Returning Workers Keep COVID-19 at Bay With Core Body Temperature Wearable

May 21, 2020 by Gary Elinoff

Fever is one of the first symptoms of infection. Now, a new wearable combines core body temperature sensors with Bluetooth connectivity for real-time health monitoring.

u-blox, a manufacturer of positioning and wireless communications devices and greenTEG, a specialist in heat flux sensors, have jointly announced CORE, its new venture brand. CORE is a wearable that continuously monitors core body temperature—commonly understood as the temperature of blood as it leaves the heart’s aortic valve. 


CORE module

The CORE wearable has been repurposed for COVID-19 health monitoring. Image used courtesy of u-blox


The wearable was originally designed for extreme athletes (such as ultra-marathoners or Ironman competitors) to help them track fluctuations in core body temperature and avoid overheating. Since physicians have determined elevated body temperature to be one of the first indications of the COVID-19 infection, the device has been repurposed to catch the first signs of a fever.

The developers anticipate interest from business owners concerned about worker safety as well as members of the general public. This device may help people catch early signs of illness and take the appropriate measures to avoid spreading their infection

CORE is held close to the body with a patch or a belt.


The gSKIN body patch predicts an accurate temperature reading.

The gSKIN body patch predicts an accurate temperature reading. Image use courtesy of greenTEG


The device translates sensed data into an accurate representation of core body temperature using an algorithm.


The u-blox NINA-B306 Bluetooth 5 Low Energy Module

The CORE device depends on u-blox’s NINA-B306 Bluetooth low energy (BLE) module, which features internal antennas, for low-power, highly-reliable connectivity.

greenTEG's VP of sales and marketing Holger Hendrichs, explains why the company chose the u-blox BLE module: “We needed a small and pre-certified low power Bluetooth module that could help keep the size of the overall solution to a minimum while offering the connectivity options, the considerable memory, and the reliability our application required. The u-blox NINA-B306 looked like a promising candidate."



The NINA-B306. Image used courtesy of u-blox

Hendrichs says the choice was clear when they learned the NINA-B306 used the ANT+ protocol to interface with Garmin devices.

u-blox feels their participation in CORE demonstrates the power of their BLE 5 module in wearable applications. Pelle Svensson, u-blox's senior principal of product strategy for short-range radio devices explains the appealing traits of the NINA-B3 for wearables: its small size, low-power consumption, a full megabyte of Flash memory, and a powerful Arm Cortex-M4 microprocessor.


Device Specifics

The device communicates wirelessly using standards-based BLE and ANT+ communication profiles. It utilizes both Android or IoS apps. The sampling rate is 1 Hz with output data streams including core body temperature, skin temperature, heart rate, timestamp, data quality, and battery level. The device is available in a 50 mm x 40 mm x 8.3 mm package and weighs 12 grams.


gSKIN body temperature patch

gSKIN body temperature patch. Image used courtesy of greenTEG


When compared to electronic ingestible pills, the chest-mounted CORE has a higher temperature accuracy—approximately ± 0.33 (1σ); ± 0.26 (MAD). 


monitoring of elevated body temperature

CORE (green) vs. ePill (blue) monitoring of elevated body temperature. Image used courtesy of greenTEG

Skin temperature accuracy, from 20°C to 42°C, is ±0.05°C (typical) or ±0.13°C (maximum). 

CORE’s actual sensor element measures 2 mm x 2 mm x 0.5 mm.


CORE sensor

CORE sensor. Image used courtesy of greenTEG

From Health Monitoring to Research

While this device is immediately relevant as employees cautiously return to work, the data gathered from CORE can also be valuable in research. As such, greenTEG is looking for other organizations to help advance knowledge about COVID-19, using data from CORE.  

As CORE points out, measuring tiny changes in core temperatures is relevant to a wide variety of medical concerns aside from the current pandemic. Svensson concludes, “In these uncertain and testing times, it’s encouraging to see our technology help keep people safe and, hopefully, flatten the curve.”


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Have you ever been involved with a design that has direct effects on public health or health research? What design precautions did you take with the consequences of the final application in mind? Share your experiences in the comments below.