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Automode

41 important questions on Automode

HOW DOES THE SYSTEM REGULATE BLOOD GLUCOSE? HOW DOES THE PUMP ADJUST THE INSULIN?

The automated basal insulin dose is calculated and delivered every 5 minutes, based on the following:

▪ Total active insulin on board (basal and bolus)
▪ Sensor glucose (SG) data including:
    ▪ The magnitude or how far away the current glucose is from target
    ▪ The trend or rate of change away from or towards the target
    ▪ The duration of time or how long the glucose has been away from target The delivery is tuned based on the past six days of sensor glucose and insulin delivery history

WHAT INSULIN DELIVERY HISTORY IS USED?

If it is available, the most recent six full days of insulin delivery history and glucose (SG) response within the previous two week period are used. The pump can use as few as two full days (midnight to midnight) of insulin delivery history for this calculation. The 5 minute automated basal insulin delivery also depends on the recent basal and bolus insulin delivery and glucose (SG) response during the current day.

DOES AUTO MODE FACTOR IN BODY WEIGHT OR BMI?

No, the calculations use TDD, total daily dose only.

WHAT WILL CAUSE A PATIENT TO EXIT OUT OF AUTO MODE INTO MANUAL MODE?

There are number of things that take a patient out of Auto Mode:

1. Turning off Auto Mode
2. Prolonged high above 250 mg/dL
3. Safe Basal for 90 minutes
4. Most pump alarms (example, No Delivery alarm)
5. Manual suspend for 4 hours

HOW LONG CAN A TEMP TARGET OF 150 MG/DL BE PROGRAMMED FOR?

The Temp Target can be set for 30 minutes up to 12 hours (default of 2 hours), in 30 minute increments.

HOW MANY TIMES PER DAY ARE PATIENTS GOING TO HAVE TO TEST THEIR BG?

Patients need to calibrate their sensor at least twice a day, as well as any time the system requests a BG for confirmation. Patients are also recommended to check their BGs with meals. During the pivotal trial, patients checked their BG an average of 7 times a day.

IS THE LEARNING PERIOD 48-HOURS OR 6 DAYS? WOULD IT BE BETTER IF THE PATIENT WAITS TO HAVE AT LEAST 6 DAYS OF INSULIN DELIVERY HISTORY BEFORE TURNING ON AUTO MODE?

The MiniMed 670G system requires at least 48-hours of insulin delivery history (ending at a midnight) before the system can utilize the Auto Mode feature. For an optimal experience, patients should have at least 6 days of insulin delivery history and CGM data before starting Auto Mode for the first time.

IF A PATIENT’S TOTAL DAILY DOSE ON OCCASION FALLS BELOW 8 UNITS, WILL THE SYSTEM STILL WORK FOR THE PATIENT?

The system looks for at least two full days of insulin delivery history in the last 6 days that is above or equal to the 8 unit threshold.

WHAT HAPPENS IF THE PATIENT STOPS USING THE PUMP? HOW LONG IS THE HISTORY STORED? WHAT DATA IS USED?

If insulin has been suspended for less than 4 hours, then there is no start up time required.

If you have been using Auto Mode and you turn off your pump for more than 4 hours and less than two weeks, there will only be a five hour warm up period once the pump is restarted.

If the pump is not used for insulin delivery for more than 12 days, the system will require another Auto Mode warm-up period. The pump uses the most recent 6 days of data out of the past two weeks.

WHAT IF A PATIENT DECIDES TO TAKE A BREAK ON SENSOR FOR A COUPLE OF MONTHS AND COME BACK TO AUTO MODE, HOW DOES THAT AFFECT USING THE FEATURE? DOES AUTO MODE TAKE THE PAST 6 DAYS OF TOTAL DAILY DOSE WITHOUT THE SENSOR ON?

Auto Mode warm-up requires up to 2-3 days of insulin delivery history, but Auto Mode warm-up does not require a sensor

IS THE LEARNING PERIOD WEIGHTED?

The learning period is weighted such that the days with insulin delivery history leading to a higher maximum delivery estimate are given the most weight. On the other hand, the most recent day of insulin delivery is not given more weight.

CAN THE 48-HOUR LEARNING PERIOD FOR AUTO MODE INITIATION BE REPEATED WHENEVER THE PATIENT OR HCP CHOOSES?

Yes, resetting the pump will clear all pump settings, including Auto Mode’s 48-hour learning period.

FOR THE 48-HOUR WARM-UP PERIOD, SHOULD PATIENTS BE FASTING?

No, patients should follow their normal bolus and basal regimen during the Auto Mode warm-up period. We recommend that patients do not fast during their warm-up period.

