The tested prototype temperature sensor is composed of a miniaturized electronic sensor (capsule), which uses wireless technology to transmit temperature data to a dedicated monitor. The performance assessment was based on the comparison with commercially available analog tools (VitalSense, Jonah鈩?ingestible core temperature capsules) considered as gold standards.
The variability (mean absolute deviation) of the calculated difference score around its mean value was taken as a reliability index. Thus, 6 pairs of capsules (1 Jonah鈩?1 e-Celsius鈩?prototype temperature sensor) were constituted. All the electronic capsules were first tested in a water bath heated to 37 掳C and then implanted intra-abdominally in 6 male Sprague Dawley rats. The capsules' performances were assessed while rats were in free living conditions (24 h alone in cage) and then again during the cooling process (anesthesia+ice). In a second step, a test was designed to assess the maximum distance of communication between sensors and the monitor.
The mean absolute deviation of the difference scores was greater in the 24 h free living conditions (卤0.17 掳C) compared to the water bath conditions (卤0.04 掳C). No difference was observed when compared to the cooling stage (卤0.1 掳C). Considering that 50%of the data collected as a satisfactory performance criterion, the Jonah鈩?device could not be used at a distance exceeding 0.5 m while the maximum distance recorded for the e-Celsius鈩?was 3 m. The minimum life span for the tested e-Celsius鈩?and Jonah鈩?capsules was 14 days. The development of a precise calibration method is needed to finalize its validation.