AAPS Logarithmic Dynamic ISF
Visualize how Insulin Sensitivity Factor changes dynamically based on current blood glucose using the AndroidAPS logarithmic formula.
2.5
25.0
Total Daily Dose (Weighted Average)
Weighted TDD: 40.0 U
⅓
⅓
⅓ · last 8h × 3
1%
300%
30 min
120 min
Calculation
ISF = 1800 ÷ (40 × 1.00 × ln(144 ÷ 45 + 1))
ISF = 34.6 mg/dL/U ÷ 18 = 1.92 mmol/L/U
Dynamic ISF at current BG
1.92 mmol/L/U
(34.6 mg/dL/U)
Dynamic ISF Curve
About Dynamic ISF
- Formula: ISF = 1800 ÷ (TDDweighted × AdjustFactor × ln(BG_mg/dL ÷ Divisor + 1)). The logarithmic function makes ISF decrease as blood glucose rises.
- Weighted TDD: AAPS uses equal ⅓ weighting of three values: 7-day average TDD, yesterday's TDD, and last 8 hours of insulin use extrapolated to 24h (×3).
- Adjustment Factor: Scales the overall sensitivity. Values >100% make you more insulin resistant (lower ISF), values <100% make you more sensitive (higher ISF).
- Insulin Divisor: Insulin-type constant used in the logarithm. AAPS defaults: Lyumjev 75, Fiasp 65, Rapid-acting 55.
Disclaimer
This calculator is for educational purposes only. The Dynamic ISF formula is part of AndroidAPS and should only be adjusted under guidance of your healthcare provider or experienced looping community.