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The accuracy and precision of four infrared aural canal thermometers during cardiac surgery
Author(s) -
Imamura M.,
Matsukawa T.,
Ozaki M.,
Sessler D. I.,
Nishiyama T.,
Kumazawa T.
Publication year - 1998
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1998.tb05281.x
Subject(s) - medicine , thermometer , infrared thermometer , thermocouple , standard deviation , limits of agreement , mean difference , accuracy and precision , nuclear medicine , surgery , infrared , statistics , mathematics , optics , materials science , confidence interval , physics , quantum mechanics , composite material
Background: Four infrared aural canal thermometers are currently available in Japan: Geniusr̀, Thermoscanr̀, Quickthermor̀, and Thermopitr̀. We therefore tested the hypothesis that each is sufficiently accurate and precise for clinical use. Methods: For the purpose of this investigation, we considered accuracy to be the mean difference between the test thermometers and the reference thermocouple. Precision was considered to be the standard deviation of the difference between the test and reference values. We evaluated ten patients undergoing cardiopulmonary bypass with moderate hypothermia (≅30°C). Aural canal temperatures were measured in random order with each infrared thermometer, and compared with readings from a thermocouple positioned at the contralateral tympanic membrane. Results: Compared to the thermocouple, the Geniusr̀ and Thermoscanr̀ both had regression slopes >0.85 and correlation coefficients near 0.87; in contrast, slopes of the Quickthermor̀ and Thermopitr̀ regressions were 0.68 and 0.53, respectively. The correlation coefficients for each were <0.65. The accuracy (offset, or bias) was near 0°C with both the Geniusr̀ and Thermoscanr̀ thermometers. In contrast, it was 1.1°C with the Quickthermor̀ and a full 2.3°C with the Thermopitr̀. The precision (standard deviation) of the measurements, however, was ≅0.8°C in each case. Conclusion: We conclude that none of the tested aural canal infrared thermometers was sufficiently accurate and precise for perioperative use.