Noninvasive measurement of aqueous glucose solution at physiologically relevant blood concentration levels with differential continuous-wave laser photoacoustic technique

Glucose sensitivity of the optical power balance shift (OPBS) method, which we previously proposed, has been improved by numerical correction of laser drift and by data analysis. The detection limit is determined by the stability and resolution of instruments. This paper describes our approach on both the system and data analysis to extend the OPBS dynamic range towards low concentration levels. With our approach, we obtained a standard error of measured glucose concentration as low as ±50 mg/dL from glucose aqueous solution at physiologically relevant blood concentration levels (0-400 mg/dL). The result indicates that this method has high potential for non-invasive blood glucose monitoring.