(a) Diagram of adherence IVR electronics module showing major functional components (boxes) and dataflow (arrows). (b) Plot showing relationships between reference temperature, comparator reference voltage (Vref), and the 4-bit Vref generator parameter. Each point represents a reference temperature that is set in software by the generator 4-bit value (0–15). Here a generator value of 11 is set to select a reference temperature of 34°C. Dotted lines indicate Vref values selected for IN/OUT determination and “Logging On” “Logging Off” functionality in the in vitro and in vivo testing of adherence IVR devices.