Multi-leaf collimator

US6388816B2 · kind B2 · utility

Assignee

• Elekta AB · SE

Inventors

• Kevin Brown · Horsham, GB
• Christopher Snook · Gräfenberg, DE
• William R. Harwood

Key dates

• Filing date: Feb 22, 2001
• Grant date: May 14, 2002
• Expiry date: Feb 22, 2021

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61N5/1042
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A collimator for a therapeutic linear accelerator comprising first and second opposed arrays of individually longitudinally moveable elongate leaves, and a blocking element arranged transverse to the two arrays and moveable in that transverse direction, thereby to move into a gap between the tips of a leaf from the first array and a leaf from the second array. The blocking element and the two arrays can be in the same plane, thereby reducing the overall height of the device. As the tips of the leaves are usually profiled, it is preferred that the side edges of the blocking element are profiled to a complementary shape. The side edges of the leaves are usually non-vertical in order to allow for the divergence of the radiation beam. Each leaf will have a different angle. Accordingly, it is preferred that the tip of the blocking element has a variable angle, in order to match the angle of whichever leaf is adjacent. This could be achieved, for example, by making at least the tip in a laminar fashion so that each lamination can slide to form a tip which is angled. Alternatively, a rotatable element could be incorporated into the tip. It is also preferred that the blocking element has a…