Sliding Mode Control of Steerable Needles.
Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires noa prioriknowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue andex vivoliver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation.
Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235 USA ( daniel.c.rucker@vanderbilt.edu ).
D Caleb
DC
Rucker
Rockwell Automation, Inc., Shirley, NY 11967 USA ( jadav.das@gmail.com ).
Jadav
J
Das
Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 USA ( hunter.b.gilbert@gmail.com ).
Hunter B
HB
Gilbert
Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 USA ( philip.j.swaney@vanderbilt.edu ).
Philip J
PJ
Swaney
Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235 USA ( michael.i.miga@vanderbilt.edu ).
Michael I
MI
Miga
Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 USA ( nilanjan.sarkar@vanderbilt.edu ).
Nilanjan
N
Sarkar
Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 USA ( robert.webster@vanderbilt.edu ).
Robert J
RJ
Webster
Image-guided interventions; medical robotics; needle steering; nonholonomic systems; sliding mode control; surgical robotics