The Application of the ELFI-TECH Monitor for Measurement of Blood Pressure, Cardiac Output and Extend of Regional and Neuraxial Anesthesia: The Elfitor Study

The elfitor device is a small non invasive device that uses dynamic light scattering to measure skin bloodflow, blood velocity, coagulation and hemodynamic parameters. In this study, the investigators will investigate whether the elfitor device is able to detect changes in bloodpressure, cardiac output during general anesthesia. Furthermore, the investigators will investigate changes in cutanuous blood flow in different parts of the body during peripheral nerve or neuraxial block.Being able to monitor these entities, under- and overdosing of general and local anesthetics may be prevented, resulting in favorable hemodynamics and better intra and postoperative pain relieve.