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Revolving permanent magnet causes rotating particle motion that makes new detection schemes possible in magnetomotive ultrasound

Evertsson, Maria LU ; Sjostrand, Sandra LU ; Erlov, Tobias LU ; Svensson, Ingrid LU ; Andersson, Roger LU ; Cinthio, Magnus LU and Jansson, Tomas LU (2019) 2019 IEEE International Ultrasonics Symposium, IUS 2019 In IEEE International Ultrasonics Symposium, IUS 2019-October. p.2373-2375
Abstract

Magnetomotive ultrasound, MMUS, can reveal the presence of a magnetic contrast agent by applying an external magnetic field. If the interaction between the agent and the field is strong enough, a movement that can be detected by ultrasound is induced in the surrounding tissue, thereby inferring the contrast agent distribution. Electromagnets have been used to generate the necessary magnetic field, but due to their size, weight, and propensity to heat up, they are impractical to work with. Furthermore, the resulting magnetic force is directed mainly along the symmetry axis of such magnets, and thus the resulting movement is primarily a one-dimensional oscillation. We suggest the use of a rotating permanent magnet that generates a... (More)

Magnetomotive ultrasound, MMUS, can reveal the presence of a magnetic contrast agent by applying an external magnetic field. If the interaction between the agent and the field is strong enough, a movement that can be detected by ultrasound is induced in the surrounding tissue, thereby inferring the contrast agent distribution. Electromagnets have been used to generate the necessary magnetic field, but due to their size, weight, and propensity to heat up, they are impractical to work with. Furthermore, the resulting magnetic force is directed mainly along the symmetry axis of such magnets, and thus the resulting movement is primarily a one-dimensional oscillation. We suggest the use of a rotating permanent magnet that generates a two-dimensional particle motion, and that this makes new detection schemes for MMUS possible. A prototype probe, containing a rotating neodymium magnet, was used to move a metallic sphere embedded in tissue-mimicking material. Cine loops recorded any in-plane movement with the magnetic probe placed in two different positions. A two-dimensional movement was demonstrated, using both our previously developed MMUS algorithm as well as a phase-based motion tracking algorithm. The conventional 1D MMUS processing detected the axial component in both magnetic probe positions, whereas the two-dimensional motion tracking algorithm estimated a rotational motion from the same measurements. The added dimension of motion could engender possibilities to more precise signal processing and thus improve robustness of magnetomotive motion detection. Moreover, the incorporation of a permanent magnet makes for a more practical device, as compared to using electromagnets.

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author
; ; ; ; ; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
2D, Magnetomotive, motion tracking, permanent, rotating
host publication
2019 IEEE International Ultrasonics Symposium, IUS 2019
series title
IEEE International Ultrasonics Symposium, IUS
volume
2019-October
article number
8925951
pages
3 pages
publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
conference name
2019 IEEE International Ultrasonics Symposium, IUS 2019
conference location
Glasgow, United Kingdom
conference dates
2019-10-06 - 2019-10-09
external identifiers
  • scopus:85077614648
ISSN
1948-5719
1948-5727
ISBN
978-1-7281-4597-6
9781728145969
DOI
10.1109/ULTSYM.2019.8925951
language
English
LU publication?
yes
id
d6c5f6d9-3eba-44fc-a4cb-5dbf8dc15613
date added to LUP
2020-01-27 14:16:55
date last changed
2020-01-30 03:59:26
@inproceedings{d6c5f6d9-3eba-44fc-a4cb-5dbf8dc15613,
  abstract     = {<p>Magnetomotive ultrasound, MMUS, can reveal the presence of a magnetic contrast agent by applying an external magnetic field. If the interaction between the agent and the field is strong enough, a movement that can be detected by ultrasound is induced in the surrounding tissue, thereby inferring the contrast agent distribution. Electromagnets have been used to generate the necessary magnetic field, but due to their size, weight, and propensity to heat up, they are impractical to work with. Furthermore, the resulting magnetic force is directed mainly along the symmetry axis of such magnets, and thus the resulting movement is primarily a one-dimensional oscillation. We suggest the use of a rotating permanent magnet that generates a two-dimensional particle motion, and that this makes new detection schemes for MMUS possible. A prototype probe, containing a rotating neodymium magnet, was used to move a metallic sphere embedded in tissue-mimicking material. Cine loops recorded any in-plane movement with the magnetic probe placed in two different positions. A two-dimensional movement was demonstrated, using both our previously developed MMUS algorithm as well as a phase-based motion tracking algorithm. The conventional 1D MMUS processing detected the axial component in both magnetic probe positions, whereas the two-dimensional motion tracking algorithm estimated a rotational motion from the same measurements. The added dimension of motion could engender possibilities to more precise signal processing and thus improve robustness of magnetomotive motion detection. Moreover, the incorporation of a permanent magnet makes for a more practical device, as compared to using electromagnets.</p>},
  author       = {Evertsson, Maria and Sjostrand, Sandra and Erlov, Tobias and Svensson, Ingrid and Andersson, Roger and Cinthio, Magnus and Jansson, Tomas},
  booktitle    = {2019 IEEE International Ultrasonics Symposium, IUS 2019},
  isbn         = {978-1-7281-4597-6},
  issn         = {1948-5719},
  language     = {eng},
  month        = {12},
  pages        = {2373--2375},
  publisher    = {IEEE - Institute of Electrical and Electronics Engineers Inc.},
  series       = {IEEE International Ultrasonics Symposium, IUS},
  title        = {Revolving permanent magnet causes rotating particle motion that makes new detection schemes possible in magnetomotive ultrasound},
  url          = {http://dx.doi.org/10.1109/ULTSYM.2019.8925951},
  doi          = {10.1109/ULTSYM.2019.8925951},
  volume       = {2019-October},
  year         = {2019},
}