The feasibility assessment of the auto tuning respiratory compensation system with ultrasonic image tracking technique

• Main Authors: Shu-Kan Nieh, 聶叔衎
• Other Authors: Ho-Chiao Chuang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/2tn5h7

碩士 === 國立臺北科技大學 === 機電整合研究所 === 102 === The purpose of this study is to evaluate the feasibility assessment of the auto tuning respiratory compensation system with ultrasonic image tracking technique. According to the respiratory motion, the maximum range of organ displacement surrounding the lower lobe of lung is Superior-Inferior. The SI direction is issued with respiratory compensation in this study. However, there is respiratory signal delay in the system through generating ultrasound image, image processing, and signal transferring. For compensating the signal delay time, this study approaches the design of phase-lead compensator in the controller. There are two variants, variable “a” and gain of compensator, in the design of phase-lead compensator. When fixing the delay time for compensating, the variants will increase as the frequency of respiratory signal raise up. When fixing the frequency of respiratory signal, the variants will also increase as the delay time raise up. Before design of phase-lead compensator, we analyzed the system delay and concluded the respiratory delay time as 0.254+0.023 seconds in this study. For evaluating the feasibility assessment of the auto tuning respiratory compensation system with ultrasonic image tracking technique, there are 5 different frequencies of sine wave for simulating the respiratory signal as 0.5, 0.333, 0.25, 0.2, and 0.167 Hz. According to the varying frequency of sine wave, we tuned the variants of the compensator through the relationship of curve fitting. The conclusion is the rate of compensating the respiratory motion is stable and improved through phase-lead compensator. The rate of compensation promotes to 7.04-18.82% rather than without compensator, and the average of the compensation rate is approximately 97%. As a result, the auto tuning respiratory compensation system with ultrasonic image tracking technique is feasible. The advantages of the auto tuning respiratory compensation system as follows: 1. Non-invasive ultrasound sensor for active respiratory compensation. 2. Continuously radiotherapy treatment with this system. 3. Independent system suited for any treatment couch. 4. Operating easily for auto tuning respiratory compensation system.