A glucose meter (or glucometer) is a medical device for determining the approximate concentration of glucose in the blood. It is a key element of home blood glucose monitoring (HBGM) by people with diabetes mellitus or with proneness to hypoglycemia. A small drop of blood obtained by pricking the skin with a lancet is placed on a disposable test strip, which the meter reads and uses to calculate the blood glucose level. The meter then displays the level in mg/dl or mmol/l.

Since approximately 1980, a primary goal of the management of type 1 diabetes has been the achievement of closer-to-normal levels of glucose in the blood for as much of the time as possible, guided by HBGM several times a day. The benefits include a reduction in the occurrence rate and severity of long-term complications from hyperglycemia as well as a reduction in the short-term, potentially life-threatening complications of hypoglycemia.

Characteristics

• Size: The average size is now approximately the size of the palm of the hand, though some are smaller or larger. They are battery-powered.

• Test strips: A consumable element containing chemicals that react with glucose in the drop of blood is used for each measurement. For some models this element is a plastic test strip with a small spot impregnated with glucose oxidase and other components. Each strip can only be used once and is then discarded. Instead of strips, some models use discs that may be used for several readings.
  • Coding: Since test strips may vary from batch to batch, some models require the user to enter in a code that may be found on the vial of test strips, or a chip that comes with the test strip. By entering the coding or chip into the glucose meter, the meter will be calibrated to that batch of test strips. However, if this process is carried out incorrectly, the meter reading can be up to 4mmol/L inaccurate. The implications of an incorrectly coded meter can be serious for patients actively managing their diabetes. For miscoded meters, the probability of making an insulin dose error of 2 units is 50%. The probability of making an insulin dose error of 3 units is 24%, compared to 0.49% when using a no coding meter. This may place patients at increased risk of hypoglycaemia. No Coding meters currently in the market include the ACCU-CHEK Compact Plus, Bayer Breeze2, Bayer Contour, HDI Sidekick, Nova Max, Prodigy AutoCode, and WaveSense Presto.