Abstract: A circuit (10) comprising a latching device (20) operatively arranged to change from a first output state to a second output state as a function of a magnetic field (40) applied in a first direction, to maintain the second output state when the magnetic field is either no longer applied in the first direction or applied again in the first direction, and to change from the second output state to the first output state as a function of a magnetic field applied in a second direction, a power switching device (30) coupled to a power source (15), a load (35) and the latching device and operatively arranged such that the power switching device connects the power source and the load when the latching device is in the second state and disconnects the power source and the load when the latching device is in the first state, a magnetic switching device (25) coupled between the latching device and the power source and having an open default disconnected state and operatively arranged to change from the open default stat

Abstract: A packaging system (15) for an ingestible capsule comprising an ingestible capsule (20) having a pH sensor (22) and an outer surface (24), packaging (16) for the capsule comprising an open well (28) having an inner surface (46-49) and a holding volume (33) defined by the inner surface of the well and the outer surface of the capsule, the inner surface of the well configured and arranged to engage at least a portion (25) of the outer surface of the well, and the holding volume configured to and arranged to contain a pH calibration fluid and to hold the pH sensor submerged in the pH calibration fluid when the pH calibration fluid is added to the well, whereby the packaging provides for calibrating the pH sensor without removing the capsule from the packaging.