title: Plastic hollow waveguides: properties and possibilities as a flexible radiation delivery system for CO2-laser radiation.
abstract: OBJECTIVE
  One significant inconvenience of the CO2 laser is the lack of flexible fibers essential for endoscopic applications. The goal of this study is to test the feasibility of hollow waveguides in view of a practical use in medicine.
  
  
  METHODS
  Various types of plastic hollow waveguides for flexible delivery of CO2 laser radiation were examined. The transmission losses, divergence angle, damage threshold, and input and output beam profiles were determined. The interaction process between radiation transmitted through these guides with soft as well as hard tissues was studied.
  
  
  RESULTS
  Plastic hollow waveguides can transmit high power (up to 50 W) with low losses (straight guide 1 dB/m) even through bendings. The divergence angle is < 13 degrees. Cutting quality and extent of thermal damage are comparable to incisions performed with a free laser beam.
  
  
  CONCLUSIONS
  The results of this study show good cutting quality and durability of these flexible plastic hollow waveguides, which render possible to deliver CO2 radiation in the power range needed for most surgical applications with affordable transmission losses. Plastic hollow waveguides are, therefore, a real alternative to replace the mirror arms.
authors.affiliation: Institute of Applied Physics, University of Berne, Switzerland.
authors.forename: P H
authors.initials: PH
authors.lastname: Cossmann
authors.forename: V
authors.initials: V
authors.lastname: Romano
authors.forename: S
authors.initials: S
authors.lastname: Spörri
authors.forename: H J
authors.initials: HJ
authors.lastname: Altermatt
authors.forename: N
authors.initials: N
authors.lastname: Croitoru
authors.forename: M
authors.initials: M
authors.lastname: Frenz
authors.forename: H P
authors.initials: HP
authors.lastname: Weber
mesh_terms: D000818:Animals; D002056:Burns / Q000473:pathology; D002245:Carbon Dioxide; D005240:Feasibility Studies; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D008592:Menisci, Tibial / Q000473:pathology / Q000601:surgery; D010969:Plastics; D018583:Pliability; D013552:Swine
chemical_list: D010969:Plastics; D002245:Carbon Dioxide