Source: AppleInsider

New patent applications revealed this week show that Apple has investigated technology with advanced physiological sensors for measuring workout activity from inside the user’s ear canal.

Apple currently has a number of fitness-oriented features available in its iPod line, but the Cupertino, Calif., company’s latest patent describes an extremely advanced system using unique technology. Among a number of described methods for measuring exertion during physical exercise include sensing light that travels through the user’s earlobe to determine blood oxygen levels.

In one of the examples provided in, an earbud could include infrared photodetectors that would measure the user’s body temperature, heat flux and heart rate.

“From infrared radiation in the user’s ear, sensors… can detect minute temperature variations due to the user’s heart beats,” the application reads. “Heart rate can be calculated based on time between beats and the user’s temperature can be set as the ‘DC Component’ (or average or median value) of the detected temperature distribution. Other sensors can also be used for tracking the same physiological metrics or different physiological metrics.”

In another example, a light source and photodetector allow the hardware to determine a user’s blood oxygen content. Such a system would “detect the portion of such light that passes through the user’s earlobe, the remaining light having been absorbed within the user’s earlobe. From the relative absorption of these two wavelengths of light, the user’s blood oxygen content can be calculated.”

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