Data accuracy validation for CORE - How it works?

A common question we get from coaches is how CORE works, as well as its accuracy. We have already explained that in a previous blog post, but let us explain this topic further. It is very important, and we want to be very clear about it. Because CORE works, and it’s very accurate!

Some context about core body temperature monitoring solutions

First, we would like to add some context about core body temperature monitoring solutions that will help to understand our point better, as well as why CORE is so unique.

Up to now, core body temperature monitoring solutions were either invasive, not accurate, or non- continuous. Thermometers can monitor the temperature inside the body (not only skin surface temperature), but there is always a deviation, and no thermometer could feasible monitor for more than a few minutes.

To try solving this lack of continuous monitoring, we have two solutions: electronic pills and probes. The former are small pills you swallow to monitor the temperature inside your body. Although accurate and continuous, the monitoring will last only a few hours, the time the pill takes to go from the entrance to the exit. They are also expensive, and cumbersome. That’s the reason why, despite being used by researchers and athletes from time to time, its adoption is very low.

The alternative, just for medical uses, are internal probes. That is better than e-pills in terms of continuous monitoring (they would last as much as needed) but is a very invasive method. That’s why they are only used for clinical applications, for patients laying on bed quite likely unconscious.

CORE offers a new alternative that is both continuous and non-invasive. It measures the core body temperature using a miniaturized energy transfer sensor, combined with an AI algorithm that crunches the data to deliver a continuous stream of core body temperature data. Also, it is non-invasive, and has a battery that could last 6 days (more than enough for all the applications). But is it as accurate as the options mentioned before? It is, indeed. In fact, we used all of them to validate the data coming from CORE and improve our algorithm to similar accuracy levels.

Validating CORE with e-pills in different sports scenarios.

As explained in a previous post, at CORE we have tested our device through a clear protocol, involving professional athletes. We asked them to wear CORE while training and competing both indoors and outdoors, monitoring their core body temperature before, during, and after the workout. At the same time, we tested athletes with one of the methods mentioned before. It was mostly the electronic pill, but we also used probes to get a better data to validate the accuracy of the device.

As a result, we managed to build a device that has the same level of accuracy as invasive methods, as shown in the following charts.

 Comparison between CORE and a e-pill

 Comparison between e-pill and CORE

Comparison between CORE and e-pill
Comparison between e-pill and CORE.


Not bad, right? The data validation shows that our device works, and it is as accurate as electronic pills. All through non-invasive means.

Validating CORE for medical purposes

CORE is not a medical device. However, we are also testing it for medical purposes, working with some partners in the field to get a device that accurately monitors fever on real-time and through non-invasive means (our plan is to get CORE approved as medical device in the near future). The tests are performed by healthcare professionals, combined with other methods for data validation. Below, you will find a couple of charts showing the latest results.

 Comparison between CORE and the e-pill measuring fever

Comparison between e-pill and CORE

These tests show that CORE monitors fever in real time with accuracy. Today, our accuracy is ±0.21 °C, which is similar to the accuracy of the e-pill. However, our approach is to keep improving our technology so it will remain an ongoing process until we get the best accuracy possible. We have already shown that it is possible!