[jacquesm]

So, for those of you that feel that this is worthy of hacking: Diabetes is one of those diseases that seems right where your average hacker would like it to be. A single value (Blood Glucose Level) which you can read using some sensor and an automated delivery method. Connect A to B using some 30 lines of Python and call it a day. But it is not that simple. The manufacturers of these devices have to go through some pretty strict testing regimes in order to ensure the devices work well when produced in quantity. And that is where the trick lies. Doing this once, for yourself with nobody at risk but you if you fuck up and getting away with it is easy. Doing it repeatably for 10's of millions of people with all your risks analyzed and regulators happy is very, very hard.

[bayesian_horse]

That's not the point.

There are three things to an "artificial pancreas": glucose sensor,insulin pump, and the control logic. The difference between an artificial pancreas and the "manual" operation is just that the control logic is automated.

You even can't "fuck up" very easily, unless you add other diabetic stupidities on top of a malfunctioning control logic. Two failure conditions: a) Too little (or no) insulin delivered. b) Too much insulin.

The second one is the more dramatic/short term. The insulin pump has a limited supply of insulin. The speed of injection is limited. There are probably additional safeguards in the pump's software around knowing you are not an elephant breaking into a candy shop. And you feel the pump acting. You can pull it out if it behaves strangely.

Too little insulin delivered may be trickier, but you still have to check the glucose levels occasionally, probably multiple times a day.

Patients already use "algorithms" for insulin delivery. But they are comparatively shitty and designed for example to deliver insulin as a bolus after a meal. Continuous administration of insulin over a pump already has a lot of benefits. A continuous monitoring already has benefits.

[liamzebedee]

Although I would highlight - there is additional high risk now if the sensor becomes faulty, in which case, more insulin could be delivered for incorrect levels while you sleeping, etc.

[bayesian_horse]

I don't know if insulin pumps are used while sleeping. After all, there's a needle inserted in your skin.

You wake up from hypoglycemia, long before there is more trouble. And the sensor doesn't post glucose levels for example if it gets detached.

[wbrasky]

Insulin pumps (and their cannula; not a "needle") are installed 24/7. They can be "suspended" and the insulin delivery hose unhooked, but they are generally there, and active, at all times. Likewise, a CGM (continuous glucose monitor) will provide, as the name says, continuous monitoring. Both use adhesives to keep them attached and generally remain so, even while sleeping.

Hypoglycemia also may not lead to "waking". After all, a diabetic coma may result from low blood glucose, depending on how quickly it crashes.

Source: my girlfriend is Type 1.

[bayesian_horse]

Diabetic coma is caused by prolonged hyperglycemia (too much blood sugar) and diabetic ketoacidosis. Many diabetic patients go through months of hyperglycemia and even ketosis before they even know that they have diabetes.

Hypoglycemia in healthy adults mainly results from not eating and develops rather slowly. It's hard to recognize at first, but it will get a lot more obvious before it gets serious.

Hypoglycemia in diabetic patients is more often caused by too much insulin delivered at mealtime and this happens more quickly. Patients can become unconscious before they notice the problem, but usually they recover even without treatment. The goal of diabetes treatment is to avoid this hypoglycemia, also because the body reacts with increased glycogenesis leading to an overshoot of blood sugar.

There are sometimes suicide attempts with insulin. This rarely succeeds, it can result in brain damage, but mostly the patients wake up sometime later.

At night an insulin pump would not need to deliver that much insulin. There are also very long-acting types of insulin, which may be preferable to the short-term insulin in the pump to achieve the "baseline" during the fasting period. Or not. That's a strategy question, I guess. I had type 2 for a short time, and I used long-term and short-term insulin at meal times, with the finger-pricking type of measurement.

I don't think insulin pumps would carry enough insulin or are able to deliver enough.

My point is that there is a relatively large margin of error for any algorithm or software before serious harm occurs, and that the continuous monitoring and delivery is already superior in achieving good glucose curves, regardless if the control loop is manual or automatic.

I've read that continuous sensors help patients to have fewer incidents of hypoglycemia.

[liamzebedee]

Haha, I'm the OP, I use the insulin pump ;)

> You wake up from hypoglycemia, long before there is more trouble

And this is one of the main styles of diabetic death - not waking up (diabetic comatose).

