Frequently Asked Questions

ACE & GM3+ Blood Glucose Test Strips are Biosensor test strips. They work on the amperometric principle.

Amperometric detection is based on measuring the oxidation or reduction of an electro active compound at a working electrode (i.e. sensor). A constant electrical potential is applied to the working electrode with respect to a second electrode called reference electrode. The applied potential is an electrochemical driving force that causes the oxidation or reduction reaction. This reaction generates a small amount of current which is measured by the Glucometer.

Applying the above principle to the ACE & GM3+ tets strips; the biological sensing element here is the enzyme, Glucose Oxidase, which is immobilized on the working electrode of the Gluco-strips. The glucometer is used to apply a constant potential to the test strip. When the blood sample is applied to the Gluco-strip, a redox reaction takes place. This is detected by the meter as a change in the current which is related to the quantity of sugar present in the sample. The ACE/ GM3+ Blood Glucose Meter shows this as your blood sugar reading.

Testing                                     Normal Expected Readings

For many people meter accuracy becomes an issue when they purchase a new meter and compare it to their old one, or go to the doctor to have a lab test and notice a seemingly large difference between the two test results. At first glance, you would expect all blood glucose monitors and lab equipment to give the same results. After all, they're measuring the same thing--the amount of glucose in a specific blood sample. Blood Glucose monitors and lab equipment are calibrated, or set, to measure blood glucose in different ways and will give different results.

Never compare your meter with another meter. Even two labs would not give identical readings.

• When you compare two readings obtained from two different sources - one from a lab and another from a Glucometer or between two different Gluco-monitors or between two different labs there can be a difference of + 20%. 
• No two monitors, even the same model from the same manufacturer, will give identical results every time. Also, some products are calibrated to give a whole blood test result, while others are calibrated to provide plasma equivalent results. Still others are calibrated somewhere in-between.
• To compare results between monitors, you would still need to know the blood glucose value of the blood sample you were testing. To do this requires a lab test that's why manufacturers tell consumers that the only way to check the accuracy of a meter is to compare its test result to a lab result, and not to another meter.

1. Be sure your Meter is properly coded to match the test strips you are using. An improperly coded Meter may not give accurate results
2. Don't eat for four hours before your lab test. If you have eaten recently, your Meter test results from a finger tip (capillary) sample may be up to 70 mg/dl higher than the lab's blood glucose level using a samples taken from a vein (venous)
3. Make sure that both samples are drawn at the same time. Even 15 minutes may make a big difference. Your blood glucose level can change quickly over short periods of time due to insulin action or the effects of food or exercise
   Ask if the lab test was done within 30 minutes of drawing the blood. Glucose levels of whole blood samples left sitting at room temperature will drop 7 mg/dl each hour due to glycosis (the process by which red blood cells continue to consume glucose for energy)
4. If the lab test can't be performed immediately, the red blood cells shoul be separated from the plasma within 30 minutes
5. Ensure that the laboratory uses a good auto-analyzer to test your blood sample. If the laboratory is using a photometer, the reference control solution is to be prepared fresh for the test
6. Never use your Meter with stored blood because preservatives will cause inaccurate results
7. Ask if your hematocrit is normal. If you have a very high or very low hematocrit (red blood cell count), your Meter's test results may be inaccurate
8. Your Meter is considered accurate is it falls within plus or minus 20% of the lab results

GM3/ Digilyser Blood Gluco-monitor uses whole blood to measure glucose. Lab equipment uses only the plasma portion of blood; meaning that the red blood cells are removed before glucose is measured. Because of this difference in sample types, whole blood test results are approximately 12% lower than plasma test results

Since blood flows from capillaries to vein and the blood reaches vein only after the required glucose absorbed/ consumed by the cells surrounding the capillaries, the glucose is more in capillaries compared to vein. Many studies & trials reveal that the difference can range from 5-10%(fasting) to 20-26%(after meal containing carbohydrates). However in children the difference can vary more than 20% even in fasting. Other factors influence variation in blood glucose results include heamtocrit (red blood cell count), presence of alcohol in blood, other individual reasons, drug interactions etc.

