Abstract: A device for signalling the ingestion of medicaments in tablet form packed in blister packs in which the various tablet compartments on one side are delimited by a metal foil sheet which is common to the pack as a whole. A sheet (12) of insulating material has provided therein holes (20) which are so arranged as to correspond to the positions of the tablets in the pack. Electrodes (10, 11) having an electrically conductive surface are disposed circumferentially around each hole on one side of the sheet. A first number (10) of these electrodes is mutually connected to a first signal conductor, and a second number of these electrodes is mutually connected to a second signal conductor.