Design of adaptive controller for brachytherapy systems

نوع: Type: thesis

مقطع: Segment: Masters

عنوان: Title: Design of adaptive controller for brachytherapy systems

ارائه دهنده: Provider: Roya Faridi

اساتید راهنما: Supervisors: Professor Soheil Ganjefar, Professor Abbas Ramezani

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Professor Majid Ghaniee, Professor MohammadAmin Ghasemi

زمان و تاریخ ارائه: Time and date of presentation: 2022

مکان ارائه: Place of presentation: online

چکیده: Abstract: One of the most challenging steps in brachytherapy is the insertion of needles inside or next to the target tissue. In these medical procedures, needles are inserted into tissue to guide the position of radioactive sources. Low-dose radioactive sources are permanently inserted into the tissue, while a high-dose radioactive source is temporarily placed in the desired position in order to deliver the prescribed dose to clinical targets. As a result, accurate needle placement directly affects the radiation dose delivery and treatment outcomes of patients. Any deviation from the target position of the radioactive sources can lead to optimal dose distribution and insufficient tumor coverage. Therefore, it is important to develop a robust and mathematical tool that can perform automatic needle placement with high accuracy for various medical procedures and conditions. In this dissertation, we propose a new concept for automatic needle insertion using a new automated robotic system. The mathematical model of this system is presented in detail, which allows the design of model predictive control as well as adaptive control of model predictors that can be used to manage the mechanism. The purpose of this study is to minimize the displacement and change the angle of the needle tip so that the external force and torque of the needle that is applied to the tissue and leads to the deviation of the needle, in this study, these values are considered using a steel needle. Stainless steel and human-simulated tissue samples were calculated in a metal forming research laboratory. The selection of the exact model of the needle, which is considered as Bernoulli Euler beam, and the division of the continuous mass of the needle into several discrete parts are other researches of this dissertation.