Reagent-less whole-blood glucose meter

A method for determining the concentration of an analyte in a patient, in no particular sequence, comprising:

• providing an optical detection system which is portable and sized and configured to be small enough to fit in the palm or pocket of the patient, the detection system comprising a housing, at least one source of electromagnetic radiation, at least one detector, an optical path extending between the source and the detector, and a filtering system in the optical path, the filtering system configured to allow passage of at least one of the following wavelengths emitted by the source:
• about 4.2 μm, about 5.25 μm, about 6.12 μm, about 7.4 μm, about 8.0 μm, about 8.45 μm, about 9.25 μm, about 9.65 μm, about 10.4 μm, about 12.2 μm;
• providing a disposable sample element comprising a reagentless sample cell and an opening, the sample cell and the opening being in fluid communication through a sample supply passage, the sample cell being formed at least in part by at least one window constructed from a material selected from the group consisting of polyethylene and polypropylene;
• installing the sample element into the housing of the optical detection system;
• positioning the sample element such that the sample cell is located at least partially in the optical path and such that the opening of the sample element is exposed outside the housing;
• extracting a sample of biological fluid from the patient;
• contacting the opening of the sample element with the sample, such that a portion of the sample is drawn into the sample element;
• transporting the sample portion from the opening to the sample cell through the supply passage via capillary action;
• transmitting a calibration beam of radiation from the source through the sample element, but not through the sample portion, such that a calibration signal is generated by the optical detection system, the sample element having a first window separation where the calibration beam passes through the sample element;
• transmitting an analyte beam of radiation from the source through the sample element and through the sample portion, such that an analyte signal is generated by the optical detection system, the sample element having a second window separation where the calibration beam passes through the sample element, the second window separation being different from the first window separation;
• and
• correcting the analyte signal using the calibration signal to substantially eliminate the absorption of the sample element.