Despite current treatments for type 1 diabetes, maintaining blood glucose levels within a good range is a difficult task. A primary source for poor glucose control in adolescents is skipping insulin boluses at mealtimes. Advances in glucose sensors have motivated the research towards closed-loop delivery systems to automatically regulate glucose levels. Closed-loop delivery (artificial pancreas) is composed of an insulin pump, a continuous glucose sensor and a dosing algorithm that calculates the insulin dose to infuse based on sensor readings. The performance of a closed-loop delivery after a missed bolus may be improved if the computer program that calculates the insulin is enhanced with a meal detection module. The meal detection module will automatically detect the meal (which had no bolus delivered), and signal the delivery of more insulin.

The aim of this study is to assess the safety and efficacy of a closed-loop delivery with and without meal detection module compared to conventional pump therapy in regulating post-prandial glycemic levels after omission of a meal bolus.

The primary hypothesis is that closed-loop delivery with no meal detection module will reduce the mean increase in postprandial glucose levels after a missed bolus compared to conventional pump therapy.

Despite current treatments for type 1 diabetes, maintaining blood glucose levels within a good range is a difficult task. A primary source for poor glucose control in adolescents is skipping insulin boluses at mealtimes. Advances in glucose sensors have motivated the research towards closed-loop delivery systems to automatically regulate glucose levels. Closed-loop delivery (artificial pancreas) is composed of an insulin pump, a continuous glucose sensor and a dosing algorithm that calculates the insulin dose to infuse based on sensor readings. The performance of a closed-loop delivery after a missed bolus may be improved if the computer program that calculates the insulin is enhanced with a meal detection module. The meal detection module will automatically detect the meal (which had no bolus delivered), and signal the delivery of more insulin.

The aim of this study is to conduct a randomized, three-way, cross-over trial to compare the efficacy of closed-loop delivery, closed-loop delivery with a meal detection module, and conventional pump therapy. The study aims to compare these three interventions for 9 hours in adolescents with poorly controlled type 1 diabetes.

Each 9 hours will include two meals of different carbohydrate content, of which one will not have a carbohydrate-matched prandial bolus. This study will allow for the assessment of the safety and efficacy of closed-loop delivery with and without a meal detection module compared to conventional pump therapy in regulating post-prandial glycaemia.

The aim of this study is to assess the safety and efficacy of a closed-loop delivery with and without meal detection module compared to conventional pump therapy in regulating post-prandial glycemic levels after omission of a meal bolus.

The primary hypothesis is that closed-loop delivery with no meal detection module will reduce the mean increase in postprandial glucose levels after a missed bolus compared to conventional pump therapy.

The secondary hypotheses are:

1. Closed-loop delivery with meal detection module will reduce the mean increase in postprandial glucose levels after a missed bolus compared to conventional pump therapy.
2. Closed-loop delivery with meal detection module will reduce the mean increase in postprandial glucose levels after a missed bolus compared to closed-loop delivery with no meal detection module.

Inclusion Criteria:

1. Clinical diagnosis of type 1 diabetes for at least 12 months. (The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide level and antibody determinations are not needed.)
2. The participant will have been on insulin pump therapy for at least 3 months.
3. HbA1c 7.5% to 12%.
4. Self-reported or documented history of missed-bolus for meals during the previous 6 months.

Exclusion Criteria:

1. Clinically significant nephropathy, neuropathy or retinopathy as judged by the investigator.
2. Severe hypoglycemic episode within one month of screening.
3. Pregnancy.
4. Current use of oral glucocorticoid medication (except low stable dose). Stable doses of inhaled steroids are acceptable.
5. Known or suspected allergy to the trial products, including the meal content.
6. Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator.
7. Failure to comply with team's recommendations (e.g. not willing to eat meals/snacks, not willing to change pump parameters, etc.).