Patent ID: 6989891

Claim:
An apparatus for determining the concentration of an analyte in a biological fluid sample drawn from a patient, the apparatus comprising: a near-patient optical detection system comprising: a source of electromagnetic radiation; a detector; an optical path extending between the source and the detector; and a filter in the optical path, the filter configured to allow passage of at least one of the following wavelengths emitted by the source: 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 10.4 μm, about 12.2 μm; and a sample element configured for removable engagement with the optical detection system, the sample element comprising: a reagentless sample cell configured to hold the biological fluid sample, the sample cell being located in the optical path upon engagement of the sample cell with the optical detection system, the sample cell being defined by at least one window which is transmissive of infrared radiation; a sample supply passage extending from and in fluid communication with the sample cell; wherein the optical detection system further comprises a sample extractor configured to draw the biological fluid sample from the patient, and the sample supply passage is configured to conduct the biological fluid sample into the sample cell.