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.

Report Date:

1988-02-29

Pagination or Media Count:

26.0

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 and Electric Field Detection and Detectors
• Biomedical Instrumentation and Bioengineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE