Capsule endoscopy is a minimally invasive diagnostic technology for gastrointestinal diseases providing images from the human’s digestion system. Developing a robust and real-time localization algorithm to determine the orientation and position of the endoscopic capsule is a crucial step toward medical diagnostics. In this thesis, we propose a novel model-aided real-time localization approach to estimate the position and orientation of a magnetic endoscopic capsule swimming inside the stomach. In the proposed method, the governing equations of the motion of an ellipsoidal capsule inside the fluid, considering different hydrodynamics interactions, are derived. Then, based on the dynamic model, an Extended Kalman Filter (EKF) driven by the noisy measurements of the multiple magnetic sensors is developed. According to the simulations, the proposed method not only can accurately localize the endoscopic capsule but also can identify the unknown parameters of the dynamic model. The results confirm the superiority of our proposed method compared to the conventional localization technique in the presence of dynamic model uncertainties and corrupted sensor data. Experimental realization of the proposed technique proves the achievement of high accuracy in the trajectory estimation of the magnetic endoscopic capsule.
The active endoscopic capsule enables the physician to steer the device to any desired position and direction, resulting in a better diagnose of the disease. Due to the model uncertainties and the existence of disturbances in the gastrointestinal system, traditional control methods cannot achieve robust performance and stability. To overcome this issue, in this thesis, we propose an optimal robust sliding mode controller for 5 DOF control of the capsule endoscope using an electromagnetic actuation system. The efficiency of the proposed control method is compared with a feedback linearization controller method considering the model uncertainties and external disturbances. Simulations and experimental testing are used to verify the performance of the suggested trajectory control method.