Negative Corrections

I have one thing that I am not pleased with when it comes to the T:slim. I think that it is everybody's complaint.  The T:slim does not do negative corrections or backwards corrections.  If you have no idea what that is I will try to explain it but first I am going to have to explain about carbs and our equation that we use to dose Rose.

We have all heard of carbohydrates before but learning to recognize what foods have carbs and which ones don't are essential for T1D's.  Luckily there are some really cool apps out there that you can search for specific foods.  I can't imagine trying to memorize all of the foods and their carb amount.   We also read a ton of labels.  On all of your food that you buy from the store they list how many carbohydrates there are per serving.  Here is an example of a label and where to find carbs.

http://lowcarbdiets.about.com/od/nutrition/ss/nutritionlabels_5.htm

In this food label there are 15 g of carbohydrates in every 20g serving.  When we were first diagnosed I was just guessing how big a serving size it but you never knew for sure.  So I bought myself a scale and I love it.  I no longer have to count our every carrot or piece of cereal because I just put it on a scale. Here is one that is similar to mine. Two things to consider buying a scale is to make sure you can zero out the amount when adding new food to plate and also comes with ounces and grams.

http://www.sears.com/ozeri-pronto-digital-multifunction-kitchen-and-food-scale/p-00824520000P?prdNo=3&blockNo=3&blockType=G3

Okay so now that you know a little bit more about carbs and how to find them here is Rose's equation that we use to calculate out her insulin dosage. 

First we have to calculate if there is a correction dosage.  

(Blood Glucose- Target Blood Glucose) / Insulin Sensitivity Factor

For Rose her equation looks like this...

(BG-150)/200

Once we have figured out her correction dosage than we need to figure out how much insulin she will need to eat her food. Rose's ration right now is 1 unit of insulin for every 60 carbs.  For example a piece of bread has 15 g of carbohydrates.  Rose would need 0.25 units if she ate that piece of bread. 

Last part of figuring out Rose's insulin dosage is adding up the two above answers to the equations.  This is how we lived for almost four months until we got the pump.  The pump does all of our calculations for us and then it doses her too.  So cool.  

Remember how I said that T-slim doesn't do negative corrections or backwards corrections.  When we are trying to figure out Rose's correction dosage is doesn't account for Rose being lower than her target BG.  For example...  If I tested her blood and she was at 100.  

100-150= -50  

 -50/200= -0.25 

For her food she is having a piece of pizza. One piece of Cheese pizza is 27g.  

27/60= 0.45 units of insulin for pizza

Rose should only need what ever the correction plus the food insulin to eat pizza.  

Which is 0.45 - 0.25= 0.20 units of insulin.  The T-slim would not calculate the negative amount of insulin so the T-slim would say that she still needed 0.45 units for the pizza. 

Sorry that is a ton of numbers but I hope it helps you better understand what we do every time we eat.  For a while I hated eating and I still hate meal times.  Not only do I have to cook and serve dinner but I also have 2-3 minutes of calculating insulin dosages.  The pump has made it a lot easier but we still have to make sure the pump is calculating properly. 

I hope you have a wonderful Thanksgiving.  We have so much to be thankful for and we are so blessed.