The invention relates to a device for detecting electrical potentials on a patient. The optical system also comprises a lens module, an image capturing module, an anti-shake device and a switching device. The pump has a housing defining a pump interior, a driven magnet coupled to a pump impellor positioned in the pump interior, where the pump housing has an inlet and an outlet, and the is to be immersed in a fluid and to pump a fluid through the interior of the pump from the inlet to the outlet. The depressions are formed on the emitting surface. A bumper beam is joined to the mounting plates on the left and right sides of the vehicle body. A magnetic force is generated between the first coil, the first magnet and the first auxiliary magnet by a voltage provided to the first coil, moving the seat along the first axis along the first guide element.