The invention is directed to a method and arrangements for the suppression of debris in short-wavelength radiation sources based on a plasma, particularly for EUV sources for semiconductor lithography. The shielding member and the let-off means are arranged in the door. The predictive models for road reliability are built from libraries of data about sensed variances and road segments. The patient transfer device includes a heart rate sensor positioned to provide a heart rate measurement of the patient when the patient is received on the patient transfer device.