title: A high-resolution, three-dimensional thin endoscope for fetal surgery.
abstract: BACKGROUND
  Fetal surgery is receiving considerable attention. However, surgeons must have great skill to perform this surgery. For assisting with the operation, the three-dimensional (3D) endoscope is very useful because it allows the surgeon depth perception. However, the diameter of existing 3D endoscopes is approximately 10 mm. Therefore, the authors have developed a high-resolution, thin, 3D endoscope for use in fetal surgery.
  
  
  METHODS
  The authors' system uses two 1/10-in. micro charge-coupled device (CCD) cameras at the tip of the endoscope and achieves a diameter of 5.4 mm. The endoscope's angle of convergence is 2.6 masculine, which very closely approximates the angle of convergence for humans. Thus, the surgeon experiences little visual fatigue. The view angle is 87 masculine.
  
  
  RESULTS
  The authors compared image quality and depth perception between their system and conventional 3D and 2D endoscopes. Theoretical investigation of image quality allowed the surgeon to distinguish a line 0.2 to 0.25 mm wide. Furthermore, the depth perception with the thin 3D endoscope was almost the same as with an 11-mm normal 3D endoscope. In addition, with the 3D endoscope, a higher percentage of questions were answered correctly in the depth perception evaluation experiment in a water environment than with the 2D instrument.
  
  
  CONCLUSIONS
  According to these experiments, the thin 3D endoscope has a sufficiently high image quality and depth perception even in a water environment.
authors.affiliation: School of Engineering, University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-8656, Japan. etsuko@bmpe.t.u-tokyo.ac.jp
authors.forename: E
authors.initials: E
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Ando
authors.forename: H
authors.initials: H
authors.lastname: Yamashita
authors.forename: I
authors.initials: I
authors.lastname: Sakuma
authors.forename: T
authors.initials: T
authors.lastname: Fukuyo
authors.forename: K
authors.initials: K
authors.lastname: Ando
authors.forename: T
authors.initials: T
authors.lastname: Chiba
mesh_terms: D004724:Endoscopy / Q000379:methods*; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D020669:Fetoscopes; D005333:Fetus / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008866:Microsurgery / Q000295:instrumentation / Q000379:methods; D008953:Models, Anatomic; D011247:Pregnancy; D025321:Surgery, Computer-Assisted / Q000379:methods