IF A PATIENT HAS DONE THE INITIAL 48-HOUR WARM UP TO ENTER AUTO MODE AND CHANGES THE SENSOR AFTER DAY 7, WOULD THEY NEED TO WAIT ANOTHER 48-HOURS AFTER CHANGING TO RE-ENTER AUTO MODE?

Changing the sensor will not require a new learning period.

WHAT IS THE MAXIMUM BASAL DELIVERY? HOW IS IT CALCULATED?

The personalized maximum basal rate is determined by the patient’s past 6 days of insulin delivery history and the glucose response. The algorithm adapts on a daily basis and this limit is not based on any Manual Mode settings (e.g. basal rates, max bolus). The maximum delivery is designed to keep the patient well-controlled while preventing lows from over-delivery of insulin. If the patient has been receiving a Maximum Basal for 4 hours then the system will begin Safe Basal delivery. (See Safe Basal section.)

WHAT IS THE MINIMUM BASAL DELIVERY?

The minimum basal delivery is 0 units/hour. If the algorithm delivers 0 units/hour or a very small amount (<7.5% of algorithm-estimated average basal rate) of basal insulin for 2.5 hours, the system will exit auto basal delivery and begin Safe Basal delivery (See Safe Basal section). This personalized minimum basal rate is determined by the patient’s past 6 days of insulin delivery history and the glucose response.

WHAT IS THE TYPICAL RANGE OF AUTO BASAL DELIVERY?

This is different for every patient. Auto Basal can range in magnitude between 0 units/hour and the maximum basal delivery.

HOW MUCH BASAL CAN BE AUTOMATICALLY DOSED WITH AUTO MODE? WHAT PERCENT ABOVE A PATIENT’S NORMAL BASAL RATE CAN THE SYSTEM DELIVER? HOW MUCH EXTRA BASAL INSULIN CAN AUTO MODE DOSE?

Auto Mode can suspend basal delivery or provide basal rates up to a personalized maximum basal rate that is determined by the past 6 days of insulin delivery history and glucose response. For more information, please review the answer to the question: “What is the maximum basal delivery?” Patients will still need to enter carbohydrates for meal boluses and confirm correction boluses.

HOW IS THE AUTOMATED BASAL INSULIN CALCULATION AFFECTED BY MEAL OR CORRECTION BOLUSES?

The algorithm takes into account active insulin from boluses delivered and adjusts the automated basal insulin as needed.

DO PATIENTS STILL NEED TO TAKE CORRECTION BOLUSES? WHEN?

There may some situations when patients would like to take correction boluses in Auto Mode. In order to receive a correction bolus, the patient needs to enter a BG. When the system receives a BG over 150 mg/dL and the system determines that a bolus is needed to bring the SG down to 150 mg/dL, a bolus will be recommended and the patient may accept this bolus.

Note: If active insulin is on board then a correction bolus may not be recommended.

AFTER A MEAL BOLUS, WHEN SG STARTS RISING, WHEN/HOW SOON DOES THE ALGORITHM START TO HANDLE THE HIGHS?

The algorithm will start handling highs immediately at the next 5 minute interval by accounting for the active insulin that was delivered with the meal bolus, as well as the current SG value, and recent insulin delivery and SG trends.

WHAT HAPPENS IF THE PATIENT BOLUSES AFTER THEY EAT?

For best results, patients should bolus prior to meals. If patients were to enter carbohydrates significantly (for example, 45 minutes) after the meal event, Auto Mode may deliver insulin based on sensor glucose values up to the maximum delivery limit until a carbohydrate entry occurs and the meal bolus is delivered. Auto Mode will take the meal bolus and previously delivered insulin into account in order to determine how much insulin to deliver. Patients should follow the same guidance for these situations as is suggested for standard pump therapy.

2 I HAVE HEARD THERE ARE TWO DIFFERENT LEVELS OF SAFE BASAL … CAN YOU DESCRIBE THIS? CAN IT SWITCH LEVELS WHILE IN SAFE BASAL?

Safe Basal delivery is calculated by the algorithm to deliver a safe, conservative basal rate based on historical insulin dosing, independent of sensor glucose values. There are two possible delivery rates in Safe Basal:

▪ Nominal rate
▪ Low rate – a lower rate than the nominal Safe Basal rate. It is triggered in Safe Basal if additional low glucose protection is needed during this period.

WHAT HAPPENS DURING SAFE BASAL … DOES THE PATIENT GET ALERTS?

During Safe Basal, the user will receive all alerts the system provides in Auto Mode, including all CGM alerts (as long as SG values are available). There is also an optional alert when Safe Basal has started due to a minimum delivery, maximum delivery or sensor underread detection event. This optional alert is enabled by default. The patient will also receive an alert when the system transitions into Manual Mode.

