Usefulness of a simple device to measure aural canal temperature

In patients with spinal cord injury, rectal temperature is difficult to use as body temperature due to impairment such as defecation disturbance. We developed an earphone type device to measure aural canal temperature that can be also used during exercise in patients with spinal cord injury and evaluated its usefulness. The subjects consisted of 11 healthy male students. They exercised for 30 minutes using an ergometer until the heart rate increased to 150-160 bpm. Aural canal temperature, rectal temperature, and non-contact tympanic membrane temperature were measured before, during, and after exercise. This device for the measurement of aural canal temperature was produced by cutting the tip of a commercially available earphone and connecting a thermocouple wire to it. This device is very small and causes no discomfort even during long wearing or inconvenience during exercise. The aural canal temperature obtained in this study was very stable compared with the rectal temperature or non-contact tympanic membrane temperature and thus may be useful for monitoring body temperature.