An artificial ventricle (12 or 14) comprising: an inlet (16 or 26) for receiving blood; an outlet (18 or 28) for discharging blood; a chamber (20 or 30) disposed between the inlet (16 or 26) and the outlet (18 or 28); a mechanism for actuating the artificial ventricle (12 or 14) between an expanded configuration and a contracted configuration, wherein in the expanded configuration blood flows into the inlet (16 or 26) and in the contracted configuration blood flows out of the outlet (18 or 28); and characterised in that the chamber (20 or 30) has a resilient outer wall and the mechanism for actuating the artificial ventricle (12 or 14) between the expanded configuration and the contracted configuration includes: a first pad disposed on the resilient outer wall of the chamber (20 or 30), the first pad having a magnetic field generator; and a second pad disposed on the resilient outer wall of the chamber (20 or 30) opposite of the first pad, the second pad having a material which is attracted to the magnetic field generator when the magnetic field generator generates a magnetic field, wherein the second pad moves towards the first pad when the magnetic field generator generates a magnetic field and thereby actuates the artificial ventricle (12 or 14) to the contracted configuration by contracting the resilient outer wall of the chamber (20 or 30), and wherein the resilient outer wall of the chamber (20 or 30) actuates the artificial ventricle (12 or 14) to the expanded configuration when the magnetic field generator is not generating a magnetic field and the material is not attracted to the magnetic field generator. an inlet (16 or 26) for receiving blood; an outlet (18 or 28) for discharging blood; a chamber (20 or 30) disposed between the inlet (16 or 26) and the outlet (18 or 28); a mechanism for actuating the artificial ventricle (12 or 14) between an expanded configuration and a contracted configuration, wherein in the expanded configuration blood flows into the inlet (16 or 26) and in the contracted configuration blood flows out of the outlet (18 or 28); and characterised in that the chamber (20 or 30) has a resilient outer wall and the mechanism for actuating the artificial ventricle (12 or 14) between the expanded configuration and the contracted configuration includes: a first pad disposed on the resilient outer wall of the chamber (20 or 30), the first pad having a magnetic field generator; and a second pad disposed on the resilient outer wall of the chamber (20 or 30) opposite of the first pad, the second pad having a material which is attracted to the magnetic field generator when the magnetic field generator generates a magnetic field, wherein the second pad moves towards the first pad when the magnetic field generator generates a magnetic field and thereby actuates the artificial ventricle (12 or 14) to the contracted configuration by contracting the resilient outer wall of the chamber (20 or 30), and wherein the resilient outer wall of the chamber (20 or 30) actuates the artificial ventricle (12 or 14) to the expanded configuration when the magnetic field generator is not generating a magnetic field and the material is not attracted to the magnetic field generator. a first pad disposed on the resilient outer wall of the chamber (20 or 30), the first pad having a magnetic field generator; and a second pad disposed on the resilient outer wall of the chamber (20 or 30) opposite of the first pad, the second pad having a material which is attracted to the magnetic field generator when the magnetic field generator generates a magnetic field, wherein the second pad moves towards the first pad when the magnetic field generator generates a magnetic field and thereby actuates the artificial ventricle (12 or 14) to the contracted configuration by contracting the resilient outer wall of the chamber (20 or 30), and wherein the resilient outer wall of the chamber (20 or 30) actuates the artificial ventricle (12 or 14) to the expanded configuration when the magnetic field generator is not generating a magnetic field and the material is not attracted to the magnetic field generator.