New concept for the non-invasive determination of physiological glucose concentrations using modulated laser diodes.

The detection of small absorption differences is one of the basic requirements for the non-invasive determination of blood substrates. As conventional spectrometers are limited in their detection capabilities of small absorption changes, semiconductor lasers are applied for this purpose. By using a special modulation scheme, physiological glucose concentrations could be successfully predicted. The results demonstrate the feasibility of using small and inexpensive laser diodes for the spectroscopic determination of glucose in aqueous solutions as a step towards a portable non-invasive glucose sensor for self- monitoring of diabetic patients.