Advancement of low-power microwave sensors for non-invasive lactate monitoring

Lactate is an important biological marker in sports, clinical and agrifood settings. Work to develop novel sensors to detect it non-invasively has been ongoing for over a decade, but still there are no suitable solutions on the market. The gold standard remains to be blood gas analysis – a highly accurate method which is also labour intensive, invasive, and requires relatively large blood volumes. Handheld electrochemical analysers have become more widely available, but they too require blood extraction, and overall acceptance has been poor due to variation in results and the lack of true real-time monitoring capabilities in most realistic settings. This work presents the advancement of a low-power microwave sensor for real-time non-invasive monitoring of blood lactate by presenting the latest results from a proof of concept device which is now in wearable form-factor, and is shown to provide adequate performance (0.6721 mmol/L 95% mean error). The sensor is currently able to provide a lactate measurement every 10s with no measurement latency. Further, the sensor eliminates single-use waste resulting from current commercial devices.