The invention relates to a device for selective modification/destruction of organic tissue and to the use thereof for biomedical purposes, which includes a magnetic field generator (1) housed in a Faraday cage (6), with coils/conductors and a device for controlling the electrical intensity and voltage parameters of the terminals (7). Said generator consists of a device for generating chaotic magnetic fields ( ) coils/conductors having a geometric configuration (FIG. 1) which generates chaotic magnetic field lines, characterised topologically in space by chaotic field lines, which surround the magnetic field lines contained within a magnetic torus or KAM island (2), said structure being topologically controlled in space since it is contained within the Faraday cage (6). In addition, the invention also includes one or more devices generating polarised electromagnetic frequencies (infrared, microwave or X-ray) (3, 3.1, 3.2) with focussing capacity (4), coherence with the resonant frequency and polarisation in the direction of maximum absorbance of the nanoparticles/biomolecules oriented in the KAM island (2) which will submerge the target tissue for the selective modification or destruction. The device may operate at the X-ray frequency with or without the use of nanoparticles/biomolecules, in which case the destruction of the target tissue (4) occurs by controlling, in the direction of the paths, the secondary electrons and other charged particles produced by the X-ray beam, in the target tissue (4), by modulating the magnetic field intensity of the magnetic KAM island (2) in the target tissue (4), and the direction of incidence of the magnetic KAM island with respect to the X-ray beam in the target tissue (4).
