Friday, July 22, 2011

My Thoughts on Closing the Loop

"Closed Loop System"

When I have idle time at work I use it to review any and all information related to Diabetes. Yesterday I stumbled across a site called and was scrolling through the numerous summaries regarding new research, nutrition etc...

I reviewed the topic related to closing the loop, since a cure is too distant at the moment, perhaps the focus should be on designing a complex computer feedback system whereby a Continuous Glucose Sensor communicates with a microscopic mega computer that in turn uses fancy algorithms to communicate with the pump telling it what to do.  Sounds pretty cool, except for a couple of things...

My issue and the researchers mainly in Europe feel the challenge is how the computer program will account for things like, spontaneous activity, stress, and the human bodies biochemistry, aka "Diabetic Curve Balls" that get thrown our way on a daily diabetic basis. I have to say I can't see the system being too successful, just my humble opinion.

I know, I am a natural sceptic.

I think they need to focus on insulin analogues that respond to micro changes in blood glucose, like a non-diabetics where the minute the body senses a micro increase the beta cells send out the first responders. Now I am not a biochemist, nor really that smart, I get by, but this just seems logical   Don't know if its possible and I am sure they are working on it.

When I reflect on such things, I can't help to marvel at how truly amazing the human body is designed, how complex our inner workings really are.

What do you all think about this?




Kathy said...

I had and islet cell transplant 3 years ago. I had 2 years of being insulin free and now take a small dose of insulin. I feel wonderful and don't have to worry about lows. My body just feels right.

When I compare what the artificial pancreas can accomplish at its very best to what I have and the way I feel, It is like comparing Pinocchio to a real boy.

Reyna said...

"Smart Insulin" would be wonderful. Anything that makes managing diabetes less rigorous would make this D' Mama extremely happy.

Good to read your blog again Trev!

Sarah said...

I agree with you Trev, my husband does, too...the thing for me is it's just more mechanical tools. As we've used the CGM more and see how inaccurate it can be I know that they will have to do A LOT more work for it to truly work well all the time. I am flabbergasted though that some believe it's a "Cure" what could is curing about pump site changes every two-three days? What is curing about still having a CGM site? These are just tools, not a cure at all. IMHO :) Now smart insulin that's something more hopeful to my husband and I!

Jonah said...

I have a number of issues with the concept of an artificial pancreas- the limitations of current glucose sensing technologies, the limitations in current absorption from insulin pumps (not to mention site failures), my own adhesive allergies, and cost.

But I still think there's a large potential for it to help- to reduce extreme lows and to help to curb highs, to help us (or our doctors) to determine correct basal rates and I:Cs.

And who knows? Maybe, with next decade's sensors and next decade's insulins and a different sort of insulin infusion system, it could work better.

Anonymous said...

There are "puck" like pumps that have been put into the bodies of Type 1 individuals that are no longer available in the US that interest me the most right now. The people who still have them (at their own very high cost) get insulin (special insulin) refills every few months in Europe somewhere. They have said they wouldn't trade it for the world. The insulin is internally dispersed so it works WAY faster. From what I've read over the last year or so, we are way out from the commercially available closed loop system and insulin action is actually a large part of the issue. The CGM accuracy is obviously way off the mark, but I think they could improve on that with out a lot of effort already...$$$ and testing is just not worth it to anyone yet. Why improve when everyone is scrambling and pushing to have the current device? Our Dexcom system will make me crazy quite often, but damn if I would give it up! Faster insulin would make things so much more predicatable...and personally I'd like a new system or delivery of glucagon for lows. This juice, cookie, tabs thing seems a bit silly in this age of accuracy. A cure of course, but I won't turn down new gadgets either!

Natalie said...

I think it's a lovely idea in theory. But there are a couple of obstacles to be overcome first.

I think the most important one right now is glucose sensor lag time and inaccuracy. The sensor would have to be real-time and accurate before I would trust it to determine what amount of insulin I should have. An internally implanted sensor that measured blood glucose instead of interstitial fluid may be a possibility, but it isn't here yet. And it would need a reliable algorithm to determine how much insulin to give. I don't think the algorithms are good enough yet.

The second obstacle is not having a stable glucagon solution available. If you're low, you need the glucagon to bring you up, and the sensor/pump system would need a reliable algorithm for how much glucagon you would need.

But once these problems are solved, I think it's a real possibility. It doesn't matter whether your BG is high because of food or stress or illness -- the artificial pancreas would give you the appropriate amount of insulin to bring you down. And if you were low, you'd get the appropriate amount of glucagon to bring you up. It would be like the basal of the pump -- a continuous feedback mechanism that was working continuously. I don't think it's coming all that soon, but if they eventually DID come up with a reliable one, it would really help, especially with tiny children who can't describe symptoms!