently inserted straight into the tissues. Using a robotic system to control the needle insertion would ease the task for the surgeon.
We use an online 3D model of flexible needle in interaction with soft tissues to model the current state of the insertion. Using this model, we design a control law to compute the motion to apply to the needle base in order to steer the tip toward a target region. Close-loop control is performed by tracking the position of the needle in visual feedback. Two different controls are used:
Tissue motion also induce needle bending outside the tissue which can modify the tip trajectory. Visual tracking of the needle shaft is used to update online the position of the tissue in the interaction model. The model can then be used to provide a prediction of the needle trajectory and a more accurate control of the needle trajectory.
|Hybrid steering of a flexible needle||Needle insertion under tissue motion||Needle steering under 3D US guidance|