Noninvasive and continuous measurement of body temperature variations based on CW-PA protocol

Over the last few years, we have developed two protocols based on the continuous-wave photoacoustic (CW-PA) technique and dedicated much effort to exploring the noninvasive and continuous monitoring of blood glucose levels. So far, all of the experiments have been performed in vitro and have shown promising characteristics. However, before further developing our sensor, we tested the approach in vivo with a dedicated custom-made detection cell. After testing several different body parts, we then applied our previously developed frequency-shift protocol to monitor physiological changes in local body temperature induced by placing/removing an ice-pack close to the test site as proof of concept. Though qualitative, the measurements revealed excellent correlation between the sensor response and expected temperature profile and demonstrated the potential of the CW-PA protocol for in vivo monitoring of biological parameters.