Blood Glucose Meter History
Originally all that was available were urine test tapes or dipsticks. These were coated with a chemical that changed colour when dipped in urine and this colour was compared to those on a colour chart. A simple method but not very precise. Glucose does not even show up in the urine until the levels are over 10mmol/L (180mg/dL).
Also, as it is in the urine it is obviously on the way out of the body and gives no indication of the situation at the present time. It must have been hell trying to adjust your insulin dose based on these results.
Next (in 1965 - history is measured in decades, not eons here!) came the test strips that measured the glucose in whole blood. Invented by Ernie Adams and produced by what was then the Ames Company in Indiana, USA (now part of Bayer) they sold under the brand name Dextrostix(r).
These worked in a very similar way to the urine strips. They were impregnated with a reagent that resulted in an enzymatic reaction with the glucose in the blood and changed colour. The more glucose there was the darker the colour.
It was a finicky method as you had to add a drop of blood then wipe off the excess, time it carefully for 1 minute and visually assess the results. A blue colour developed which you again had to compare to a colour chart - definitely subject to 'operator error' though some folk apparently were very good at reading them. Practise makes perfect I suppose.
They were useful for deciding if you were very high or very low at that time, but still did not give you any feedback as to how much either way. However any information must have been a godsend to struggling diabetics.
Then a man, to whom all we diabetics should be grateful, Anton H. Clemens, developed the first blood glucose meter, known as an Ames Reflectance Meter. Making use of the Dextrostix he came up with a devise that read the light reflected off the strip (called reflective photometry).
Basically if you shone a beam of light onto the strip the darker the blue colour was the less light would pass through it. It was measuring the intensity of the colour. The reflected light was read by a photoelectric cell which translated the result to a swinging needle on a numbered dial.
Compared to what had been available this was much more accurate, but it was very bulky and reliant on rechargeable batteries that gave problems - weak batteries meant incorrect numbers.
It was never intended to be used by the home market, being aimed at doctors who would use them in their surgeries to screen patients for high blood sugars, or in hospital emergency departments where they were great for deciding if the unconscious patient was in a diabetic coma or just dead drunk.
And this is where Dr Richard K Bernstein enters the picture. He was an engineer, not a doctor at that time, and had been a type1 diabetic from the age of 13. By the time he was in his 30's he was losing his fight with diabetes.
He had innumerable complications and was looking at an early death. He read an article in a journal about the Ames Reflectance Meter and saw the potential it had. He was fortunate his wife was a physician as one was required to be a doctor to be able to purchase one, they were not for sale to the general public. You also had to have serious money (or plenty of motivation) because the price at that time was $650!
He soon found out that his BG's were all over the place and was able to adjust his insulin dose to control the extreme highs and lows. However he was still suffering from progressive complications.
It took a number of years, the application of engineering trouble-shooting principals, lots of further research (and plenty of blood letting!) but eventually he discovered that it was necessary to keep your blood glucose levels as near to normal as possible to avoid and possibly reverse diabetic complications.
If you are thinking "Yea, right, what is so world breaking about that" you must remember that at the time nobody knew this! In fact his physician told him it was not possible for humans to normalise their blood sugars.
When one is desperate one is prepared to try the impossible and this is just what Bernstein did. It took a year of continuous testing - only made possible by this new blood glucose monitor - and experiments with the effects of different foods but eventually he got his BG down to around normal 24/7. His complications largely reversed themselves and his quality of life improved enormously.
He was so pleased and excited about the results he wanted everyone to try this and share in his success, so he set about attempting to get the attention of the medical fraternity. Of course they grabbed at the idea and passed the message on to their patients - did they heck!
Instead they refused to recognise it at all, refuting the findings and coming up with lame excuses like the fact "no patient would be prepared to use such a device" and "patients should not be allowed to 'doctor' themselves". It is a scenario that we see in professional people all the time - they do not like their pet concepts or entrenched ideas being challenged.
He sent reports about his methods and results to medical journal after medical journal and all were rejected. Eventually he did manage to published a report on his experiences in the medical journal, Diabetes Care, but that still did not get him anywhere.
By refusing to listen the medical fraternity denied their patients the advantages of good blood glucose control and delayed the development of meters for home use for many years. No company was going to sink money into a product that the mainstream practitioners refused to recognise.
In 1978, frustrated by the medical fraternity's attitude and realising that he would get nowhere with them unless he became 'one of them' he, at the age of 45, gave up his job and entered medical school to train as a doctor. He now runs his own medical practise, specialising in diabetes and is a testament to his own techniques as he is the longest living type 1 diabetic around.
If you want to know more of his story and that of these original meters check out these websites:-
Strangely enough it was in the US itself that the most opposition occurred. In England and Israel especially doctors were quick to see the advantages of self monitoring.
It was the late 1980's before BG monitors really took off for sale to the US home market, and that for use of Type 1 diabetics only. It took a lot longer before it was suggested we Type 2's use them, in fact some are still not so advised.
The Glucometer and the Accuchek meter were the brand names that dominated the market then and in fact became synonymous with BG monitors at the time, sort of like Hoover for vacuum cleaners or Kleenex for tissues.
Not that test strips were totally out of fashion yet. Affordability kept them going - you could cut them in half lengthways and get twice the strip for your money!
Diabetic care has never been cheap.
A new technology for meters had also been found that, like the reflective photometry, still used an enzyme on the strip to convert the glucose to something that could be measured, but differed in that it did not use the colour change as a means of measuring but instead the number of electrons produced by the enzymatic reaction. This number was then converted to that of blood glucose concentration.
Both these methods of measuring blood glucose are still used by BG monitors today and both have their advantages and disadvantages.
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