Life-enhancing Plastics: Plastics And Other Materials In Medical Applications Plastics and Other Materials in Medical Applications

This book enables readers without specialist knowledge to understand the ways in which materials can be used to enhance people’s lives. The range is vast — from simple contact uses, through artificial limbs, to permanently implanted devices. To appreciate the medical applications of materials, it is necessary to understand why they are used. Therefore, a discussion on the nature and behaviour of materials is preceded by a survey of the evolution of modern surgical techniques. The effect of "foreign" materials on the body’s immune system is then considered, followed by a study of specific uses of materials, including extra-corporeal machines and implanted devices. The last chapter deals with new and highly sophisticated techniques — including minimal access surgery, robotics, nanotechnology, natural polymers, and the growth of "artificial" organs — and concludes with a look at the future. Engineering / Acoutics Life-Enhancing Plastics: Plastics and Other Materials in Medical Applications 4 Preface 8 CONTENTS 10 Chapter 1 Surgical Techniques 14 1.1. Introduction 14 1.2. Historical Perspective 14 1.2.1. The Discovery of Anaesthesia 16 1.2.2. Combating Infection 17 1.2.3. Shock 18 1.3. Under the Knife — Surgical Specialities 19 1.3.1. Neurosurgery — The Brain 20 1.3.2. Vascular Surgery 21 1.3.3. Operating on the Lungs and Heart 22 1.3.4. The Lungs 23 1.3.5. Surgery on the Lungs 24 1.3.6. The Heart 25 1.3.7. Heart Surgery 27 1.3.8. The Heart Transplant Operation 28 1.3.9. Heart/Lung Transplantation 28 1.3.10. Other Thoracic Surgery 29 1.3.11. The Repair of Defective Heart Valves 31 1.3.12. Liver Surgery 33 1.3.13. Kidney Surgery 34 1.3.14. Kidney Transplantation 35 1.4. The development of Microsurgery 37 1.4.1. The Use of Microscopes 38 1.4.2. The Application of Microsurgery 38 Facial Nerve Grafting 39 Hand Transplantation 39 1.5. Conclusion 40 References 41 Chapter 2 Material Properties 42 2.1. Introduction 42 2.2. Structure/Property Relationships in Materials 42 2.2.1. Metals 44 The Introduction of Imperfections into the Crystal Lattice 45 The Effect of Grain Structure 45 The Introduction of a Second Phase 46 2.2.2. Ceramics 47 2.2.3. Polymers 48 The Polymer Chain 48 Methods of Creating Specific Properties 49 (a) Greater Flexibility 49 (b) Enhanced Rigidity 50 Molecular Architecture 51 2.3. Polymers compared with other Materials 54 2.4. Prosthetic Limbs 56 2.4.1. Prosthetics from Earliest Times 56 2.4.2. Artificial Legs and Feet 58 Materials Used in Lower Limb Prostheses 64 2.4.3. Artificial Arms and Hands 64 The Development of Artificial Arms and Hands 65 Current Concerns 70 Materials for Arm and Hand Protheses 71 References 71 Chapter 3 Materials in a Hostile Environment 74 3.1. Introduction 74 3.2. The Immune Reaction 74 3.2.1. Early Discoveries 74 3.2.2. Some Questions and Answers 75 The Nature of Lymphocytes 76 How do Lymphocytes distinguish between “Self” and “Nonself"? 76 3.3. Dealing with the Immune Reaction 77 3.3.1. The Composition of Human Blood and its Circulation 77 3.3.2. The Causes of Blood Damage 78 3.3.3. The Blood Clotting Mechanism 79 3.4. Designing for Biocompatibility 80 3.4.1. How the Scene has Changed 80 3.4.2. Chemistry to the Rescue 81 3.4.3. Copying Nature 81 3.5. Conclusion 83 References 83 Chapter 4 Contact Applications 84 4.1. Introduction 84 4.2. Dressings 84 4.2.1. Simple Coverings 84 4.2.2. Interactive Dressings 85 4.2.3. Artificial Skin 86 Chronic Wounds 86 Burns 86 4.2.4. Tissue Engineering 87 4.3. Supports 88 4.3.1. Rigid Supports 88 4.3.2. Flexible Supports 89 4.3.3. Corrective Supports 89 Passive Supports 90 Active Supports 90 4.4. Contact Lenses 91 4.4.1. Early Attempts 91 4.4.2. The Introduction of Plastic Contact Lenses 91 4.4.3. Soft Plastic Contact Lenses 92 4.4.4. Gas Permeable Lenses 92 4.4.5. Disposable Contact Lenses 93 4.4.6. Comparisons & Recent Developments 93 4.4.7. A New Approach 94 4.5. Hearing Aids 96 4.6. Conclusion 96 References 97 Chapter 5 Short Term Contact Devices 98 5.1. Introduction 98 5.2. Catheters 98 5.3. Drain Tubes 100 5.4. Angioplasty Devices 103 5.5. Extracorporeal Machines 107 5.5.1. Kidney Dialysis Machines 107 The Principles of