What T1D control has in common with Nuclear Reactors

For those of you that have read my first couple of post you understand what I am doing. I’m coping. My daughters 4th birthday is today and it is also the second week of us trying to control her T1D. I tend to relate difficult subjects to things I am familiar with in order to cope with them. So yes, I am relating T1D control to Nuclear Reactors (My wife calls me her Sheldon). You can start laughing now but just keep reading. In the end T1D control is way more complicated than nuclear physics.
A nuclear reactor is relatively simple. Hot rock (yes, Uranium pellets look like a rock) heats water, water turns to steam (directly or indirectly), steam turns turbines, turbines go roundy roundy, electricity is produced. To put it simply the reactor being critical is when the reactor is "turned on. " This simply means that the reactor is in a steady state. Think of this state as a BG of 100. Not too high, not too low, just right. For the reactor power to go up (supercritical) or go down (subcritical) it needs units of reactivity. Think of this as Insulin and Food. For reactor power to go up positive units of reactivity are introduced. This is often done by relatively cold water being introduced into the core (not like a bucket, more like drawing heat from the core). For a person this is done by ingesting food. When someone ingest food inherently and eventually their BG goes up. For reactor power to go down, negative units of reactivity are introduced. This can be done by stopping the cold water from getting into the core, or inserting control rods. Think of this as either letting a high BG ride and coast down or injecting insulin. The rate at which power goes up or down is determined by the amount of reactivity inserted. Larger amounts of positive reactivity spike power faster. This is very similar to drinking apple juice and getting your BG up immediately following a low. Or, you can eat carbs with fat and have a much slower but longer increase (Pizza).
The main point is that both reactivity and insulin are not instantaneous. If you eat a candy bar but don’t bolus till 10 minutes afterward the damage is already done. The rate at which your BG went up means it will spike early and continue to rise until the insulin can bring it down. This is called power turning in reactors or “chasing it” in T1D control. Most reactors used for power production are designed to be safe. That is to say the more heat you add to a reactor the more it wants to “shutdown”. This is the safety of the reactor. This is like having Lantus in your body. It’s there just in case everything else went wrong.

What have I learned in two weeks?

  1. Planning is crucial. Plan meals, count carbs, get in front.
  2. Sometimes WAG’s are as good as it gets.
  3. Nuclear physics is way less complicated than T1D control due to the human element.
  4. I’m a nerd and I will always take the nerdy approach to problem solving.
  5. I’m still just as Restless as day 1.

Happy Birthday Felicity!


You’re doing great. I have many analogies I’ve used over my 53 years with T1D. My favorite is riding a unicycle on a high wire. The balancing pole is food, insulin and exercise, the net is CGMS, which I started using in 2007, and they were not as accurate as they are today.

You are on the right path.


Your on the right track!

Long term, this is as much an art as a science. Watch the data and keep good written/computer records. You will develop experience that will help you put adequate ‘controls’ on the system.

Note: I do not think of this as a deterministic system. It is a more complex, multivariate system than they initially express to you. That understanding will come in time. For now, keep in the back of your head, that you are dealing with a more ‘meta-stable’ system. Its dynamic and noisy. There’s a lot to do with predictive statistics down the line…your gonna be a great “type 3,” which is what we call our type 1 allies. Welcome to our community!


It is the failure of diabetes to be perfectly analogous to mechanical processes which is the chief difficulty of managing the disease. For example, the fact that food spikes blood sugar quickly while insulin takes it down slowly will always make diabetes more difficult to control than nuclear reactors. Also, the range of factors operative in diabetes is always much larger and less predictable than what is going on in mechanistic processes. Since you can’t anticipate the effects of stress, circumambient temperature, and hormonal fluctuations on changes in the blood sugar level, it is always going to be unpredictable.

My strategy is to operate with super-control and super-stability for the things I can control, so I eat exactly the same measured amount of the same food at the same time every day of my life forever, and I have exactly the same activity level every day of my life forever. Despite that, the blood sugars fluctuate all over the place. For example, my pre-dinner blood sugar levels over the last eight days with a constant insulin, food, and exercise dosing were: (on a scale where 5.0 = normal): 5.3; 5.2; 10.3; 5.9; 5.5; 7.9; 6.2; 6.0. So what accounts for the 10.3 on one day and the 5.2 the day before? The answer is: absolutely nothing you can measure, anticipate, or calculate for!


This would be very difficult for me to do, and reduce my quality of life. However with tools we have today, (faster insulin, CGMS, pump, and newer “smart pumps”), very good control can still be obtained, as evidenced by the many success stories on sites like this.

