The purpose of this study is to compare two continuous glucose sensors, one placed subcutaneous (under the skin) and one placed intradermal (in the skin) over 12-14 hours.

This was a single site, non-randomized study. The study consisted of a screening visit (Visit 1), during which the subject was consented and the inclusion and exclusion criteria confirmed, an experimental intervention (Visit 2) and a follow-up visit (Visit 3). The experimental intervention was based on an initial glucose clamp involving a basal intravenous (IV) insulin infusion and IV insulin boluses plus IV glucose infusion / IV glucose boluses as required to maintain euglycemic, hypoglycemic and hyperglycemic plateaus respectively in 41 subjects with Type 1 or Type 2 Diabetes. At the end of hour five of the study the glucose clamp was discontinued and subjects given a standardized meal to stimulate a hyperglycemic excursion

Each subject participated in one experimental intervention. During the glucose clamp intervention, the subject's blood glucose was continuously monitored either by means of the Biostator or by frequent venous blood glucose measurements based on a standard lab method (YSI STAT2300 analyzer), and measured by means of the BD Technologies test devices, and the Medtronic Guardian CGM. Once the clamp was discontinued the Biostator was discontinued as well. During the unclamped period and meal the subjects BG was monitored via the YSI Glucose Analyzer, the BD CGM sensor and the Medtronic Guardian CGM.

Inclusion Criteria:

• Otherwise healthy male and female subjects with Type 1 or Type 2 diabetes mellitus
• Signed informed consent
• Age between 18 and 65 years, inclusive
• Body mass index between 19 and 30 kg/m², inclusive
• HbA1c < 11 %

Exclusion Criteria:

• Uncontrolled arterial hypertension (diastolic blood pressure >90 mm Hg and/or systolic blood pressure >160 mm Hg)
• Impaired hepatic function measured as alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥ three times the upper reference limit
• Impaired renal function measured as creatinine > 1.2 times above the upper limit of normal.
• Severe acute diseases, i.e. cardiac, pulmonary, gastrointestinal, hepatic, neurologic, or infectious that might interfere with the performance of this study, as judged by the Investigator.
• Severe chronic diseases, as judged by the investigator other than Type 1 Diabetes
• Current use or recent exposure to any medication that in the opinion of the investigator could have an influence on the patient's ability to participate in this study or on the performance of the test device.
• Known microvascular (diabetic) complications (other than diabetic non-proliferative retinopathy), such as e.g. history of laser coagulation, proliferative diabetic retinopathy, known diabetic nephropathy or neuropathy requiring treatment
• Positive serology for Hepatitis B, Hepatitis C or HIV
• Pregnancy, breast-feeding or intention of becoming pregnant or not using adequate contraceptive measures.
• Known current or recent alcohol or drug abuse
• Blood donation of more than 500 ml within the last three months
• Anticoagulant therapy
• Mental incapacity, unwillingness or language barriers precluding adequate understanding or co-operation
• Previous participation in a study involving the GBP-based sensor
• Has taken more than 4000 mg or more of acetaminophen within the past 24 hours (i.e. 13 or more regular strength or 8 or more extra strength Tylenol in the past 24 hours)
• Any skin condition that may be judged to have affect on study ( e.g., bad sunburn, pre-existing dermatitis)