Dialysis 107 Early Dialysis Machines 107 Improvements in the Design of Dialysis Machines 109 Haemodialysis Systems 112 Peritoneal Dialysis 114 Materials used in Dialysis 114 5.5.2. The Heart-Lung Machine — Blood Oxygenator 114 Early Developments 115 Later Developments 115 5.6. Conclusion 118 References 118 Chapter 6 Medium Term Implants 120 6.1. Introduction 120 6.2. The Mechanical Heart 120 6.2.1. Artificial Hearts 120 6.2.2. Ventricular Assist Devices 124 Continuous Drive Pumping Devices 125 Pulsed Drive Pumping Devices 126 6.3. Holding Things Together 129 6.3.1. Sutures 129 Non-Absorbable Sutures 129 Absorbable (Resorbable) Sutures 130 6.3.2. Resorbable Wound Healing Devices 131 6.4. Limb Extension Techniques 133 6.4.1. Traction 133 6.4.2. Extension 135 6.5. Pins, Patches and Plates 135 6.6. Conclusion 135 References 136 Chapter 7 Permanent Implants 138 7.1. Introduction 138 7.2. Artificial Heart Valves 138 7.2.1. The Mechanical Heart Valve 139 7.2.2. Tissue Valves 141 7.3. Cardiac Assist Devices — Pacemakers 144 7.4. Cardiac Assist Devices — Defibrillators 149 7.5. Cosmetic and Reconstructive Surgery 149 7.5.1. Breast Implants 149 7.5.2. Implantation into Other Areas 154 7.6. Dental and other Facial Implants 154 7.6.1. General Dentistry 155 7.6.2. New Teeth for Old — Crowns 158 7.6.3. New Teeth for Old—Implants 159 7.6.4. New Teeth for Old — Dentures 162 7.7. Reconstruction of the Jaw 162 7.8. Conclusion 163 References 163 Chapter 8 Load-bearing Implants 164 8.1. Introduction 164 8.2. Replacement Hip Joints 164 8.2.1. Types of Artificial Hip Joints 166 8.2.2. Factors Governing the Design of the Hip Joint 168 8.3. Knees, Ankles and Feet 169 8.3.1. Replacement Knee Joints 169 8.3.2. Replacement Ankle Joints 171 8.3.3. Surgery on the Bones of the Foot 173 8.4. Shoulders, Elbows and Hands 174 8.4.1. Replacement Shoulder Joints 174 8.4.2. Replacement Elbow Joints 176 8.4.3. Surgery on the Wrists and Hands 177 8.4.4. The Next Generation — Problems to be overcome 179 Design 179 Materials 180 Performance 180 8.5. Conclusion 180 References 181 Chapter 9 The Tools of the Surgeon 182 9.1. Introduction 182 9.2. Early Surgical Instruments 185 9.2.1. The Ancient World 185 9.2.2. The Next Thousand Years–(500–1500 AD) 189 9.2.3. Four Hundred Years of Progress – (1600–1900 AD) 191 9.2.4. The Twentieth Century 193 9.3. Conclusion 196 References 196 Chapter 10 Meeting New Challenges 198 10.1. Introduction 198 10.2. Minimally Invasive Surgery 198 10.2.1. Cardiovascular Intervention 199 10.2.2. Cancer Research 200 10.3. The Coming of Robotics 201 10.4. Nanotechnology 205 10.4.1. Spider Silk 205 10.4.2. Artificial Muscles 208 10.4.3. Nanobes and Nanofilaments 210 10.5. A Look into the Future — A Miscellany of Technologies 211 10.5.1. General Considerations 211 10.5.2. Harnessing the Mind 212 10.5.3. New Materials 215 10.6. Conclusion 217 References 218 Further Reading 220 Surgery 220 Biomaterials 220 Nanotechnology 220 Index of Names 222 Subject Index 226 Life-Enhancing Plastics: Plastics and Other Materials in Medical Applications......Page 4 Preface......Page 8 CONTENTS......Page 10 1.2. Historical Perspective......Page 14 1.2.1. The Discovery of Anaesthesia......Page 16 1.2.2. Combating Infection......Page 17 1.2.3. Shock......Page 18 1.3. Under the Knife — Surgical Specialities......Page 19 1.3.1. Neurosurgery — The Brain......Page 20 1.3.2. Vascular Surgery......Page 21 1.3.3. Operating on the Lungs and Heart......Page 22 1.3.4. The Lungs......Page 23 1.3.5. Surgery on the Lungs......Page 24 1.3.6. The Heart......Page 25 1.3.7. Heart Surgery......Page 27 1.3.9. Heart/Lung Transplantation......Page 28 1.3.10. Other Thoracic Surgery......Page 29 1.3.11. The Repair of Defective Heart Valves......Page 31 1.3.12. Liver Surgery......Page 33 1.3.13. Kidney Surgery......Page 34 1.3.14. Kidney Transplantation......Page 35 1.4. The development of Microsurgery......Page 37 1.4.2. The Application of Microsurgery......Page 38 Hand Transplantation......Page 39 1.5. Conclusion......Page 40 References......Page 41 2.2. Structure/Property Relationships in Materials......Page 42 2.2.1. Metals......Page 44 The Effect of Grain Structure......Page 45 The Introduction of a Second Phase......Page 46 2.2.2. Ceramics......Page 47 The Polymer Chain......Page 48 (a) Greater Flexibility......Page 49 (b) Enhanced Rigidity......Page 50 Molecular Architecture......Page 51 2.3. Polymers compared with other Materials......Page 54 2.4.1. Prosthetics from Earliest Times......Page 56 2.4.2. Artificial Legs and Feet......Page 58 2.4.3. Artificial Arms and Hands......Page 64 The Development of Artificial Arms and Hands......Page 65 Current Concerns......Page 70 References......Page 71 3.2.1. Early Discoveries......Page 74 3.2.2. Some Questions and Answers......Page 75 How do Lymphocytes distinguish between “Self” and “Nonself"?......Page 76 3.3.1. The Composition of Human Blood and its Circulation......Page 77 3.3.2. The Causes of Blood Damage......Page 78 3.3.3. The Blood Clotting Mechanism......Page 79 3.4.1. How the Scene has Changed......Page 80 3.4.3. Copying Nature......Page 81 References......Page 83 4.2.1. Simple Coverings......Page 84 4.2.2. Interactive Dressings......Page 85 Burns......Page 86 4.2.4. Tissue Engineering......Page 87 4.3.1. Rigid Supports......Page 88 4.3.3. Corrective Supports......Page 89 Active Supports......Page 90 4.4.2. The Introduction of Plastic Contact Lenses......Page 91 4.4.4. Gas Permeable Lenses......Page 92 4.4.6. Comparisons & Recent Developments......Page 93 4.4.7. A New Approach......Page 94 4.6. Conclusion......Page 96 References......Page 97 5.2. Catheters......Page 98 5.3. Drain Tubes......Page 100 5.4. Angioplasty Devices......Page 103 Early Dialysis Machines......Page 107 Improvements in the Design of Dialysis Machines......Page 109 Haemodialysis Systems......Page 112 5.5.2. The Heart-Lung Machine — Blood Oxygenator......Page 114 Later Developments......Page 115 References......Page 118 6.2.1. Artificial Hearts......Page 120 6.2.2. Ventricular Assist Devices......Page 124 Continuous Drive Pumping Devices......Page 125 Pulsed Drive Pumping Devices......Page 126 Non-Absorbable Sutures......Page 129 Absorbable (Resorbable) Sutures......Page 130 6.3.2. Resorbable Wound Healing Devices......Page 131 6.4.1. Traction......Page 133 6.6. Conclusion......Page 135 References......Page 136 7.2. Artificial Heart Valves......Page 138 7.2.1. The Mechanical Heart Valve......Page 139 7.2.2. Tissue Valves......Page 141 7.3. Cardiac Assist Devices — Pacemakers......Page 144 7.5.1. Breast Implants......Page 149 7.6. Dental and other Facial Implants......Page 154 7.6.1. General Dentistry......Page 155 7.6.2. New Teeth for Old — Crowns......Page 158 7.6.3. New Teeth for Old—Implants......Page 159 7.7. Reconstruction of the Jaw......Page 162 References......Page 163 8.2. Replacement Hip Joints......Page 164 8.2.1. Types of Artificial Hip Joints......Page 166 8.2.2. Factors Governing the Design of the Hip Joint......Page 168 8.3.1. Replacement Knee Joints......Page 169 8.3.2. Replacement Ankle Joints......Page 171 8.3.3. Surgery on the Bones of the Foot......Page 173 8.4.1. Replacement Shoulder Joints......Page 174 8.4.2. Replacement Elbow Joints......Page 176 8.4.3. Surgery on the Wrists and Hands......Page 177 Design......Page 179 8.5. Conclusion......Page 180 References......Page 181 9.1. Introduction......Page 182 9.2.1. The Ancient World......Page 185 9.2.2. The Next Thousand Years–(500–1500 AD)......Page 189 9.2.3. Four Hundred Years of Progress – (1600–1900 AD)......Page 191 9.2.4. The Twentieth Century......Page 193 References......Page 196 10.2. Minimally Invasive Surgery......Page 198 10.2.1. Cardiovascular Intervention......Page 199 10.2.2. Cancer Research......Page 200 10.3. The Coming of Robotics......Page 201 10.4.1. Spider Silk......Page 205 10.4.2. Artificial Muscles......Page 208 10.4.3. Nanobes and Nanofilaments......Page 210 10.5.1. General Considerations......Page 211 10.5.2. Harnessing the Mind......Page 212 10.5.3. New Materials......Page 215 10.6. Conclusion......Page 217 References......Page 218 Nanotechnology......Page 220 Index of Names......Page 222 Subject Index......Page 226 Whilst the main thrust of this book is on the ways in which materials, especially plastics, can be used to solve problems in surgery and medicine, I felt it would be valuable-particularly for those readers without a medical background-to provide a general overview of the principal surgical procedures, and the ways in which surgeons have developed and improved their art.