The device (1) has a case (11) with a hollow crown (16-1) that is made of a biocompatible material e.g. ceramic, and permeable to electromagnetic waves, where the crown form an annular throat in u-shape. A biocompatible material e.g. titanium, base of the case closes an opening of a hollow part of the column in a sealed manner. Dimension of a magnet (13) is compatible with a central housing (22) closed by an interior wall of the column, where two sides of the housing are opened.
