Abstract
Measurements of the magnetic field of the human brain in a clinical setting require a higher level of performance from the instrumentation than is generally acceptable for laboratory research. We describe several significant advances that are intended for such neuromagnetic applications as well as for a broader range of biomagnetic studies. We report the development of a closed-cycle refrigerator capable of sustaining a SQUID-based sensor without introducing significant deterioration of the noise level. This eliminates the need for liquid cryogen and permits the sensor to be operated in various orientations, including inverted. The performance of a new type of magnetically shielded room is then evaluated for neuromagnetic studies. It has the advantages of being pre-fabricated and of providing a large interior for convenient clinical studies. Its ceiling supports a versatile gantry that holds one or two sets of magnetic sensors. This arrangement, when used with a magnetic system for precisely determining the sensor positions with respect to the patient’s head, is feasible for precise localization of neural sources within the brain. We end with an example of the kinds of clinical studies that are now being carried out with the aid of neuromagnetic measurements.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
D. Cohen, Magnetoencephalography: evidence of magnetic fields produced by alpha rhythm currents, Science 161: 784 (1968).
D. Cohen, Magnetoencephalography: detection of the brain’s electrical activity with a superconducting magnetometer, Science 175: 664 (1972).
G. L. Romani and L. Narici, Principles and clinical validity of the biomagnetic method, Med. Prog thee. Tech. 11: 123 (1986).
R. Hari and R. J. Ilmoniemi, Cerebral magnetic fields, CRC Critical Rev. in Biomed. Eng. 14:93 (1986).
S. J. Williamson and L. Kaufman, Analysis of neuromagnetic signals, in: “Handbook of Electroencephalography and Clinical Neurophysiology,” A. Gevins and A. Rémond, Elsevier, Amsterdam (1987), Chapter 14.
S. J. Williamson, G. L. Romani, L. Kaufman, and I. Modena, “Biomagnetism: An Interdisciplinary Approach,” Plenum Press, New York (1983).
R. Ilmoniemi, R. Hari, and K. Reinikainen, A four-channel SQUID magnetometer for brain research, Electroenceph clin. Neurophvsiol 58: 467 (1984).
S. J. Williamson, M. Pelizzone, Y. Okada, L. Kaufman, D. B. Crum, and J. R. Marsden, Magnetoencephalography with an array of SQUID sensors, in: “Proceedings of the 10th International Cryogenic Conference - ICEC10”, Butterworth, London (1984), p. 339.
G. L. Romani, R. Leoni, and C. Salustri, Multichannel instrumentation for biomagnetism, in: “SQUID ‘85: Superconducting Quantum Interference Devices and their Applications,” H. D. Hahlbohm and H. Lübbig, eds., Walter de Gruyter, Berlin (1985), p. 919.
J. E. Zimmerman and R. Radebaugh, Operation of a SQUID in a very low-power cryocooler, in: “NBS Special Publication 508,” National Bureau of Standards (1978).
J. E. Cox and S. A. Wolf, Magnetic and vibrational characteristics of a close cycle refrigerator, in: “NBS Special Publication 508,” National Bureau of Standards (1978).
D. B. Sullivan, J. E. Zimmerman and J. T. Ives, Operation of a Practical SQUID Gradiometer in a Low-Power Stirling Cryocooler, in: “NBS Special Publication 607,” National Bureau of Standards (1981).
E. Tward and R. Sarwinski, A closed cycle cascade Joule Thomson refrigerator for cooling Josephson junction devices, in: “NBS Special Publication 698,” National Bureau of Standards (1985).
Y. Okada, L. Kaufman, and S. J. Williamson, Hippocampal formation as a source of endogenous slow potentials, Electroenceph clin. Neurophysiol 55: 417 (1982).
A. Mager, The Berlin magnetically shielded room (BMSR), Section A: Design and construction, in: “Biomagnetism,’ S.N. Erné, H. D. Hahlbohm, and H. Lübbig, eds., Walter de Gruyter, Berlin (1981), p. 51.
M. Ibuka, H. Hosomatsu, and S. Naito, A SQUID magnetometer using a niobium thin-film microbridge, IEEE Trans. Instrum. and Meas IM-30:251 (1981).
V.O. Kelhä, J. M. Pukki, R. S. Peltonen, A. J. Penttinen, R. J. Ilmoniemi, and J. J. Heino, Design, construction, and performance of a large-volume magnetic shield, IEEE Trans. Magn. MAG-18:260 (1982).
J. E. Zimmerman, SQUID instruments and shielding for low-level magnetic measurements, J. Appl. Phys. 48: 702 (1977).
Fabricated by Vacuumschmelze GmbH, Hanau, Federal Republic of Germany.
J. Vrba, M. Burbank, H. Ensing, A. Fife, E. Heijster, C. Marshall, J. McCubbin, D. McKenzie, M. Tillotson, K. Watkinson, H. Weinberg, and P. Brickett, Integrated biomagnetic robotic system, in: “Biomagnetism: Applications and Theory,” H. Weinberg, G. Stroink, and T. Katila, eds., Pergamon Press, New York (1984), p. 52.
D. Barth, W. Sutherling, J. Engle, Jr., and J. Beatty, Neuromagnetic evidence of spatially distributed sources underlying epileptiform spikes in the human brain, Science 223: 293 (1984).
J. Beatty, D.S. Barth, and W. Sutherling, Magnetically localizing the sources of epileptic discharges within the human brain, Naval Res. Rev. 2: 20 (1984).
G.B. Ricci, Clinical magnetoencephalography, Nuovo Cimento 2D: 517 (1983).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1988 Springer Science+Business Media New York
About this chapter
Cite this chapter
Buchanan, D.S., Paulson, D., Williamson, S.J. (1988). Instrumentation for Clinical Applications of Neuromagnetism. In: Fast, R.W. (eds) Advances in Cryogenic Engineering. A Cryogenic Engineering Conference Publication, vol 33. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-9874-5_12
Download citation
DOI: https://doi.org/10.1007/978-1-4613-9874-5_12
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-9876-9
Online ISBN: 978-1-4613-9874-5
eBook Packages: Springer Book Archive