These are chat archives for nightscout/intend-to-bolus

13th
Mar 2015
Toby Canning
@TC2013
Mar 13 2015 02:00
Does anyone have a definitive answer as to the small unit of measurement a 522/722 will delivery in a 5 minute period via temp basal?
The commands have to be given in ,05U increments, but I don't think that means you can divide by 12 and round to the nearest .05 increment.
I'm pretty sure based on the links Monica posted earlier that there are 20 equal deliveries (1 every 3 minutes).
I'm trying to figure out if I should round to the nearest tenth or hundredth for estimating the delivery over a 5 minute period.
diabeticgonewild
@diabeticgonewild
Mar 13 2015 11:20
So do 15 minute temp basals
(15 min/(3 Dexcom readings)*(5 pump deliveries))
Hovorka either uses 12 or 15 minute basal deliveries depending on the trial
I would round to the nearest hundreth, to the closest value in the hundreths place, for example, either 0.10 or 0.05
Or for example 0.15 or 0.20
diabeticgonewild
@diabeticgonewild
Mar 13 2015 11:37

My class opened up. (And yes, I love engineering classes...especially cheat sheets! And getting to store things in my calculator which has an SD card...I have an HP 50G)

Both exams are closed book and closed notes. For each exam, you may use one 8.5"x11" cheat sheet (front and back, typed or hand-written), ten pages of blank scratch paper, a hand-held or computer built-in calculator during the exam. Up to three restroom breaks are allowed. You will write all your answers on the scratch paper, scan your answers as a single multi-page PDF file and upload to Blackboard. The submitted exam must meet the same requirements as the homework submission (see the homework submission requirements above under "Homework Assignments").

Bill McBain
@mcbill
Mar 13 2015 15:57

@TC2013 Here is how minimed 722 and 522 pumps make basal deliveries...... Any amount over .25/hr would be delivered as a second click on the hour and it'd waterfall with the =MOD remainder following this chart. This is super Important as we talk about changing temp basals more frequently than every 15-30 minutes for folks who have low basals because true insulin-on-board in our calculations may not be what we think it is.

.05 1 dose -- on the hour
.10 2 doses -- on the hour, :30
.15 3 doses -- on the hour, :20, :40
.20 4 doses -- on the hour, :15, :30, :45
.25 5 doses -- on the hour, :12, :24, :36, :48

Scott Leibrand
@scottleibrand
Mar 13 2015 18:01
@mcbill what happens when you get up to 1U/hr? Does it administer 20 doses, one every 3 minutes?
Matthias Granberry
@mgranberry
Mar 13 2015 18:54
I think he's saying that it would deliver 4 0.05u clicks at 0, 12, 24, 36, and 48
Bill McBain
@mcbill
Mar 13 2015 18:54
Yeah
I'm creating a chart .05 to 5u right now.
What I don't know is how temp basals deliver though. (like if you had lower basal rate for first 24 minutes of hour and at :25 put it up hihger would and then increase it would the the delivery at :36 even those those extra clicks would have normally happened at :12 and :24
Wish we could pick brain of an old minimed software engineer... Any on here... or LinkedIn
Bill McBain
@mcbill
Mar 13 2015 19:06
I believe this chart shows how basals get delivered under normal circumstances. Each click you hear is .05 u of insulin. Not sure how temporary basals change how the spread of clicks are programmed. https://app.box.com/shared/static/3gjb7sm0s88sz2ckug8aakewtudcrdtf.xlsx
Bill McBain
@mcbill
Mar 13 2015 19:13
The older mm pumps (like 508) had .1u clicks and would deliver every 10 minutes and so if you had a low basal rate like .2u per hour you'd get a click at :00 and one at :10 and then nothing for another 50 minutes and under warmer conditions this lead to humolog crystallization for many folks. It was a big issue 10-14 years ago when I was a diabetes camp counselor.
Bill McBain
@mcbill
Mar 13 2015 19:35
For insulin on board are folks looking at ((basal insulin onboard + bolused insulin)-basal insulin needed for current time)? For now I'm ignoring basal entirely and just using a bell curve that starts 20 minutes post bolus and ends 180 minutes after bolus. It then looks at stacked multiple boluses (so usually I've got tail end of breakfast bolus still active when evaluating lunch insulin needs.) I know the impacts anecdotally, but is there any clinical published research or generally accepted books that dictate how I should be shifting these curves and carb decay for high fat and protein meals?
Toby Canning
@TC2013
Mar 13 2015 19:35
@mcbill Very helpful, thank you!
Bill McBain
@mcbill
Mar 13 2015 21:22
I don't have a minimed usb stick yet. Can anyone who has one confirm if the mmcommander or decoding-carelink snippets can pull insulin delivery history on a granular enough level to see the specific times at which basal insulin are given within a particular hour
Ben West
@bewest
Mar 13 2015 21:22
depends on model
not the stick
the pump models have different firmware that choose different verbosity on that feature
starting with X23 series, the pump history logs include scheduled basal rate changes
before X23 series, only unscheduled changes (eg temp rates) are logged, you can use that along with the schedule of rates itself to determine what happened
Scott Leibrand
@scottleibrand
Mar 13 2015 21:39
I don't think that's what he's asking. the question is, does anything the pump reports indicate exactly when each microbolus was delivered to effectuate the scheduled temp basal?
Matthias Granberry
@mgranberry
Mar 13 2015 21:44
I can tell you that the t:slim reports all deliveries of IOB as both a discrete dose and an update to the daily total (along with the current IOB displayed), but their design seems to be patient-focused vs. litigation-related. I just wish the BT interface was enabled on the things.
Ben West
@bewest
Mar 13 2015 21:45
ah, like many things it's possible, but we have no way to know how
I mean, it's possible to reconfigure the pump in trace mode to get all kinds of minutia out about motor/strokes and stuff apparently