Abstract: A method of non-invasive determination of the concentration of at least one analyte in the blood of a mammal, includes the steps of projecting near-infrared radiation on a portion of the body of the mammal, the radiation including a plurality of wavelengths; sensing the resulting radiation emitted from the portion of the body; deriving from the sensed resulting radiation emitted from the portion of the body a first expression for the magnitude of the sensed radiation as a function of wavelength of the sensed radiation; pretreating the first expression to minimize the influence of offset and drift to obtain a second expression for the magnitude of the sensed radiation as a function of wavelength; and performing multivariate analysis of the second expression to obtain a value for the concentration of the analyte.

Abstract: Radiation in the near infrared over a limited range of wavelengths about 1660 nanometers is projected on a portion of the body, for example, the ear, of the patient. The resulting radiation emitted by the portion, either scattered from the portion or transmitted after absorption and scattered by the portion, is processed to derive an expression of the resulting radiation as a function of the wavelength. The second derivative of this function over a very narrow range of this function between 1640 and 1670 nanometers is expanded and the glucose concentration is determined from the magnitude, or intensity, of the scattered or transmitted radiation at the maximum or minimum point of this derivative apparatus for non-invasive determination of glucose concentration in the patient. Radiation in the near infrared is transmitted through a first fiber-optic radiation conductor to the outer surface of a portion of the patient's body, penetrating into the portion.