Closed-loop strategy is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required insulin dosages based on the sensor's readings. A dual-hormone closed loop strategy regulates glucose levels through the infusion of two hormones: insulin and glucagon.

The objective of this study is to compare, in a randomized multicenter trial, the effectiveness of single-hormone closed-loop, dual-hormone closed-loop, and sensor-augmented pump therapy with low-glucose suspend in regulating day-and-night glucose levels in outpatient settings for 15 weeks in adolescents and adults.

The investigators hypothesize that dual-hormone closed-loop will reduce time spent in hypoglycemia compared to single-hormone closed-loop, which in turn will be more effective than sensor-augmented pump therapy with low-glucose suspend.

Inclusion Criteria:

1. Males and females ≥ 12 years of old.
2. Clinical diagnosis of type 1 diabetes for at least one year.
3. The subject will have been on insulin pump therapy for at least 3 months.
4. HbA1c ≤ 11%.

Exclusion Criteria:

1. Clinically significant nephropathy, neuropathy or retinopathy as judged by the investigator.
2. Recent (< 6 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery.
3. History of pheochromocytoma or insulinoma (glucagon could induce a hormonal response of these tumors)
4. Beta-blockers at high dose based on investigator's evaluation of dosage interference with glucagon (glucagon can modify effect of beta-blockers, mostly evident at very high doses)
5. Chronic indometacin treatment (can prevent glucagon effect on liver thus its ability to raise glucose)
6. Chronic acetaminophen treatment (can interfere with glucose sensor measurements)
7. Warfarin chronic treatment if INR monitoring cannot be evaluated (can increase the risk of bleeding)
8. Anticholinergic drug (risk of interaction)
9. Pregnancy.
10. Severe hypoglycemic episode within two weeks of screening.
11. Current use of glucocorticoid medication (except low stable dose and inhaled steroids).
12. Known or suspected allergy to the trial products
13. Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator.
14. Anticipating a significant change in exercise regimen between admissions (i.e. starting or stopping an organized sport).
15. Treatments that could interfere with glucagon