• Insufficient quantity of blood gives erroneous readings. This can be observed if the drop of blood on the test area dries up before the completion of the test or if the test area is not fully covered by the blood drop
• Storing Glucose-strips in places of excessive heats or at room temperatures exceeding 30 degree centigrade
• If you use alcohol/spirit to clean puncture site, wait for it to completely dry before taking a sample
• Incorrect calibration code
• Low/ defective batteries. Use good quality alkaline batteries only
• Change the batteries once they are shown to be weak
  

ERRORS OF IMPRECISION:
These are the irregular or random errors. The commonest causes of scatter (imprecision) are:

1. Faulty technique: incorrect and variable pipeting, inadequate mixing of samples with reagents, incubation of tests at inconsistent temperatures or for incorrect length of time.
2. Reliable test results can only be achieved if the methods are written clearly and insufficient details, and followed exactly by all the members of staff.
   Dirty glassware.
3. Too heavy a workload resulting in faulty technique, mistakes being made, or short cuts being utilized.
4. Too low a workload resulting in loss of concentration.
5. Faults in colorimeter / spectrophotometer / analyzer, and unreliable main supply.
6. Use of dirty or finger marked cuvettes, air bubbles in sample, vapor present in cuvettes.
7. Incomplete removal of interfering substances in serum, like RBCs, or protein.

ERRORS OF INACCURACY:
These are regular or consistent errors. All the results differ from the correct result by approximately the same value. The commonest causes are:

1. Use of unsatisfactory reagents:  impure chemicals, wrong preparation, improper storage, use beyond working life / expiry date, improper balance,
   bad quality of distil water, Un-calibrated volumetric apparatus.
2. Incorrect or infrequent calibration of a test method.
3. Poor controls / standards: wrongly prepared or stored controls or standards or used after expiry.
4. Readings on incorrect filter.

• Rest for three to five minutes before measuring your blood pressure. Do not talk.
• Sit in a comfortable position, with your legs and ankles uncrossed and your back supported.
• Place your arm, raised to the level of your heart, on a table or a desk, and sit still.
• Wrap the correctly sized cuff smoothly and snugly around the upper part of your bare arm. The cuff should fit snugly, but there should be enough room for you to slip one fingertip under the cuff.
• Be certain that the bottom edge of the cuff is 1 inch above the crease of your elbow.

You should have your monitor checked periodically. Proper care and storage are also necessary. make sure the tubing is not twisted when the monitor is stored, and keep it away from heat. Periodically check the tubing for cracks and leaks.

Ask your doctor or nurse or our sales team to teach you how to use your blood pressure monitor correctly. Proper use of it will help you and your doctor achieve good results in controlling your blood pressure.

• Proper Cuff Size is very important. Ask a medical professional to tell you the cuff size you need based on the size of your arm. Blood pressure readings will be wrong if your cuff is of wrong size
• The dispaly of the monitor must be easy to read
• Auto-inflation models are easier for self use
• After sales support is essential to ensure that you use if for a long time to come

Since the digital monitor is automatic, it is the most popular blood-pressure measueing device. The blood pressure is easy to read, because the numbers are shown on a screen. Some electronic monitors have a paper printout that gives a record of the blood pressure reading.

The digital monitor is easier to use than the aneroid unit, it has a gauge and stethoscope that are one unit, and the numbers are easy to read on the display area. The device also has an error indicator. Furthermore, deflation is automatic. Inflation of the cuff is either automatic or manual, depending on the model. This blood pressure monitoring device is good for hearing-impaired patients, Since there is no need to listen to heart sounds through the stethoscope.

A disadvantage of the digital monitor is that an irregular heart rate changes the accuracy.

One advantage of this monitor is that it can easily be carried from one place to another. Also, the cuff for the device has a built-in stethoscope, so you don't need to buy a separate stethoscope. In addition, the aneroid monitor costs less than digital monitors do. Aneroid monitors range in price from about Rs.500-700.

The aneroid monitor also has some disadvantages. First, it is a complicated device that can easily be damaged and lose accuracy. The device is also difficult to use it it doesn't have the special festure - a metal ring - thatmakes it easier to put the cuff on. In addition, the rubber bulb that inflates the cuff may be difficult to squeeze. This monitor may not be appropriate for hearing-impaired people, because of the need to listen to heart sounds through the stethoscope.

To measure your blood pressure at home, you can use either an aneroid monitor or a digital monitor. The aneroid device has a dial gauge that is read by looking at a pointer. The cuff is inflated by hand by squeezing a rubber bulb. Digital monitors have either manual or automatic cuffs. The blood pressure reading flashes on a small screen. Choose the type of monitor that best suit your needs.

Click here to see our Safe Care range of Digital Blood Pressure Monitors.