Non-invasive blood chemistry measurement by stimulated infrared

Abstract

An apparatus for measuring the concentration of a selected solute in a solution. This apparatus is particularly suitable for measuring the concentration of blood components, such as blood glucose. A beam of exposing light is imaged through a wall of a containment vessel onto a region of the sample adjacent to this wall to induce from said selected solute emission of light that includes at least one emission peak that can be used to calculate the concentration of this solute. At least one detector is positioned to maximize the strength of detected signal, if other components of this solution strongly absorb the emitted light. The exposing light is directed such that the detected signal is maximized as a function of the path of this exposing light. A particular embodiment is a non-invasive blood glucose tester that can be used painlessly by diabetics to monitor their blood glucose levels. In this embodiment, the containment vessel is preferably one of the patient's fingers. At least two additional detected signals are monitored and processed at wavenumbers suitable for eliminating temperature and pressure effects on the calculated blood glucose levels.