Bioimpedance in Biomedical Applications and Research (eBook)

Franco Simini is Professor of Biomedical Engineering at the Universidad de la Republica in Montevideo, Uruguay, where he founded the “Nucleo de Ingenieria Biomedica,” a joint project of the Faculty of Medicine and the Faculty of Engineering.  Pedro Bertemes Filho is Professor of Electrical Engineering at the Universidade do Estado de Santa Catarina (UDESC), Brazil, since 2004, lecturing electronic instrumentation, sensors and transducers, and introduction of biomedical engineering for master and doctorate students.  He finished the Electrical Engineering undergraduate course in 1995 at UDESC. Master in Biomedical Engineering in 1998 at the Federal University of Santa Catarina (UFSC) and PhD in Medical Physics in 2002 at the University of Sheffield (UK). Leader of the biomedical engineering research group at UDESC. Pioneer on bioimpedance device in Brazil for clinical studies on cervical cancer screening. Member of IEEE, ISEBI, SBEB, IFMBE and ATINER. Peer reviewer over 10 international journals. Main areas of research interest are electrical bioimpedance, bioinstrumentation and biosensors.

Preface 6
Acknowledgments 8
Contents 9
List of Contributors 11
List of Abbreviations 13
1 Introduction 17
2 Electrical Impedance Spectroscopy 20
2.1 Electrical Impedance Spectroscopy Basics 20
2.2 Tissue Impedance Basics 22
2.3 Measuring Tissue Impedance 26
2.3.1 The Bipolar Technique 26
2.3.2 The Tetrapolar Technique 27
2.3.3 Basic Hardware Concepts 28
2.4 Basic Voltage Measuring Concepts 34
2.5 Desired Hardware Specifications 38
2.6 Discussions 39
References 40
3 Basic Electrical Impedance Tomography 43
3.1 Introduction 43
3.1.1 Basic Principles 43
3.2 Hardware 44
3.2.1 Injection Protocols 44
3.2.2 Calibration, Validation and Sources of Error 45
3.3 Imaging 45
3.4 EIT Systems 49
3.5 Clinical Applications 50
3.5.1 Pulmonary Function 50
3.5.2 Breast Imaging 53
3.5.3 Brain Imaging 53
3.5.4 Hyperthermia 55
3.5.5 Gastrointestinal 55
3.6 Variations of EIT 56
3.6.1 Magnetic Resonance Electrical Impedance Tomography 56
3.6.2 Magnetic Induction Tomography 56
3.7 Summary 56
References 57
4 Electrical Impedance Tomography to Detect Trends in Pulmonary Oedema 59
4.1 Introduction 59
4.2 Physics and Clinical Wish List 60
4.3 Hardware Architecture 62
4.4 Review of EIT Systems 63
4.5 Suggested Design Options 65
4.5.1 Discrete Components with No Digital Processing 65
4.5.2 Standard Evaluation Board 66
4.5.3 Discrete Components with Digital Processing 66
4.5.4 Suggested Design 67
4.6 Inverse Problem 68
4.6.1 Mathematical Background 68
4.6.2 First Part of the Solution: Forward Problem-Solving 69
4.6.3 Second Part of the Solution: Regularization 69
4.7 Comparison of Reconstruction Implementations 69
4.7.1 Phantom and Volunteer Experimental Data 70
4.7.2 GREIT Reconstruction Algorithm 70
4.7.3 Comparison of Reconstructions 71
4.8 EIT Using a Standard Board 72
4.9 Electrical Phantom to Test EIT Systems 73
4.10 Current Leakage to Adjacent Chest Sections 76
4.11 Discussion and Conclusion 76
References 77
5 Electrical Impedance Signal Analysis for Medical Diagnosis 79
5.1 Introduction 79
5.2 Final Remarks 91
5.3 Conclusions 93
References 94
6 Tissue Engineering Instrumentation Based on Electrical Impedance Measurements 100
6.1 Overview About Tissue Engineering 100
6.2 Dielectric Spectroscopy 102
6.3 Overview of Electrical Impedance Technique Applied to Tissue Engineering 103
6.4 Conclusion 111
References 112
7 Basics of Numerical Simulations of Bioimpedance Phenomena 114
7.1 Introduction 114
7.2 Current Conduction 115
7.3 Electrode-Tissue Interface 120
7.4 Numerical Simulations: Equations 121
7.4.1 Influence of Magnetic Effects 122
7.4.2 Induced Current Electrical Impedance Tomography 124
7.5 Simulations in Practice: A FEMM Case 124
7.5.1 Calculation of (Bio)Impedance 128
7.6 Conclusion 129
References 129
8 Numerical Basics of Bioimpedance Measurements 130
8.1 Introduction 130
8.2 Mathematical Model 131
8.3 Computational Technology 133
8.4 Sensitivity Analysis 137
8.5 The Online Numerical Simulator 140
8.6 Discussion 141
8.7 Conclusion 146
References 146
9 Focused Impedance Method: Basics and Applications 149
9.1 Introduction: How the Idea Evolved and a Brief Outline of the Possibilities 149
9.2 Focused Impedance Measurement (FIM): Basics 152
9.2.1 Basic Configuration and Visualisation 152
