Patient position monitoring device for monitoring a patient during irradiation, whereby two or more measurement units are used to measure the distances to contact points on the patient skin corresponding to the beam isocenter

摘要

Device for monitoring the position of a patient during irradiation, especially during a CT scan prior to treatment or surgery. The device has two or more distance measurement instruments for measuring the distance to a contact point (18, 20, 22, 38) on the patient skin. The measurement instruments are aligned so that distance measurement is relative to the isocenter of the treatment beam. An evaluation unit determines whether a patient's position has changed from at least two distance values.