Electromagnetic Interaction with Biological Systems PDF
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Electromagnetic Interaction with Biological Systems Electromagnetic Interaction with Biological Systems Edited by James C. Lin University of Illinois Chicago, Illinois Plenum Press - New York and London Library of Congress Cataloging in Publication Data Electromagnetic interaction with biological systems I edited by James C. Lin. p. cm. Proceedings of the Joint Symposium on Interactions of Electromagnetic Waves with Biological Systems, held as part of the Twenty-Second General Assembly of the Inter national Union of Radio Science, August 25-September 2, 1987, in Tel Aviv, Israel. Includes bibliographies and index. ISBN 978-1-4684-8061-0 ISBN 978-1-4684-8059-7 (eBook) DOl 10.1007/978-1-4684-8059-7 1. Nonionizing radiation - Physiological effect - Congresses. 2. Nonionizing radia tion - Diagnostic use - Congresses. 3, Nonionizing radiation - Therapeutic use Congresses. 4. Nonionizing radiation-Safety measures-Congresses. I. Lin, James C. II. International Union of Radio Science. General Assembly (22nd: 1987: Tel Aviv, Israel) QP82.2.N64E44 1989 612/.01448 - dcl9 88-38957 CIP Proceedings of the Joint Symposium on Interactions of Electromagnetic Waves with Biological Systems, held as part of the Twenty-Second General Assembly of the International Union of Radio Science, August 25-September 2, 1987, in Tel Aviv, Israel © 1989 Plenum Press, New York Softcover reprint of the hardcover I st edition 1989 A Division of Plenum Publishing Corporation 233 Spring Street, New York, N.Y. 10013 All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher PREFACE Ever since the early 1940's, electromagnetic energy in the nonionizing spectrum has contributed to the enhanced quality of life in a variety of ways. Aside from their well-known roles in communication, entertainment, industry and science, electromagnetic energy has come into wide spread use in biology and medicine. In addition to the intended purposes, these energies produce other effects which have been shown to influence the life processes of living organisms. It is noteworthy that these energies are not only harmless in ordinary quantities but are actually necessary for modern life, indeed without which life as we know it would be impossible. The purpose of this book is to present a succinct summary of the interaction of electromagnetic fields and waves with biological systems as they are now known. The subject matter is interdisciplinary and is based primarily on presentations scheduled for a joint symposium at the XXII General Assembly of the International Union of Radio Science, held in Tel Aviv, Israel from Tuesday, August 25 to Wednesday, September 2, 1987. The symposium was jointly sponsored by the Bioelectromagnetics Society in cooperation with the International Radiation Protection Association. The choice of topics was made to facilitate the application and to stimulate the use of nonioni zing electromagnetic energy in biology and medicine, and to increase the awareness and to promote the consideration of radiation safety by electrical engineers and experimental physicists. Therefore, the book is organized into three parts: Part One is devoted to selected topics of current applications and investigations in diagnostics and therapeutic uses of nonionizing electromagnetic energy including noninvasive sensing, radiometry and thermography, diagnostic imaging, and hyperthermia treatment for cancer. In Part Two, the biological effects are summaried for stationary, time-varying as well as radio frequency and microwave fields. The physical properties of and mechanisms for the interaction of electromagnetic energies with biological molecules, cells and tissues are also discussed. Part Three surveys available safety protection guides from North America, Eastern and Western Europe as well as other parts of the world; a special emphasis is placed on rationales leading to the establishment of exposure standards and protection guides. I take pleasure in expressing here my appreciation to the Naval Medical Research and Development Command in Bethesda, Maryland, for its support of the research covered in my own chapter. The Walter Reed Army Institute of Research in Washington, D.C., and the Office of Chief of Naval Research, Arlington, Virginia provided generously for the travel of many of the authors to the URSI General Assembly. The occasion has permitted v engineers and scientists from many countries an opportunity to interact and exchange their latest findings and observations with one another. Lastly, it is a pleasure to recognize the secretarial assistance of Kristine Grzyb and Su Lee, whose skill and diligence have made the tasks of writing and editing less of a drudgery, and to acknowledge the cooperation of the authors, whose intellectual endeavor made the publication of this volume a reality. James C. Lin University of Illinois Chicago, Illinois vi CONTENTS PART I MEDICAL DIAGNOSTICS AND THERAPY Microwave Noninvasive Sensing of Physiological Signatures ••••••••••• 3 J.C. Lin Microwave Radiometry and Thermography ••••••••••••••••••••••••••••••• 27 Y. Leroy, A. Mamouni, J.C. Van de Velde and B. Bocquet Progress in Magnetic Resonance Imaging for Medical Diagnosis •••••••• 39 H. Weiss Technical and Clinical Advances in Hyperthermia Treatment of Cancer 59 J.W. Hand PART II BIOLOGICAL EFFECTS AND MECHANISMS Biological Responses to Static and Time-Varying Magnetic Fields ..........................•..••....................... 83 T.S. Tenforde Biological Effects of Radio Frequency Electromagnetic Radiation ...........•...•....•.•.............•.............. 109 W.R. Adey Biological Responses to Microwave Radiation: Reproduction, Development and Immunology •••••••••••••••••••.