acoustic imaging cameras, microscopes, phased arrays, and holographic systems

acoustic imaging cameras, microscopes, phased arrays, and holographic systems

acoustic imaging cameras, microscopes, phased arrays, and holographic systems Edited by Glen Wade University of California at Santa Barbara SPRINGER SCIENCE+BUSINESS MEDIA, LLC

Library of Congress Cataloging in Publication Data Main entry under title: Acoustic imaging "Lectures on acoustical holography and imaging presented at the University of California in Santa Barbara, California, March, 1975." Includes bibliographical references and index. 1. Acoustic holography-congresses. 1. Wade, Glen. TA1550.A26 774 76-21 Lectures on Acoustical Holography and lmaging presented at the University of California in Santa Barbara. California, March. 1975 ISBN 978-1-4757-0826-4 ISBN 978-1-4757-0824-0 (ebook) DOI 10.1007/978-1-4757-0824-0 1976 Springer Science+Business Media New York Originally published by Plenum Press. New York in 1976 Softcover reprinl oflhe hardcover IsI edilion 1997 AI/ righ ts 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. microjilming. recording. or otherwise. without written permission [rom the Publisher

Preface The ability to "see" with sound has long been an intriguing concept. Certain animals, such as bats and dolphins, can do it readily, but the human species is not so endowed by nature. However this lack of natural ability can be overcome by applying the appropriate technology. For example, in various laboratories recently, workers have been able to obtain true-focussed, orthographic images in real time of objects irradiated with sound rather than light. Crossectional images have been available for a much longer period of time, stemming from the development of the pulse-echo techniques first used in the sonar systems of World War I. By now a wide variety of system concepts for acoustic imaging exist. Some of the newer systems range from the purely holographic to the purely lens types. It is apparent that ultrasonic energy can give an image of an object not obtainable with light. For example, a particular object may be embedded in material completely opaque to light but relatively transparent to sound. In addition, soft tissue in the human body frequently provides little contrast for optical radiation, and for x-rays, but large contrast for sonic radiation. Also, the cumulative effect of x-rays may impose severe damage to these tissues, whereas low-intensity sound may be entirely safe. For these reasons, this comparatively new field, combining as it does in many instances acoustics and optics, is bringing to a number of areas of scientific, medical and engineering endeavor, investigative instruments of great power. The technological developments in this field are already having significant effects not only in diagnostic medicine as implied above, but also in nondestructive testing, seismic sensing, oceanic search and even microscopy. This book deals with these themes on a level ranging from purely tutorial exposition to treatments describing the latest research progress. Topics are covered from both analytical and experimental viewpoints and include the v

vi PREFACE general background, the historical development, the categorization and characterics of the modern systems, the detailed descriptions of these systems, and their applications for acoustic imaging. The book is replete with examples of the applications, particularly in the medical area in terms of diagnostic imaging of internal bodily structure. Before the final draft was completed, the various presentations in the book were tested on students in an Extension Course given at the University of California entitled "Acoustical Holography and Imaging." The editor gratefully acknowledges the whole-hearted cooperation of the contributing authors and the institutions with which they are associated. He also expresses appreciation for the advice and assistence of the staff at the University of California Extension, in particular Dr. Sidney Goren, Ms. Judy Weisman, Mr. John Maxwell and Mr. Larry Nicklin. Glen Wade Santa Barbara, California March 1976

Contents 1 THE PROPAGATION OF ACOUSTIC WAVES, Byron B. Brenden 1 1.1 INTRODUCTION 1 1.2 DESCRIPTION OF THE WAVE 2 1.2.1 Description in Terms of Particle Displacement 2 1.2.2 Description in Terms of Pressure 3 1.3 MATERIAL PROPERTIES AND WAVE VELOCITY 5 1. 4 ENERGY AND INTENSITY 9 1. 5 RADIATION PRESSURE 10 1.6 VELOCITY POTENTIAL 11 1.7 REFRACTION AND REFLECTION AT LIQUID SOLID INTERFACES 1.B TRANSMISSION THROUGH A THIN PLATE 1. 9 ABSORPTION 1.10 INTERACTION OF AN ACOUSTIC WAVE WITH A FREE LIQUID 12 17 lb lb 2 HISTORICAL PERSPECTIVES, G. Wade 21 I. INTRODUCTION 21 II. EARLY PIONEERS 23 2.1 Langevin 23 vii

viii CONTENTS 2.2 Sokolov 23 2.3 Muhlhauser 28 2.4 Pohlman 29 2.5 Firestone 31 III. HOLOGRAPHIC APPROACHES 32 3.1 Sonographic Plate 32 3.2 Point-by-Point Scanning Systems 33 3.3 Liquid-Surface Systems 33 IV. SOLID-SURFACE SYSTEMS 36 V. BRAGG-DIFFRACTION SYSTEMS 38 VI. SYSTEMS USING PIEZOELECTRIC READOUT 39 VII. CONCLUSION 40 VIII. REFERENCES 41 3 INTRODUCTION TO ACOUSTIC IMAGING SYSTEMS, Lawrence W. Kessler 43 Abstract 43 Basic Imaging Systems 43 Categories of Acoustic Imaging Systems 47 Characteristics of Sound Propagation 48 System Concepts 49 a) Piezoelectric systems b) Thin layer receptors c) Surface distortion methods of reception 49 52 54

