Every diabetic knows that one of the major burdens of the disease is managing supplies. From insulin to alcohol wipes, diabetes is a resource-intensive disease, and running out of anything has the potential for disaster. This is especially true for glucose test trips, the little electrochemical dongles that plug into a meter and read the amount of glucose in a single drop of blood.
As you might expect, glucose test strips are highly proprietary, tightly regulated, and very expensive. But the chemistry that makes them work is pretty simple, which led [Markus Bindhammer] to these experiments with open source glucose testing. It’s all part of a larger effort at developing an open Arduino glucometer, a project that has been going on since 2016 but stalled in part thanks to supply chain difficulties on the chemistry side, mainly in procuring glucose oxidase, an enzyme that oxidizes glucose. The reaction creates hydrogen peroxide, which can be measured to determine the amount of glucose present.
With glucose oxidase once again readily available — from bakery and wine-making suppliers — [Markus] started playing with the chemistry. The first reaction in the video below demonstrates how iodine and starch can be used as a reagent to detect peroxide. A tiny drop of glucose solution turns the iodine-starch suspension a deep blue color in the presence of glucose oxidase.
While lovely, colorimetric reactions such as these aren’t optimal for analyzing blood, so reaction number two uses electrochemistry to detect glucose. Platinum electrodes are bathed in a solution of glucose oxidase and connected to a multimeter. When glucose is added to the solution, the peroxide produced lowers the resistance across the electrodes. This is essentially what’s going on in commercial glucose test strips, as well as in continuous glucose monitors.
Hats off to [Markus] for working so diligently on this project. We’re keenly interested in this project, and we’ll be following developments closely.
Very well written but i stay with my therapy dog. He smell the chemical changes and tips me with his nose to warn me. Pure love :-)
Incredible medical sensor tech, plus they’re cute to boot
boop even!
And on the average, they last about 15 years. And much cheaper (dog food) than test strips on per day basis
Interesting, we’re considering a diabetic service dog for my daughter as she goes away to college. Pretty expensive, though, and we’re worried that we’ll be “over-solving” the problem. She has no issues detecting when she’s hypoglycemic; she feels it quite well, and her CGM is a good monitoring tool. So a dog would only be useful when she’s asleep — she’s very hard to rouse — and we’re afraid that it wouldn’t be fair for a trained service dog to have so little service to render.
My friend Elizabeth has a zippy quick cheap precise machine to measure everything in blood using only a speck of it. Looking for more investors.
Shut up and take my money.
He’s making a sarcastic comment about Theranos, dude…
Woosh.
This 👆
This method of measuring glucose has been around for decades. There’s a lot more to accurately and reliably measuring glucose in human testing than the chemical reaction used. Coma and death is the potential result of an inaccurate blood glucose measurement.
Whatever, it’s still based on that chemical reaction. Currently measurement errors of ±15 % are considered tolerable. Sure, it takes more, but it’s feasible I think. I am interested in the technical challenge, not in marketing DIY test strips. But that was clear from the start, wasn’t it?
This is nothing but a toy. Anyone who thinks that they can use this to control insulin dependent diabetes would be putting their life at risk. Proven reliable FDA certified glucose test strips are remarkably inexpensive and accurate compared to laboratory tests. Easy Touch strips are about 20 cents each. There’s no reason for an open source glucometer.
There’s sure a reason for an open source glucometer: education, research etc.
I pay more than one USD per strip. I must be getting ripped off.
I strongly support this effort. It is definitely not a waste of time.
If you’re implying that Elizabeth’s machine is more sophisticated than this chemical reaction, you might have missed something.