Monitoring the human body is a key element of digital health science. Low-cost sensors derived from smartphones or smartwatches may give the impression that sensors are readily available; however, to date, very few of them are actually medical devices.
Designing medical devices requires us to undertake a specific approach demanding special skills, as it concerns the integrity of the human body. The process is tightly framed by state regulations in order to ensure compliance with quality assessment, risk management and medical ethics requirements.
This book aims to give biomedical students an overview on medical devices design. It firstly gives a historical and economical approach, then develops key elements in medical device design with reference to EU and US regulations, and finally describes sensors for the human body. The clinical approach is presented as the central element in medical device qualification and this offers a perspective on the use of numerical simulation, particularly since its continued growth in the USA; despite the fact that the approach is strictly limited by regulations.
Table of Contents
Foreword ix
Reynald CONVERT
Chapter 1. Medical Device: Definition, History and Economic Background 1
1.1. Definition 1
1.2. Examples of medical devices 3
1.2.1. Surgery equipment 3
1.2.2. Medical imaging 5
1.3. Medical device industry 10
1.3.1. The industrial sector 10
1.3.2. Importance of medical device in the economy 11
Chapter 2. Medical Device Design and Development 13
2.1. Medical device design is much more than device design. 13
2.2. Product ideation and conceptualization 15
2.3. Regional and international standard for addressing regulation and compliance need 18
2.4. EU medical device regulation (MDR2017) 20
2.5. Design control regulations (for FDA 21CFR820) 21
2.6. Risk management procedures (ISO 14711) 25
2.7. Conclusion 28
Chapter 3. Medical Sensors 29
3.1. Selection of medical sensors 29
3.1.1. Introduction 29
3.1.2. Electric signalization 29
3.1.3. Thermal measurement 37
3.1.4. Biomechanical measurements 42
3.1.5. Exercises 50
Chapter 4. Measurement Quality 51
4.1. Measurement quality 51
4.1.1. Introduction 51
4.1.2. Calibration 52
4.1.3. Vocabulary 53
4.1.4. Metrological testing 55
4.1.5. Evaluating uncertainties 58
4.2. Key notions in signal processing 64
4.2.1. Signal sampling 64
4.2.2. Denoising a signal 66
4.2.3. Time frequency representation 71
4.2.4. Extracting the information for high quantity of noisy data 73
4.2.5. Exercises 78
Chapter 5. Numerical Simulation and Medical Devices 81
5.1. Role of numerical simulation in medical device design 81
5.1.1. General design workflow for medical device 81
5.1.2. Introduction example 82
5.2. General context 83
5.2.1. Agency policies 83
5.2.2. Report structure 85
5.3. Report details 87
5.3.1. Background 87
5.3.2. Question of interest 87
5.3.3. Computation model 88
5.3.4. Model risk 91
5.3.5. Model validation 93
5.3.6. Ranking the model credibility 94
5.3.7. Computational model credibility assessment 95
5.3.8. Results and discussion 96
Chapter 6. Global Ethics Rule Beyond Clinical Trials 99
6.1. Medical ethics, from Hippocrates to the Declaration of Geneva 99
6.2. Evolution of ethics rules for clinical trials 102
6.3. Declaration of Helsinki 106
6.4. Ethics for engineers 116
Chapter 7. Clinical Trials Process 121
7.1. Clinical trials in the design process 121
7.1.1. Before clinical testing 121
7.1.2. Institutional guidelines 123
7.1.3. Clinical trials before going to market (EU - MEDDEV 2.7/1) 124
7.1.4. Bibliographically-based clinical proof and demonstration of equivalence 125
7.1.5. Clinical trials after going to market (EU - MDR2017 and EU - MEDDEV 2.12-1 rev 8) 126
7.2. Insight: MDR2017 and the French implementation 127
7.3. Classification of clinical trials 132
7.4. Insight: the ISO 14155 137
7.4.1. Ethics consideration 137
7.4.2. Planning of the clinical investigation 139
7.4.3. Clinical investigation follow-up 140
7.4.4. Ending a clinical investigation 142
Chapter 8. Introduction to Biostatistics 145
8.1. Introduction 145
8.2. Selection rules for statistical processing 145
8.3. Hypothesis testing 147
8.3.1. General principle on hypothesis testing 147
8.3.2. Error of the first and second king, power of a test 150
8.3.3. Comparing two sets of variables: parametric or nonparametric testing 154
8.3.4. Example: pressure applied by a compression bandage 157
8.4. Linear regression 158
8.4.1. Mathematics of linear regression 158
8.4.2. Analysis of variance 160
8.4.3. Correlation between parameters 164
Chapter 9. Longitudinal Practice with Sensor Design 167
9.1. Design 167
9.2. Session 2: building an IMU-based sensor 168
9.2.1. Step 1: software installation 169
9.2.2. Step 2: wiring 169
9.2.3. Step 3: uploading code to the board 170
9.3. Session 3: signal procession and metrology 171
9.4. Session 4: sleep apnea 172
Chapter 10. Longitudinal Practice Focused on Clinical Trial 175
10.1. Session 1: frailty problems 175
10.2. Session 2: project draft 176
10.3. Session 3: design of a clinical trial (1) 177
10.4. Session 4: design of a clinical trial (2) 177
10.5. Session 5: defense in front of the IRB 178
Appendix: Clinical Trial Form 179
References 193
Index 199
