Patent ID: 7663458

Claim:
A coil system for contact-free magnetic navigation of a magnetic body in a three-dimensional working space accessible in the z-direction of an orthogonal x, y, z coordinate system, said coil system comprising fourteen individually controllable individual coils that generate three magnetic field components B x , B y and B z and five magnetic field gradients from a diagonally symmetrical and spur-free gradient matrix GM GM = ( ⅆ B x ⅆ x ⅆ B y ⅆ x ⅆ B z ⅆ x ⅆ B x ⅆ y ⅆ B y ⅆ y ⅆ B z ⅆ y ⅆ B x ⅆ z ⅆ B y ⅆ z ⅆ B z ⅆ z ) , wherein two of the three diagonal elements of the gradient matrix GM and one of the extra-diagonal elements are to be generated with the individual coils from the three gradient element pairs of the gradient matrix GM that are symmetrical to the diagonal; wherein at least six of the individual coils are provided, of which at least two are situated on frontal surfaces of the coil system and remaining individual coils of the coil system lie on at least one non-quadric, tube-shaped generated surface extending in the z-direction and enclosing the working space; and wherein at least four of the individual coils are distributed in a circumferential direction of the coil system on at least one further, non-quadratic tube-shaped generated surface surrounding the working space, said at least one further generated surface being located within the at least one first generated surface.