Just Another Cyborg Day

Throughout the month of September, Tim Maly of Quiet Babylon has been posting cyborg-themed articles to honor the 50^th anniversary of the first use of the term. I’m reading them with a fair bit of interest: ever since I got my own machine part, I’ve been asking people what they think about the future of cybernetics. One thing I’ve learned – most people think cyborg parts will make you a better ass-kicking machine.

I don’t buy it. I’ve talked to folks who think that someday people will voluntarily chop off their legs to replace them with better, stronger, computer-driven mechanical appendages. None of them can really answer my question: Why should they? Yes, some people do things just ‘because it's cool.’ But if they really want to run 70 miles per hour, they could forgo the surgery and just buy a motorcycle.

I’ve also talked to people – let’s call them cyborg purists – who think that if there’s no feedback loop, it’s not a cyborg. To these people devices like my insulin pump, no matter how high tech, aren’t real cyborg parts because they can’t sense changes in their environment and respond appropriately. But a lot of prosthetics don’t need active feedback systems – some of the newest artificial legs work by passively storing and rereleasing elastic energy at each step. And machines can improve: last year I “upgraded” my pump system by adding a continuous glucose monitor (CGM). The two machines don’t talk to each other – they’re not even made by the same company, but the CGM gives me a constant stream of blood sugar readings, and I can use the data to make more informed decisions about what my insulin pump is doing. In short, it’s a feedback system, which I guess makes me even more cyborgy now. But it still requires a lot of attention.

“Yeah, sure” you say. “How much work could that possibly be?” Let me show you, as I go through

ONE CYBORG DAY

MIDNIGHT: I fold the last pile of laundry and (finally) get into bed. I plug in my CGM receiver to recharge overnight – it reads 135 mg/dl: a little higher than normal for a non-diabetic, but still in my target range. It’s safe to sleep.

4:30 AM: My turn to get up in the middle of the night to walk the puppy. I check the CGM before I stagger downstairs – it’s reading 132 and the trend line is flat, which means I’ve been pretty stable while sleeping. That’s good news: one bad dream can send my blood sugar raging toward maple syrup territory.

6:00 AM: The alarm goes off. I hit the snooze button in my sleep. Twice.

6:20 AM: I actually wake up. Husband is already up making school lunches and breakfast for the family, so I check the CGM against a blood drop measurement. CGM: 117, Glucose meter: 138. I enter the blood drop reading into the CGM to correct the drift. While I’m at it, I also bolus 3.55 units of insulin for breakfast: soft boiled eggs with toast and a glass of milk (29 grams of carbohydrate). The insulin takes about 15 minutes to become active, so I have time to shower and dress before I eat.

6:45 AM: The CGM is buzzing – it wants to be calibrated again. Another blood drop goes into the glucose meter. This time, it’s 126: clearly, the breakfast insulin is starting its job. I plug numbers into the CGM and hurry down to eat.

7:20 AM:  Morning chaos: one kid is running for the high school bus, the other is looking for socks before the elementary school bus arrives, I’m throwing together my papers for work, fielding questions, and feeding the puppy. I’m so busy I forget to drink my glass of milk until the CGM buzzes its “LOW -- 70” alarm at me. My blood sugar has dropped to 70 mg/dl. I drink my milk like a good cyborg.

7:45 to 9:15 AM: My blood sugars start to rise as my breakfast makes its way through my digestive system and into my bloodstream. The CGM reads 82 with an upward arrow when I pull out of my driveway, 105 when I walk into my office, and slowly creeps up to 120 as I read journal articles over the course of the next hour.  I decide it’s safe to start some fine-motor laboratory work.

10:45 AM: After an hour and a half of mounting thin sections of brain onto slides, the CGM buzzes, letting me know that my blood glucose has slowly slid back down to 70 mg/dl. By the time I clean up, wash my hands, and eat one Twix bar (15 grams of carbohydrate), the CGM is reading 63.