CONTENTS ix d) Light-Sound interaction Concluding Remarks REFERENCES 4 SPECKLE AND SENSITIVITY IN MODERN SYSTEMS, G. Wade I. INTRODUCTION 60 61 63 65 65 II. III. IV. SPECKLE AND RINGING SENSITIVITY REFERENCES 66 71 77 5 SCANNED ACOUSTIC HOLOGRAPHY, Byron B. Brenden 79 5.1 INTRODUCTION 79 5.2 IMPROVED CONFIGURATIONS 80 5.3 BLOCK DIAGRAMS 81 5.4 PRELIMINARY ANALYSIS 83 5.5 SOURCE-RECEIVER RECIPROCITY 86 5.6 THE GEOMETRY OF IMAGING 87 5.7 MAGNIFICATION 94 5.8 RESOLUTION 94 5.9 SIMULTANEOUS SOURCE-RECEIVER SCAN 95 5.10 ABERRATIONS 96 REFERENCES 98 6 LIQUID SURFACE HOLOGRAPHY, Byron B. Brenden 99 6.1 INTRODUCTION 99

x CONTENTS 6.2 DESCRIPTION OF THE ACOUSTICAL FIELD 6.3 INTERACTION OF LIGHT WITH THE LIQUID SURFACE 6.4 THE DYNAMICS OF LIQUID SURFACE MOTION 6.5 EFFECTS PRODUCED BY PULSING THE SOUND WAVES REFERENCES 7 THEORY ON IMAGING WITH ARRAYS, Albert Macovski INTRODUCTION IMAGING ARRAYS ARRAYS USING ELECTRONIC SCANNING AND FOCUSING SYSTEMS PROVIDING TWO-DIMENSIONAL FOCUSING 8 INTEGRATED ELECTRONICS FOR ACOUSTIC IMAGING ARRAYS, James D. Meindl ABSTRACT I. INTRODUCTION 101 104 106 109 110 III 111 111 114 122 127 127 128 II. SYSTEM REQUIREMENTS A. Resolution B. Field of View C. Range D. Frame Rate E. Additional Factors 130 131 131 132 133 133

CONTENTS xi F. Classification Scheme 133 III. SINGLE TRANSDUCER SYSTEMS 134 A. Manual Scan 135 1 ) Unfocused 135 2 ) Acoustic Focus 150 B. Mechanical Scan 151 IV. LINEAR ARRAY SYSTEMS 152 A. Manual Scan 152 B. Mechanical Scan 155 1) Acoustic Focus 155 2 ) Electronic Focus 157 3 ) Holographic 157 C. Electronic Scan 159 1 ) Rectilinear Scan 159 2 ) Sector Scan 162 a) Unfocused 162 b) Cylindrical Focus 166 3 ) Orthogonal Scan 167 4 ) Holographic 169 D. Additional Approaches 169 V. AREA ARRAY SYSTEMS 170 A. Acoustic Foucus 170

xii CONTENTS B. Electronic Focus 176 C. Holographic 182 VI. CONCLUSIONS 183 VII. ACKNOWLEDGEMENTS 184 VIII. REFERENCES 184 9 BRAGG-DIFFRACTION IMAGING, G. Wade 9.1 INTRODUCTION 9.2 DESCRIPTION OF THE SYSTEM 9.3 THE LIGHT-SOUND INTERACTION 9.4 SPATIAL FOURIER TRANSFORMS 9.5 FILTERING CAPABILITY OF A BRAGG DIFFRACTION SYSTEM 9.6 STRENGTHS AND WEAKNESSES OF BRAGG DIFFRACTION IMAGING 189 189 193 195 197 201 207 9.6.1 Improving Sensitivity by Holographic Detection of Images 208 9.6.1.1 The Hologram as a Temporal Filter 209 9.6.1.2 Noise Limitations in Bragg-Diffraction Imaging 214 9.6.1.3 Noise Reduction and System Improvement by Holographic Recording 217 9.6.2 Speckle and Ringing 220 9.6.3 Cylindrical Lenses, Optical and Acoustic 220

CONTENTS xiii 9.7 FINAL GENERAL REMARKS 226 9.8 REFERENCES 226 10 IMAGING WITH DYNAMIC-RIPPLE DIFFRACTION, Lawrence W. Kessler 229 11 Introduction Principle of Operation-Interface Response Characteristics Application to Practical Systems References IMAGING USING LENSES, C. F. Quate 229 230 235 239 241 INTRODUCTION 241 SCANNING ACOUSTIC MICROSCOPE 242 Background 242 Outline of a System 246 Present Form of the Instrument 248 Acoustic Absorption in Liquids 254 Absorption in Biological Material 263 Present Work on Mammalian Cells and Tissue Sections 267 (A) Simple Cell Systems 267 (B) Living Normal Human Diploid Cells 269 (C) Tissue Sections 271

xiv CONTENTS (1) Normal Tissue 271 (2) Tissue Sections Showing Pathology 274 FRESNEL ZONE PLATE 277 Description of Imaging Methods 277 Imaging System and Results 284 CYLINDRICAL ELECTRONIC LENS 289 Some Results 298 FINAL REMARKS ON LENS SYSTEMS 299 REFERENCES 302 12 APPLICATIONS AND GENERAL CONCLUSIONS, C. F. Quate REFERENCES 307 315 SUBJECT INDEX 319