9.2.1.1 FIM-8, Eight-Electrode Version 152
9.2.1.2 FIM-6, Six-Electrode Version 154
9.2.1.3 FIM-4, Four-Electrode Version 155
9.2.2 Instrumentation 155
9.2.3 Sensitivity Distribution in FIM Using Analytical and Numerical Methods 157
9.2.3.1 Sensitivity Based on Lead Fields 157
9.2.3.2 Sensitivity Using Finite Element Method 159
9.2.3.3 Focused Impedance 162
9.2.4 Sensitivity Distribution in FIM Using Experimental Methods 165
9.2.4.1 Sensitivity in 2D 166
9.2.4.2 Visualisation of Sensitivity in 3D 169
9.2.4.3 Sensitivity in 3D 171
9.2.5 Advantages and Disadvantages of Different Versions of FIM 173
9.2.6 Visualisation in Terms of Equipotentials or Point Sensitivity? 174
9.3 Application of FIM 175
9.3.1 Lungs Ventilation Measurement 175
9.3.1.1 Localised Measurement 175
9.3.1.2 Mapping of the Upper Thorax for Lungs Ventilation 177
9.3.2 Pneumonia Detection in Babies for Autodiagnosis 179
9.3.3 Gastric (Stomach) Emptying 181
9.3.4 Determination of Subcutaneous Abdominal Fat Thickness 183
9.3.5 Non-invasive Breast Tumour Characterisation Using FIM 186
9.4 Measurement Challenges 191
9.4.1 Repeatability and Reproducibility 191
9.4.2 Effect of Body Movements 192
9.4.3 Noise Due to Skin-Electrode Movements 192
9.4.4 Person-to-Person Variation 193
9.5 Future Prospects 193
9.6 Conclusion 194
References 195
10 Clinical Applications of Electrical Impedance Spectroscopy 198
10.1 Overview 198
10.2 Basic Principles 200
10.2.1 Biological Aspects 200
10.2.2 Physical Aspects 202
10.3 Changes in Tissues that Can Alter Their Passive Electrical Characteristics 203
10.3.1 Extracellular Space (ES) 203
10.3.2 Cells 204
10.3.3 Intracellular Space 205
10.4 EBIS Applications Different from Cancer and by Body Systems 205
10.4.1 Digestive 205
10.4.1.1 Mouth (Oral) Mucosa 205
10.4.1.2 Teeth 205
10.4.1.3 Tooth Caries 206
10.4.1.4 Length of Dental Canal 207
10.4.1.5 Tongue 208
10.4.1.6 Esophagus 208
10.4.1.7 Stomach 209
10.4.1.8 Small Intestine 210
10.4.1.9 Large Intestine (Colon and Rectum) 211
10.4.2 Respiratory System 212
10.4.3 Cardiovascular 213
10.4.4 Genitourinary System 214
10.4.5 Skin 214
10.4.6 Musculoskeletal System 217
10.4.6.1 Bone 217
10.4.6.2 Muscle 217
10.5 Cancer and EBIS 218
10.6 The Future: Chronic Diseases and EBIS 220
References 222
11 Body Composition by Bioelectrical Impedance Analysis 230
11.1 Introduction 230
11.2 Body Composition 230
11.2.1 Practical Uses of Body Composition Assessment 231
11.2.2 Methods for Body Composition Assessment 231
11.3 Electrical Bioimpedance Concept 232
11.3.1 Definition 232
11.3.2 Principles and Assumptions 232
11.3.3 Validation of BIA 234
11.3.4 Precision and Reproducibility of BIA Measurements 234
11.3.5 Advantages and Limitations 235
11.4 BIA Approaches 236
11.4.1 Single Frequency Bioimpedance Analysis (SF-BIA) 236
11.4.2 Multiple Frequency Bioimpedance Analysis (MF-BIA) 236
11.4.3 Bioelectrical Spectroscopy (BIS) 237
11.4.4 Bioimpedance Vector Analysis (BIVA) 237
11.4.5 Differential Impedance Analysis (DIA) 238
11.5 Types of Measurement in the Body Composition Assessment by Electrode Configuration 239
11.5.1 Hand to Foot Bioimpedance 239
11.5.2 Foot-to-Foot or Leg-to-Leg Bioimpedance 239
11.5.3 Hand-to-Hand Bioimpedance (HH-BIA) 240
11.5.4 Segmental Bioimpedance Analysis (SBIA) 240
11.5.5 Segment Localized Electrical Bioimpedance Analysis: SLBIA 241
11.6 Factors Affecting Body Composition Estimations by BIA 241
11.7 BIA Parameters 242
11.7.1 Evolution from Formulas to Raw Data: Resistance, Reactance, Impedance, and Phase Angle 242
11.8 Clinical Applications 242
11.9 Conclusions 246
References 246
12 Bioimpedance for Analysis of Body Composition in Sports 253
12.1 Introduction 253
12.2 The Use of BIA in Sports 254
12.3 Characteristics of the Selected Parameters of the Bioimpedance Method in Sports 256
12.3.1 The Use of Directly Measurable Parameters in Sports 256
12.3.2 The Use of Indirectly Measurable Parameters for Assessment of Performance 259
12.4 Fat Mass 261
12.5 Measurement of Morphological Asymmetries Using BIA 262
References 264
13 Wavelet Analysis in Impedance Rheocardiography 267
13.1 Impedance Rheocardiography 267
13.2 Measuring Technique and Data Analysis Algorithms 268
13.3 Wavelets 270
13.4 Assessment of Beat-to-Beat Cardiovascular Hemodynamic Parameters 273
13.5 Correlation Analysis of Respiration, R-R Interval, and Stroke Volume 275
13.6 Final Remarks 277
References 278
Index 280