Personal monitoring device

A device for monitoring the physical activity of persons comprising a movement detector electrically coupled to drive electrical time-delay means the output of which is connected to drive an alarm device the arrangement being such that the alarm device is held in its OFF condition in the presence of movements detected by the movement detector and is switched to its ON condition in the absence of such movements after a time delay determined by said time delay means, said movement detector comprising at least one tubular housing with a cylindrical side wall closed with end caps and containing a freely movable ball and means operable according to movement of the ball within the housing to establish an electrical signal representative of the physical activity of a said person at an output terminal connected to the input of said time-delay means, wherein said time-delay means comprises first and second time-delay circuits connected in series, the input of the first time-delay circuit being connected to the output terminal of the movement detector and the outputs of each of the first and second time-delay circuits being connected to the alarm device, said first time-delay circuit incorporating a manually-operable reset device and said second time-delay circuit being non-cancellable, the arrangement being such that if the first time-delay circuit activates the alarm the second time-delay circuit provides a time interval prior to its effecting latching of the alarm during which time interval the alarm can be manually cancelled by operation of said reset device, and said first time-delay circuit further includes means for automatically disabling the movement detector during the period that the first time-delay circuit produces a signal to turn on the alarm device.