The Core Body Temperature (CBT) is one of the most relevant vital parameters to assess the state of the human body. Many processes in the human body are closely linked to CBT. However, CBT is also one of the most difficult parameters to monitor continuously and non-invasively.
While skin temperature measurement is easy to implement, it has been shown to deviate up to 6°C from CBT.
Alternatively, a heat flux sensor in combination with PPG allows for reliable continuous monitoring of CBT as reported in prior scientific articles.
Methodology and validation
The CardioMood 287-2 integrates a heatflux sensor from GreenTeg. Its data are combined with PPG derived BPM to improve accuracy.
CBT was validated versus electronic pills as a reference to assess the accuracy of the device and the algorithm. CardioMood 287-2 raw measurement values were recorded during a clinical study with volunteers that were vaccinated for Covid. About half of them got a fever. Their body temperature was subsequently recorded and plotted against the temperature reference. The sensor signals were algorithmically combined to yield a single temperature output per day while at the same time compensating for physiological thermoregulation.
The CBT algorithm is self-calibrating, meaning that, after a certain calibration time, the algorithm will automatically determine several system parameters. From this moment on, CBT can be calculated using these parameters.
The measurement of Core Body Temperature (CBT) with the CardioMood via the GreenTeg Heatflux sensor has been EU-MDR certified. A dedicated separate process is in progress with the FDA.
Specification of Core Body Temperature
|Measurement range||34.0°C to 42.0°C||93.2°F to 107.6°F|
|Data update period||28 seconds|