So anyways… There had been a bit of chatter on FU about how a few of us want a pump that calculates IOB based on both bolus and basal insulin.
I use xdrip+ to capture my CGM data and I use Nightscout for reporting (I use a Dexcom G5 transmitter, a Sony SW3 watch as the collector, and a Samsung Galaxy S5 phone). xdrip+ does a great job of tracking IOB for boluses and doing BG predictions based on carbs on board; however, it does not take into account either temporary basals or extended bolus - both of which I use. I recently started to use a lot more temp basals for putting the brakes on a downward trend that will end in a low (or at least end in glucose tab consumption) or to stop an upwards trend that will result in a high. xdrip+ also does not have an insulin curves for Fiasp, so since my switch to Fiasp, the prediction does not work as well.
I figured that the openAPS systems would calculate some sort of total IOB, so I installed AndroidAPS to see if if would give me the IOB information I was looking for. I picked Android APS because it runs directly on an Android phone, does not require a “rig” or extra hardware to run, and directly can get the CGM data from xdrip+. Pretty much install the software and play with it - my kind of easy (ok you do have to compile the APK but the instructions are pretty easy to follow on the GitHub site.).
Sure enough, AndroidAPS keeps track of IOB in an intelligent way. You can see in the picture below IOB is made up of a bolus IOB (including extended boluses) and a basal IOB. For example (1.98 bolus/ 0.05 basal) in the picture below. Basal can be positive or negative based on your standard basal profile. Estimated carbs on board (COB) are also tracked. OpenAPS also logs all the temp basals and extended bolus to Nightscout for record keeping. Android APS also has Fiasp curves that I can use.
The purple line to the right of the green BG line are the predictions of BG based on IOB and carbs on board. There are three predicted lines because the algorithm takes into account that carb absorption is not an exact science and uses three models of carb absorption speed to calculate
After having negative thoughts about positive and negative basals I realized that I actually like it. It helps understand how much you deviate from the normal and you know if you are going for a run or something that you want negative IOB of a certain amount at the start a run.
AndriodAPS runs the openAPS oref0 algorithm and was designed to control a Sooil Dana R pump. The algorithm issues both positive and negative temp basal rates to the pump control to the target BG. It can also work with a “Virtual Pump” with the user doing the “temp basals” when reminded. There is also an MDI option (it even has curves for long acting insulin).
After joining the AndroidAPS Facebook group, I noticed that some people were “open looping” with Omnipods. At first I thought - these folks are nuts. There is no way that I would manually enter basal rates on my Omnipod controller a million times a day but then I though - hey may as well give it a shot (no pun intended) - I will try for a couple of days to see if I can learn anything.
So I have been using it for a few days. Here are the messages that show up on my watch to change the temp basals. I then go in and tweak the basal rates on my Omnipod controller.
Here is a yesterday of data - with a couple of examples.
For Event #1 - I did not bolus correctly for a piece of pie covered with whipping cream. It was a wild guess. I knew temp basals were not going to do it, so I did a couple of boluses. I knew that I gave too much insulin, but there was a recommendation to turn off the basal. This lead to a pretty nice landing without going low.
For Event 2 - I really need to change my morning IC ratio as I gave too much insulin, but again, the recommendation to cut back on the insulin worked and I was at an ok place for lunch.
This is an ongoing experiment. Here are my feelings so far:
I love being able to look at the total IOB. Seeing the total IOB has made me realize that I probably need to tweak my basal rates in a few places of the day where I do not feel like doing basal testing. In the first couple of days I significantly changed my basals for the better - moved more insulin to basal from the bolus. It just gives a better view of what is going which helps me learn.
The openAPS algorithm is pretty cool. It was mentioned on another thread that there is a new oref1 algorithm that is better than the oref0 I have been playing with. It has been fun to try the openAPS algorithm out without having to buy any hardware. I just had to install some software on my phone.
I hate that the pod beeps every time I cancel a temp basal - this is annoying. Does anyone know if you can turn if off?
Open loop control is not optimal but it is ok to do for a short while. In a way it is like sugar surfing where you have to pay attention to the BGs throughout the day and make corrections. I do ignore the temp basal suggestions when I am in meetings etc. as I do not want to be fiddling with my phone. I also do not wake up to adjust basals, but will adjust them if/when I am awake. It still works ok if you ignore it but would likely be better if you did ever command.
When I sugar surf, I usually get impatient and go big with my correction boluses and often land with a glucose tab or two. I find that the AndroidAPS algorithm is more rational and does not overcorrect for me (yet).
So I have seen the future and I want to get this loop closed with the Omnipod. As you may know, people are looking into this but progress is slow.
As a final thought - you probably can think of a bunch of problems with this arrangement that I will probably agree with (examples: How does AndriodAPS know exactly how much basal was given during that temp basal? It does not communicate with the pump - or - Insulin absorbtion curves are not accurate… etc.). But I see it the other way - If I can get 90% of the way there it is still better than nothing