Prediction of Propofol Effect Compartment Concentrations

The goal of this observational study is to learn about the prediction of the effect of Propofol by means of EEGs. The main questions it aims to answer are: * Develop models that can reliably predict the effect of Propofol * Select the most well suited model for clinical practice * Compare this model to already existing models (e.g. Schnider-model) Participants will asked to allow us to collect and use the EEG data recorded during the operations.