Page 422 - Handbook of Biomechatronics

The Artificial Pancreas 417

Fig. 3 Process of introducing blood into the capillary space of an ACCU-CHEK strip.

The electrochemical strips used by most glucose meters include an elec-
trode that is provided with a bias voltage usually generated using a digital-to-
analogue converter (DAC) as shown in Fig. 4. The current flow through the
strip to a second electrode is proportional to the glucose concentration, and
that current is generally fed into a transimpedance amplifier (current-to-
voltage converter) followed by an analogue-to-digital converter. The
amount of current is small, with the full-scale range between 10 and
50 μA, so sensitive, low noise circuitry is required. In addition, the