A Blood Sugar Monitor Meter (or glucometer ) is a medical device for determining the approximate concentration of glucose/sugar in the blood. It is a key element of home blood glucose monitoring (HBGM) by people with diabetes mellitus or hypoglycemia. A small drop of blood, obtained by pricking the skin with a lancet, is placed on a disposable test strip that 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 and type 2 diabetes mellitus has been achieving closer-to-normal levels of sugar/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.
There are several key characteristics of Blood Sugar Monitor Meters which may differ from model to model and should be used for comparison between blood sugar meters:
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 sugar/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 is used once and 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 manually enter in a code found on the vial of test strips or on 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 4 mmol/L (72 mg/dL) inaccurate. The implications of an incorrectly coded meter can be serious for patients actively managing their diabetes. This may place patients at increased risk of hypoglycemia. Alternatively, some test strips contain the code information in the strip; others have a microchip in the vial of strips that can be inserted into the meter. These last two methods reduce the possibility of user error.
Volume of blood sample:
The size of the drop of blood needed by different models varies from 0.3 to 1 μl. (Older models required larger blood samples, usually defined as a “hanging drop” from the fingertip.) Smaller volume requirements reduce the frequency of unproductive pricks.
Alternative site testing:
Smaller drop volumes have enabled “alternate site testing” — pricking the forearms or other less sensitive areas instead of the fingertips. Although less uncomfortable, readings obtained from forearm blood lag behind fingertip blood in reflecting rapidly changing glucose levels in the rest of the body.
Testing times:
The times it takes to read a test strip may range from 3 to 60 seconds for different models.
Display:
The glucose value in mg/dl or mmol/l is displayed in a small window. The preferred measurement unit varies by country: mg/dl are preferred in the U.S., France, Japan, Israel, and India. mmol/l are used in Canada, Australia, China and the UK. Germany is the only country where medical professionals routinely operate in both units of measure. (To convert mmol/l to mg/dl, multiply by 18. To convert mg/dl to mmol/l, divide by 18) Many machines can toggle between both types of measurements; there have been a couple of published instances in which someone with diabetes has been misled into the wrong action by assuming that a reading in mmol/l was really a very low reading in mg/dl, or the converse.
Glucose vs. plasma glucose:
Glucose levels in plasma (one of the components of blood) are generally 10%–15% higher than glucose/sugar measurements in whole blood (and even more after eating). This is important because home blood glucose meters measure the glucose in whole blood while most lab tests measure the glucose in plasma. Currently, there are many meters on the market that give results as “plasma equivalent,” even though they are measuring whole blood glucose. The plasma equivalent is calculated from the whole blood glucose reading using an equation built into the glucose meter. This allows patients to easily compare their glucose measurements in a lab test and at home. It is important for patients and their health care providers to know whether the meter gives its results as “whole blood equivalent” or “plasma equivalent.”
Clock/memory:
All meters now include a clock that is set for date and time, and a memory for past test results. The memory is an important aspect of diabetes care, as it enables the person with diabetes to keep a record of management and look for trends and patterns in blood sugar/glucose levels over days. Most memory chips can display an average of recent glucose readings.
Data transfer:
Many meters now have more sophisticated data handling capabilities. Many can be downloaded by a cable or infrared to a computer that has diabetes management software to display the test results. Some meters allow entry of additional data throughout the day, such as insulin dose, amounts of carbohydrates eaten, or exercise. A number of meters have been combined with other devices, such as insulin injection devices, PDAs, and even Game Boys. A radio link to an insulin pump allows automatic transfer of glucose readings to a calculator that assists the wearer in deciding on an appropriate insulin dose. One model also measures beta-hydroxybutyrate in the blood to detect ketoacidosis (ketosis).
Hospital glucose meters:
Special glucose/sugar meters for multi-patient hospital use are now used. These provide more elaborate quality control records. Their data handling capabilities are designed to transfer glucose results into electronic medical records and the laboratory computer systems for billing purposes.
Here is a quick feature comparison of commonly sold glucometers:
| Meter | Size (inches) | Weight | Multisite | Sample Size | Test Time | Memory | Strips | Software |
|---|---|---|---|---|---|---|---|---|
| MyGlucoHealth Meter |
Yes | 0.3 microliters |
3 secs | 250 test | MyGlucoHealth Test Strips | Yes |
| Meter | Size (inches) | Weight | Multisite | Sample Size | Test Time | Memory | Strips | Software |
|---|---|---|---|---|---|---|---|---|
| GlucoPack |
No | 3 microliters |
9 secs | uploaded | GlucoPack Blood Test Strips | Yes |
Source: Wikipedia, Diabetesnet
