What is the obstacle to a fully reusable glucose meter?

See title, why are disposable strips needed?

They get clogged with blood. You really want go back to the old way?

I’ve read about two other types of meter which may or may not be still in development; once I heard that early tests were not so good, I stopped reading about them.

The first one used serum from under the forearm skin, rather than blood. I don’t know if it clogged like a test strip would, or if it used test strips, but the early tests said it wasn’t useful as a test device because skin serum changes glucose level with too long of a delay behind changes in blood glucose level, i.e., your blood glucose could have dropped dangerously low and your skin serum would still be showing normal.

The other one was an optical system which shone a light through the skin (similar to how a blood glusoce meter shines a light through the blood in the test strip) and judged the quantity of glucose based on some technical stuff. Problems occurred because (go figure) everybody’s skin is a different color, and even for one person, the color can change throughout the day based on tanning, exercise, blood pressure…

What is the obstacle to cheap, disposable test strips?

The obstacle is that there is no or little profit in cheap, disposable test strips.

The manufacturers of them want to make a lot of money. Under my current health plan, they’re about $1.25 apiece. The manufacturer (with rebate) will give you a free meter. I’m supposed to test 6 times a day, or more, if I feel bad.

What about giving people an option? People who wanted to pay for the strips could continue to do so, but people who didn’t want to do that or couldn’t afford 10 strips a day or whatever could get a non-strip meter and then learn to clean it. E.g. sort of like how soldiers in the Army learn to clean their rifle. Maybe for some people, having to spend a half hour every weekend to field-strip, clean, and reassemble their meter is worth not having to buy strips every week.

Patient: “Done, Diabetes Educator!”
Diabetes Educator: “Patient, why did you reassemble that meter so quickly?”
Patient: “Because you told me to?”

Walmart sells them for $0.20-0.40 each so there probably isn’t much financial incentive to create reusable ones at that price. There is work on implants and contact lenses to provide constant glucose monitoring but who knows when they hit the market.

I don’t see how they would get clogged or how cleaning would be so hard, according to wiki it says strip readers use a chemical to oxidize the blood drop and then apply current and interprets how it changes the current.

So I was imagining a reusable model with a small depression with two electrodes, put a drop of blood bridging them along with a drop of the chemical solution and hit the power button, after the reading wipe with some isopropyl on a paper or whatever.

How would that get clogged?

Quite the contrary.
The profit is so good that the mfg’s don’t want (you) to find another way to do it.

That’s my point. The test strips are profitable because they’re so expensive. As others said, the retail price is from about twenty cents to about a buck apiece. Do you really think they cost much more than five cents to make (and probably closer to a penny)? I doubt it. They’re being sold on the razors-and-blades model pioneered by King Gillette.

Any possibility for DIY strips? After all, I assume they are impregnated with some ordinary chemical that you could buy. You ought to be able to cut a couple hundred strips out of one sheet of lettersize paper (93.5 square inches). And a color chart to match the color.

I imagine it would be a bit more complicated than that.

You wouldn’t want to test the blood while it’s still on the person’s body, to get accurate readings. So you need to get enough blood to squeeze a drop onto some non-reactive surface (wax paper or cling wrap, maybe?), but that would take more blood than the current test strips, which suck it up via capillary action.

Also, the oxidizing chemical – does that need to be precisely measured? And how long can it be stored before use? I’d expect the drug companies would find a way to sell you this at a high price. And I expect they’d try to make sure the cleaning solution is something more propriety and more expensive than simple iisopropyl.

There are now constantly monitoring glucose meters in production. I believe they work on the optical method mentioned earlier, but I’m not positive. If you hook up one of these constant monitors to an insulin pump (possibly combined with a glucagon feed as well), you have an artificial pancreas. There was a paper in the New England Journal of Medicine in July of this year reporting on an early trial of such a system, that gave significantly better overall glucose levels throughout the trial than more traditional methods of control. I didn’t seen in the paper exactly how the glucose monitor used worked, but I know that the two devices communicated with an iPhone app, which did all the management. Nifty stuff.

Hmm. I believe you, but I wonder how they overcame this issue for pulse oximeters?

In a way, that’s how the earliest strips worked. But, with naked eye assessment of colour, the plus/minus was in the range of 100’s of mg% (10 to 15 mmol/l) [see for example the first paragraph of this study]. And that was with 'commercially manufactured colour test strips. DIY strips would have to perform even worse.

Not to mention the problem the old strips posed for the colorblind, which comprise about 10-11% of the population.

‘Continuous glucose monitors’ are available and common technology as an attachment for an insulin pump. They have a small disposable needle/probe set that goes into the skin and must be replaced every few days. These sets are fairly expensive, and most pump-wearing diabetics I know don’t use them, or don’t use them full time, due to this. This is NOT the same thing as an artificial pancreas, which are closed-loop systems, and still experimental; a pump with a CGM isn’t and still requires input and decision-making from the user and most users would rather have that level of control.

‘Alternate site testing’ meters are also very common. Most standard glucometers will do alternate site testing from the forearm or the base of the thumb. They’ve been on the market several years. The feature isn’t popular, and it’s not very accurate.

Optical systems - supposedly, they’ve been ‘in development, we’ll have it ready next year’ for the last ten years. I think this falls into the category of diabetes urban legend, frankly…though, as a Certified Diabetes Educator, it would be a big help getting folks to test more.

A question if I may about the quoted fragment above:

Among your patients who have adequate insurance or financial resources so that economics doesn’t enter into their testing decisions, do you still find widespread resistance to self-testing? Or is it mostly a matter of resistance by folks who don’t want to, or can’t, spend the money?

At what testing frequency do you hit the big increment of resistance? Ever, one a week, once a day, 3x/day, 5x/day, etc?

Obviously each patient has his/her own threshold of resistance, but I’m wondering if there’s some fairly common cut-off point(s).

I should have googled it first. I was amazed by how high tech these strips. No DIY possibilities for them.