To investigate how pulse wave velocity, aortic augmentation index and the arterial pulse wave given by the Arteriograph contributes to preoperative assesment, intraoperative and intensive care monitoring.

Inclusion Criteria:

For the "preoperative" arm:

• Signed informed consent form
• Arterial catheter for hemodynamic monitoring

For the "intraoperative" arm:

• Signed informed consent form
• Arterial catheter for hemodynamic monitoring
• The operation will presumably last for more than 2 hours

For the "intensive care unit" arm:

• Signed informed consent form
• PiCCO monitor for hemodynamic monitoring

Exclusion Criteria:

For the "preoperative" arm:

• Pregnancy
• Subject belongs to a vulnerable group (ISO 14155:2011) e.g.: study member, medical student

For the "intraoperative" arm:

• Pregnancy
• Subject belongs to a vulnerable group (ISO 14155:2011) e.g.: study member, medical student
• Measuring blood pressure on both arms is not possible
• Insertion of an arterial catheter is not necessary or contraindicated
• Insertion of a central venous catheter is not necessary or contraindicated

For the "intensive care unit" arm:

• Pregnancy
• Subject belongs to a vulnerable group (ISO 14155:2011) e.g.: study member, medical student