Patient detecting apparatus

An apparatus for detecting a patient, comprising:

• a plurality of pressure detecting devices which are adapted to be placed on a bed such that the pressure detecting devices are arranged in a widthwise direction of the bed, and which detect respective pressures and produce respective pressure signals representing the detected pressures;
• and
• a position detecting means for detecting, based on the pressure signals supplied from the pressure detecting devices, a position, in the widthwise direction of the bed, where the patient is present;
• wherein the pressure detecting devices comprise respective bags each of which is filled with a fluid, and wherein the apparatus further comprises a fluid-amount control means for controlling an amount of the fluid present in each of the respective bags of the pressure detecting devices, the fluid-amount control means comprising changing means for identifying a first bag of the respective bags that supports a greatest portion of a total weight of the patient, and changing the respective amounts of the fluid present in the respective bags of two or more pressure detecting devices so that a second bag of the respective bags that is different from the first bag supports a greatest portion of the total weight of the patient.