EMI stability indicator for tympanic thermometer

摘要

The present invention is directed to an electronic device for sensing and indicating the presence of electromagnetic interference in the vicinity of a electronic thermometer and preventing the display of a core body temperature reading when the electromagnetic interference exceeds a predetermined threshold. Disclosed is a tympanic thermometer comprising circuitry and a microprocessor that takes a a plurality of voltage readings from the null input of an operational amplifier in the circuitry. After taking into account ambient temperature conditions into the temperature calculations, the microprocessor compares the average value of the voltage readings taken from the null input against a predetermined threshold in the memory of the microprocessor. If the value exceeds the predetermined threshold, then the microprocessor prevents the display of the core body temperature and directs a display to write an error message. However, if the value does not exceed the predetermined threshold, the microprocessor directs the displays the core body temperature taken by the tympanic thermometer.