The Robotics Institute

RI | Centers | CFR | Seminar

Foundations of Robotics Seminar, July 6, 2011
Time and Place | Seminar Abstract



Tip-Steerable Needles

John Swensen
LIMS Lab

Johns Hopkins University

 

Time and Place

Wednesday, July 6, 2011
NSH 1507
Talk 1:30 pm

Abstract

 

Percutaneous needle therapies play a major role in modern medicine. The ability to steer and control a needle during insertion promises to improve the scope, accuracy, repeatability, and precision of needle interventions.

Tip-steerable needles are complex, flexible dynamical systems that interact with the tissue to produce steering. The magic of steering these needles lies at the tip: you need to know the dynamics from the needle base to needle tip (a modeling problem), figure out the tip orientation from medical images (a state estimation problem) and reorient the needle tip (a control systems problem) to guide the needle where you want it to go.

In this talk, I will address all three of these issues---modeling, control, and estimation. First, I will present a new model of the torsional dynamics of tip-steerable needles. The model is analogous to controlling a flexible rod, of changing length, by wiggling it from one end. I will also demonstrate a strategy for controlling the tip of the needle to a plane in the tissue. Finally, I will present recent progress on developing a state observer which evolves on the manifold of SO(3) for determining the tip orientation.

 

Bio

 

John Swensen is a graduate student in the Locomotion in Mechanical and Biological Systems Laboratory at Johns Hopkins University. Prior to attending Johns Hopkins, he worked on the James Webb Space Telescope and star tracker projects at Ball Aerospace and Technologies Corporation in Boulder, CO from 2003 to 2006. As an undergraduate, he worked as an intern developing autonomous farm equipment at Autonomous Solutions, Inc in Logan, UT.

 


The Robotics Institute is part of the School of Computer Science, Carnegie Mellon University.