A high-resolution, three-dimensional thin endoscope for fetal surgery

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 lip of the endoscope and achieves a diameter of 5.4 mm. The endoscope's angle of convergence is 2.6 degrees, which very closely approximates the angle of convergence for humans. Thus, the surgeon experiences little visual fatigue. The view angle is 87 degrees. 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. Conclusion According to these experiments, the thin 3D endoscope has a sufficiently high image quality and depth perception even in a water environment.