Page 426 - Handbook of Biomechatronics

The Artificial Pancreas 421

Fig. 7 Schematic diagram of a three electrode force-sense test-strip monitor. (Based on
DiCristina, J., 2017. Maxim Tutorial 4659: Blood Glucose Meters. https://www.
maximintegrated.com/en/app-notes/index.mvp/id/4659 (Retrieved 10 August 2017).)

Analogue front ends from Maxim and Microchip, among many, inte-
grate all of the functionality described above into a single package with
the specification and performance required by blood glucose meters. This
integration drives the low cost of these devices in an extremely competitive
market.

3.3.4 Peripheral Functions
Most blood glucose meters use a custom liquid-crystal display (LCD) that
can be driven with an LCD driver integrated in the microcontroller. Others
feature a more complicated dot-matrix LCD that requires using a module
with the glass, bias voltages, and drivers assembled together into a single inte-
grated module. A dot-matrix display also requires memory to store the mes-
sages to be displayed. High-end instruments provide color displays that
require additional and higher voltages than both the monochrome types.
Backlighting can be added using one or two white LEDs or an electrolumi-
nescent source.
Most meters include the ability to upload test results to a computer.
These are typically based on industry standard USB or Bluetooth interfaces
and are generally used to upload patient data to the user’s health-care
provider.
Low-end meters with simple displays can run directly off of a single lith-
ium coin cell or two alkaline AAA batteries. To maximize battery life,