An electric toothbrush comprises a body portion and a head including a motor, a moving portion, a handle, and a gear arrangement between the moving portion and the motor. In order to provided an improved signal and power supply transmission with reduced constructional complexity and enhanced operation possibilities, an integrated signal and power supply transmission arrangement is provided, comprising a supply board, a main board, an insulating plate, at least one transformer arrangement, and at least one signal transmission arrangement. The extracting of each of the first features includes: acquiring a difference between sums or mean values of pixels of the plurality of first areas in the corresponding combination to obtain a first difference vector in the direction of the first axis, and obtaining a second difference vector in the direction of the second axis. The flash card reader includes a CompactFlash connector, coupled to the IDE converter, for receiving a CompactFlash card through a single slot in the single-slot multi-flash-card reader, the CompactFlash connector making electrical connection with the CompactFlash card for signals in the CompactFlash interface.