By Topic

Development of a biomagnetic measurement system for brain research

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

8 Author(s)
M. Ueda ; Superconducting Sensor Lab., Chiba, Japan ; A. Kandori ; H. Ogata ; Y. Takada
more authors

The tail of the dewar of the authors' system has a special shape that makes it possible to measure the brain activity of anyone lying on a bed regardless of head shape or size. It allows the parietal, one side of the temporal and the occipital regions to be measured simultaneously. In the system, 128 axial first-order gradiometers are mounted at intervals of about 26 mm. The diameter and baseline length of the pickup coil are 14 mm and 50 mm, respectively. The authors use square-shaped double-washer DC-SQUIDs with additional positive feedback to improve the flux resolution. System reliability is improved by hermetically sealing the SQUID in a ceramic package and including a heater resistor to eliminate trapped flux. To decrease the liquid helium evaporation rate, output cables are made with flexible printed circuits. The read-out electronics are based on the Direct Offset Integration Technique, which is a highly simplified feedback method. The white noise level measured in a magnetically shielded room is less than 10 fT//spl radic/Hz above 5 Hz. This system has successfully been applied to measuring auditory evoked fields.<>

Published in:

IEEE Transactions on Applied Superconductivity  (Volume:5 ,  Issue: 2 )