| Summary: | 碩士 === 國立臺北科技大學 === 製造科技研究所 === 100 === This study drove the treatment couch for reverse motion, opposite from the direction of the targets, in order to offset organ displacement generated by respiratory motion. A strain gauge was used to replace a pressure transducer as a respiratory signal capture device to obtain abdomen respiratory signals. The simulated respiratory system (SRS) position error is approximately 0.45~1.42mm, while the respiratory compensating system (RCS) position error is approximately 0.48~1.42mm. Compare with the pressure transducer RCS, the position error can be improved by an amount of 67.7%. This study verified the effect of RCS in offsetting the target displacement by three methods. The first method was using the SRS to simulate organ displacements, human respiratory and being compensated by RCS. Then the target movement was analyzed by fluoroscopy images and the results suggested that compensated rate can be improved to 85.72%. The Second method was using LINAC to irradiate 300cGy dose on the EBT film. The results show that when the input respiratory signals of SRS are sine wave signals, the average dose in the target area and the 95% isodose area after compensation is improved by 1.4~24.4% and 15.3~76.9%, respectively. If human respiratory signals are input to the SRS, the average dose in the target area and the 95% isodose area after compensation is improved by 31.8~67.7% and 15.3~86.4%, respectively. Gamma passing rate after compensation can be improved to 100% only when the displacement of the respiratory motion is within 10~30mm. The third method was capturing patients’ respiratory signals, while using the fluoroscopy to observe their diaphragm and activating RCS to offset the displacements of targets. The experimental results suggested that, a displacement of 67.3~75.6% can be offset. The results proved that the proposed RCS can contribute the compensation of organ displacement caused by respiratory motion.
|
|---|
