A method of producing a photocatalyst according to the invention comprises forming an amorphous titanium oxide and heat-treating it in an atmosphere containing oxygen, whereby a photocatalyst having a good photocatalysis can be obtained. The small form factor desktop computer can be formed of a single piece seamless housing that in the described embodiment is machined from a single billet of aluminum. Remote maintenance of the prosthesis using the detected data is possible via a remotely located remote control unit that can access the storage and evaluation unit via the telephone network.