Simultaneous patient-side measurement of hemoglobin, glucose, and cholesterol in finger-stick blood

Abstract

We describe a multianalyte assay system for patient-side use comprising single-use plastic cartridges and a small monitor. Hemoglobin, glucose, and cholesterol can be simultaneously measured in 3 min in an unmeasured volume of blood. The sample is drawn by capillary action into four channels for delivery to assay-specific stacks containing a set of closely apposed layers. The distal layer is a membrane that acts as the optical surface for reflectance optics. For glucose and cholesterol assays, erythrocytes are removed by a fibrous filter layer and oxidase-peroxidase chemical reactions contained in the optical membrane generate a colored product. For hemoglobin measurement, blood is lysed by detergent contained in a porous disk. The amount of color reaching the optical membrane is measured by fiber optics. To ensure fail-safe operation, sensors verify sample sufficiency and degree of hemolysis. The assays perform comparably with laboratory methods.