Performance testing of an innovative telemetric temperature sensor in animals

This study consists of a first assessment of a new technological solution (e-Celsius™ prototype) designed to perform intra peritoneal (IP) temperature measurements in animals. 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™ 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™+1 e-Celsius™ prototype temperature sensor) were constituted. All the electronic capsules were first tested in a water bath heated to 37°C and then implanted intra-abdominally in 6 male Sprague Dawley rats. The capsules' performances were assessed while rats were in free living conditions (24h 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 24h free living conditions (±0.17°C) compared to the water bath conditions (±0.04°C). No difference was observed when compared to the cooling stage (±0.1°C). Considering that 50% of the data collected as a satisfactory performance criterion, the Jonah™ device could not be used at a distance exceeding 0.5m while the maximum distance recorded for the e-Celsius™ was 3m. The minimum life span for the tested e-Celsius™ and Jonah™ capsules was 14 days. The development of a precise calibration method is needed to finalize its validation. ► e-celsius reliability and accuracy performances are similar to those of existing systems. ► The distance of transmission for e-celsius allows considering applications in animal studies. ► The study aims at testing in animals a new telemetric sensor for temperature measurement.