Assessment of an Aural Infrared Sensor for Body Temperature Measurement in Children

Abstract

A newly marketed device measures body temperature using an ear probe that detects infrared radiation from the tympanic membrane. It is simple to use and gives a reading in 1-2 seconds. Its accuracy was evaluated in a group of children, aged 1 month through 10 years, by comparing it with either rectal (n = 65), or oral (n = 48) temperatures obtained with a standard electronic thermometer, IVAC (San Diego, CA). The average elapsed time between readings was 11 minutes. Overall, 60 rectal and 40 oral temperatures (88.5%) were higher with IVAC than with the aural sensor. The difference ranged from -0.7 degrees C to +2.5 degrees C. The correlations between the infrared ear-probe values and the rectal and oral temperature readings were 0.77 and 0.75, respectively. Because the average reading using the aural sensor was lower than that using the IVAC, the sensitivity of the aural sensor for detecting clinically important levels of fever was low. None of seven patients with a rectal temperature of 39 degrees C or more and only 7 of 27 with a rectal temperature of 38 degrees C or more were identified by the aural sensor as having temperatures above these cutoff levels. Similarly, none of three patients with an oral temperature of 39 degrees C or more and only three of eight with an oral temperature of 38 degrees C or more were identified correctly by the aural sensor. The authors conclude that the aural sensor is unsatisfactory for detecting clinically significant fevers in a pediatric outpatient setting.

Tympanic membrane temperature as a measure of core temperature

“…Some concern has been raised about the inability of ear thermometers to detect a rise in core temperature caused by fever26 or exercise,27 but we have not found this to be a problem. The characteristic biphasic fever pattern13 14 was apparent using all core sites, and the changes in the febrile patients occurred at more or less the same time (fig 2).…”

Comparison of daily rhythm of rectal and auricular temperatures in horses kept under a natural photoperiod and constant darkness

“…This high difference between AT and RT was also observed in goats and squirrel monkey with values of 7 and 5.9 1C, respectively (Piccione et al, 2005a, b, c;Fuller et al, 1985). Among species, the variation in the differences between AT and RT could be due to anatomic differences of the ear (Pelagalli and Botte, 1999) and consequently, to the variation in the positioning of the infrared probe during the AT assessment (Rhoads and Grandner, 1990). When a probe is directed toward the side of the canal rather than toward the tympanic membrane, temperatures measurements will vary, because there is a temperature gradient in the ear canal (Fraden and Lackey, 1991).…”

Smart wearable body sensors for patient self-assessment and monitoring

“…These models have been used to monitor blood oxygen saturation (SpO2), heart rates, and record hand posture while manipulating objects, such as eating or dressing [19,20]. A newly marketed device measures body temperature through the use of an ear probe which detects infrared radiation from the tympanic membrane [21]. Another approach which could be more convenient for patients is the placement of sensors in clothing, such as a vest or shoe.…”