An Optical Actuation System and Curvature Sensor for a MR-compatible Active Needle.
A side optical actuation method is presented for a slender MR-compatible active needle. The needle includes an active region with a shape memory alloy (SMA) wire actuator, where the wire generates a contraction force when optically heated by a laser delivered though optical fibers, producing needle tip bending. A prototype, with multiple side heating spots, demonstrates twice as fast an initial response compared to fiber tip heating when 0.8 W of optical power is applied. A single-ended optical sensor with a gold reflector is also presented to measure the curvature as a function of optical transmission loss. Preliminary tests with the sensor prototype demonstrate approximately linear response and a repeatable signal, independent of the bending history.
Center for Design Research, Stanford University, Stanford, CA, USA.
Seok Chang
SC
Ryu
Center for Design Research, Stanford University, Stanford, CA, USA.
Zhan Fan
ZF
Quek
LSIIT, Strasbourg University - CNRS - INSA, Strasbourg, France, pierre.renaud@insa-strasbourg.fr.
Pierre
P
Renaud
Intelligent Fiber Optic Systems Corporation ( www.ifos.com ), Santa Clara, CA, USA, rjb@ifos.com.
Richard J
RJ
Black
Department of radiology, Stanford University, Stanford, CA, USA, bdaniel@stanford.edu.
Bruce L
BL
Daniel
Center for Design Research, Stanford University, Stanford, CA, USA.
Mark R
MR
Cutkosky