Speaker
Description
Dynamic properties are a response of a sample to an applied dynamic stress. Changes in tissue viscoelasticity can be an indication of serious health issues; the flow induced in response to shear stress tells us about fluid viscosity.
Nuclear Magnetic Resonance (NMR) signal can be sensitized to measure displacements; its spatially-resolved NMR, also known as Magnetic Resonance Imaging (MRI), can provide a spatial distribution of stresses. However, conventional NMR and MRI instruments are big, expensive, and can only be used in a specially adapted laboratory. Portable NMR instruments are small, portable, inexpensive, and can be used virtually anywhere. The NMR signal comes from a “sensitive volume” outside the magnet array, greatly expanding the range of potential applications.
A well-controlled sensitive volume can be used as an integrator to measure dynamic properties, turning a portable NMR device into a versatile sensor. Its combination with a shear wave actuator enables portable NMR elastometry (see Fig. for optics- vs NMR-measured shear wave speeds). A NMR-measured response to shear stress can yield the flow index. A time-resolved detection of the transition time for a spin-up cylinder permits a completely non-invasive measurement of fluid viscosity. All our devices are homebuilt and can be assembled in a physics laboratory.
W. Selby, V. Belzile, J. Marshall, I. Mastikhin; Completely noninvasive viscosity characterization using a portable magnetic resonance sensor. Physics of Fluids 1 July 2025; 37 (7): 073119.
William Selby, Phil Garland, Igor Mastikhin. Transient shear wave elastometry using a portable magnetic resonance sensor. Magnetic resonance in Medicine (2025) 94(1):373-385.
Selby, W., Garland, P., and Mastikhin, I. "A Simple Portable Magnetic Resonance Technique for Characterizing Circular Couette Flow of Non-Newtonian Fluids", Journal of Magnetic Resonance (2022) 345, 107325.
Selby, W., Garland, P., and Mastikhin, I. "Dynamic Mechanical Analysis with Portable NMR", Journal of Magnetic Resonance (2022) 339, 107211
| Keyword-1 | portable NMR |
|---|---|
| Keyword-2 | rheometry |
| Keyword-3 | elastometry |