Feasibility Study to Determine the Optimal Calibration Method for Glucose Sensors

Inclusion Criteria: * Informed consent obtained after being advised of the nature of the study * Male or female aged 18 to 75 years (both inclusive) * The subject has Type 1 diabetes (as defined by WHO) for at least 24 months * Body Mass Index (BMI) \<= 35 kg/m2 Exclusion Criteria: * Subject is actively enrolled in another clinical trial or took part in a study within 30 days * Experienced recurrent severe hypoglycaemic unawareness (as judged by the investigator) * A history of drug or alcohol dependence * Positive result for HIV antibodies * Positive result for Hepatitis B antigen or Hepatitis C antibodies * Any other significant concomitant disease such as endocrine, cardiac, neurological, malignant, other pancreatic disease or uncontrolled hypertension as judged by the investigator * Patient is pregnant, or breast feeding during the period of the study * Patient donated blood in the last 3 months