In my earlier days of NPH and Regular MDI, I followed a more constant regimen as you described with similar results that were very unpredictable.

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Belated Happy Birthday Felicity… (from your elder diabetic uncles and aunts)

Complex analogy, not certain I comprehend its nuances “well”, but I grasp the imagery.

Please consider it is possible to make no mistakes, and yet still have situations occur. Do not be afraid. I offer fear is as dangerous (more?) than our illness itself.

Remember to laugh. Teach your daughter you are not afraid, and perhaps, she will not learn to fear so well?

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I have the same idea. This process is very similar to what Peter Checkland might call a “Messy Problem” It requires a holistic approach similar to a “Sytem of Systems” analysis.
Open or closed there are too many peturbations within the variables to give a simple A+B=C.
My real fear is where this is going. To view T1D control as a closed loop system is nuts. The predictive analysis of the algorithms is inherently a feed forward approach to problem solving. A large contingent in Systems Theory is that pure feed forward systems eventually degrade into a chaotic state. Even predictive models such as the Winter and Holt models utilize a combination of feedback and feedforward analysis to correct the system. I fear people think that a truly “Bionic Pancreas” or “Closed Loop” system is the answer to all of our problems. We need to understand the systemic problem as well as the elegant solution equally and I don’t think either is truly possible.

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Here’s some technical stuff, for fun, if your super hungry for it. Otherwise, it will be here waiting in a couple of years when you might actually need it.

People have a variety of opinions about closed loop and what may/may not be possible. I suppose anything is possible in the future, but I wont comment here…you can read about that all over the place. I have posted stuff thats worth being aware of. You will have to forge your own path. Your kiddo will, eventually, be the one running the show. Perhaps sooner than you might imagine.



I always like for new diabetics to know that $30 insulin is available, over the counter, no prescription needed, from Walmart. It is called R (short acting) and NPH ( long acting). In a pinch, it is there if you need it.

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There may be state requirement for RX, so check with local Wal-Mart.

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A few years ago Japanese researchers trying to develop a closed-loop insulin delivery system were forced to resort an exotic theory of mathematics developed by David Berlinsky and others to model the absurd way blood sugars bounce around. What Banting and Best developed was a drug to prevent diabetics from going into ketoacidosis, not a device to normalize blood sugars, and even when we add a complex delivery system to it, it is always going to be difficult to imitate physiological blood sugar levels.


Here is the study: the need to resort to chaos theory to cope with the complexities of blood glucose variability in diabetes speaks volumes:

Conf Proc IEEE Eng Med Biol Soc., 2004;1:750-3.

A blood glucose prediction system by chaos approach.

Katayama T, et al.

For suppressing the development of diabetes mellitus and the onset of complications, an insulin therapy has been used for suppressing and normalizing the change of a blood glucose. In a blood glucose control by linear method such as conventional ARMA, however, there exists problem that results in the frequency of hypoglycemia. In a blood glucose prediction by a chaos theory, there also exists problem that results in the lower accuracy on behalf of the impossibility in the long-time prediction. For the improvement in the prediction accuracy of the blood glucose that looks like complicated time series, we propose a system combining the deterministic chaos theory using equal time interval, local fuzzy reconstruction method, and minimal linear model. By local fuzzy reconstruction method, we can predict the fasting blood glucose in the short term and then we can estimate the appropriate amount of insulin shot based on the measured bedtime blood glucose. Using the system, the change of blood glucose can be suppressed and normalized and the number of the insulin dosage a day can be reduced to once. Here we report the high effective result of applying the system to type II diabetes mellitus patient.

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I’m an electrical engineer and can relate to your analysis. I can get an A1C of 5.8 or less, because I’m the one controlling the inputs and outputs. I can’t even imagine trying to do this with a child! I’m very happy my kids are not T1D. I have no problem dealing with this, but it would be very stressful trying to manage my kids! FYI, Solar is the future, not Nuclear!!

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Thanks for the encouragement. This platform is really nice for like minded individuals dealing with the same situations. I recommend SSRN. They have tons of new research on not only the medical endo side of the house but also the psychological side. A lot of it is from Type 2 but they have interesting articles.

Insert the great energy debate between a nuclear and electrical engineer. Solar panels versus a-neutronic fusion reactions using Deuterium and H3. It’s kinda like that tootsie pop commercial. “How many licks does it take? The world may never know.”

