MESA+ University of Twente
The BIOS Lab-on-a-chip group

Lactate monitoring for intensive care and endurance sports

bios_logo.psdSkin Lactate Monitor

Lactate is an important biomarker and indicator of stress and exertion. Today, many devices exist to measure lactate, both for medical (intensive care unit) and (top) sport applications. Most of the measurements require a significant amount of blood and the analysis is done in a laboratory. Some of the more recent products require less blood and perform a point-of-care analysis. This is a great improvement, but still blood is required which can be uncomfortable for the subject or user. The procedure to measure lactate sample-by-sample is cumbersome and stressful for the subjects, and incomplete because it yields a snapshot only, not a continuous monitoring of the lactate concentration level.

The solution is to develop a device that can monitor the lactate level continuously. We envision a new lactate-measuring device, which generates a very small current (nA range) proportional to the lactate concentration of a subject. The measuring method is based on enzymatic chemical reaction, in which the lactate molecules will be enzymatically converted and the product can be oxidized, resulting in a small current proportional to the lactate concentration. We propose to use modified micro electrodes, just passing the human skin. They measure the lactate concentration in the subcutaneous interstitial fluid, not in the blood vessels. Therefore, these electrodes will not irritate and can stay there for a longer time. Thus, the device can continuously monitor the lactate level.

Cross-sectional view of the lactate-specific amperometric sensor showing the working electrode, modified with an enzyme-containing coating in contact with the interstitial fluid

Further information: Dr. Wouter Olthuis / W.Olthuis@utwente.nl / BIOS / Carré 2409