So took the plunge into building/using Android APS over the past few evenings when time has allowed and oh boy…. what a complex beast it is.
Don’t get me wrong now its built, installed and working with a virtual pump i could repeat the process in a quarter of the time and have a good understanding on what i’m doing and why. I’m sure the real fun part will be using it in a open loop with a physical pump and then fine tuning the settings and going into a fully closed loop
The major errors i had resolved around Nightscout integration, understanding calculations (ISF and Basal rates) another added fact is this was being all configured on a second phone as not to disrupt his existing phone used for his Dexcom readings.
Once the NS profile was setup correctly (plenty of orange warnings) and the AAPS setup was completed it has started recommending TBRs which when we have the pump i will start administering manually.
Insulin to carb ratio (I:C) [g]
Used existing carb ratios or 1u:20g as these seem to be working well and have been for the past few weeks. We do get the odd day where he is high/low but put these down to him having 29g of carbs and still being dosed for 1U, Its so hard to correctly dose when 0.5U is the only option available. Im sure this number will change to something more granular after being on the pump for a while
The Insulin Sensitivity Factor (ISF)
Again with only giving him 0.5u increments of insulin this is hard to work out correctly, following the guide here, he is approx having 10 units of Insulin a day (long and short) which calculates as 8.33 meaning every unit of insulin will drop his blood sugar around 8.33mg/dL
Basal rates [unit/hour]
William is currently on 3.5u of Lantus per day which as a per hour unit works out at 0.15~ rounded to 2 decimal places.