Hang in there, Restless Daddy! Your post shows us all that you have a good grasp of the basics of diabetes, and that understanding will go a long way in helping you help Felicity. That being said, also know that total control of all elements of this disease is totally impossible. A million little things can affect blood sugar and insulin interaction, and you cannot track, control, or even understand them all. Yet we all get by, and we all continue to try to live rich and fulfilling lives.

As a person who was diagnosed with this disease as a 12-year-old child, I will tell you that one of the best things you can do for Falicity is just to love her, encourage her, and do everything in your power NOT to make diabetes the focus of her life. She is a little girl with diabetes, not a diabetic who happens to be a little girl. Make her life rich and full with experiences and adventures while keeping track of the diabetes in the background. Don’t ignore it, but don’t make it the total focus of her young life.

Over the years, many of us have learned that the right insulin pump and a CGM are game changers. I am on the OmniPod, and I love the freedom that being tubeless gives me. I know that the OmniPod is great for children because there are no tubes to get tangled in anything; however, many other pumps work just as well. As a nerd, you have a great field to research. You know your child, her activities and dreams, her eating habits and lifestyle. Choose what you and your wife feel will be best for her.

Give her a birthday hug from all of us. My doctor told my mother when I was diagnosed that I could live to be 99 because I would take better care of myself than other kids. I think that was true. I have lived with diabetes for the last 52 years with no major complications. I grew up, got a bachelor’s and master’s degrees, married, raised two beautiful daughters, taught in a college for 30 years, retired, and now am enjoying my grandson. Felicity can grow up to do anything she wants to do, and diabetes does not have to ever stand in her way. Don’t stress, Daddy. Care for her, love her, and watch her grow. She will be incredible.


Are you a nuke?:stuck_out_tongue_closed_eyes: My husband was on a submarine for several years. You sound like on! Anyways, two weeks in?!?! If this is how you think you and your daughter will be just fine!!! Timing is everything and you are lightyeats ahead of where I was in your diabetes journey! It occasionally still throws me for a loop but once I figured out how to time meals and insulin I was in a much better place. Have you found the Juicebox podcast yet? It’s great stuff. You’d like it.

Yeah, I was a Nuke for 10 years. You can take the Nuke off the ship but you cant take the ship outta the Nuke. My wife still calls me her Sheldon. Much of the statistical insight came from graduate school. We are getting the hang of this and hopefully her DEXCOM will arrive in the next few days. Thanks for making me smile today.


How it going? Just checking in!

Also checking in with you. Has your Dexcom surprise pack arrived yet?

Please keep us updated :+1:t3:

Just got our Dexcom G-6 last night. When I put it on my daughter there was a lot more blood than I thought. Ive read mixed reviews about this. Thoughts?
Her number was off a bit after the warmup. We tested her at a 204 and the Dexcom had her at a 178. I calibrated it and she went to bed. Throughout the night she was consistently higher than the dexcom so about 0230 when she was about 20 points so off I calibrated it. Then her numbers were higher than the glucose strip. At 0500 I tested her and she was at a 119 but the Dexcom showed 133. After I rolled her over it corrected.
0705 Now she has eaten. We use almond milk if she gets cereal and she ate a protein bar. 37 Carbs 1 unit (40:1 ratio). At 0720 I can tell where the sugar hit and the insulin started flattening her out. I thought we were in the clear. Oh, Nay Nay. 0810 Then the carbs kicked in and she shot to 303 double up arrows and the thing is beeping at me every 5 minutes. I turned the reminder on to every 1 hour but it still keeps beeping at me. Ive raised her limit to 400 just to shut off the beeping. I know she’s high stop reminding me, I cant do anything right now because she still has her insulin from breakfast working.
Then the poop really hit the fan. We gave her .5 units at 0900 to bring her down. she was gently coasting down till she was 80 at 1100. My wife is much more worried about a low. I am more worried about highs. She texted me to ask what to do. I said to feed her lunch. She replied with what I thought was “do I give her a juicebox?” what she actually said was " I just gave her a juicebox." I told her to give a roll of Smarties instead of a Juicebox. She heard " give her a roll of Smarties" If your already laughing you know where this is going. She got lunch, Gogurt, Smarties, and a juice box with only 1.5 units to cover carbs. My daughter was in heaven. insert : rocketman by Elton John :. I came back to my phone an hour and a half later and she’s still at 324 and had peaked around 390. We gave an extra .5 units and will now discuss lessons learned. by “discuss” I mean I will profusely apologize for my miscommunication.
I really cant make this crap up. I’m only now to where I’m laughing at it.

On the plus side her numbers have equaled out now that she’s not laying on the thing.

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