The scanner apparatus has a feed device for picking up checks from an input receptacle and transferring them to a conveyor mechanism which conveys the checks through the interior of the apparatus. A method of detecting transition between two states of a communication network corresponding to different loss rates of sent data includes: a step of determining a probability of transition, and a step of determining the existence of a transition on the basis of said probability. Embodiments of the method may also include receiving a response from the portable device relating to permission to disable camera functionality. Elastomeric traction pads are on the bottom of the mouthguard and are grippingly engaged by the posterior teeth of the lower jaw.