- Krzysztof Czuba, T. Mitamura, Eric Nyberg. 1998. Can Practical Interlinguas Be Used for Difficult Analysis Problems. Abstract: A method and apparatus in which a blunt interior needle is positioned within a larger external needle and a sample cavity is formed at the blunt end of the interior needle. An optical fiber extends from the sample cavity up the interior needle and to a light source and light detector. A reflective surface is placed at the end of the sample cavity reflects light back to the optical fiber. A beam splitter separates the incident and reflected light. To make an in-vivo measurement of chemical concentrations in a body, the needle is inserted into the body and fluids are aspirated into the sample cavity. Light is then transmitted to the cavity by the optical fiber and is transmitted from the cavity to a detector by the same fiber. By measuring the amount of light reflected, one can determine the amount of light absorbed in the cavity and may thus determine concentrations of selected chemicals.
