Preface	6
	Acknowledgements	8
	Contents	9
	1 Introduction	13
	1.1 Benefits to the Society and Individuals	14
	1.1.1 Quality of Life	14
	1.1.2 Health—Rehabilitation and Injury Prevention	15
	1.1.3 Physical Well-Being—Sport and Recreation	16
	1.2 Sport and Rehabilitation	17
	1.2.1 Advantages of Biofeedback	17
	1.2.2 Biofeedback Requirements and Success Conditions	17
	1.2.3 Motor Learning	19
	1.3 Elements of Biofeedback System	19
	1.3.1 Sensing	20
	1.3.2 Processing	20
	1.3.3 Feedback	21
	1.3.4 System Example	22
	1.4 Technology	22
	1.4.1 Quantification	23
	1.4.2 Sensors	23
	1.4.3 Devices	25
	1.4.4 Communication	28
	1.5 Vision	31
	References	33
	2 Biomechanical Biofeedback	37
	2.1 Biofeedback	37
	2.1.1 Definition	37
	2.1.2 Categorization	38
	2.2 Biofeedback Use	39
	2.3 Operation of the Biofeedback Loop	40
	2.3.1 Biofeedback Success Conditions	40
	2.3.2 Sensing	40
	2.3.3 Feedback Categories	41
	2.3.4 Feedback Modalities	43
	2.3.5 Feedback Timing	43
	2.4 Example—Motor Learning with Augmented Feedback	44
	2.4.1 Motor Learning Basics	44
	2.4.2 Biomechanical Biofeedback with Augmented Feedback	46
	2.5 Benefits and the Need for Augmented Biofeedback	48
	Note	49
	References	49
	3 Biofeedback System	51
	3.1 Background	51
	3.2 Architecture	53
	3.3 System Elements	54
	3.3.1 Sensor(s)	54
	3.3.2 Processing Device	55
	3.3.3 Feedback Device (Actuator)	55
	3.3.4 Users and Communication Channels	55
	3.3.5 Optional Elements	56
	3.4 System Operation	56
	3.4.1 Operation Modes	57
	3.4.2 Timing	57
	References	58
	4 Biofeedback System Architectures	60
	4.1 Implementation Diversity	60
	4.2 Constraints	60
	4.2.1 Space Constraint	61
	4.2.2 Time Constraint	61
	4.2.3 Computation Constraint	61
	4.2.4 Other Constraints	62
	4.3 Properties	63
	4.3.1 Structure	63
	4.3.2 Functionality	63
	4.3.3 Physical Extent	64
	4.4 Architectures	64
	4.4.1 User Architecture	64
	4.4.2 Instructor Architecture	65
	4.4.3 Cloud Architecture	66
	4.5 Classification and Comparison	67
	4.5.1 User Architecture	68
	4.5.2 Instructor Architecture	69
	4.5.3 Cloud Architecture	69
	References	70
	5 Biofeedback Systems in Sport and Rehabilitation	71
	5.1 Background	71
	5.2 Sensing	72
	5.2.1 Optical Motion Capture Systems	72
	5.2.2 Inertial Sensor Motion Capture Systems	73
	5.2.3 Sensor Properties and Limitations	74
	5.3 Processing	78
	5.3.1 System Implementations	78
	5.3.2 Motion Signal Processing	79
	5.4 Communication	81
	5.4.1 Transmission Delay	81
	5.4.2 Communication Technologies	81
	5.5 Feedback	82
	5.5.1 Biofeedback Loop Delays	83
	5.6 Real-Time Systems	86
	5.6.1 Processing	86
	5.6.2 Communication	87
	References	88
	6 Performance Limitations of Biofeedback System Technologies	90
	6.1 Selected Technologies	90
	6.2 Requirements of Biofeedback Applications	91
	6.3 Inertial Sensor Properties	91
	6.3.1 Accelerometer and Gyroscope Biases	93
	6.3.2 Constant Bias Errors	93
	6.3.3 Bias Variation	95
	6.3.4 Noise Measurement Methodology	96
	6.3.5 Bias Measurement Error	99
	6.3.6 Influence of the Sensor White Noise on the Derived Parameters	100
	6.3.7 Bias Compensation Options	102
	6.4 Smartphone Inertial Sensor Performance Comparison	104
	6.4.1 Measurement Results	105
	6.4.2 Long Term Bias Variation	106
	6.5 Motion Acquisition with Inertial Sensors	108
	6.5.1 Experimental Design	109
	6.5.2 System Comparison and Validation	112
	6.6 Processing and Communication	114
	6.6.1 Signal and Data Processing	116
	6.6.2 Communication Demands of Sensors and Actuators	118
	6.6.3 Communication Technologies	119
	References	123
	7 Applications	126
	7.1 Application Variety	126
	7.1.1 Properties and Requirements	126
	7.1.2 Typical Application Scenarios	127
	7.2 Application Examples	128
	7.3 Golf Swing Trainer Application	129
	7.3.1 Objective and Functionality	129
	7.3.2 System Architecture and Setup	130
	7.3.3 Results	134
	7.3.4 Discussion	135
	7.4 Smart Golf Club Application	136
	7.4.1 Objectives and Functionality	136
	7.4.2 Background	137
	7.4.3 System Architecture and Setup	138
	7.4.4 Application Testing	143
	7.4.5 Results	145
	7.4.6 Future Development	151
	7.5 Smart Ski Application	152
	7.5.1 Objectives and Functionality	152
	7.5.2 Background	153
	7.5.3 System Architecture and Setup	154
	7.5.4 Application Tests	158
	7.5.5 User Interfaces	160
	7.5.6 Results	161
	7.5.7 Future Development	165
	7.6 Water Sports	165
	7.6.1 Objectives and Functionality	165
	7.6.2 Background	166
	7.6.3 System Architecture and Setup	167
	7.6.4 Results	170
	7.6.5 Future Development	176
	7.7 Swimming Rehabilitation Application	176
	7.7.1 Objectives and Functionality	177
	7.7.2 Background	177
	7.7.3 System Architecture and Setup	179
	7.7.4 Results	182
	7.7.5 Future Development	186
	References	186
	Index	190