Sharif Digital Repository

Hydrocephalus is a desease which causes by unnatural accumulation of cerebrospinal fluid in the brain ventricles. One of the most convenient ways to treat hydrocephalus disease is to use a brain shunt which consists of ventricular catheter, valve and distal catheter. Ventricular catheter obstruction is the main reason for shunt replacement in the human brain. This project attempts to remove obstruction of the ventricular catheter by mechanical forces. For this purpose, a magnet and a variable magnetic field suggested to apply mechanical force on a brush sliding on the shunt. On the inner surface of the ring-shaped magnet, brushes have been embedded and the magnet is placed on the outer... 

Different types of motion mechanisms can be found in any complicated or simple mechanical structure and linear motion is one of the most frequently used mechanisms for sure. In recent years, a wide variety of designs are developed to create linear motion, each one having many positive and negative points. Among already existing designs, those based on linear actuation are more considerable compared to those using a mechanical convertor to transform rotary motion to linear motion. This thesis presents two newly designed linear motors which utilize linear electromagnet actuators in their structures. In this study nonlinear models are developed for two linear motors. Although all conditions and...