what is the principle of blood glucose monitoring in glucometers ?
Whenever I measure blood glucose in my home glucometer - quite often - the question arises in my mind that what is the principle of this measurement ?
Tags: blood glucose, measurement, principle
September 2nd, 2010 at 10:50 am
This is important because homeblood glucose meters measure theglucose in wholeblood while most lab tests measure theglucose in plasma. Currently, there are many meters on the market that give results as "plasma equivalent," even though they are measuring wholeblood glucose. The plasma equivalent is calculated from the wholeblood glucose reading using an equation builtinto theglucose meter. This allows patients to easily compare theirglucose measurementsin 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 "wholeblood equivalent" or "plasma equivalent." One model measures beta-hydroxybutyratein theblood to detect ketoacidosis (ketosis).
So this is the principle of the measurement plasma vs. whole blood reading the importance being the art of detecting ketoacidosis a very important component in the diabetic condition of the patient.
Good question.
September 2nd, 2010 at 10:50 am
The principle behind blood glucose meters is based on reactions that are analyzed by electrochemical sensors. On each strip, there are about 10 layers, including a stiff plastic base plate, and other layers containing chemicals or acting as spacers. For instance, there is a layer containing two electrodes (silver or other similar metal). There also is a layer of the immobilized enzyme, glucose oxidase, and another layer containing microcrystalline potassium ferricyanide. Specifically, the reaction of interest is between glucose and glucose oxidase. The glucose in the blood sample reacts with the glucose oxidase to form gluconic acid, which then reacts with ferricyanide to form ferrocyanide. The electrode oxidizes the ferrocyanide, and this generates a current directly proportional to the glucose concentration.
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. 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" since glucose levels in plasma are generally 10%–15% higher than glucose measurements in whole blood .