Telemetry Pill Measurement of Core Temperature during Active Heating and Cooling

摘要

The agreement between core temperature measurements obtained using an ingestibletemperature pill telemetry system (T sub pill) and rectal (T sub re) and esophageal (T sub es) thermocouples was compared under conditions of both increasing and decreasing body temperature. Nine subjects participated in four 3-h trials: cold (18 deg C) water rest (CWR); cold water exercise (CWE); warm (36 deg C) water rest (WWR); and warm water exercise (WWE). During exercise trials, subjects completed three bouts of 15-min rest, followed by 45-min exercise on a cycle ergometer at 50% of peak oxygen uptake. The temperature pill was taken 10-12 h before testing. Root mean squared deviation (RMSD) was calculated for each pair of measurements (T sub pill vs. T sub re, T sub pill VS T sub es, T sub re VS. T sub es) for each trial. An RMSD of '0' indicates perfect agreement, and as RMSD increases, agreement worsens. On CWR, the RMSD for T sub pill-T sub es (0.23+/-0.04) was lower (P<0.05) than for T sub pill-T sub re (0.43+/-0.10) or T sub re-T sub es (0.46+/-0.09). There were no significant differences in RMSD between measurement pairs on any other trial (overall average RMSD=0.26 deg C). These results suggest the telemetry pill system provides a valid measurement of core temperature during conditions of decreasing as well as increasing body temperature and during steady state.