Principles and Applications of Ubiquitous Sensing

Waltenegus Dargie, Associate Professor, Dresden University of Technology, Germany.Professor Dargie holds a PhD in Computer Engineering from the Technical University of Dresden, Germany (2006). His educational background in electrical engineering, electronics, and computer engineering inspired him to consolidate these subject areas in a single book. He has rich teaching and research experience at various universities, having taught wireless sensor networks, computer networks, and stochastic processes for more than eight years. These courses have enabled him to collect a vast amount of material used in this book. In 2010 he co-authored a book on wireless sensor networks, which is now being used as a text book in many universities around the world (Fundamentals of Wireless Sensor Networks: Theory and Practice, Wiley).

"This book provides a concise review of sensing methods and many sensor types, with a focus on medical applications"...."Readers interested in learning about many types of sensing methods will find this book extremley interesting and well worth reading" IEEE, Oct 2017

• Preface xiiiAbout the Companion Website xvList of Abbreviations xvii1 Introduction 11.1 System Overview 21.1.1 Sensing System 21.1.2 Conditioning System 31.1.3 Analogue-to-digital Signal Conversion 31.1.4 Processor 41.2 Example: AWireless Electrocardiogram 41.3 Organisation of the Book 72 Applications 92.1 Civil Infrastructure Monitoring 92.1.1 Bridges and Buildings 102.1.2 Water Pipelines 172.2 Medical Diagnosis and Monitoring 212.2.1 Parkinson’s Disease 212.2.2 Alzheimer’s Disease 252.2.3 Sleep Apnea and Medical Journalling 262.2.4 Asthma 282.2.5 Gastroparesis 312.3 Water-quality Monitoring 34References 393 Conditioning Circuits 443.1 Voltage and Current Sources 443.2 Transfer Function 453.3 Impedance Matching 513.4 Filters 563.5 Amplification 613.5.1 Closed-loop Amplifiers 633.5.2 Difference Amplifier 65References 704 Electrical Sensing 724.1 Resistive Sensing 734.2 Capacitive Sensing 784.3 Inductive Sensing 844.4 Thermoelectric Effect 91References 945 Ultrasonic Sensing 965.1 UltrasonicWave Propagation 1005.2 Wave Equation 1065.3 Factors Affecting UltrasonicWave Propagation 108References 1116 Optical Sensing 1146.1 Photoelectric Effect 1166.2 Compton Effect 1206.3 Pair Production 1266.4 Raman Scattering 1276.5 Surface Plasmon Resonance 131References 1337 Magnetic Sensing 1367.1 Superconducting Quantum Interference Devices 1367.1.1 DC-SQUID 1397.1.2 RF-SQUID 1417.2 Anisotropic Magnetoresistive Sensing 1427.3 Giant Magnetoresistance 1487.4 Tunnelling Magnetoresistance 1517.5 Hall-effect Sensing 155References 1578 Medical Sensing 1608.1 Excitable Cells and Biopotentials 1618.1.1 Resting Potential 1628.1.2 Channel Current 1668.1.3 Action Potentials 1668.1.4 Propagation of Action Potentials 1678.1.5 Measuring Action Potentials 1718.2 Cardiac Action Potentials 1758.2.1 Propagation of Cardiac Action Potentials 1778.2.2 The Electrocardiogram 1808.2.2.1 Re-entry 1818.2.2.2 Loss of Membrane Potential 1828.2.2.3 Afterdepolarisations 1838.3 Brain Action Potentials 1858.3.1 Electroencephalography 1888.3.2 Volume Conduction 1938.3.3 Electrode Placement 195References 1989 Microelectromechanical Systems 2029.1 Miniaturisation and Scaling 2029.1.1 Physical Properties 2039.1.2 Mechanical Properties 2039.1.3 Thermal Properties 2049.1.4 Electrical and Magnetic Properties 2059.1.5 Fluid Properties 2059.1.6 Chemical Properties 2069.1.7 Optical Properties 2069.2 Technology 2069.2.1 Growth and Deposition 2079.2.2 Photolithography 2079.2.3 Etching 2099.3 Micromachining 2099.3.1 Surface Micromachining 2109.3.2 Bulk Micromachining 2119.3.2.1 Reactive Ion Etching 2129.3.2.2 Micromolding 2159.3.2.3 Non-silicon Micromolding 2169.3.2.4 Plastic Micromolding 2179.4 System Integration 2189.5 Micromechanical Sensors 2209.5.1 Pressure and Force Sensors 2209.5.1.1 Piezoelectric Effect 2229.5.1.2 Piezoresistance 2269.5.1.3 Fabrication of a Piezoresistive Sensor 2279.5.2 Flow Sensors 2279.5.2.1 Floating Plate 2289.5.2.2 Artificial Hair Cell 2319.5.3 Accelerometers 2349.5.3.1 Fabrication of an Accelerometer 2359.5.4 Gyroscopes 2369.5.4.1 Fabrication of a Gyroscope 246References 24910 Energy Harvesting 25310.1 Factors Affecting the Choice of an Energy Source 25310.1.1 Sensing Lifetime 25410.1.2 Sensor Load 25410.1.3 Energy Source 25510.1.4 Storage 25610.1.5 Regulation 25710.2 Architecture 26310.3 Prototypes 26510.3.1 Microsolar Panel 26510.3.2 Microgenerator 26910.3.3 Piezoelectricity 272References 27511 Sensor Selection and Integration 27811.1 Sensor Selection 27811.1.1 Accuracy 27811.1.2 Sensitivity 28011.1.3 Zero-offset 28011.1.4 Reproducibility 28011.1.5 Span 28111.1.6 Stability 28111.1.7 Resolution 28211.1.8 Selectivity 28211.1.9 Response Time 28211.1.10 Self-heating 28211.1.11 Hysteresis 28311.1.12 Ambient Condition 28311.1.13 Overload Characteristics 28311.1.14 Operating Life 28411.1.15 Cost, Size, andWeight 28411.2 Example: Temperature Sensor Selection 28411.2.1 Resistance Temperature Detectors 28411.2.2 Thermistors 28511.2.3 Thermocouples 28611.2.4 Infrared 28611.3 Sensor Integration 28711.3.1 Dead Volume 28711.3.2 Self-heating 28711.3.3 Internal Heat Sources 29411.3.3.1 External Heat and Radiation Sources 296References 29612 Estimation 29812.1 Sensor Error as a Random Variable 29912.2 Zero-offset Error 30312.3 Conversion Error 30512.4 Accumulation of Error 30912.4.1 The Central LimitTheorem 31312.5 Combining Evidence 31512.5.1 Weighted Sum 31612.5.2 Maximum-likelihood Estimation 32212.5.3 Minimum Mean Square Error Estimation 32512.5.4 Kalman Filter 32812.5.5 The Kalman Filter Formalism 334References 335Index 337