Varian Medical Systems Inc
SYSTEMS AND METHODS FOR ENERGY MODULATED RADIATION THERAPY

Abstract:

A method performed by a medical device, includes: providing a permanent magnetic field by a permanent magnet; operating an electromagnet to provide a first electromagnetic field with a first electromagnetic field value; and operating the electromagnet to provide a second electromagnetic field with a second electromagnetic field value; wherein the first electromagnetic field and the permanent magnetic field forms a first total magnetic field with a first total magnetic field value, and wherein the second electromagnetic field and the permanent magnetic field forms a second total magnetic field with a second total magnetic field value; wherein the first total magnetic is formed when an electric field in an accelerator or an energy level of a particle beam has a first value, and wherein the second total magnetic field is formed when the electric field in the accelerator or the energy level of the particle beam has a second value.