Patent ID: 7030396
Filing Date: 2006-04-18
Classification: A61N

Abstract:
1. A medical particle irradiation apparatus comprising: a rotating gantry carrying an irradiation unit emitting particle beams; a first ring member located within and supported by said rotating gantry such that it can rotate relative to said rotating gantry; a second ring member fixedly located across a path of said particle irradiation unit moving in the circumferential direction of said first ring member, from said first ring member; a position retaining unit disposed on said rotating gantry, said position retaining unit being in contact with both said first and second ring members to keep the positions of said first and second ring members in the circumferential direction substantially unchanged regardless of the rotation of said rotating gantry; a moving floor guide unit disposed on each of said first and second ring members, said moving floor guide unit having a substantially level portion at the bottom; and a flexible moving floor located between said first and second ring members, said flexible moving floor moving as said rotating gantry rotates while being guided by the respective moving floor guide units disposed on said first and second ring members, to form therein a therapy room into which a therapy bed is slid, wherein said position retaining unit comprises a first rotational element having an uneven portion which meshes with a first uneven portion disposed on said first ring member, a second rotational element having an uneven portion which meshes with a second uneven portion disposed on said second ring member, and a shaft member which couples said first and second rotational elements together, wherein said shaft member is attached to said rotating gantry such that said shaft member is free to rotate on its axis.