Systems, devices, and methods are described for moving a patient to and from various locations, care units, etc. A variable calculator calculates and output a manipulated variable on the controlled system based on of a target value such as a target temperature and a feedback value such as the measured temperature of the controlled system. By this invention, a straightforward method of potassium formate production and removal of excess reactant are realized very efficiently. The level-correction circuits are constructed such that they correct the signal applied to the signal line so that it is greater than or less than the unstable-region voltage, and outputs it to the input end of the authentication circuits, so that unstable-region voltage is not applied to the input end.