Title :
An AC magnetizing field biosusceptometer using a SQUID based sensor with additional compensation module
Author :
Della Penna, S. ; Gratta, C. Del ; Cianflone, F. ; Erné, S.N. ; Granata, C. ; Pentiricci, A. ; Pizzella, V. ; Russo, M. ; Romani, G.L.
Author_Institution :
Dept. of Clinical Sci. & Bioimaging, "G. D\´\´Annunzio" Univ., Chieti, Italy
fDate :
6/1/2003 12:00:00 AM
Abstract :
We present a new SQUID based susceptometer for liver iron concentration (LIC) assessment. The instrument is operated with an inhomogeneous AC magnetizing field. The susceptometer is based on 7 channels, each consisting of a sensing unit and of an additional unit for the compensation of the applied field residual and its variation. Each unit is a second order gradiometer and is coupled to a dc SQUID with a parallel washer configuration. The compensation module output is digitally processed and coupled to the sensing gradiometer by means of an additional feedback path. The estimation of LIC is based on a numerical model of the subject´s torso obtained from the segmentation of ultrasound images.
Keywords :
SQUID magnetometers; biomagnetism; biomedical electronics; biomedical measurement; biomedical ultrasonics; image segmentation; liver; medical image processing; SQUID based sensor; SQUID based susceptometer; alternating current magnetizing field biosusceptometer; applied field residual; biomagnetic liver biopsy; compensation module; diagnosis; feedback path; haematological diseases; inhomogeneous AC magnetizing field; liver Fe concentration assessment; magnetic susceptibility; numerical model; parallel washer configuration; second order gradiometer; segmentation; sensing gradiometer; sensing unit; subject´s torso; ultrasound images; Biosensors; Image segmentation; Instruments; Iron; Liver; Magnetic sensors; Numerical models; Output feedback; SQUIDs; Torso;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.813733
