Sleep Monitoring
Sleep monitoring

Core Body Temperature for Sleep monitoring

This short note describes the use of Core Body Temperature sensor for Sleep monitoring and some results obtained in collaboration with the University Hospital in Bern, Switzerland.

About the use of Core Body Temperature for Sleep Monitoring

What is Core Body Temperature?

Sleep monitoring

Core body temperature is one of the four primary vital signs of our body. Core body temperature refers to the temperature of the body’s organs. It fluctuates following physiological processes, such as circadian cycles, menstruation, illness or physical activity.

Therefore, it can allow to gain more insight about the internal or external parameters affecting those natural mechanisms. Many devices on the market attempt to estimate core body temperature via skin surface temperature.

Due to the complexity of thermal regulation and environmental conditions, this estimate does not come close to the accuracy and reliability of greenTEG’s Core Body Temperature Sensor. This technology currently supports three sensing solutions based on your application needs. The wearable core body temperature sensing solutions are described in details here.

How Core Body Temperature Sensor can be used for Sleep Monitoring?

This case study presents core body temperature measurements conducted with the gSKIN® BodyTemp KIT – now CORE Body Temperature Sensor. The measurements were taken on the forehead, on the chest, and on the upper arm during sleep, daily life, and physical activities.

In this experiment, the heat flux signal was combined with several other parameters, resulting in an accuracy of <0.15° C measured on the wrist.

The study consists of 20h measurements of 6 healthy candidates between 25 and 70 years old in the sleep-wake laboratory of a university hospital.

For the thermal resistance compensating algorithm the heat flux signal was combined with several other parameters resulting an accuracy of <0.15° C measured on the wrist.

Sleep monitoring

In another study conducted at the sleep lab of the University Hospital in Bern, Switzerland, the measurement accuracy on the chest with the core body temperature sensor of better than ±0.2°C could be demonstrated – see the following graph describing the temperature evolution versus the timestamp.

sleep monitoring
Fig 2. Sleep monitoring: the temperature evolution versus the timestamp
Remark: The measurement was interrupted between 7-9 because of battery re-charging.

This short video by Schweizer Radio und Fernsehen relates well the advantages of Core Body Temperature monitoring for Individual Health Monitoring including Sleep and Circadian Cycle TrackingN.B. For copyright reasons, this video is only available in Switzerland.

Core Body Temperature Monitoring for Health & Wellness by greenTEG & Schweizer Radio und Fernsehen

Circadian Cycle Visible in Core Body Temperature Measurements

The measurements nicely resolve the temperature cycle between the highest value during daytime (~37.5 °C) and lowest value during night time (~36.5 °C). These peaks are highly related to the circadian cycle, an important signature for early diagnostics, ovulation tracking, burn-out syndrome, and sleep quality.

Circadian Rhythm can also affect sport performance: a recent investigation of Olympic swim speed evolution demonstrated that the fastest times could be obtained towards the end of afternoon. [1] This discrepancy in performance is believed to related to the variation of Circadian rhythm. Learn more with the full blog article available here.

Why choosing Core Body Temperature Sensor for your Sleep Monitoring?

greenTEG offers the world’s first core body temperature sensor for continuous and non-invasive measurements. The combination of our miniaturized sensor and AI-based algorithms are the backbone of our technology.

Sleep monitoring


  • Integration solution into any wearable in contact with skin. Chest-worn or wrist-worn.
  • Accurate algorithm to determine core body temperature.
  • SMD mountable 2mm x 2mm XU sensor.

Additionnally, greenTEG’s CALERA® technology has been developed and validated by more than 10 clinical trials showing for all position, clinical grade accuracy.

  • Validation study of Chest-worn device, available here.
  • Validation study of wrist-worn device, available here.
  • Validation study of upper-arm-worn device, available here.
  • Validation study for baby monitoring, available here.

Do you want to use the Core Body Temperature sensor to perform sleep monitoring?

Contact our team of experts to help you adapt our solution to your project!

  • Discover all the Use Cases related to our technology, here.
  • Explore our product line, here.
  • Discover all the peer-reviewed publications using our technology, here.

[1] Lok R, Zerbini G, Gordijn MCM, Beersma DGM, Hut RA. Gold, silver or bronze: circadian variation strongly affects performance in Olympic athletes. Sci Rep. 2020 Oct 8;10(1):16088. doi: 10.1038/s41598-020-72573-8. PMID: 33033271; PMCID: PMC7544825.