> And the sensor doesn't post glucose levels for example if it gets detached.

I was more referring to the circumstance when you're lying on your sensor in a funny way, and it begins reporting incorrect levels.

[bayesian_horse]

You can loose consciousness from hypoglycemia, but normally the body will do everything it can, even autophaging your heart muscle proteins to bring it back up. Unless you have been fasting for a really long time, it will just release glucose from glycogen reserves and you recover quickly.

The diabetic coma thing is the opposite spectrum when the blood sugar is extremely high but the cell metabolism has to run on ketogenic fuel because it gets no glucose. Which leads to ketoacidosis, which can ultimately lead to a coma.

[devoply]

meh still it seems extremely trivial for pretty much any well funded startup to do... and extremely surprising that it does not exist. i mean if theranos can exist, why the hell is this problem not solved?

[jacquesm]

Well funded start-ups (and established players) are all working on this. Given that the market is huge and Diabetes is yours for life you can bet that a lot of clever people have spent a lot of time on this. Not all of the companies that work on this problem have made it, on top of that it is a patent minefield. It will take you a few 10's of millions of $ or Euros to get to market and you would need to do everything right the first time. Then you still don't know much about how your device will function in the field until enough time has passed that you can judge by the returns where you got it wrong. Doing a respin is expensive.

So, Theranos can exist, and if the money that had gone to Holmes and then this indeed would be a solved problem. But it didn't. Note that there are pumps with a closed loop option on the market today, but they are neither convenient nor simple to use. It is work in progress. I fully expect a simple to use closed loop system to be available in quantity somewhere in the next year or two based on recent market research. The time is indeed ripe. The basic tech is there and the pumps have achieved a level of miniaturization and reliability that it is feasible, there are still problems to overcome but those are all within the realm of the possible, do not require unobtanium and enough parties are working on it (competition is fierce) that at least one of them will solve it within that time frame.

[bayesian_horse]

Continuous glucose sensors are relatively new.

It's surprisingly tricky to measure chemical concentrations continuously without replacing the "sensor". Blood and other liquids attack and clog everything.

Without continuous glucose monitoring, you can't do artificial pancreasing.

[myrryr]

It is, closed loop system are about to be legal in New Zealand, and the pumps the govt supplies will support it.

It has just taken time.

[phkahler]

See Boeing MCAS for an example of how a seemingly simple fix is actually not.

[abtinf]

Note that glucose is only a proxy for the actual thing we want to control, which is insulin.

[dreamcompiler]

Um...no. Excess glucose kills you slowly with tissue damage and ketoacidosis. Too little glucose kills you quickly by starving your brain of something it needs. So glucose is very much the stuff we want to control. The mechanism for regulating glucose is insulin.

[friedegg]

Excess glucose doesn't cause diabetic ketoacidosis, but rather too little insulin. You can run high blood sugar for literally years without going into DKA (although it does damage your body). It's even possible in certain, rare circumstances to enter DKA with normal blood sugar.

[dreamcompiler]

You're right. DKA is the result of the body burning fat for fuel when insufficient insulin prevents it from burning glucose. I should have remembered that. My patients with DKA always had a BGL of 500 or more (5x normal), so that's why I mistakenly associated DKA with high sugar.

[DoreenMichele]

Insulin controls blood glucose. So how do you figure blood glucose is merely a proxy for insulin and not the actual thing an artificial pancreas is intended to control?

[Fr0styMatt88]

My guess - where does the target blood glucose level come from in a non-diabetic? The thing the body can't produce is insulin. Higher than target blood glucose is a sign that not enough insulin is being produced. I can roughly see the logic there.

[DoreenMichele]

As I understand it, target blood glucose levels for diabetics are based on normal blood glucose levels in healthy (non-diabetic) individuals. So presumably a healthy body has some internal mechanism for determining when and how much insulin to produce/release into the blood stream.

As far as I know, we haven't figured out what that mechanism is. But I'm not diabetic and I'm much less prone to being hypoglycemic than I once was, so my reading on the subject is fairly casual compared to when I did things like wrote a research paper on Functional Hypoglycemia in part for my own edification.

[bayesian_horse]

That's wrong.