title: Nonmagnetic rigid and flexible outer sheath with pneumatic interlocking mechanism for minimally invasive surgical approach.
abstract: We developed a nonmagnetic rigid and flexible outer sheath with pneumatic interlocking mechanism using flexible toothed links and a wire-driven bending distal end. The outer sheath can be switched between rigid and flexible modes easily depending on surgical scenes, and the angle of its distal end can be controlled by three nylon wires. All components of flexible parts are made of MRI-compatible nonmagnetic plastics. We manufactured the device with 300-mm long, 16-mm outer diameter, 7-mm inner diameter and 90-mm bending distal end. Holding power of the device in rigid mode was maximum 3.6 N, which was sufficient for surgical tasks in body cavity. In vivo experiment using a swine, our device performed smooth insertion of a flexible endoscope and a biopsy forceps into reverse side of the liver, intestines and spleen with a curved path. In conclusion, our device shows availability of secure approach of surgical instruments into deep cavity.
authors.affiliation: Graduate School of Information Science and Technology, The University of Tokyo, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Yamashita
authors.forename: Siyang
authors.initials: S
authors.lastname: Zuo
authors.forename: Ken
authors.initials: K
authors.lastname: Masamune
authors.forename: Hongen
authors.initials: H
authors.lastname: Liao
authors.forename: Takeyoshi
authors.initials: T
authors.lastname: Dohi
mesh_terms: D019723:Endoscopes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008280:Magnetics; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation*; D011312:Pressure; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*