# US 9,437,340 B2 · Leaf module for a multi-leaf collimator and multi-leaf collimator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,437,340 B2 - Document ID: US9437340B2 - Status: Granted - Kind: B2 - Application number: 14/415,097 - Filed: 2013-07-18 - Published: 2015-06-18 - Granted: 2016-09-06 - Earliest claimed: 2012-07-19 - Assignees: Deutsches Krebsforschungszentrum; Precisis AG - Applicants: Deutsches Krebsforschungszentrum; Precisis AG - Inventors: Gernot Echner; Armin Runz; Martin Baumann; Stefan Ueltzhöffer - Web page: https://patentgrep.com/patent/US9437340B2 ## CPC - G21K 1/046: {varying the contour of the field, e.g. multileaf collimators} - A61N 5/1045: {using a multi-leaf collimator, e.g. for intensity modulated radiation therapy or IMRT} - F04C 2270/041: Controlled or regulated - G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS ## Abstract The invention relates to a leaf module (102) for a multi-leaf collimator (132), comprising a leaf unit (104) and a leaf drive unit (106), wherein the leaf unit (104) comprises a leaf (108) for shielding beams from a selected area, and the leaf unit (104) is mounted displaceably in an adjusting direction (110), wherein the leaf drive unit (106) is designed to displace the leaf unit (104) linearly in the adjusting direction (110), and wherein the leaf drive unit (106) comprises at least one drive mechanism (112), being designed in such a way that the drive mechanism (112) operates based on pneumatic actuation. Furthermore, the invention relates to a multi-leaf collimator (132) comprising a plurality of leaf modules (102) according to the invention. The invention is based on the objective of designing a leaf module (102) and a multi-leaf collimator (132) as compactly as possible, while achieving a simple, reliable and variable adjustability of the leaf unit (104). The invention is regarded to be particularly suitable for implementation in Cobalt-60 or mid- to low-end linac radiotherapy apparatuses. ## Claims ### Claim 1 A multi-leaf collimator comprising: a plurality of leaf modules, each leaf module comprising a leaf unit comprising a leaf for shielding beams from a selected area, the leaf unit being mounted displaceably in an adjusting direction, and a leaf drive unit configured to displace the leaf of the leaf unit linearly in the adjusting direction, the leaf drive unit comprising at least one drive mechanism that operates based on pneumatic actuation, and a single reservoir for compressed gas configured to supply compressed gas to several or all drive mechanisms that comprise at least one side of the multi-leaf collimator, wherein the at least one side of the multi-leaf collimator includes more than one leaf module, and wherein the drive mechanism comprises a pressure cylinder. ### Claim 2 (depends on 1) The multi-leaf collimator according to claim 1, wherein the single reservoir communicates with a pressure cylinder being comprised by the drive mechanism. ### Claim 3 (depends on 1) The multi-leaf collimator according to claim 1, wherein the drive mechanism further comprises a piston, wherein the piston is linked directly or indirectly to the leaf unit, and wherein a displacement of the piston results in a displacement of the leaf unit. ### Claim 4 (depends on 3) The multi-leaf collimator according to claim 3, wherein the piston comprises a sealing element. ### Claim 5 (depends on 4) The multi-leaf collimator according to claim 4, wherein the sealing element is an o-ring. ### Claim 6 (depends on 1) The multi-leaf collimator according to claim 1, wherein the leaf unit comprises a guiding rod extending in the adjusting direction, and wherein the guiding rod is a separate part being attached to the leaf. ### Claim 7 (depends on 6) The multi-leaf collimator according to claim 6, wherein the guiding rod is displaceably arranged in a pressure cylinder being comprised by the drive mechanism. ### Claim 8 (depends on 7) The multi-leaf collimator according to claim 7, wherein the pressure cylinder provides a linear guidance to the guiding rod. ### Claim 9 (depends on 6) The multi-leaf collimator according to claim 6, wherein the guiding rod is linked to a piston being comprised by the drive mechanism. ### Claim 10 (depends on 1) The multi-leaf collimator according to claim 1, wherein the leaf drive unit is configured to displace the leaf unit in the adjusting direction and additionally provide guidance to the leaf unit with respect to any direction being oriented perpendicularly related to the adjusting direction. ### Claim 11 (depends on 1) The multi-leaf collimator according to claim 1, wherein the leaf comprises a high density material. ### Claim 12 (depends on 11) The multi-leaf collimator according to claim 11, wherein the high density material is selected from the group consisting of brass, lead and tungsten. ### Claim 13 (depends on 1) The multi-leaf collimator according to claim 1, wherein the multi-leaf collimator comprises two assemblies of leaf modules, wherein the leaf modules of each assembly face each other. ### Claim 14 (depends on 13) The multi-leaf collimator according to claim 13, wherein each assembly of leaf modules comprises one single reservoir for compressed gas. ### Claim 15 (depends on 13) The multi-leaf collimator according to claim 13, wherein the multi-leaf collimator is configured for application in a Cobalt-60 radiotherapy apparatus. ### Claim 16 (depends on 13) The multi-leaf collimator according to claim 13, wherein a single reservoir for compressed gas is provided and configured to correspond with and simultaneously supply the two assemblies of leaf modules. ### Claim 17 (depends on 1) The multi-leaf collimator according to claim 1, wherein the leaf unit comprises a guiding rod extending in the adjusting direction, and wherein the guiding rod is an integral part of the leaf. ### Claim 18 (depends on 17) The multi-leaf collimator according to claim 17, wherein the guiding rod is displaceably arranged in a pressure cylinder being comprised by the drive mechanism.