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WE‐G‐213CD‐06: Implementation of Real‐Time Tumor Tracking Using Robotic Couch
Author(s) -
Buzurovic I,
Yu Y,
Podder T
Publication year - 2012
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 - 10.1118/1.4736207
Subject(s) - computer science , amplifier , tracking (education) , controller (irrigation) , motion control , encoder , rotary encoder , simulation , artificial intelligence , robot , bandwidth (computing) , telecommunications , psychology , pedagogy , agronomy , biology , operating system
Purpose: The purpose of this study was to present a novel method for real‐ time tumor tracking using a commercially available robotic treatment couch, and to evaluate tumor tracking accuracy. Methods: Commercially available robotic couches are capable of positioning patients with high level of accuracy; however, currently there is no provision for compensating tumor motion using these systems. Elekta's existing commercial couch (PreciseTM Table) was used without changing its design. To establish the real‐time couch motion for tracking, a novel control system was developed and implemented. The tabletop could be moved in horizontal plane (laterally and longitudinally) using two Maxon‐24V motors with gearbox combination. Vertical motion was obtained using robust 70V‐Rockwell Automation motor. For vertical motor position sensing, we used Model 755A‐Accu‐ Coder encoder. Two Baumer‐ITD_01_4mm shaft encoders were used for the lateral and longitudinal motions of the couch. Motors were connected to the Advance Motion Controls (AMC) amplifiers: for the vertical motion, motor AMC‐20A20‐INV amplifier was used, and two AMC‐Z6A8 amplifiers were applied for the lateral and longitudinal couch motions. The Galil DMC‐4133 controller was connected to standard PC computer using USB port. The system had two independent power supplies: Galil PSR‐12‐ 24‐12A, 24vdc power supply with diodes for controller and 24vdc motors and amplifiers, and Galil‐PS300W72 72vdc power supply for vertical motion. Control algorithms were developed for position and velocity adjustment. Results: The system was tested for real‐time tracking in the range of 50mm in all 3 directions (superior‐inferior, lateral, anterior‐ posterior). Accuracies were 0.15, 0.20, and 0.18mm, respectively. Repeatability of the desired motion was within ± 0.2mm. Conclusions: Experimental results of couch tracking show feasibility of real‐time tumor tracking with high level of accuracy (within sub‐millimeter range). This tracking technique potentially offers a simple and effective method to minimize healthy tissues irradiation.Acknowledgement: Study supported by Elekta,Ltd. Study supported by Elekta, Ltd.