Assessment of MR compatibility and machinability using the fuzzy comprehensive evaluation method for material selection of MR device.

ABSTRACT Objective To develop magnetic resonance (MR) robot used in the magnetic field environment, materials selected for manufacturing robot should have good MR compatibility and machinability. Therefore, it is becoming increasingly urgent to develop an evaluation method considering the above two factors at the same time. Methods A series of experiments were done to study the interaction between the magnetic field of MR scanner and the material samples, and to determine the samples' machinability. Four kinds of materials including metal and plastics with different geometric shape were used to test the artifacts, force and torque in magnetic resonance image (MRI) tube according to standard method. Three items including surface roughness, cutting force and chip shape were analyzed to evaluate the machinability of four samples. The fuzzy comprehensive evaluation method was adopted to process these experimental data for choosing the most suitable robot material in MR environment. Results The quantized values of MR compatibility and machinability are achieved, and a new methodology for material selection are developed, which provides systematic guideline for engineer and researcher to choose suitable robot materials used in an MRI tube. Polyformaldehyde of four kinds of material is determined to be the most suitable one for MR robots or devices. Conclusion A thorough examination of four commonly used engineering materials has been discussed and the fuzzy comprehensive evaluation method is suitable for choosing MR compatible robot materials. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 45B: 1-12, 2015 [ABSTRACT FROM AUTHOR]