A DIY ‘bionic pancreas’ is changing diabetes care

How quickly does a glucagon shot trigger GNG and how quickly can GNG raise glucose levels?

Severe hypoglycemia to the point of what was described (death) is not reported in any of the recent device studies.

Level 2 or moderate hypoglycemia, very different from death, is reported at < 0.5% in recent closed loop system studies.

> Current CGM's can still require hours of "warm up", and many current pumps still must be removed for things like swimming so they don't get penetrated with water.

Current CGMs are water resistant but conveniently one is also not administering insulin while swimming either. The bionic pancreas is also dependent on CGMs and has the same limitations.

I'm really not sure what point you're getting at. Hypoglycemia is not what's being improved upon with current advancements, it's time in target.

I'm not going as far as to claim Medtronic's approach (I believe the only one commercially available with so-called meal prediction based on historical CGM and offers full correction boluses) is the optimal one, just that it is an approach that is at least very good (~80% time in target) and while it still requires meal announcements it's just the first step of what they're trying to do. Clearly we can expect further iterations of these algorithms as the technology matures.

> Inreda uses two identical CGMs for noise reduction purposes just so they can get clean data with less of a lag.

Just giving an example that this is possible without external input or data, your statement was that you will need a-priori information which is not necessarily the case. Whether such a system is optimal is a different question.

I haven't seen the raw data and highly doubt enough of it even exists for anyone to make a claim whether or not such a system can be optimized to the point necessary.

> None of the systems claiming you don't have to do anything in terms of meal announcement are _working_ in the sense of achieving euglycemic parity, which should be the goal.

For clarity to any less knowledgeable readers while time spent in euglycemia is a very important outcome measure it cannot come at the expense of severe hypoglycemia or severe hyperglycemia/diabetic ketoacidosis (i.e. an algorithm that improves euglycemia to 95% but has a 2% severe hypo time is less acceptable than 80% euglycemia and 0.5% severe hypo.)

To my knowledge no system on the market/generally available right now is claiming to be completely input free. The closest to my knowledge is again the MiniMed 780G discussed in my first point which will assuredly be iterated on.

Also to be clear I'm not being dismissive of what your company is working on, it's a very interesting and novel approach. It may even be necessary to achieve the optimal product. I look forward to reading about your results when you publish them. I'm just presenting alternatives and a brief overview of what other approaches are for HN readers who are likely unfamiliar with the topic being discussed.

1. Time in severe hypoglycemia - ideally 0%

2. Time in severe hyperglycemia/diabetic ketoacidosis - ideally 0%

3. Time in euglycemia (also called time in target) - clinical target is >70% and for reference the median healthy non-diabetic is in target ~90-95% of the time.

Closed loop systems are very good at #1 and #2 as it takes a while for levels to get to the severe state and insulin can be administered (or withheld) based on CGM.

When we talk about algorithming out of meal announcements it's whether historical patient-specific blood glucose levels and insulin administrations (i.e. a prediction of what you eat and when) combined with CGM can keep #3 acceptable, not necessarily optimal. Medtronic is using this approach and their newest model more or less eliminates the need for accurate carb-counting but they still require meal announcements. The hope/idea is that this can potentially be eliminated in further iterations.

Another important thing to keep in mind which is sometimes lost in these discussions is that we don't treat numbers we treat patients (i.e. what are the clinical outcomes). Generally speaking, we assume the closer to normal the better but we don't have actual data about how much an extra X% outside of target ranges matters in terms of clinical outcomes and complication rates. We only really started getting this data with CGM and complications in these mild states would require very large cohorts and long (10-20 year) follow-ups to detect differences as they're likely to also be mild.

So while you're absolutely correct regarding the limitations and that an algorithm cannot outperform accurate carb-counting and meal announcements the missing piece is that it may be sufficient. Particularly if said algorithms result in improved time-in-target for patients who aren't good at managing their diabetes and find meal announcements cumbersome.

That's good news, right? That means that everything that people now come up with has well-documented prior art?

If you have a kid in their teens or 20's who is not entirely ignoring it out of spite, you're way ahead of the game. This problem is much harder to solve than tracking carbs and insulin doses, or changing diet/etc.

The person has to be ready to attack it. And for many young folks (and I assume older as well) this is where the problem lies. It takes a lot to really accept this is going to be your entire life, especially at an age where everyone (seemingly) around you are living these amazing care-free young adult lives, while you have this constant monkey on your back being a buzzkill. Very few individuals have the desire to "do their research" and start hacking on their health the way the HN community would tend to approach things.

Short of commenting on how heartbreaking it is as a parent to watch your kid go through this, I really have no good answers. I guess the topic of this discussion is it - a magic device you can slap on once a week and never think about again. Short of a device like that, I can't see this problem turning to technical vs. human any time soon.

One thing about these pumps that doesn't seem to be advertised widely enough: they don't handle full sun well, so always keep at least one layer of clothing over the pump.

She has a samsung s-20 phone, previously we had a pixel 3 which bricked itself on Christmas Eve. I had a LG G7 which we tried to use, but although this is claimed to be compatible it turned out not to work. So we had injections over Christmas which was not great, but when the new phone turned up on 27th all was well again. Google replaced the Pixel, so I now have the replacement handset and it is ready to go as a fail over.

The current external artificial pancreas solutions operate subcutaneously, and your pancreas gets to work more directly with your blood. Subcutaneous blood sugar readings lag about 20 minutes compared to actual blood (finger pricks), and subcutaneous insulin delivery lags behind a healthy pancreas by even longer.

What I love about this story is that the DIY community managed to break the log-jam of the manufacturers and the regulatory authorities by simply providing them with proof that it can work and can work reliably enough to be allowed on the market. That shortcut probably shaved at least a decade (possibly more) off the progress charts. Manufacturers were (to some degree rightly so) antsy about closed loop systems because it would require them to assume much more liability than they are normally used to, the symptom->diagnosis->action loop that you can engage in by close monitoring and patching together available systems cuts the human out of the loop: the system will function autonomously and a software error or hardware glitch has the potential to kill someone.

So the manufacturers were effectively all waiting on each other to show that this can be done safely and that holding pattern had already lasted for multiple years. In the meantime, the larger manufacturers had some time to gain the upper hand over reliability and teething problems of the newer generation of pumps and those came together just in time with continuous monitoring to enable a big step forward in a very hacked (but fully functional) way. No single manufacturer would have taken that risk at this point in time without that push. But now that it is done they can't be left behind either or they'll lose market share rapidly.

It's a pity that there are not more diseases (at least, not that I'm aware of) that would benefit from this approach, diabetes is unique in that respect.

Best of luck there. By the way: if you want to stay current with the developments in this field the best spot to look for is the announcement of trials, and sometimes the calls for volunteers for such trials.