Master of Sciences (Engineering), Case Western Reserve University, 2024, EECS - Electrical Engineering

Atrial fibrillation, a prevalent heart condition, poses significant health risks. Traditional treatment involves cardiac ablation catheters guided by x-ray fluoroscopy, which provides limited two-dimensional heart images and subjects patients to substantial radiation. Utilizing magnetic resonance imaging (MRI) in these procedures offers three-dimensional catheter visualization and eliminates radiation exposure. The MRI's magnetic field can be leveraged in order to control a robotic ablation catheter with small electromagnetic coils in the catheter tip. However, these coils may interact negatively with the MRI's radio-frequency transmitter, causing potential overheating. Prior research led to the development of a compact catheter prototype, primarily to demonstrate its fundamental operational principles. Nevertheless, this prototype's limited size renders it unsuitable for practical application within the human body. The aim of this thesis is to engineer a full-scale catheter, a task that presents considerable challenges due to the demanding conditions of the MRI environment and the occurrence of standing waves on uncoupled elongated wires. This prototype is designed to meet the kinematic workspace specifications identified in earlier studies, while also ensuring full compatibility with a human subject. The prototype maintains a low heat output and does not interfere with the MRI's functionality.

Committee: M. Cenk Cavusoglu (Committee Chair); David Kazdan (Committee Member); Mark Griswold (Committee Member) Subjects: Biomedical Engineering; Electrical Engineering; Engineering; Medical Imaging; Medicine; Robotics

Master of Sciences (Engineering), Case Western Reserve University, 2022, EECS - Electrical Engineering

Atrial fibrillation is a common cardiac condition which can place the patient at risk for many serious medical issues. Current interventional procedures employ cardiac ablation catheters guided using x-ray fluoroscopy imaging, which generates restricted two-dimensional images of the heart, and exposes the patient to a high dose of radiation. Three-dimensional catheter position data can be obtained and radiation exposure can be mitigated by using Magnetic Resonance Imaging (MRI) for this procedure. The magnetic field of the MRI machine can be strategically leveraged to steer and actuate a robotic ablation catheter, by energizing small embedded electromagnetic coils within the catheter tip. These coils however, may undesirably interact with the MRI machine's rotating radio-frequency (RF) magnetic field, potentially leading to excessive heating of the catheter or power supply damage. This thesis aims to characterize the RF response of actuation coils used in a novel MRI guided catheter system, and design an actuation coil set prototype which can safely operate in the MRI environment. The proposed final actuation coil set consists of 3 coils wound over the catheter body, and aims to improve the RF behavior of the coil set by implementing improved design elements such as a new winding pattern, wire gauge variation, and utilization of capacitors within the system. The final prototype presented successfully meets the required standards and is able to perform desired actuations.

Committee: M. Cenk Cavusoglu (Committee Chair); Francis Merat (Committee Member); Mark Griswold (Committee Member) Subjects: Biomedical Engineering; Biomedical Research; Electrical Engineering; Electromagnetics; Electromagnetism; Engineering; Medical Imaging; Robotics; Robots; Surgery

Master of Science (M.S.), University of Dayton, 2015, Mechanical Engineering

An active, feedback vibration control strategy with the goal of abating gear whine noise in rear-wheel and all-wheel drive vehicles is developed. The control strategy was implemented using two small inertial (proof mass) actuators, mounted on the rear subframe of a luxury all-wheel drive sedan with independent rear suspension, as the active elements in this application. Acceleration information measured by accelerometers nearly-collocated with the actuators was used as the feedback signal. The effectiveness of active vibration control was successfully demonstrated by examining the extent of reduction in the shaker induced vibration of the rear subframe as well as the sound pressure inside the vehicle. The evaluation of the active control scheme was extended to rolling dynamometer tests, during which effective reduction of vibration of rear subframe and the pressure inside the vehicle were demonstrated.

Committee: Reza Kashani Ph.D. (Committee Chair); Dave Myszka Ph.D. (Committee Member); David Perkins Ph.D. (Committee Member) Subjects: Mechanical Engineering