The Bio-Inspired Artificial Pancreas for the Home

The purpose of the study is to evaluate the safety and effectiveness of a closed-loop insulin delivery system (also known as an artificial pancreas) which is made up of three components that communicate with each other:

1. A glucose sensor that measures glucose every 5 minutes
2. A control algorithm that calculates the required insulin dose
3. An insulin pump that delivers the insulin calculated

In addition to assessing the closed-loop insulin delivery system on its own, the study aims to evaluate the system when combined with a personalised bolus calculator that adapts over time. Standard bolus calculators are widely used in type 1 diabetes self-management to calculate insulin boluses at mealtimes and are incorporated in all insulin pumps and in some glucose meters. A standard bolus calculator uses a generic formula taking into account the target glucose level, current glucose level, carbohydrate content of meal (grams), insulin: carbohydrate ratio (the amount of carbohydrate (grams) covered by 1 unit of insulin), insulin sensitivity factor (the reduction in blood glucose by 1 unit of insulin) and insulin-on-board (IOB, the remaining active insulin from the previous bolus). Some bolus calculators additionally consider parameters such as exercise, but all lack the ability to automatically adapt over time to respond to individual needs.

Finally, the study aims to compare the closed-loop insulin delivery system to standard pump therapy (also known as an open-loop insulin delivery system) in combination with continuous glucose monitoring (referred to as sensor augmented pump).

The Diabetes Technology group at Imperial College have developed a unique closed-loop insulin delivery system known as the Bio-inspired Artificial Pancreas (BiAP) and a personalised bolus calculator known as the Advanced Bolus Calculator for Diabetes (ABC4D).

Overview of the complete closed-loop system (artificial pancreas) used in this study is as follows:

1. A commercially available continuous subcutaneous glucose sensor (Dexcom G5 CGM system).
2. The BiAP control algorithm implemented in a low-power handheld device (developed at Imperial College)
3. An insulin infusion pump (Tandem t:slim) for insulin delivery.

   In one part of the study the closed-loop system will be evaluated in combination with:
4. The ABC4D adaptive bolus calculator implemented in a smartphone (as an app)

All the components will be tested together as a combined system.

Eligibility Criteria:
Inclusion Criteria:

* Adults over 18 years of age
* Type 1 diabetes confirmed on the basis of clinical features and a random c-peptide \<200 pmol/L
* Type 1 diabetes for greater than 1 year
* Continuous subcutaneous insulin infusion for greater than 6 months
* Structured education done (either 1:1 or group education)
* HbA1c \<10% (86mmol/mol)
* A negative pregnancy test in female participants of childbearing age

Exclusion Criteria:

* More than one episode of severe hypoglycaemia (defined as hypoglycaemia requiring 3rd party assistance) in the preceding year
* Impaired awareness of hypoglycaemia (Gold score \>4)
* Pregnant or planning pregnancy
* Breastfeeding
* Enrolled in other clinical trials
* Have active malignancy or under investigation for malignancy
* Severe visual impairment
* Reduced manual dexterity
* Ischaemic heart disease
* Anti-anginal medications
* Regular use of paracetamol
* Unable to participate due to other factors, as assessed by the Chief Investigator