Ingestible sensors correlate closely with peripheral temperature measurements in febrile patients

BACKGROUNDS: Reliable non-invasive methods for measuring body temperature are essential for the diagnosis and monitoring of infectious disease. METHODS: This study used Intraclass Correlation Coefficients (ICC) and the Bland- Altman plot to analyse the agreement between temperature measurements using an ingestible capsule sensor, a skin sensor and two non-invasive peripheral temperature measurements (axillary and infrared non-contact), collected from a population of febrile patient admitted for infectious disease. RESULTS: Of the 77 febrile patients screened, 26 patients were enrolled. The ICC between axillary temperature measurements (Taxi) vs. non-contact measurements (Tno-c) were 0.34 [−0.18; 0.63], 0.87 [0.55; 0.94] between Taxi vs. ingestible capsule measurements (Tcap) and 0.12 [−0.09; 0.37] between Taxi vs. Tetac. The mean difference between Taxi vs Tno-c was −1.18 °C with limits of agreement (LoA) from −2.96 to 0.58 °C. The mean difference between Taxi vs Tcap was 0.48 °C, with LoA from −0.60 to 1.56 °C. The mean difference between Taxi vs Tetac was −4.23 °C with LoA from −7.22 to −1.23 °C. CONCLUSIONS: Ingestible capsule measurements are reliable enough to adequately estimate the core body temperature in clinical practice. Its non-invasiveness, and the real-time remote control offer new opportunities for future research into fever during infectious diseases.