A blood glucose meter, also known as a blood glucose meter, is an electronic device that measures blood sugar levels. Blood glucose meters are divided into two types: photoelectric type and electrode type. The photoelectric blood glucose meter is similar to a CD player, and has a photoelectric head. Its advantage is that the price is relatively cheap. The disadvantage is that the probe is exposed to the air, which is easily polluted and affects the test results; the electrode type test principle is more scientific, and the electrode port is hidden. contamination can be avoided. So how should we choose a blood glucose meter? How to maintain the blood glucose meter? Let’s take a look at the details below.
1 Principle of Blood Glucose Meter
According to the sugar measurement technology, the common blood glucose meters on the market can be divided into two categories: electrochemical test and light reflection technology test.
The electrochemical test is: the electrons generated by the reaction of the enzyme and glucose are then used to read the number of electrons, and then converted into a glucose concentration reading. Its advantage is that the price is relatively cheap, but the disadvantage is that the photoelectric blood glucose meter is similar to a CD player. Generally, it is relatively accurate in a short period of time. After using it for a period of time, it must be calibrated at the maintenance station.
Light reflection technology: It is an intermediate (colored substance) produced by the reaction of enzyme and glucose. The device detects the intensity of the reflected light on the reflective surface of the test strip, and converts the intensity of the reflected light into glucose concentration. The electrode port of this type of blood glucose meter is built in, which can avoid pollution and has high accuracy.
2 Measurement method of blood glucose meter
1. Chemical colorimetry
Principle: The early blood glucose meter used the glucose oxidase colorimetry method. The test strip changed color after reacting with the blood. After the time, the blood drop was wiped off and then put into the blood glucose meter to obtain the blood glucose value by measuring the chromatogram.
Advantages: Compared with biochemical analyzers, it measures faster and uses less blood.
Disadvantages: The earlier technologies, most of which are measured by the electrode method in modern times, use less blood and measure faster, so the chemical colorimetric method market has basically been eliminated.
2. Glucose oxidase electrode measurement method
Principle: measure blood sugar by measuring the amount of current generated by the reaction between glucose in blood and glucose oxidase in the test strip. Most of the mainstream models on the market are glucose oxidase measurement methods.
Advantages: Compared with biochemical and chemical methods, it is faster (within 30 seconds) and uses less blood (less than 5 microliters).
Disadvantages: Since the oxygen content in the air is much larger than the hydrogen content, the test paper is more easily affected by the air than the dehydrogenase method, so it requires stricter storage in a closed and dry environment. Generally, the test strip should be used within 5 minutes after it is taken out of the container, otherwise the measurement may be inaccurate due to the dampness of the test strip. Generally, the test strips in barrels are required to be opened and the test strips are taken out. Required to be used up within 3 months.
3. Glucose dehydrogenase electrode measurement method
Principle: By measuring the glucose in the blood and the glucose in the test paper The amount of electrical current produced by the glucose dehydrogenase reaction measures blood glucose.
Advantages: In addition to the advantages of oxidase, it is specific to glucose, not disturbed by oxygen, easy to store, and can be used until the expiration date is over after opening the can.
Disadvantage: Slight reaction to xylose.
4. Glucose dehydrogenase electrode measurement method
Principle: By measuring the glucose in the blood and the glucose in the test paper The amount of electrical current produced by the glucose dehydrogenase reaction measures blood glucose.
Advantages: In addition to the advantages of oxidase, due to the less hydrogen in the air, it also overcomes the disadvantage that oxidase is not easy to store. Generally, it can be used until the end of the validity period after opening the can.
Disadvantages: Dehydrogenase not only reacts to glucose in the blood, but also reacts to maltose, galactose, and xylose in the blood. The measurement is prone to false blood sugar, so the general hospital does not recommend using the dehydrogenation method.
How to choose a blood glucose meter
1. Choose a blood glucose meter that suits you:
a , Whether it is easy to carry: You can monitor blood sugar at any time when traveling or visiting relatives.
b. Test time: If time is important to you, then you should choose a blood glucose meter that can read quickly.
c. Operation process: Some instruments have many detection steps, and the test is easy to fail, so products with simple operation process should be selected.
d. Display size: For elderly patients or patients with vision loss, a blood glucose meter with a larger display window should be used.
e. Temperature range: Many blood glucose meters have a specified temperature range. Therefore, when purchasing, make sure that the temperature of the blood glucose meter you choose can work properly in the local environment.
