Basic Introduction to Bioelectromagnetics, Third Edition

Contents......Page 3
Preface......Page 9
1.1 Introduction......Page 12
1.2 Electric field concepts......Page 13
1.3 Magnetic field concepts......Page 18
1.4 Sources of electric fields (Maxwell’s equations)......Page 22
1.5 Sources of magnetic fields (Maxwell’s equations)......Page 25
1.6 Electric and magnetic field interactions with materials......Page 28
1.8 Waveforms used in electromagnetics......Page 32
1.9 Sinusoidal EM functions......Page 34
1.10 Root mean square or effective values......Page 36
1.11 Wave properties in lossless materials......Page 39
1.12 Boundary conditions for lossless materials......Page 41
1.13 Complex numbers in electromagnetics (the phasor transform)......Page 45
1.14 Wave properties in lossy materials......Page 47
1.15 Boundary conditions for lossy materials......Page 52
1.16 Energy absorption......Page 53
1.17 Electromagnetic behavior as a function of size and wavelength......Page 55
1.18 Electromagnetic dosimetry......Page 59
2.1 Introduction......Page 64
2.2 Low-frequency approximations......Page 65
2.3 Fields induced in objects by incident E fields in free space......Page 67
2.4.1 Capacitor-plate electrodes......Page 72
2.4.2 Displacement current......Page 77
2.4.3 In vitro electrode configurations......Page 78
2.5 Electrodes for reception and stimulation in the body......Page 85
2.5.1.2 Intracellular recording: receiving signals from the brain and nerves......Page 87
2.5.1.3 Impedance imaging......Page 88
2.5.1.4 Impedance monitoring for lung water content and percent body fat......Page 89
2.5.2.1 Cardiac pacemakers and defibrillators......Page 92
2.5.2.2 Pulsed electromagnetic fields......Page 93
2.5.2.4 Ablation......Page 94
2.6 Fields induced in objects by incident B fields in free space......Page 95
2.7 E field patterns for in vitro applied B fields......Page 102
2.8 Measurement of low-frequency electric and magnetic fields......Page 110
2.9 Summary......Page 119
3.1 Introduction......Page 120
3.2.1 Spherical waves......Page 121
3.2.2 Planewaves......Page 125
3.3.1 Planewave reflection at metallic interfaces......Page 127
3.3.2 Planewave reflection and refraction at dielectric interfaces......Page 137
3.4.1 Waves in metals......Page 144
3.4.2 Waves in lossy dielectrics......Page 146
3.4.3 Energy absorption in lossy media......Page 147
3.5.1 TEM systems......Page 150
3.5.2 TEM systems for exposing biological samples......Page 158
3.5.3 Waveguides......Page 163
3.5.3.1 TE and TM mode patterns in rectangular waveguides......Page 164
3.5.3.2 Mode excitation and cutoff frequencies......Page 165
3.6 Resonant systems......Page 169
3.7 Antennas......Page 175
3.8.1 Diffraction from apertures......Page 188
3.8.2 Diffraction from periodic structures......Page 191
3.9 Measurement of mid-frequency electric and magnetic fields......Page 194
3.10 Summary......Page 197
4.1 Introduction......Page 199
4.2 Ray propagation effects......Page 201
4.2.1 Refraction at dielectric interfaces......Page 202
4.2.2 Optical polarization and reflection from dielectric interfaces......Page 204
4.2.3 Ray tracing with mirrors and lenses......Page 207
4.2.4 Imaging with lenses......Page 210
4.2.5 Graded-index lenses......Page 213
4.3 Total internal reflection and fiber optic waveguides......Page 214
4.3.1 Multimode optical fibers......Page 216
4.4 Propagation of laser beams......Page 218
4.4.1 Linewidths of laser beams......Page 219
4.4.2 The Gaussian spherical profile......Page 220
4.4.3 Propagation characteristics of a Gaussian beam......Page 221
4.4.4 Focusing a Gaussian beam with a lens......Page 223
4.4.5 Applying the Gaussian beam equations......Page 224
4.5 Scattering from particles......Page 226
4.5.1 Rayleigh scattering......Page 227
4.5.2 Mie scattering......Page 228
4.6.1 Light scattering in tissues and photon migration......Page 231
4.6.2 Tissue absorption and spectroscopy......Page 232
4.7 X-Rays......Page 235
4.8 Measurement of high-frequency electric and magnetic fields (light)......Page 236
4.9 Summary......Page 237
5.1 Introduction......Page 238
5.2 Polarization......Page 241
5.3 Electrical properties of the human body......Page 244
5.4 Human models......Page 245
5.5 Energy absorption (SAR)......Page 247
5.5.1 SARs at low frequencies......Page 248
5.5.2 SAR as a function of frequency......Page 249
5.5.3 Effects of polarization on SAR......Page 252
5.5.4 Effects of object size on SAR......Page 253
5.6 Extrapolating from experimental animal results to those expected in humans......Page 254
5.7 Numerical methods for bioelectromagnetic simulation......Page 256
5.7.1 The FDTD method......Page 258
5.7.1.1 Computation of fields in a human under a 60-Hz power line......Page 259
5.7.1.2 Computation of SAR from cellular telephones......Page 261
5.7.2 The impedance method......Page 263
5.7.2.1 Calculation of the E fields induced near implants during MRI......Page 264
5.7.2.2 Modeling an implant in the human body......Page 265
5.7.2.3 Results of the numerical calculations......Page 266
5.7.3 The finite difference/finite element method......Page 270
5.7.3.1 The finite difference method (FDM)......Page 271
5.7.3.2 The finite element method (FEM)......Page 272
5.8.1 Allowable frequencies......Page 273
5.8.2 Limits on absorbed power......Page 274
5.8.3 Localized exposure limits......Page 275
5.8.4 Induced current and shock guidelines......Page 276
5.8.5 Power-line and static field limits......Page 277
5.9 Conclusion and summary......Page 278
References......Page 279
6.2 Fundamental potential and challenges......Page 280
6.3 Hyperthermia for cancer therapy......Page 284
6.3.1.1 Capacitive applicators......Page 286
6.3.1.2 Inductive applicators......Page 287
6.3.1.3 Radiative applicators......Page 290
6.3.1.4 Invasive applicators......Page 294
6.3.2 Engineering problems remaining in hyperthermia......Page 295
6.4.1 Magnetic resonance imaging......Page 296
6.4.2 Nuclear magnetic resonance spectroscopy......Page 300
6.5.2 Spatial/temporal cellular integration......Page 302
6.5.7 Rectification by cellular membranes......Page 303
6.6.1 Low-frequency applications......Page 304
6.6.2 Medium-frequency applications......Page 306
6.6.3 High-frequency applications......Page 307
6.7 Conclusion......Page 308
Electrical properties of human body......Page 309
Definition of variables......Page 313
Decibels......Page 320
Index......Page 322