6.1.2. Extended bolus

The extended bolus is supported by insulin pumps and it is a bolus amount applied constantly over a specified time period. For MDI treatment, Diabetes:M Bolus Advisor splits the proposed extended bolus and it can be used even when users are on MDI therapy.

The algorithm which Diabetes:M uses is explained in details in the article
Bolus Calculator with Nutrition Database Software, a New Concept of Prandial Insulin Programming for Pump Users
by Ewa Pańkowska M.D., Ph.D., Marlena Błazik, M.D.
https://journals.sagepub.com/doi/10.1177/193229681000400310

According the rules published in the article Diabetes:M performs the following calculations:

CU = carbohydrates / 10
FPU = (proteins * 4 + fats * 9) / 100
IRFactor = 10 / I:C

IF CU + FPU = 0 THEN
     → CUperc = 0

IF CU + FPU > 0 THEN
     → CUperc = CU / (CU + FPU)

CU_FPU_correction = NBSBCorrection / 100

bolusNormal = 0.0
IF CU_perc >= 0.2 AND CU_perc <= 0.8 THEN
     → bolusNormal = CU * IRFactor * (1 - CU_FPU_correction)

IF CU_perc > 0.8 THEN
     → bolusNormal = CU * IRFactor

bolusExtended = 0.0
IF FPU >= 1 AND CU_perc < 0.2 THEN
     → bolusExtended = FPU * IRFactor

IF FPU >= 1 AND CU_perc >= 0.2 AND CU_perc <= 0.8 THEN
     → bolusExtended = FPU * IRFactor * (1 + CU_FPU_correction)

IF FPU<1 THEN
     → duration = 0

IF CU_perc > 0.8 THEN
     → duration = 0 hours

IF FPU >= 1 AND FPU < 2 THEN
     → duration = 3 hours

IF FPU >= 2 AND FPU < 3 THEN
     → duration = 4 hours

IF FPU >= 3 AND FPU < 4 THEN
     → duration = 5 hours

IF FPU >= 4 THEN
     → duration = 8 hours

The final calculation

bolusStandard = bolusNormal + correction + exerciseBolusAdjustment + sicknessBolusAdjustment

bolusStandard must be applied immediately
bolusExtended must be applied over duration hours.

total bolus = bolusStandard + bolusExtended