Abstract: A fall detector unit is worn by a patient and performs a wakeup when an acceleration signal exceeds a predetermined threshold. A barometer provides a series of pressure readings over a pressure examination period to provide a first pressure difference value. The pressure signals are further monitored over a compensation period after the examination period to obtain a second pressure difference value representing background environmental changes. The first pressure difference value is compensated by the second pressure difference value to obtain a total pressure difference value and thus derive a total height difference value. The fall detector unit determines a fall event using the total height difference value.

Abstract: The social alarm system includes a fall detector unit, worn by the user, having an accelerometer to detect a fall. A controller monitors for an acceleration signal which exceeds a wake-up or starting threshold and, in response, distinguishes between a fall event and a non-fall event based at least on the acceleration signal. A counter unit maintains a count of the non-fall events over a monitored time period such as one day. An alarm signal unit generates an inactivity alarm signal when the count of non-fall events is below a count threshold within the monitored time period.