Evaluation of the Electronic Nose for Diagnosis of MS We will apply a four-phase approach in order to achieve the objectives of this research. In the first phase we will collect suitable breath samples from each patient and compare the patient data to age-adjusted healthy controls. In the second phase we will analyze the collected breath samples with the electronic nose setup. In the third phase we will carry out auxiliary chemical analysis, using gas-chromatography linked with mass spectrometry (GC-MS), of the breath samples under different aspects. The fourth phase will aim at the improvement of our electronic nose setup and will be conducted in parallel to the first three phases.