Requisites for the remote-controlled wide-view CCD camera unit for natural orifice transluminal endoscopic surgery placed in the intraperitoneal cavity.

In natural orifice transluminal endoscopic surgery (NOTES) using a single endoscope, the visual field moves unstably and a wide blind space is formed. We used wireless two wireless CCD cameras (270,000 and 380,000 pixels) placed on the abdominal wall of pigs and a conventional endoscope (410,000 pixels) at the same time to assess whether it was possible to observe the entire process of sigmoidectomy by NOTES. The titanium dioxide-coated lens was used as an antifogging apparatus. To control the CCD image frames, a magnetic body was affixed to the back of the CCD camera unit. To select a suitable visual-transmitter, three frequency bands were assessed: 0.07 GHz, 1.2 GHz, and 2.4 GHz. The cameras showed good performance for monitoring all procedures of the sigmoidectomy. The magnetic force most suitable to control the cameras was found to be 360 mT, and the best transmission frequency was 1.2 GHz. The battery could be used for up to 4 hours with intermittent use. The issue of lens fogging could be resolved by a water supply into the anal canal and a more than 12-hour ultraviolet irradiation. We verified that the CCD camera with the titanium dioxide-coated lens may be useful as the second eye in NOTES.