A searching section V3 of a content sales site 1 searches a content database V2 in accordance with search conditions inputted in a search condition inputting section M5 and generates an offerable content list. Preferably, the displaceable roller can be urged toward or away from the conveying member to adjust the tension of the conveying member. Further, the nano-crystalline coatings includes crystalline grains with an average size in a range of about 1 to 999 nanometers, and more preferably in a range of about 10 to 200 nanometers. A search image is created of any detected anomaly and its neighbourhood, and the search image is used to convolute the image signal being examined, creating a response image signal. The present invention is particularly well suited for use in minimally invasive surgical procedures.