•••••••••••••• 141 H. Chiang and B. Shao Pulsed Radiofrequency Field Effects in Biological Systems ••••••••••••••••••••••••••••••••••••••••••••••••••••• 165 J.C. Lin Physical Mechanisms for Electromagnetic Interaction With Biological Systems •••••••••••••••••••••••••••••••••••••••••• 179 P. Bernardi and G. D'Inzeo PART III SAFETY GUIDES AND RATIONALES Protection Guides for RF Radiations: Recent Developments in the U.S.A •...•....•.•.....•.••..•....•...•....•••.•.•.••. 215 D. Justesen vii Eastern European RF Protection Guides and Rationales •••••••••••••••• 221 S. Szmigielski Western European Population and Occupational RF Protection Guides •••••••••••••••••••••••••.•.•••••••••••••.• 245 K.H. Mild Canadian and Other National RF Protection Guides •••••••••••••••••••• 257 M.A. Stuchly International Health Criteria Documents and Guidelines for Electromagnetic Fields •••••.•••.•••..••••••••••••••••••••••• 271 P. Czerski and J.H. Bernhardt Panel Discussion on Standards ••••.•••••••••••.•••••••••••••••••••••• 281 J.M. Osepchuk Contributors 291 Index .....•••.•.....•.....•••••.••....•..•.....••.••.••••..••••••••• 293 PART I MEDICAL DIAGNOSTICS AND THERAPY MICROWAVE NONINVASIVE SENSING OF PHYSIOLOGICAL SIGNATURES James C. Lin Department of Bioengineering University of Illinois Chicago, IL 60680-4348 INTRODUCTION Knowledge of the physiologic or pathophysiologic status of the heart and vessels as a transportation system for blood, and lungs as the site of gas exchange are factors that can greatly assist medical practitioners in the management of cardiovascular and pulmonary diseases. In light of prevalence of mortality and morbidity associated with heart, vascular and lung diseases, considerable efforts have been devoted to the development of noninvasive diagnostic techniques which not only are safe, but also offer the possibility of earlier detection as well as quantification of these disease states. Most recently, the advantage afforded by non-contact and remote sensing has engendered a great deal of excitement regarding the use of such technologies for monitoring patients with critical burns and premature developments, and personnel fell prey to such hazardous environments as fire, chemical or nuclear contamination and natural or man-caused disasters. The application of microwaves for noninvasive sensing of physiological variables may be classified into active and passive modes (Fig. 1). The quantity of interest in both situations is energy transfer between a source and a receiver. This involves the analysis of waves that propagate from emitter to receiver. There are several possible methods for active sensing. Spatially resolved images may be formed through either projection or tomographic reconstruction processes to depict dielectric permittivity changes associated with tissue structural discontinuities (Larsen and Jacobi, 1986). Alternatively, time-varying signatures can be detected to permit active interrogation of cutaneous and subcutaneous tissue movements, even though the spatial resolution that can be attained is somewhat limited. In the case of reflection measurement, the microwave energy transmi tte'd from the source antenna is backscattered by the biological target and received by the detection system. The backscattered wave provides information on the biological target and on factors that govern the propagation to and from the biological target. In contrast, passive measurement involves observation of microwave emissions from subcutaneous tissues, and conversion of those thermally generated microwave emissions to tissue temperatures. This radiometric technique can noninvasively measure subcutaneous tissue temperatures to a depth of several centimeters. Moreover, when medical radiometric measurements are made at several different frequencies or positions, it is possible to retrieve the 3 temperature profiles as a function of depth in tissue. However, a stable and unique solution to this inverse problem is not guaranteed. Nevertheless, some promising approaches have emerged in recent years. The objective of this paper is to provide an overview of active modes of noninvasive microwave sensing for interrogation of movements attending cardiovascular and pulmonary activities, and to present recent developments in clinical and laboratory experimentation. The discussion will begin with a brief summary of the principal phenomena associated with microwave propagation and scattering in biological tissues. < PROJECTION-DIRECT < RESOLVED-IMAGING TOMOGRAPHY-INVERSE ACTIVE UNRESOLVED-INTERROGATION-IDENTIFICATION-- DIRECT < SUBSURFACE SINGLE FREQUENCY-TOPOGRAPHY- DIRECT . (THERMOGRAPHY) PASSIVE-RADIOMEGRY MULTI-SPECTRAL--PROFlLE-- INVERSE Fig. 1. Active and passive modes for microwave noninvasive sensing of physiological variables. PROPAGATION AND SCA'ITERING OF MICROWAVES Microwaves are refracted, scattered and transmitted at boundaries separating different material media. These phenomena are governed by the source frequency, antenna configuration, dielectric permittivity and geometry of the biological body or tissue. The transmission and backscattering (reflection) are characterized by the transmission coefficent T, and reflection coefficient R, respectively. For a plane wave impinging normally from a medium of permittivity E l' on a medium of permittivity E2, T (1) where E = EO ( E -j a/wE) with relative dielectric constant E ,free-space permittivity E , r conductQ1 vity a, and radian frequency w = 2nf r (frequency). The reflectiono coefficient is given by ~=T-l. The fraction of incident power reflected by the discontinuity is R and the transmitted fraction is 4
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