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SU‐E‐T‐247: A Solution to the Real‐Time Safety Interlock Control of the Linac and the Externally Mounted Multi‐Leaf Collimator
Author(s) -
Tan Youheng,
Li Yongjie,
Yao Jonathan
Publication year - 2011
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3612198
Subject(s) - collimator , linear particle accelerator , video graphics array , interlock , computer science , computer hardware , splitter , engineering , optics , electrical engineering , beam (structure) , physics , field programmable gate array
Purpose: This study aims to provide a solution for a real‐time safety interlock control of the linac and the externally mounted dynamic multi‐leaf collimator (dMLC) from other manufacturers, between which it is difficult to build a bridge because of the internal interfaces unopened to other manufacturers. Methods: An external dMLC is mounted on the linac head. They can not work corporately and safely if no interlock control is built between them. Our solution is to set a VGA splitter between the linac control computer and its monitor, and from this VGA splitter a VGA signal grabber is connected to the MLC control computer. Through this connection, the data sent to the linac console monitor is also captured and sent to the MLC control computer real time in a form of image. By analyzing this captured image using methods of feature extraction and pattern recognition, the current setting of the linac is extracted and used to judge whether the current setting of the linac is consistent with that stored on the MLC control computer. Results: The display format on the monitor is generally fixed for a specified accelerator, which is helpful for the quick and accurate extraction of the parameter setting of the linac from the captured image. When the parameter settings on linac control computer and MLC control computer are not identical, the MLC control computer pops up an error message, and at the same time, a NOT READY signal is sent to the READY/NOT‐READY circuit in the linac, and hence a safety interlock control is realized. Conclusions: Externally mounted dMLC is an economic solution to upgrade the linac that has no built‐in dMLC. Safety interlock control between them can be effectively realized simply using a VGA signal grabber and a control signal sent to the linac. Funding support: This work was supported by the Program for New Century Excellent Talents in University of China (NCET‐07‐0151) and the Natural Science Foundations of China (61075109, 30730036).