An Active Steering Device for Endoscopes

Abstract

This paper describes an original active steering device for endoscopes and horoscopes. Its mechanical structure is based on a tubular hyper-redundant mechanism. Distributed SMA actuators with their own local controller are integrated in this structure for producing bending forces in reaction to the interaction detected between the instrument and its environment. The SMA actuators are two thin NiTi springs in an antagonist configuration. Joint actuation relies on martensite/austenite phase transformation in NiTi alloys. The global behavior of the endoscope is controlled through a multi-agent approach.

Analytical modeling of a segmented unimorph actuator using electrostrictive P(VDF-TrFE) copolymer

“…Steerable forceps have been designed for laparoscopic surgery by utilizing four Ti-Ni SMA tubes for actuation; the forceps are capable of a bending range of 30 • [12]. Endoscopes and arthroscopes have also been developed with segmented designs using SMA springs and wires to actuate bending between segments [13][14][15]. Fukuda et al [16] have designed a SMAbased microactive catheter system that adds two degrees of freedom and can bend up to 32 • .…”