Starting Loop: Usage
How Exactly Do I Use My Loop App?
Once you’ve built Loop, added your pump, CGM, and Settings, you may wonder how to use the interface. High-level information about Pre-meal, Meals, Bolus, and Overrides is provided below. For information on other Loop operational aspects, such as Health App, Using ICE Info, Apple Watch, iPhone Widget, Loop Notifications, and Pump Battery, refer to the indicated Loopdocs page.
Before we get into details, heed this warning:
Do NOT allow any app (other than Loop) to write carbohydrate data to Apple Health
Loop writes and reads the carbohydrate levels to and from Apple Health. If another app writes this data, Loop will pick up that amount. If you then enter that value into Loop, you will have duplicate meal entries. Loop will respond by adding insulin in response to the incorrect carbohydrate information. This will impact the Loop BG projection and Loop will deliver more insulin than required.
This button can be used to tell Loop to begin to drive your BG toward a level that you would like to be at mealtime. It doesn’t replace pre-bolusing for food, but it can help you begin to move your BG in the right direction for up to an hour before meal time. You’ll select that desired pre-meal range in your Settings. When you want to use this feature, simply push the Pre-Meal button to start the process. If you have not entered a pre-meal range during set up, this button is inactive (it will appear as gray on your Loop toolbar). Some people prefer not to use the Pre-Meal function because tapping on pre-meal will cancel any overrides you may have set. If you think you might not want to use this feature, then never enter a value for it in the Settings menu. Once a range is entered, however, the only way to restore it to an inactive state would be to delete all your settings and start over. But keep in mind that you can set it up and then simply not use it.
It’s about an hour before dinner. What do I do?
This is the perfect time to press the Pre-Meal Icon on your Toolbar at the bottom of your Status Screen. It’s the one that is second from the left and looks like fork, knife and plate/timer.
The Pre-Meal Icon will adjust your target blood glucose (BG) to the number that you selected in your Loop Settings. Some Loopers forego this button and just pre-bolus 10-30 minutes before eating using the carb entry icon (Meals). Others don’t bother with pre-bolusing at all – the choice is yours.
To enter your Meals, press the Meal Icon in your Toolbar at the bottom of your Status Screen. It’s the one that on the left and looks like fork, knife and plate. This opens the Carb Entry Window.
The label says Add Carb Entry, but savvy Loopers also account for Protein and Fat.
Amount Consumed: Enter the effective grams of carbs to be consumed
Date: Choose the time that your food will be eaten (default is now)
If you want to pre-bolus, enter the carbs you plan to eat and advance the time to when you will eat themto get that insulin started. Loop will calculate how much insulin you can take now while keeping your BG above your suspend threshold.
Some loopers don’t modify the time. For carbohydrates, many Loopers leave meal time as the current time, while for slower absorbing food likes proteins and fats, you can scroll the dial to some future time period (typically one to two hours).
Food Type: You can use the Lollipop (2 hours), Taco (3 hours) or Pizza (4 hours) to help Loop characterize the type of food you are eating (and how long your body may take to absorb it), or you can select the far right Plate icon to reveal many different food items. You can either select the icon that best represents your item or you can select abc in the lower left corner to type a simple description of the food you’re eating. This is very helpful if multiple adults are helping to care for the person with diabetes.
Absorption Time: If you tap an icon, your Absorption Time will be pre-entered for you based upon the item that you selected; however you are always free to select your own Absorption Time, by scrolling the Absorption Time wheel. For example, the food icons suggest that chocolate will absorb in two hours, but you know from your own experience that it stays with you for closer to four. You can select the chocolate icon and scroll the Absorption Time to select four hours.
Select Continue to move to the Bolus screen.
NOTE – the carbs have not been saved yet. You may choose to Save without Bolusing and then the carb entry is saved. If you hit Carb Entry at upper left to return to the previous Carb Entry Screen, you can modify what you just entered or hit Cancel to discard the entry.
Bolus screen: If the Loop prediction for BG using the carb entry and current IOB is above your suspend threshold, you will see a Recommended amount to bolus. To accept that recommendation, just press it and the amount will fill in automatically in the Bolus line immediately below. Otherwise, enter the bolus you’d like. The blue Save without Bolusing button will now say Deliver. Once you tap the Deliver or Save without Bolusing button, the carb entry is saved and the bolus (if any) request is sent to your pump. Remember, the radio-link needs to be active and within range for the bolus to go through.
If Loop is not recommending a Bolus because the prediction drops below the suspend threshold, you can either enter a bolus amount you feel is safe or set a 15-minute timer to recheck your BG and bolus once you’re BG has risen to an acceptable level.
Multiple Entries: Depending upon what you’re eating, you may want to record multiple entries, each with a different time stamp and absorption time. After each entry, Save Without Bolusing. When you’re done recording all entries, you can accept the new bolus recommendation, override it, or save without bolusing.
Editing your Meal Entry: You can swipe left or tap on the Active Carbohydrate section of the Status Screen to review your meal entries. If you’d like to edit an entry, tap on the entry to adjust the grams, time stamp, Absorption Time or food description/icon.
Delete: You can delete Entries by clicking Edit and then selecting the entry that you want to delete.
AB and FreeAPS: If you Save Without Bolusing, your Loop app will bolus for you as soon as the Loop algorithm recommends a bolus. The amount of your bolus will be 40% of the recommended bolus on AB, or your Partial Bolus Application (PBA) % on FreeAPS. If you are using Multiple Entries and are on an automatic-bolus version, Loop may start a bolus while you’re making the multiple entries. Make sure Loop is done with a bolus before accepting a recommendation. In this case, it is best to finish all multiple entries using Save without Bolusing and then return to the main screen, wait for any bolus in progress to finish and then select Bolus from the toolbar.
See the discussion on Meal Bolus above. Outside of Meals, you will not know if Loop is recommending a Bolus unless you press on the orange Bolus icon located in the center of the Toolbar at the bottom of the Status Screen. If you don’t bolus, Loop will deliver a portion of the Recommended Bolus during every Loop interval (approximately 5 minutes) over a 30 minute period via a Temporary Basal Rate. Of course, the amount of your Temporary Basal Rate is limited by your Maximum Basal Rate setting, which you previously set up in the Delivery Limits of your Loop Settings.
If you have Nightscout set up and Loop is recommending a bolus, it will show up on the Loop pill on the Nightscout screen.
AB and FreeAPS: Your Loop app will bolus for you as soon as the Loop algorithm recommends a bolus – there is no need to monitor the orange Bolus icon. The amount of your bolus will be 40% of the recommended bolus on AB, or your Partial Bolus Application (PBA) % on FreeAPS subject to your max bolus limit.
The Override icon is the blue heart icon that is the second from the right in your Toolbar. Overrides are a helpful way of temporarily increasing or decreasing your basal insulin delivery in advance of exercise or in response to a lingering high BG, for example. Please see the Override Strategies page to learn more about this feature. An override is selected or turned off by tapping the blue heart. The heart fills in if an override is active and the override information shows up just under the HUD in portrait mode.