First smart earring wearable: researchers at University of Washington design and test device
The wireless, low-power earring takes temperature continuously and could be even more reliable than a smartwatch for ovulation tracking
Researchers at the University of Washington have designed and tested the first wireless smart earring that can provide continuous temperature sensing for the wearer.
The Thermal Earring, while not yet commercially available, could monitor for stress, exercise, eating and ovulation just like a smartwatch.
In a small study at the University, researchers found that the smart earring actually outperformed a smartwatch for temperature accuracy - indicating a future where it could be a more accurate method for ovulation and period tracking.
The findings were published in the Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies from researchers Qiuyue Shirley Xue, Yujia Liu, Joseph Breda, Mustafa Springston, Vikram Iyer, and Shwetak Patel .
The demand for smart, wearable devices
Wearable devices with sensors have gained significant popularity in recent years and are becoming a ubiquitous part of daily life. Nearly 40% of US households possess wearables like smartwatches.
The market has since expanded to include smart rings (including Evie, first smart ring specifically designed for women out this year) and smart glasses.
However, as the researchers report:
“We observe however that an entire class of common accessories worn by millions of people every day has been largely ignored: jewellery. For example, in the United States alone, 76% of women have pierced earlobes which is nearly twice the current adoption rate of smartwatches.”
Continuous monitoring with a smart earring - that outperforms a smartwatch in testing
A key benefit of the smart earring is the ability for continuous monitoring.
Body temperature is an important vital sign which can indicate fever and is known to be correlated with activities such as eating, exercise and stress. However, continuous temperature monitoring poses a significant challenge.
The Thermal Earring takes advantage of the unique position of earrings in proximity to the head, a region with tight coupling to the body unlike watches and other wearables which are more loosely worn on extremities.
“As a result, these devices only provide one average temperature reading per day, primarily from data during sleep. In contrast, Thermal Earring takes advantage of the unique position of earrings on the head and tight coupling to the earlobe to provide a reliable measurement of earlobe temperature.
“We find in initial trials across six users in the wild (3 male, 3 female) that earlobe temperature remains stable during periods of rest with a maximum standard deviation of 0.32 °C (0.58 °F) compared to a watch that varies by over 0.72 °C (1.3 °F). This is promising for future applications such as ovulation tracking which requires 0.28 to 0.56 ◦C accuracy.”
Battery life can be 28 days in real-world tests and the actual thermal earring is small and light enough to integrate into real jewelry with fashionable designs. Typically the smart earring will have a maximum width of 11.3 mm and a length of 31 mm, weighing 335 mg - about the same as a paperclip.
A magnetic clip attaches one temperature sensor to a wearer’s ear, while another sensor dangles about an inch below it for estimating room temperature.
Applications for women’s health
While not specifically tested for in this study, the researchers noted the opportunities of the smart earring for women’s health:
“The Thermal Earring’s reliable temperature readings have the potential to enable applications such as ovulation tracking, surpassing the capabilities of current smart watches.
“During ovulation, a woman’s body temperature typically rises by approximately 0.28 to 0.56 °C (0.5 to 1.0 °F) [41]. However, smart watches struggle to accurately detect this temperature increase since their noise level exceeds the temperature change caused by ovulation.
“In contrast, the Thermal Earring provides a more reliable temperature reading, with a standard deviation close to the lower range of ovulation temperature rise. As a result, the Thermal Earring shows its theoretical potential for tracking ovulation.”
Next steps
While researchers found several promising potential applications for the Thermal Earring, their findings were preliminary, since the focus was on the range of potential uses. They need more data to train their models for each use case and more thorough testing before the device might be used by the public.
For future iterations of the device, Qiuyue Shirley Xue and team will be working to integrate heart rate and activity monitoring. She said:
“Eventually, I want to develop a jewellery set for health monitoring,”
“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.”