title: The PolyScope: a modular design, semidisposable flexible ureterorenoscope system.
abstract: OBJECTIVE
  To characterize the mechanical and optical properties of the PolyScope endoscope system and to examine the clinical outcome in patients who were undergoing ureteronephroscopy.
  
  
  METHODS
  Mechanical assessment involved measurement of the deflection angle and irrigation flow rate. Optical resolution and distortion, field and angle of view, and light transmission and output formed the optical assessment. Clinical assessment was made in a series of consecutive ureteronephroscopy procedures. The optical cord was disconnected after each procedure, and the image fiber was assessed for damage.
  
  
  RESULTS
  The mean value for the angle of maximum active tip deflection with an empty working channel was 265 degrees (261-275 degrees). Deflection was impaired most with insertion of the 3.0 F basket (10% decrease) and least with an indwelling 220 microm laser fiber (2% decrease). Irrigation flow rate was 57 mL/min with an empty working channel. Flow was reduced by 50% and 68%, with the insertion of a 200 microm or 365 microm laser probe, respectively, and by 92.5% with a 3.2F basket. No damage to the image fiber occurred. The PolyScope optics system could identify a target of about 0.125 mm at a distance of 2 to 4 mm, based on 3 line-pairs/mm needed for clear identification. Lithotripsy of renal calculi was performed for 40 stone burdens in 32 patients; the resulting stone-free rate was 87.5%.
  
  
  CONCLUSIONS
  The novel semidisposable ureteroscope system PolyScope was simple to use, effective, and reliable in this preliminary clinical evaluation. It overcomes the inherent fragility of comparable devices, which renders the need for maintenance unnecessary.
authors.affiliation: Department of Urology, University Hospital Grosshadern, Ludwig-Maximilians-University Munich, Munich, Germany. markus.bader@med.uni-muenchen.de
authors.forename: Markus Juergen
authors.initials: MJ
authors.lastname: Bader
authors.forename: Christian
authors.initials: C
authors.lastname: Gratzke
authors.forename: Sebastian
authors.initials: S
authors.lastname: Walther
authors.forename: Boris
authors.initials: B
authors.lastname: Schlenker
authors.forename: Derya
authors.initials: D
authors.lastname: Tilki
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Hocaoglu
authors.forename: Ronald
authors.initials: R
authors.lastname: Sroka
authors.forename: Christian Georg
authors.initials: CG
authors.lastname: Stief
authors.forename: Oliver
authors.initials: O
authors.lastname: Reich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004209:Disposable Equipment; D004867:Equipment Design; D005260:Female; D006801:Humans; D007668:Kidney; D008297:Male; D008875:Middle Aged; D020709:Ureteroscopes; D055815:Young Adult