WHAT SHOULD THE PATIENT DO IF THEY ARE IN SAFE BASAL?

The patient should follow the guidance on the pump user interface. No specific user action is required unless prompted by the pump.

WHAT IS CONSIDERED PROLONGED HIGH FOR THE SYSTEM?

Prolonged highs apply to both Auto and Manual Modes. When these occur, the pump will alert the user for SG values above

▪ 250 mg/dL for 3 hours, or
▪ 300 mg/dL for 1 hour

WHAT SETTINGS CAN BE ADJUSTED BY THE HCP OR PATIENT FOR AUTO MODE?

1. Insulin-to-carb ratio
2. Active insulin time

DOES AUTO BASAL USE THE ACTIVE INSULIN TIME?

In Auto Mode, only correction boluses and meal boluses take into account the active insulin time. Auto Basal is not impacted by this setting.

AFTER A PATIENT EXITS AUTO MODE AFTER A SENSOR CHECK, WHAT IS THE PROCESS TO RE-ENTER AUTO MODE?

A patient can re-enter Auto Mode with a calibrated CGM and valid BG entered into the pump. Many pump alarms (for example, No Delivery alarms) will also disable the Auto Mode setting. After clearing the alert/alarm and taking the action needed, the patient will also need to re-enable the Auto Mode setting.

CAN PATIENTS STILL SET TEMP BASAL RATES?

Only in Manual Mode. Auto Mode has a Temp Target which adjusts the SG target for Auto Mode to 150 mg/dL.

CAN PATIENTS USE SQUARE WAVE OR DUAL WAVE BOLUSES FOR MEALS?

Only in Manual Mode. Square Wave and Dual Wave boluses are not available in Auto Mode.

CAN BOLUSES BE DELIVERED FROM A BG METER FOR THE MINIMED 670G?

Yes, in Manual Mode only.

CAN I SUSPEND THE PUMP WHILE IT IS IN AUTO MODE?

Yes, the patient can suspend the pump while it is in Auto Mode. Note that if the patient suspends the pump for more than 4 hours, Auto Mode will require a 5 hour warm-up. This will be displayed on the Auto Mode Readiness status screen. Patients should suspend the pump when they are disconnected from the pump. If delivery of insulin is suspended for greater than 2 weeks, the entire 48-hour initialization would be required.

WHAT HAPPENS IF PATIENTS DISCONNECT FOR SOME TIME BUT DO NOT SUSPEND THE PUMP? IF THE PATIENT IS STILL WEARING THE SENSOR ON THE BODY BUT THE PUMP DOESN’T KNOW THEY’RE NOT REALLY RECEIVING THE INSULIN. IS THE PUMP ABLE TO ACCOUNT FOR THIS?

Anytime the patient disconnects from the pump, we recommend the patient suspend their pump. If the patient forgets to suspend the pump, Auto Mode will assume that the patient received all the insulin programmed during the disconnected time. Because of this, upon reconnecting, Auto Mode will provide a more conservative amount of insulin delivery. Patient should take a BG and may accept a recommended bolus, if needed.

WHAT ARE THE SENSOR AUGMENTED PUMP FEATURES? (4) (SMARTGUARD)

Alert on low
Suspend on low
Alert before low
Suspend before low

HOW DOES THE AUTOMODE ALGORITHM WORK?

a. PROPORTIONAL-INTEGRATIVE-DERIVATIVE+ insulin feedback (PID)
b.Algorithm based on TDD of the past 2-6 days
c.Learns/recalculates the algorithm daily
d.Target of 120 mg/dl

WHAT SETTINGS CAN BE MODIFIED IN MANUAL MODE?

a.Targets
b.Basals
c.Sensitivities/corrections
d.I:C ratios
e.Insulin action time

WHAT SETTINGS ARE FIXED IN AUTOMODE? (CANNOT BE MODIFIED)

a.Target of 120
b.Auto basal delivery
c.Sensitivities/ corrections

WHAT SETTINGS CAN BE MODIFIED IN AUTOMODE?

I:C ratios
insulin action time

THESE ARE SETTINGS FOR MEALTIME OR CORRECTION BOLUSES ONLY, NOT USED IN AUTOMODE.

WHAT ARE THE STEPS TO STARTING AUTOMODE?

a.Needs to be used for 48 hours before it can start in auto mode.
b.Must enter I:C ratios
c.Must enter active insulin time
d.Must have active CGM sensor

WHAT ARE THE ACTIONS AVAILABLE IN AUTOMODE?

a.Bolus for food/meal
b.Bolus for correction if BG over 150- will prompt for correction
c.TEMP target- move from 120 to 150 (for exercise, like a temporary basal, especially in children who are have more insulin sensitivity variability)

The question on the page originate from the summary of the following study material:

670 Q&A

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