Multi-day (3) In-patient Evaluation of Intradermal Versus Subcutaneous Basal and Bolus Insulin Infusion

INCLUSION CRITERIA Male and Female patients will be included in the trial only if they fulfill all the inclusion criteria mentioned below: * Understood and signed informed consent obtained before any trial-related activities (trial-related activities are any procedures that would not have been performed during normal management of the patient) * Type 1 Diabetes mellitus, according to clinical judgment / ADA / WHO-definition (Diabetes Care 2003; 26: 5-20) for at least 1 year. * Usage of insulin pump therapy (CSII) with carb counting for at least six months * Age in the range of ≥ 18 and ≤ 55 years * Body mass index (BMI) ≤ 32 kg/m² * HbA1c ≤ 8.0% at screening * Using ≤ than 60 U of insulin on a typical day (preferably) * Able and willing to adhere to the study procedures for the entire trial period * Negative test results for hepatitis C antibodies, hepatitis B surface antigen and HIV at screening. EXCLUSION CRITERIA Patients will not be permitted to enter the trial, if they fulfill any of the exclusion criteria mentioned below: * Previous participation in this trial or participation in a clinical trial within 3 months prior to screening examination * Any symptoms suggestive of, or a diagnosis or treatment for gastroparesis * Abnormalities in renal function (e.g. serum creatinine \> 120 µmmol/L for male, \>100 µmmol/L for female subjects or judged by the investigator that would pose a problem of clearance of injected insulin * Proliferative retinopathy or maculopathy that has required acute treatment within the last six months * Acute and severe illness apart from diabetes mellitus as judged by the investigator * Abnormalities in the laboratory parameters if judged as clinically significant by the investigator. In particular, patients with GOT/GPT \> 3 x upper limit of normal (ULN), thrombocyte count \<100/nL, INR \>1.3, PTT \>50 sec. * Clinically significant abnormalities in the ECG * Recurrent major hypoglycemia or hypoglycemic unawareness as judged by the investigator * Lipodystrophy which in the judgment of the investigator would pose a problem in terms of variability of absorption of injected insulin * Use of systemic corticoids for the last three month prior screening examination or treatment with medication known to interfere with glucose metabolism such as non-selective ß-blockers, or mono amine oxidase (MAO) inhibitors, ACE-inhibitors or thiazides, unless such medical treatment has existed for at least three months and is not changing, prior to screening examination * Any disease requiring use of anti-coagulants * Impaired hepatic or renal functions as judged by the investigator * Cardiac problems as judged by the investigator * Uncontrolled hypertension (treated or untreated) RRsyst. \>140 mmHg, RRdiast. \> 90 mmHg * Mental incapacity, unwillingness or language barriers precluding adequate understanding or co-operation * Current addiction to alcohol or substances of abuse as determined by the investigator * Allergy to plaster/adhesive * Any other condition that the investigator feels would interfere with trial participation or evaluation of results. * Females of childbearing potential who are pregnant, breast-feeding or intend to become pregnant or are not using adequate contraceptive methods (adequate contraceptive measures include sterilisation, hormonal intrauterine devices, oral contraceptives, sexual abstinence or vasectomised partner)