University of Washington researchers have created a wireless wearable in the form of a thermal earring that continuously monitors a user’s earlobe temperature.

In a study of six users, the earring outperformed a smartwatch at sensing skin temperature during periods of rest. It also showed promise for monitoring stress, eating, exercise and ovulation.

About the size and weight of a small paperclip, the earring has a magnetic clip that attaches one temperature sensor to a wearer’s ear, while another sensor dangles about an inch below it for estimating room temperature.

The earring can be personalised with fashion designs made of resin, without negatively affecting its accuracy.

Co-lead author Qiuyue (Shirley) Xue, a UW doctoral student in the Paul G Allen School of Computer Science & Engineering says many people find smartwatches and rings unfashionable, bulky or uncomfortable so earrings could be a viable alternative.

“I like to wear earrings, so we started thinking about what unique things we can get from the earlobe. We found that sensing the skin temperature on the lobe was much more accurate than the hand or wrist. It also gave us the option to have part of the sensor dangle to separate ambient room temperature from skin temperature.”

Earlobe temperature tends to vary, which presents several uses for the thermal earring. In small proof-of-concept tests, the earring detected temperature variations correlated with eating, exercising and experiencing stress and placed it within the range necessary for tracking ovulation and periods, which is not possible on current wearables.

For future iterations, Xue is working to integrate heart rate and activity monitoring. She's also interested in potentially powering the device from solar, or kinetic energy from the earring swaying and is looking into other jewellery options.

“Eventually, I want to develop a jewellery set for health monitoring,” she says. “The earrings would sense activity and health metrics such as temperature and heart rate, while a necklace might serve as an electrocardiogram monitor for more effective heart health data.”

Fit Tech magazine editor, Liz Terry said: "There are still many people who would benefit from wearables but aren't able to tolerate sleeping while wearing a watch or living with a bulky ring and we believe we're on the cusp of a new era of wearables based on jewellery that will disrupt the industry.

"Humans have worn jewellery for millennia and there are many comfortable and unobtrusive options available. As technology advances, we expect to see wearables based on things such as piercings, bracelets, earrings and pendants, opening up the market for health wearables to far more people."

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