Smart thermometers

Case study

Smart thermometers detect virus symptoms early to identify COVID-19 clusters

Now more than ever, early detection of the symptoms of contagious illness is vital to protect individual patients and entire communities. An early response to confirmed symptoms is equally important. For example, being able to rapidly and accurately identify clusters of people with high temperatures—and thus potential COVID-19 outbreaks—could help combat the spread of coronavirus. Thanks to U.S. connected health specialist, Kinsa Health, this is now possible.

For a number of years, Kinsa Health has been dedicated to developing affordable yet highly effective wireless medical devices to track and curb the spread of infectious diseases, including influenza-like illnesses.

Two such devices are smart thermometers. The first is the low cost Kinsa QuickCare oral thermometer that can provide a temperature reading in around eight seconds and the other is the Kinsa Smart Ear aural thermometer that can supply a temperature reading in as little as a second. Both devices connect via Bluetooth LE to the Kinsa App, which keeps a log of readings and serves as a ‘nurse in the pocket’ by providing users with information including guidance on the illness severity and when to seek further medical advice.

In the midst of the current pandemic or at any time in the future, Kinsa Health’s network of millions of Bluetooth LE-enabled smart thermometers are capable of not only measuring human body temperature, but also providing anonymized data through the Kinsa App to produce a temperature heat map of the U.S. known as the ‘U.S. HealthWeather map’. By following this map, government agencies and healthcare organizations are able to identify potential virus hotspots immediately.

“On the back end we anonymize and aggregate temperature and symptom inputs to [generate] an illness signal, which tells us what percentage of a population is ill in any given U.S. geography be that county, state or region,” says David Gal, Kinsa Health CTO and VP of Engineering. “Additionally, using machine learning and AI, we [extrapolate] these illness signals. We use these signals and forecasts to help predict and curb the spread of disease outbreaks.”

According to the company, these solutions are capable of making a difference in a crisis such as COVID-19. “A high fever is considered one of the key symptoms of COVID-19 so being able to track this health data is an extremely powerful way to quickly identify any new outbreaks,” says Gal. “If testing and containment resources can then be focused on these areas the spread of the virus could be significantly slowed down and lives saved.”

Low power processing

Both the QuickCare and Smart Ear devices are battery powered. Because replacing batteries frequently on the front line is not an option, Kinsa Health required an ultra low power Bluetooth LE solution that also provided sufficient onboard processing power and memory allocation to essentially run the complete smart medical applications from a single chip. Nordic’s nRF52810 SoC fit the bill.

The reliability of the Bluetooth LE connectivity and the ultra low power consumption, particularly in sleep mode, allow the Kinsa smart thermometers to transmit data relatively infrequently and extend battery life. “For the most part our devices live in a medicine cabinet, but when a user pulls out the device in the middle of flu season, the product needs to work,” says Gal. The nRF52810 has the lowest power consumption in Nordic’s proven nRF52 Series yet retains the 64 MHz, 32-bit Arm Cortex M4 processor for the performance demands of secure Bluetooth LE connectivity and fast data processing.

Moreover, Nordic’s SoftDevice (RF protocol ‘stack’) provided a major advantage for Kinsa Health throughout the development process. “The SoftDevice is unquestionably one of the most compelling reasons to use Nordic,” says Gal. “It lets us focus on application development knowing that we have a robust and well implemented Bluetooth LE solution we can rely on.” Given Kinsa Health made nine in ten of the smart thermometers sold in the U.S. in the 12 months up to March 2020, it seems most consumers agree.


According to the company, these solutions are capable of making a difference in a crisis such as COVID-19