To provide a medical service support device, a medical service support method and a medical service support system capable of properly watching patients in accordance with states of the patients. A medical service support device includes an electrocardiogram sensor attached to a patient and measuring electrocardiogram data of the patient, an analysis unit analyzing the electrocardiogram data, an acceleration sensor detecting a motion of the patient, and an attention calling unit transmitting attention calling information and patient identification information for specifying the patient toward the external portion of the device when it is determined that the patient is in a REM sleep state based on an analysis result by the analysis unit as well as determined that the patient has moved to a given state based on a detection result by the acceleration sensor.
