Inclusion Criteria:  Type 1 diabetic patients undergoing a CSII therapy for at least 6 months and using Tandem t:slim X2 for at least 4 weeks. Patient using CGM for 6 months including Dexcon G6 for at least 4 weeks. Eligible patient (according to French Society recommendations) for activation of the closed loop Informed Patient accepting the computer processing of their medical data. Patient correctly completing the 2 main self questionnaires Patient with HbA1c below 11%  Exclusion Criteria:  Pregnancy or Lactation during the study Patient with a diabetic retinopathy not controlled by laser Patient suffering from a disease or undertaking a treatment altering glucose metabolism