A medical apparatus comprising a: - a magnetic resonance imaging system for acquiring magnetic resonance data, wherein the magnetic resonance imaging system comprises a magnet; - a medical device; and - a slip ring assembly (400, 500) operable for supplying electrical power to the medical device; wherein the slip ring assembly comprises: - a cylindrical body with an axis of symmetry, - a rotating member for rotating about the axis of symmetry and for rotating about the magnet, wherein the medical device is mounted to the rotating member; - a first cylindrical conductor, wherein the first cylindrical conductor is attached to the cylindrical body; - a second cylindrical conductor, wherein the first and second cylindrical conductive elements overlap entirely, wherein the second cylindrical conductor is connected to the cylindrical body, wherein the first cylindrical conductor and the second cylindrical conductors are electrically isolated; - a first set of conductive elements (112, 712), wherein each of the set of conductive elements is connected to the second cylindrical conductor, wherein the first set of conductive elements is formed by a first cylindrical contact, wherein the first cylindrical contact is separated into the set of conductive elements by electrically isolating grooves; and - a brush assembly comprising a first brush and a second brush, wherein the first brush is operable to contact the first cylindrical conductor when the rotating member rotates about the axis of symmetry, wherein the second brush is operable to contact the set of conductive elements when the rotating member rotates about the axis of symmetry. - a magnetic resonance imaging system for acquiring magnetic resonance data, wherein the magnetic resonance imaging system comprises a magnet; - a medical device; and - a slip ring assembly (400, 500) operable for supplying electrical power to the medical device; wherein the slip ring assembly comprises: - a cylindrical body with an axis of symmetry, - a rotating member for rotating about the axis of symmetry and for rotating about the magnet, wherein the medical device is mounted to the rotating member; - a first cylindrical conductor, wherein the first cylindrical conductor is attached to the cylindrical body; - a second cylindrical conductor, wherein the first and second cylindrical conductive elements overlap entirely, wherein the second cylindrical conductor is connected to the cylindrical body, wherein the first cylindrical conductor and the second cylindrical conductors are electrically isolated; - a first set of conductive elements (112, 712), wherein each of the set of conductive elements is connected to the second cylindrical conductor, wherein the first set of conductive elements is formed by a first cylindrical contact, wherein the first cylindrical contact is separated into the set of conductive elements by electrically isolating grooves; and - a brush assembly comprising a first brush and a second brush, wherein the first brush is operable to contact the first cylindrical conductor when the rotating member rotates about the axis of symmetry, wherein the second brush is operable to contact the set of conductive elements when the rotating member rotates about the axis of symmetry. - a cylindrical body with an axis of symmetry, - a rotating member for rotating about the axis of symmetry and for rotating about the magnet, wherein the medical device is mounted to the rotating member; - a first cylindrical conductor, wherein the first cylindrical conductor is attached to the cylindrical body; - a second cylindrical conductor, wherein the first and second cylindrical conductive elements overlap entirely, wherein the second cylindrical conductor is connected to the cylindrical body, wherein the first cylindrical conductor and the second cylindrical conductors are electrically isolated; - a first set of conductive elements (112, 712), wherein each of the set of conductive elements is connected to the second cylindrical conductor, wherein the first set of conductive elements is formed by a first cylindrical contact, wherein the first cylindrical contact is separated into the set of conductive elements by electrically isolating grooves; and - a brush assembly comprising a first brush and a second brush, wherein the first brush is operable to contact the first cylindrical conductor when the rotating member rotates about the axis of symmetry, wherein the second brush is operable to contact the set of conductive elements when the rotating member rotates about the axis of symmetry.