197 1 on September 4th, 2008, in the second year after Ames reflector went on the market, the product obtained the U.S. patent number: U.S.Pstent36058 15. The first truly commercialized blood glucose meter, Dextrometer, was introduced by Ames Company in 1979. For patients, the use of the first generation blood glucose meter is very complicated. Drop the blood sample on the test paper first, rinse it with water for one minute to remove red blood cells, and then insert the test paper into the machine to read the results.
Age of urine glucose and venous glucose
From about 1840, urine glucose and venous blood glucose tests were invented until Tom Clémence invented the blood glucose meter in 1966. During this period, urine glucose and venous blood glucose tests have been the main indicators of diabetes diagnosis and disease monitoring. At that time, the urine sugar test was cauterized by Bancroft solution, which was troublesome and inaccurate. At present, it has been gradually replaced by oxidase test paper method, and it is still used in underdeveloped areas. At present, venous blood glucose measurement is mainly used for the diagnosis of diabetes.
Today: The Age of Blood Glucose Meter
The blood glucose meter was successfully developed in 1966. After more than 40 years of continuous improvement, it has developed to today's appearance.
The first generation: water-washed blood glucose meter, 1979 was introduced, in which blood was dripped on the test paper, red blood cells were washed with water after one minute, and then the test paper was inserted into the instrument to read the results, which was cumbersome.
The second generation: blood-wiping blood glucose meter, 1980. After the blood sample reacts with the test paper, the blood cells on the test paper can be read gently, with short reaction time and accurate results. 1986 introduces a blood glucose meter with memory function.
The third generation: colorimetric blood glucose meter, developed and introduced in 1987, which is easy to operate without wiping blood.
The fourth generation: 1986 introduced electrochemical blood glucose meter, and then electrochemical method replaced colorimetric method. Electrochemical blood glucose meter is small in size, convenient and short in reaction time.
The fifth generation: multi-site blood glucose meter, which can collect blood from upper arm, forearm, thigh, calf, palm and other parts with only 0.3 microliter. Encourage patients to measure blood sugar more, reduce complications and save money.
In order to avoid the pain of blood collection and make it easy to carry, scientists have developed some special types of blood glucose detectors, such as:
Cornoscope blood glucose meter: the sensor is placed in the cornea mirror, and the patient can determine the blood glucose level by observing the color and chart of the photosensitive substance on the cornea mirror. Green is normal, red is slightly increased, and purple is obviously increased. Deeply favored by patients.
Tear sugar tester: the sugar content in tears is very close to that in plasma. When human blood sugar changes, tear sugar will also change. This detection method is low in cost and painless.
Watch blood glucose meter: you can wear it on your wrist like a watch. When the blood sugar is lower than 85 mg/dl, it will give an alarm, so it can safely and effectively detect the hypoglycemia of patients at night. Although 32% patients were awakened by the alarm sound during sleep, patients were still happy to use it. The United States approved it for diabetic children in 2002.
Arm implantable blood glucose meter: It consists of subcutaneous implanted sensors and external measuring instruments. The sensor has a diameter of 6 mm, the thickness is the same as that of ordinary paper, and no power supply is needed. When the patient waves the arm with the sensor implanted in front of the measuring instrument, the measuring instrument can read the blood sugar value of the patient by pulse, and the working principle is similar to the magnetic induction burglar alarm installed on clothes sold in stores.
Tomorrow: the era of integrated blood glucose meter
It is an automatic blood glucose monitoring and insulin infusion system, which consists of an insulin pump and a blood glucose meter. Blood sugar is monitored by a matchbox-sized blood glucose meter worn on the wrist, and the results can be automatically transmitted to the insulin pump through the radio module, and then the insulin pump injects insulin according to the instructions. The instrument will continuously measure blood sugar, and according to the blood sugar level, the insulin pump will automatically inject appropriate amount of insulin to keep the blood sugar at a normal level. It completely simulates the blood glucose regulation function of normal islets. The instrument integrates micro-pump, micro-channel, silicon needle and control system, and is small in size and painless. In this way, it is not necessary to measure blood sugar every day and inject insulin, which can alleviate the pain of patients and bring great convenience. Blood sugar detector-electrochemical method and light reflection method
Electrochemical method is the principle of reflecting blood sugar value by detecting the current signal generated in the reaction process. The number of electrons generated by the reaction between enzyme and glucose is read by a current counting device, and then converted into a glucose concentration reading.
The light reflection method reflects the blood sugar value by detecting the color change of the test paper during the reaction. Through the intermediate (colored substance) produced by the reaction between enzyme and glucose, the detector detects the intensity of reflected light on the reflecting surface of the test paper and converts the intensity of these reflected light into glucose concentration.
The advantage of light reflection technology lies in its maturity and stability. In an emergency, the color change on the back of the test paper can be visually observed to help judge the level of blood sugar. However, this method will produce errors when operating in strong light environment (such as outdoor in summer); In addition, when patients with hyperlipidemia and hyperbilirubinemia are tested with this home blood glucose meter, the error will also increase.
The electrochemical law will not be disturbed by the above two factors, but the microwave oven and mobile phone in use will affect the accuracy of the instrument; Therefore, electromagnetic radiation should be avoided when using such instruments to monitor blood sugar. Can be selected according to actual use.
In any method, the test paper has a certain detection range. Beyond this range, there is no linear relationship between blood glucose concentration and potential or color depth. Above a certain concentration, the electrochemical instrument is saturated and is no longer sensitive to the change of blood sugar value.