2. The accuracy of the blood glucose meter:
The first thing to consider is the accuracy of the blood glucose meter. If the test result is inaccurate, it will mislead us and even cause the tragedy of delaying the disease. The blood glucose meters on the market today are quite accurate if used properly. However, the accuracy of the blood glucose meter may decrease after a period of use. Therefore, regular maintenance and maintenance of the blood glucose meter is required. You can also go to the hospital to test the glycated hemoglobin for comparison, because the glycated hemoglobin can reflect the real average blood sugar.
3. The simplicity of the blood glucose meter:
You can choose a blood glucose meter with fewer operation steps and lower requirements for the operator, and you can use it easily with a little training. Blood Glucose Meter.
4. Test time of blood glucose meter:
The test time of blood glucose meters currently on the market is very fast, most of them are tens of seconds, and some are even several seconds. You can choose a blood glucose meter as short as possible.
5. Test site of blood glucose meter:
Compared with traditional finger blood collection method, multi-site blood collection (finger, palm, upper arm, forearm, thigh, calf and other six major parts) ) and forearm blood collection can greatly reduce the pain of blood collection. Studies have shown that there is a good correlation between the blood glucose values measured by forearm blood collection and finger blood collection, but the postprandial blood glucose rise is first manifested from finger blood glucose, that is, the forearm blood glucose reading is delayed compared to the finger reading, this is because of the capillary of the finger. The blood vessels are rich, and the blood flow rate is about 3 to 5 times faster than that of the forearm. We can gently soften the forearm and accelerate its local blood flow to reduce the difference between the forearm and the fingers. The American Society of Good blood glucose meter adopts the whole blood method to collect blood, which saves a lot of pain and trouble for you to collect blood.
6. The memory function of the blood glucose meter:
Try to choose a device with a large memory function, so that you can check the previous blood sugar situation.
How to use the blood glucose meter
The first step: turn on the power
Part of it is to press the power switch directly, and part of it is to directly insert the test strip Automatically power on.
Step 2: Code Adjustment
The code adjustment method of the blood glucose meter is divided into the following three types:
1. Manually input the test strip correction code.
2. Insert the password chip into the machine to automatically record the correction code of the test strip.
3. No coding, no need to manually or insert a chip, the instrument will automatically recognize it.
The third step: blood collection, blood sucking
The blood collection can be done directly with the blood collection pen that comes with the blood glucose meter, and then the blood droplets are placed on the test paper, most of which are siphonic , put it in the blood-sucking area of the test strip and it will be sucked directly.
Step 4: Display the results
After the blood is sucked, a countdown will appear and the test results will be displayed. From 5 seconds to 30 seconds.
Step 5: Complete the test
Shut down. The mainstream blood glucose meter automatically shuts down when the test strip is pulled out, and some early products also need to turn off the power button. Shutdown reduces battery drain and machine wear.
Notes on using the blood glucose meter
1. The blood glucose meter is only used for blood measurement.
2. Do not place in direct sunlight or high temperature and humid places, do not drop the machine to the ground and avoid collision, and do not disassemble, repair or modify the body or wristband of the sphygmomanometer by yourself.
3. The blood glucose meter must be used with test strips of the same brand and cannot be mixed. Do not repackage the test strips, and use them within 3 months after opening (pay attention to the expiration date). Some blood glucose test strips are different for each batch. Before switching, you need to input the barcode number of the new test strip into the instrument, otherwise it will affect the test result.
4. Do not use mobile phones or other devices that generate electromagnetic interference near the blood glucose meter.
5. Please use No. 7 manganese or alkaline dry batteries (2 sections), do not use other batteries, and do not mix new and old batteries and batteries of different types! For a long time (more than 1 month) Please remove the dry battery when using.
6. Disinfect with alcohol before testing, and then take blood after the alcohol is dry, so as to avoid alcohol mixing into the blood. Iodine cannot be used for disinfection, because iodine will chemically react with the test agent on the test strip, affecting the accuracy of the test.
7. Patients make self-judgment through measurement results. Self-treatment is very dangerous. Do not self-diagnose or change your medical treatment behavior without the permission of the doctor.
8. The amount of blood collected must be sufficient to completely cover the test area of the test strip. When taking blood, it is found that the blood volume is small and cannot squeeze the finger, otherwise it will be mixed with the tissue fluid and interfere with the blood sugar concentration. In order to ensure enough blood collection, the hand can be soaked in warm water before, and then hang down for 30 seconds. In addition, press the needle once and then pop it out when piercing, so as not to pierce too shallowly.
