To send a notice appropriate to the state of a patient after installing a bed sensor on a sickbed without regard to the state of the patient while reducing erroneous notification.

The bed sensor 3 is installed on each sickbed, and slave set identification information and rescue section information on the patient are associated and stored. With respect to a litter patient, the notification is sent when a first period has passed while leaving the bed is detected. With respect to an attendant patient, the notification is sent when a second period longer than the first period has passed while leaving the bed is detected. With respect to an ambulatory patient, the notification is sent when a third period longer than the second period has passed while leaving the bed is detected. Accordingly, while the erroneous notification is reduced, the bed sensor 3 can be installed on the sickbed without regard to the state of the patient. Since the period from the detection of leaving the bed to the notification is differentiated according to the state of the patient, the notification can be sent according to the state of the patient.