Modeling, Force Sensing, and Control of Flexible Cannulas for Microstent Delivery

Abstract

This paper presents a kinetostatic modeling framework for flexible cannulas (concentric tubing robots) subject to tip loads. Unlike existing methods that allow fast computation of the beam tip position, this modeling framework provides fast computation of both the tip position and the entire shape of the deflected robot. A method for online force sensing based on inverse kinetostatic solution is also proposed and assistive telemanipulation control methods for microstent delivery are presented. The modeling framework uses polynomial approximation and linear interpolation based on elliptic integral solutions to the deflection of lightweight beams. To date, there are no systems capable of stent delivery in retinal vasculature. The modeling and control frameworks of this paper are validated experimentally on pilot studies for microstent delivery. We believe that the methods presented in this paper open the way for robot-assisted retinal microvascular stenting that may potentially revolutionize the treatment of blinding retinal vasculature diseases.