To set the interval of postural change to be executed to a patient as appropriately as possible.

The information of body weight which is a prescribed condition for classifying patients and interval information which is the interval of time to execute the postural change are related and stored in a storage part 13. An information acquisition part 11a computes the difference of the latest two execution times among executed results inputted when the postural change is executed to acquire actual interval information, and acquires the change of the state of the patient during the time. In the case of determining that an error between the actual interval information and the interval information stored in the storage part 13 is within a prescribed range in an execution determination part 11c and determining that the state of the patient during the time is not excellent in a patient state determination part 11d, an interval information updating part 11e shortens, by a prescribed length, the length of the interval information stored in the storage part 13 in relation to the classification that the patient to which the postural change is executed belongs to.