To reduce a false report by preventing reporting when a patient leaves the seat surface of a wheelchair and is not in a dangerous state such as a fall from the wheelchair.

A nurse call slave unit 1 having a sensor 3 to detect the separation of the patient from the seat is arranged in the wheelchair. Repeaters 5 for receiving a call signal transmitted from the nurse call slave unit 1 are arranged in respective places in a facility. A position detecting part 13 for detecting the position of the wheelchair is also arranged. When the sensor 3 detects the separation of the patient from the seat and a nurse call master unit 10 receives the call signal, the reporting is not performed when the position detecting part 13 detects that the wheelchair exists in a specific area where the patient safely gets off the wheelchair. Consequently, when the wheelchair exists in the specific area where the patient safely gets off the wheelchair, it is determined that the patient safely gets off the wheelchair with the aid of a medical staff.