Reivindicaciones

1. External magnetically actuated valve for an artificial intraurethral urinary sphincter, characterized in that it comprises: - A hollow cylindrical body, made of a biocompatible material. - A piston, made from a soft magnetic material, with one end in the shape of a cone or hemisphere, which moves within the inside of the cylindrical body, and - A internal permanent toroidal magnet placed in the inlet orifice of the valve cylindrical body. 2. External magnetically actuated valve for an artificial intraurethral urinary sphincter, as claimed in above claim, characterized in that the piston may have a triangular or circular section. 3. External magnetically actuated valve for an artificial intraurethral urinary sphincter, as claimed in claim 1, characterized in that the valve is closed by the attraction exerted by the permanent magnet on the internal piston. 4. External magnetically actuated valve for an artificial intraurethral urinary sphincter, as claimed in above claims, characterized in that the valve is opened from the outside by approaching an external magnet, which exerts on the piston a greater force than the internal toroidal magnet and in the opposite sense, allowing urine to pass outwards. 5. External magnetically actuated valve for an artificial intraurethral urinary sphincter, as claimed in above claims, characterized in that it is provided with a safety system based on the decreasing force exerted between the internal magnet and the piston as the magnetic field decreases with increasing distance. 6. External magnetically actuated valve for an artificial intraurethral urinary sphincter as claimed in above claims, characterized in that it is implanted by means of cytoscopy.