A miniature compliance monitor for eyedrop medication.

We developed an eyedrop medication monitor that electronically records the date and time of each medication administration over a six-week period. It records a medication usage in a 15-minute interval when the cap is removed from the bottle and the bottle is inverted. The electronic components housed inside the bottle weigh 7.5 g, including the batteries, and the total volume of the circuit is 7.5 cc. The monitor resembles commercially available 30-mL eyedrop bottles in size, shape, and weight. The monitor is accurate when tested against known patterns of usage. The electronic eyedrop monitor should be useful in assessing compliance with eyedrop medications.