Thursday, June 11, 2015

How Diabetes is Like Mission Control: Dynamic Ops

Ok, I know some of you hear "ISS Pilot" and picture me sitting in Mission Control with a joystick and a heads up display. Sorry to ruin your amazingly creative imagination, but it turns out the ISS usually flies itself. So...what do I do while sitting there watching ISS trace over Earth every 90 minutes?

I plan.

Let me explain.

In NASA terms there are two distinct phases of ISS flight: quiescent ops and dynamic ops. Those are big fancy words which essentially translate into "ISS is flying itself" and "ISS is changing how it's flying". As an ADCO Operator, I sit console during mostly quiescent periods. But its us "quiescent" folks that really dig into planning for the dynamic ops. We verify that every detail of the plan is ready for the specialist to execute, including talking to our Russian counterparts, verifying the correct procedures are linked, and double checking all of the analysis.

It turns out a life with Type 1 Diabetes has a similar scheme, except I'm less of an "Operator" and more of a "Specialist". While a dynamic operation for the space station may be something like a vehicle docking or spacewalk, for Type 1 Diabetics something as mundane as eating food without a nutrition label can quickly become a dynamic op. Trivial activities, like exercise or travel, take hours, days, or months to plan...and sometimes even longer to perfect. You see, our personal equations for how our body reacts to food and insulin only cover a normal, or "quiescent" day - a day when all ingested carbohydrates are known and the body is functioning at a steady metabolic rate and hormones are level and everything is unicorns and rainbows. Unfortunately, life is a tiny bit more unpredictable.

For me personally, it takes about 6 hours to plan for a workout session. Since I usually workout in the evening, I have to be overly conscious of what I eat at lunch to ensure there are some fats to slow down the carbs. Then I usually eat a small snack at about 4 pm, followed by a temporary basal rate that decreases the amount of insulin my pump delivers during my workout. All of this leg work is just the prep - before, during and after the workout I am vigilantly monitoring my Continuous Glucose Monitor graph and making adjusts or slowing the workout if the numbers don't match my predictions. But, just like spaceflight, sometimes Diabetes throws in a curve ball.

Here's what happened when I thought I was all set up for a mid-morning workout:


I don't have the luxury of running complex analysis before each dynamic Diabetes op, so I suffice with a more rudimentary approach - [educated] guess and check. Luckily NASA doesn't have to rely on this method very often; there are a lot of smart people, models and history to more accurately predict the outcome during space station dynamic ops [thank goodness :-].

The post-dynamic op period is essentially identical between NASA and my Diabetes management. At NASA we are constantly self-evaluating to improve our flight controller skills, planning tools, procedures, processes, etc. to ensure the next iteration of the event flows even smoother. Diabetes is the same. I take data from each dynamic op (for instance, a mid-morning workout) and determine what I could have done to improve the experience. From my picture it's clear I should have decreased the amount of insulin I was receiving, or ate more carbohydrates for breakfast, or picked a slower-paced workout. Luckily I was prepared for the "next-worse-failure" (another NASA term) by having glucose tablets handy to bring my blood sugar back into range. Looks like I need to increase my model's history for this dynamic op!

Of course my console shifts are not entirely just planning. I'm also there to monitor the system and react to any anomalies (hence the abundance of sims laced with failures leading up to certification), but the same applies to Diabetes. As much as I plan and adjust and replan and correct there will always be anomalies. Maybe the insulin in my pump got hot in the sun and lost effectiveness, maybe the 5k turns into a 10k by the time I get back to my car, maybe there is a stressful life event that affects my blood sugar, maybe my SWAG (scientific-wild-ass-guess) on the carbs in that pie was way off.

It's important to keep one's skills "sharp" (that's a needle pun) both in managing Type 1 Diabetes and controlling the International Space Station - in either case suddenly and unexpectedly one may find themselves in a role where their performance has ultimate consequences.