Instrumentation for simultaneous detection of low field NMR and biomagnetic signals

• Published in: IEEE transactions on applied superconductivity Vol. 15; no. 2; pp. 676 - 679
• Main Authors: Matlachov, A.N., Volegov, P.L., Espy, M.A., Stolz, R., Fritzsch, L., Zakosarenko, V., Meyer, H.-G., Kraus, R.H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Biomagnetics; Biomagnetism; Decay; Electronics; Exact sciences and technology; FID; Frequency; Geometry; Gradiometers; Induction generators; Instrumentation; Instruments; Magnetic field measurement; NMR; Nuclear magnetic resonance; Nuclear measurements; Protons; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; SQUID; SQUIDs; Superconducting devices; Superconducting quantum interference devices; Superconductivity; FID; Second order; Prototype; Fiberglass; SQUID; Instrumentation; kHz range; Nuclear magnetic resonance imaging; Thin film; Biomagnetism; NMR; Hz range; First order; Superconducting quantum interferometer device; Open systems; Nuclear magnetic resonance; Glass fiber; Planar technology
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2005.849997

We have built and demonstrated a simple system with open geometry that measures biomagnetic signals such as magnetoencephalogram (MEG), magnetocardiogram (MCG) and magnetomyogram (MMG) simultaneously with low field nuclear magnetic resonance (NMR) free induction decay signals (FID). The system employs LT/sub C/ SQUID gradiometers and can operate with proton Larmor frequency in the 80 Hz-10 kHz range. A pre-polarizing field of up to 60 mT is generated by resistive coils. Two different types of SQUID gradiometers were used: a tangential thin-film planar first-order gradiometer and an axial second-order gradiometer. The gradiometers were placed inside a fiberglass dewar at about 1 cm distance from a subject. All measurements were performed inside a single-layer magnetic shielded room. This system is the prototype for a system that will ultimately be capable of measuring biomagnetic signals together with magnetic resonance images (MRI).