The blood glucose analysis technique and system described herein address the issue of hematocrit interference when rapidly detecting glucose concentrations. It addresses this issue by using a differential pulse voltammetry technique in which short high, frequency voltage pulses are applied to keep the diffusion layer within the reagent of the working electrode, and the pulses are applied in a limited voltage window (or range) that is below the peak, diffusion-limited current. The readings below the peak are then used to determine glucose concentrations. With this technique, glucose concentrations can be determined relatively fast (e.g., within 5 seconds) and independently of the hematocrit levels of the fluid being analyzed.