Inside Meat Bag’s Pump – Every Setting, Every Strategy
Welcome to the trenches of insulin pump therapy. You’re here because you’ve either just strapped on a t:slim X2 with Control-IQ or you’re about to. Good. This isn’t just a device—it’s your artificial pancreas-in-training, a tiny, programmable lifeline clipped to your belt. But let’s be clear: the pump doesn’t think for you. It executes your orders. And to give good orders, you need tactical understanding. Today’s Field Journal is your guide to programming like a master strategist.
📊 SYSTEM SNAPSHOT: What’s in the Pump?
The t:slim X2 with Control-IQ is not just pushing insulin—it’s calculating, adapting, and correcting based on a constant stream of CGM data. Here’s what you’re configuring behind the scenes:
Basal rates (per hour)
Insulin-to-Carb ratios (ICR)
Correction Factors (ISF)
Target glucose settings
Active insulin time (duration of insulin action)
Temporary activity states: Sleep & Exercise
Control-IQ automated features (predictive correction boluses, basal adjustments)
And yes, every beep, buzz, and reminder is deliberate. We’ll get there.
🌙 BASAL RATES: The Backbone of Insulin Strategy
Your basal rate is your background insulin—it’s what keeps you steady when you’re not eating. On injections, this would be long-acting insulin. On a pump, it’s tiny microdoses of rapid-acting insulin every 5 minutes. That means you’re not locked into one flat dose anymore. Welcome to dynamic, programmable physiology.
Why Use Multiple Rates?
Because you’re not static. Hormones, cortisol, stress, and circadian rhythm all spike your insulin needs at different times. That’s why basal profiles are broken into time segments—often hourly. For example:
Time Basal Rate (U/hr) 12 AM - 3 AM 0.85 3 AM - 6 AM 1.05 6 AM - 10 AM 1.20 10 AM - 6 PM 0.95 6 PM - 10 PM 1.00 10 PM - 12 AM 0.90
This is not arbitrary—those early morning rises are your body’s natural dawn phenomenon. You don’t treat it with hope—you treat it with a programmed counterstrike.
🧪 BASAL TESTING: Know Thyself
Here’s how to basal test to ensure each segment is doing its job:
Fast for 4-6 hours (no food or bolus insulin).
Choose a time window to test (e.g., 3 PM–9 PM).
Ensure you’re starting between 90–120 mg/dL with no IOB (insulin on board).
Stay calm. No exercise, stress, or walking a dog who lunges at squirrels.
Track CGM or fingerstick data every 30 minutes.
Ideal Result? Flatline. No more than ±30 mg/dL over the test window.
Too much drop? Basal too high.
Too much rise? Basal too low.
Tweak the hourly rate for the time window by 0.05 to 0.10 U/hr increments. Re-test in a few days.
🍞 ICR (Insulin-to-Carb Ratio): Fuel Calibration
ICR determines how much insulin you get for your carbs. If your ICR is 1:10, you get 1 unit of insulin for every 10 grams of carbs you eat.
Setting the ICR
Morning ICRs are often tighter (e.g., 1:7) because you’re more insulin resistant.
Afternoon/evening ICRs may relax (e.g., 1:12 or 1:15).
How to Know If It’s Right?
Pre-bolus 15-20 min.
Eat a known-carb meal.
Check BG at 1hr, 2hr, and 4hr.
2hr target = back to baseline.
If BG spikes and lingers? ICR too weak.
If BG crashes? ICR too strong.
Adjust in 1-2g increments (e.g., 1:10 → 1:9 if too weak).
🎯 Correction Factor / ISF (Insulin Sensitivity Factor)
ISF tells the pump how much 1 unit of insulin will drop your BG. If your ISF is 1:40, 1 unit should drop you 40 mg/dL.
Morning ISF = weaker (1:30?)
Overnight ISF = stronger (1:50?)
Use Control-IQ’s correction bolus logs to assess. If you overcorrect or undercorrect consistently, adjust accordingly.
⏱ Active Insulin Time (Insulin Duration)
This setting affects stacking. If it’s set too short (e.g., 2 hours), the pump assumes old insulin is gone too early—and overcorrects.
Default: 5 hours
Realistic Range: 4.5–6 hours
Never set this below 3 hours. Your body isn’t that fast.
🧠 Control-IQ Automation
Here’s what Control-IQ does for you:
Predicts glucose 30 mins ahead using CGM.
Adjusts basal up if you're predicted to rise >160.
Delivers auto-correction bolus if predicted >180 (60% of calculated correction).
Reduces/stops basal if you're dropping toward 70.
Targets 112.5-160 by default.
Sleep Mode (enabled manually or by schedule):
Targets 112.5-120
No auto-corrections, but tighter basal tweaks
Exercise Mode:
Target range rises to 140–160
More aggressive basal reduction
Pro Tip: Don’t expect miracles. You still need to pre-bolus and log carbs.
🚨 ALARMS: Tactical Alerts
Low BG Alerts: Predicted drop to ≤70. Time to act—juice, tabs, pause.
High BG Alerts: Above 180. Usually means a missed bolus or site issue.
Cannula Fill Reminder: After site change, fill tubing and confirm.
Cartridge Expiry: Insulin degrades—don’t stretch past 7 days.
Battery: Charge daily. Power = survival.
🔄 Personal Profiles
Create profiles for:
Weekday vs. Weekend
Sick days
Menstrual cycle changes
Travel / Jet lag
Exercise-heavy days
Each profile can hold unique basal rates, ICRs, ISFs, and targets. Duplicate profiles, tweak a few parameters, and switch on the fly.
🔧 Final Adjustments: Tweak, Wait, Repeat
Never change more than one setting at a time unless you want chaos. After a change:
Monitor for 3–5 days.
Compare average TIR, postprandial spikes, and overnight graphs.
Don’t react to one bad day—watch the trend.
CLOSING THOUGHTS FROM THE FIELD
The pump is a tool, not a wizard. It acts on your settings, not your wishes. Precision insulin therapy means being part scientist, part detective, and part stubborn optimist.
So yes—learn your pump. But more importantly, learn your numbers. Your patterns. Your chaos.
This isn't plug-and-play—it’s program-and-respond.
Welcome to the frontlines.
