Design and analysis of a compact high-torque permanent magnet vernier machine for a portable MRI system

Low-field magnetic resonance imaging (MRI) has gained interest in recent years as a more accessible and economical alternative to conventional high-field MRI systems. Advancements in hardware design and machine learning algorithms have improved the clinical viability of low-field systems, enhancing their suitability for widespread medical usage and contributing to more equitable access to diagnostic imaging. An innovative portable low-field MRI device utilizes three rotating magnet arrays to provide spatial information required for imaging. In this system, strict size constraints necessitate compact motors capable of deliver- ing high torque consistently. Permanent magnet vernier machines (PMVM) have emerged as a promising alternative, offering high torque at low speeds through the magnetic gearing effect. This topology has been successfully employed in other direct-drive applications and is well-suited for this use case. This thesis presents the design, analysis, and assembly of a compact, torque-dense PMVM tailored for use with a novel portable MRI system. Emphasis is placed on achieving a small form factor, high torque production, and fine angular resolution. The combined electromagnetic design and control scheme establish a solid foundation for prototyping and deploying the machine in practical, high-torque, space-limited applications.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Ayar, Nina

Contributors dc:contributor

• Haran, Kiruba S.

• Permanent Magnet Machine
• Vernier
• Compact Machine
• Torque Density Maximization
• Portable Medical Devices
• Mri

Statement dc:rights

• Copyright 2025 Nina Ayar

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129994

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129994