The in vitro performance of an adherence-monitoring IVR undergoing multiple temperature cycles between 25°C and 40°C to simulate repeated insertion and removal over 100 h (4.2 days) is shown in Fig 4. The device accurately monitors the IVR status (temperature relative to 34.4°C) over 33 simulated IN/OUT cycles and 1192 measurements made on a 5 min interval. This is the equivalent of one IVR removal and replacement every 1.5 days for 50 days using a 1 h measurement cycle. The measurement frequency (1s –days) and reference temperatures (0–45° C) are set in software and cover a broad range of values appropriate for laboratory evaluation and long-term clinical use. The temporal accuracy of the device is shown in the expansion plot (Fig 4), where the simulated IVR replacements (temperature ~ 40°C) at approximately 6, 48, and 96 hours are captured at the same time by each of the three devices under test.