Electronic devices have been used previously for measuring adherence to medication, and include electronic pill monitors and inhaler dose monitors. The costs and benefits of these devices have been reviewed extensively [10–16]. Drawbacks of existing technologies include high cost, reliability, and lack of correlation with therapy adherence, i.e. opening the pill bottle as indicated by a pill monitor does not indicate ingestion of the pill. Recently, Malcolm, et al. reported a method for measuring adherence to intravaginal implant use by monitoring vaginal temperature using a commercially available DST nano-T implantable temperature logger (Star-Oddi, Gardabaer, Iceland) embedded in the device . The DST-nano-T devices encapsulated in silicone tubing of varying wall thickness to approximate an IVR accurately measured environmental temperature changes during 7 days of continuous monitoring in vitro. The devices also correctly recorded a series of insertion and removal events at 8 min intervals over 7 days of continuous use following vaginal insertion in three cynomolgus macaques. The cost of a single DST nano-T temperature logger (US$340), however, limits the potential of these devices to be widely adopted in large-scale clinical trials, particularly in resource-limited settings such as sub-Saharan Africa.