9. Do not touch the test strip when your hands are wet or dirty. After taking out the test strip to be used, please close the lid immediately and use it within the validity period. Test strips should be stored in a dry, dark place.
10. Please keep the instrument and test strip out of the reach of children. Do not consume the desiccant in the test strip jar.
The reason for the error of the blood glucose meter
Irregular operation
1. When sterilizing fingertips, wrongly Disinfectants containing iodine such as iodine and iodophor were used.
2. Before the alcohol or water used for disinfection is dry, take blood and puncture the fingertip.
3. Squeeze your fingertips hard when puncturing.
4. Squeeze your fingertips hard to form blood droplets after puncture.
5. Replace the code card in the power-on state, resulting in the failure to update the code.
6. The blood sample was wrong, and fingertip blood was not used.
7. Insufficient blood samples.
8. Repeat adding blood samples.
9. The ambient temperature during operation is not within the normal working temperature range of the blood glucose meter.
Improper storage of the test strips
1. During the transportation and storage of the test strips in the warehouse, the storage conditions of the test strips in a dry and dark environment are not met, especially in hot summer climates. Influenced by the severe heat and humidity in some areas, the test strips fail in advance, causing significant deviations in the test results.
2. When using, the test paper is exposed to the air for too long.
Physiological factors
Individual diabetics, due to their individual physiological state and the use of certain drugs or treatments, can also lead to deviations in blood glucose test results.
1. Poor blood circulation in the body makes the blood glucose values of venous blood and capillary blood have a large deviation.
2. Severe anemia.
3. Oxygen inhalation state. Since some blood glucose meters are based on the principle of glucose oxidase, the effect of oxygen causes deviations in the test results.
4. Diabetics take certain drugs such as vitamin C, etc.
5. Diabetics have high blood lipids and high blood uric acid.
6. Patients with severe diabetes such as ketoacidosis, nonketotic hyperosmolar coma, lactic acidosis and hypoglycemia coma.
How to maintain the blood glucose meter
1. Keep the blood glucose meter clean
The blood glucose meter is in use During the process, it is often polluted by dust, fibers, sundries, etc. in the environment, especially if it is accidentally polluted by blood during the test, which will affect the test results. Therefore, the blood glucose meter should be placed in a storage bag after each use and cleaned regularly. Care should be taken when cleaning the test area. Do not use alcohol or other organic solvents when wiping, so as not to damage the instrument. Use a slightly soaked cotton swab or soft cloth wipe. In addition, it is best to disinfect the outside of the fuselage daily, using a cotton swab or soft cloth soaked in disinfectant.
2. Properly store the blood glucose meter
The blood glucose meter without battery can generally be stored in the environment of -25 ~ +70 ℃, and the blood glucose meter with battery can generally be stored in – In the environment of 10 ~ +50 ℃, the relative humidity of the environment should not exceed 90%. The storage conditions of different blood glucose meters are slightly different. You can read the manual carefully. It also needs to be emphasized that the above mentioned is the storage environment of the blood glucose meter, and the environmental conditions (temperature, humidity) required to detect blood sugar will be more severe, and there will be clear labels on the manual. In addition, the blood glucose meter should avoid being stored in electromagnetic fields (such as mobile phones, microwave ovens and other accessories) for a long time, and at the same time avoid collisions and violent shocks.
3. Regularly calibrate the blood glucose meter
In addition to the need to adjust the code every time you replace a new box of test strips (except code-free blood glucose meters), you also need to regularly calibrate the blood glucose meter. After calibration, the accuracy of the blood glucose meter will drop significantly after 2000 tests, so it should be calibrated. Proofreading should be carried out immediately in the following situations: suspecting that there is a problem with the instrument, the test results are inconsistent with your own feelings (for example, you feel that you have low blood sugar, but the test results are high), or the blood glucose meter is dropped.
4. Replace the battery in time
The manual of the blood glucose meter will indicate that when there is any symbol on the screen, it will indicate that the battery is low. Although about fifty tests can still be performed after the low power symbol appears, it is best to replace the battery with a new one as soon as possible to avoid damage to the instrument and affect the test results.
5. Properly store the test strips
In clinical practice, the blood glucose meter itself is less likely to malfunction, while the test strips are more easily affected by temperature, humidity, and chemical substances. The test strip should be stored in the original bottle, and stored in a dry, cool and dark environment. Close the cap immediately after taking out the test strip, and avoid touching the test area with your fingers when taking the test strip. Single-packed test strips can be stored until the expiration date on the box, while bottled test strips should be used within one month after opening.