11:30 AM: I’m giving a talk at lab meeting today. Feeling a little nervous. But it’ll be OK. My CGM now reads 105 and looks stable.

12:15 PM: Talk’s over. CGM says my blood glucose is 136 and rising. Was it the candy bar, or the adrenaline? Either way, I’ll try to correct it at lunch.

12:30 PM: After 6 years, the mealtime drill is automatic. Wash hands. Set up glucose meter. Prick finger. Feed blood drop into machine. Read result (135). Count carbohydrates in lunch (salad and a tuna sandwich made with homemade sourdough bread, about 40 grams). Plug value into insulin pump and let it calculate bolus (4.85 u). Press “Accept,” then eat.

1:15 PM: I’m back in the lab, but this time the CGM says my blood sugar is 174 and rising fast. Maybe I underestimated how carby my bread was? Or is the adrenaline from my talk still hanging around in my bloodstream? I pull out the glucose meter for another check – the blood drop reads 213 mg/dl, definitely too high. I tell the pump to inject 2 units of insulin to drop it back down to normal.

2:15 to 3:15 PM: After an hour of hovering around 200 mg/dl (OK, definitely the adrenaline), the line on the CGM display starts to fall. Slowly at first, then fast: I’m at 100 mg/dl when I leave work for a doctor’s appointment, 83 mg/dl when I get there at 2:40 PM, and the CGM is buzzing its LOW-70 warning as I get back in my car. I eat the other Twix bar.

4:30 PM: I held steady at about 105 mg/dl for a while, but now my CGM is blaring. Not its relatively sedate “LOW-70” warning, but the loud, insistent beeps of the “LOW-55” alarm. Naturally, I’m not at home -- I’m at the violin shop with my daughter, renting a viola. (Why does this always happen in public?) I eat four peanut butter crackers (16 grams carbohydrate) and sit down. Fifteen minutes later, my CGM is displaying an upward arrow and I feel a lot better.

6:00 PM: Dinnertime! Blood drop reading at 115 mg/dl matches the CGM. I plug numbers into machines to calibrate, then bolus for husband-made chicken cacciatore with egg noodles and steamed broccoli (22 grams of carbohydrates).

8:30 PM: The CGM readings rose to 120 after dinner then fell to 80 mg/dl. I have a small dish of ice milk with the rest of my family to prop it up. It heads back up to 118.

11:30 PM: Another slow fall, this time to 72 mg/dl. I eat two peanut butter crackers to stave off the CGM alarm in the night and head to bed.

And so on, and so on, ad infinitum, probably for the rest of my life. I’m grateful for the technology - it really does make managing my condition easier and helps push back the day when I’ll have to deal with long-term complications like blindness and neuropathy. But I can’t figure out why so many people think that a machine part would be an improvement over the finely-tuned biological systems that they already have – which let them go about their business each day, without a moment’s thought.

Comments

[Dave*]

Thank you for that window into your life, Cyborg Woman. It was very interesting.

[Bernard Farrell]

Has this had much of an effect on your A1C value? Mine dropped dramatically the first six months on a CGM, after that it's a struggle (mostly because of me) to keep it at a 'reasonable' level of between 6.5 and 7.0. At least that's what I think is a good level.

[DianeAKelly]

Bernard, I've had a big improvement in A1C values with the CGM: mine dropped from the low 7's to the low 6's during the first 6 months I used it. (I'm not trying to push them any lower because I don't want to spend all my time skating over hypoglycemia.)

Personally, I think there are two really good things about the device. First, its alarms: before the CGM, I wouldn't find out that my blood sugar was too high or too low until I did a blood stick -- and I'd have no idea now long I'd been there. The alarms at least give me fair warning that something is going wrong. Second, the constant stream of trend data that the CGM displays is really helpful. It's helped me tweak my basal rates to maximum effectiveness, and I've also learned to recognize the long slow rise that comes with an occluding pump. Again, if I have a way to know that something is going wrong, I have the ability to do something about it before it gets worse.