Automated Insulin Delivery (AID) or Hybrid Closed Loop (HCL) insulin pumps are briefly reviewed and compared below. 

Overview

AID or HCL Systems:

  • Use an algorithm (set of instructions) and CGM results to adjust insulin delivery up, down or off to reduce hyperglycemia and hypoglycemia. Adjustments may include modulating basal insulin and/or adding micro-corrections. 
  • Require manual input of estimated grams of carb to determine meal boluses (in most cases)
  • Exist in some brands of commercially available insulin pumps (Health Canada approved)
  • Exist in DIY versions (not Health Canada approved). The two most common algorithms used in DIY AID are 1. Loop and 2. Oref based (OpenAPS, AndroidAPS, FreeAPSX). 
  • Use algorithms that are brand specific. Each algorithm allows for different factors to be adjusted while the system is automatically adjusting insulin. (The older concept of 50/50 basal & bolus insulin split may not apply.)

 

 Comparison of Common AID Systems

Features that may/may not be adjusted in AID mode Medtronic 670G, 770G (AutoMode) - tubing  Medtronic 780 (SmartGuard) - tubing Tandem (Control IQ) - tubing Loop DIY - tubing (old Medtronics) or Omnipod
Sensor Type Guardian 3 (calibration required)

Guardian 3  (calibration required

Dexcom  (calibration optional) Dexcom (calibration optional)
Glucose Targets (mmol/L)

6.7

8.3

5.5

6.1

6.7

8.3 
(2 hr; auto-corrections off)

Note: Corrections target 6.7

6.25 - 8.9

6.25 - 6.7 (sleep activity)

7.8 - 8.9 (exercise activity)

Note: Corrections target 6.1 

Freely customizable
Auto-Correction Boluses can be toggled on/off by user?  N/A

 Yes.

Auto Corrections can be turned off while SmartGuard will still modulate basals.  

Yes, if Sleep Activity enabled no auto-corrections are delivered. 

Control IQ includes auto-corrections. (Changing other settings can impact the corrections.)

Yes.

Dosing strategy can be auto-bolus or temp basal only.

Basal Rates adjusted by user? No No  Yes Yes
ISF adjusted by user? No No  Yes Yes
Carb Ratio adjusted by user? Yes  Yes Yes Yes
Suggested Boluses adjusted by user? No  No Yes Yes
Extended Bolus can be set? No No  Yes, max 2 hr Yes in terms of carb absorption time
Insulin Action Time can be adjusted? Yes (2-6 hr)  Yes (2-6 hr) No (5 hr) Not usually. Preset when choose insulin type. (Choosing Walsh insulin model allows to set different duration).

OpenAPS, Android APS, FreeAPSX all use the Oref algorithm and are not yet represented above.

 

 

Addressing Hyperglyemia in AID*

Medtronic 780G** Tandem CIQ Loop DIY
  • Pre-bolus 15 min
  • Reduce carb in Carb Ratio
  • Temporarily change carb ratio if a sedentary day vs active day
  • Choose lower target
  • Reduce active insulin time
  • Verify that Auto Corrections are "on" under SmartGuard settings. 
  • Give as 2 boluses 1-2 hr apart if from high fat/pro
  • Return to manual mode for correction and resume SmartGuard
**670G, 770G same options except cannot choose lower target; no Auto Corrections are possible.

  • Pre-bolus 15 min
  • Reduce carb in Carb Ratio
  • Choose lower target (sleep activity) if appropriate
  • Over-ride bolus suggestions with caution
  • Use extended 2-hr bolus if from high fat/pro
  • Increase basal rate
  • Change ISF
  • Return to manual mode for temp basals
  • Pre-bolus 15 min
  • Reduce carb in Carb Ratio 
  • Set a lower target
  • Over-ride bolus suggestions with caution
  • Reduce carb absorption time
  • Input meal in 2 sections: e.g. Part of the meal as 2 hr absorption and part as 4-6 hour absorption if high fat/pro
  • Temp overide. Note % increase is to basal, bolus & corrections all at once
  • Increase basal rate
  • Change ISF
*Patients should be directed to pump company resources. These options may not be as indicated in product manuals. Options for possible consideration if appropriate and applicable as reviewed with healthprovider and patient.  Not all options are ideal. Some are temporary.

 

 

Addressing Hypoglycemia in AID*

Medtronic 780G** Tandem CIQ Loop DIY
 
  • Increase carb in Carb Ratio
  • Lengthen Insulin Action Time
  • Choose higher target
  • Temporary: Turn auto-corrections off 
  • Return to manual mode and use reduced temp basal and manual basal rates, ISF. 
  • Bolus for carb, even if a few grams. (Not inputting grams tells the system that the insulin delivered is all for basal needs. This can increase basal over the day, and night.) 
**670G, 770G same options except there are no Auto Corrections to turn off. 

 
  • Increase carb in Carb Ratio
  • Change ISF
  • Change basal rates
  • Temporary: choose exercise activity target
  • Temporary: over-ride bolus suggestions and deliver less
 
  • Increase carb in Carb Ratio 
  • Set a higher target
  • Temporary: Over-ride bolus suggestions and deliver less.
  • Increase carb absorption time
  • Temporary overide. Note % decrease is to basal, bolus & corrections all at once
  • Decrease basal rate
  • Change ISF
*Patients should be directed to pump company resources.These options may not be as indicated in product manuals. Options for possible consideration if appropriate and applicable as reviewed with healthprovider and patient.  Not all options are ideal. Some are temporary.

 

 

Exercise Planning in AID*

Medtronic 780G** Tandem CIQ Loop DIY
 
  • Temp target (8.3 mmol/L 2 hrs with no autocorrections)
  • Set higher target (6.7 mmol/L)
  • Auto-corrections can be turned off temporarily regardless of target chosen. 
  • Return to manual mode for temp decrease basals. 

**670G, 770G same options except there are no Auto Corrections to turn off and only 2 glucose targets to choose from.

 
  • Choose exercise activity (7.8 - 8.9 mmol/L)
  • Set alternate profile with less basal and less assertive Carb Ratio and ISF. This is preferred if exercise activity not adequate. 
  • Return to manual mode for temp decrease basal prior to exercise and exercose activity during exercise (less ideal than point above).
 
  • Set higher target
  • Set Temporary overide. Note % decrease is to basal, bolus & corrections all at once.
Eat small amounts carb with no bolus - use with caution. Elevations in glucose may result in auto-corrections or increased basal during period of exercise. 
*Patients should be directed to pump company resources.These options may not be as indicated in product manuals. Options for possible consideration if appropriate and applicable as reviewed with healthprovider and patient.  Not all options are ideal.