Accession Number : ADA193815

Title :   SQUID (Superconducting Quantum Interference Device) Arrays for Simultaneous Magnetic Measurements: Calibration and Source Localization Performance.

Descriptive Note : Rept. for Sep 86-Feb 88,

Corporate Author : NEW YORK UNIV N Y

Personal Author(s) : Kaufman, Lloyd ; Williamson, Samuel J ; Costa Ribeiro, P

PDF Url : ADA193815

Report Date : 29 Feb 1988

Pagination or Media Count : 26

Abstract : Recently developed small arrays of SQUID-based magnetic sensors can, if appropriately placed, locate the position of a confined biomagnetic source without moving the array. The authors present a technique with a relative accuracy of about 2% for calibrating such sensors having detection coils with the geometry of a second-order gradiometer. The effects of calibration error and magnetic noise on the accuracy of locating an equivalent current dipole source in the human brain are investigated for 5- and 7-sensor probes and for a pair of 7-sensor probes. With a noise level of 5% of peak signal, uncertainties of about 20% in source strength and depth for a 5-sensor probe are reduced to 8% for a pair of 7-sensor probes, and uncertainties of about 15 mm in lateral position are reduced to 1 mm, for the configuration considered.

Descriptors :   *BIOMAGNETISM, *MAGNETIC DETECTORS, ACCURACY, ARRAYS, BRAIN, CALIBRATION, COILS, CONFINEMENT(GENERAL), DETECTION, DETECTORS, DIPOLES, ERRORS, HUMANS, INTERFERENCE, LEVEL(QUANTITY), MAGNETIC FIELDS, MAGNETIC PROPERTIES, MEASUREMENT, PEAK VALUES, QUANTUM THEORY, SIGNALS, SOURCES, STRENGTH(GENERAL), SUPERCONDUCTIVITY, SYNCHRONISM, QUANTUM ELECTRONICS, ELECTROMAGNETIC INTERFERENCE, NOISE(ELECTRICAL AND ELECTROMAGNETIC), BIOMEDICINE

Subject Categories : Electricity and Magnetism
      Magnetic & Electric Fld Detection & Detectors
      Biomedical Instrumentation and Bioengineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE