Study to Test Software Algorithm for Insulin Therapy and New Glucose Sensor

Inclusion Criteria: * Male or female aged 18 to 75 years (both inclusive) * Informed consent obtained after being advised of the nature of the study * The subject has Type 1 diabetes (as defined by WHO) for at least 24 months * The subject's HbA1c \<= 10% * Body Mass Index (BMI) \<= 35 kg/m2 * The subject is treated with continuous subcutaneous insulin infusion for at least 3 month Exclusion Criteria: * Subject is actively enrolled in another clinical trial or took part in a study within 30 days * Experienced recurrent severe hypoglycaemic unawareness * Total daily insulin dose \>= 1.4 IU/kg * Subject is using a medication that significantly impacts glucose metabolism (oral or topical steroids) except if stable for at least the last three months and expected to remain stable for the study duration * Allergy against insulin Lispro * A history of drug or alcohol dependence * Any other significant concomitant disease such as endocrine, cardiac, neurological, malignant, other pancreatic disease or uncontrolled hypertension as judged by the investigator * Uncontrolled hypertension with resting blood pressure over 140/90 mmHg * Patient is pregnant, or breast feeding during the period of the study * Patient donated blood in the last 3 months