Shape Memory Implants. Questo articolo non è disponibile.Shape Memory Implants

Shape memory alloy implants or "smart biomaterial" have already been used in humans for 20 years in selected countries. Restrictions in the use of biomaterials in living organisms being reduced throughout the world now the use of SMA implants continue to expand in the fields of vascular and orthopaedic surgery, minimally invasive surgery and drug delivery systems. This book is to provide a state of the art of SMA implants and devices. For the first time long-term clinical experiences and techniques of SMA biocompatibility are presented.

Basic Properties.- Bioperformance of Shape-Memory Alloys.- 1 Introduction.- 2 Medical Applications.- 2.1 Orthopedic Surgery.- 2.2 Cardiovascular Surgery.- 2.3 Gastroenterologic Surgery.- 2.4 Urologic Surgery.- 2.5 Other Medical Devices.- 2.6 FDA Status of NiTi Medical Devices.- 3 Biocompatibility of NiTi Alloys.- 3.1 Nickel Issue.- 3.2 In Vitro Biocompatibility (Cell Cultures).- 3.3 In Vivo Biocompatibility of NiTi (Animal Models).- 3.3.1 Soft-Tissue Response.- 3.3.2 Vascular-Tissue Response.- 3.3.3 Bone-Tissue Response.- 3.4 Clinical Studies of NiTi Orthopedic Devices.- References.- Processing and Quality Control of Binary NiTi Shape-Memory Alloys.- 1 Introduction.- 2 Production and Processing of NiTiNOL.- 3 Thermomechanical Treatment and Functional Properties.- 4 Quality Control of NiTiNOL Semi-Finished Shapes.- 4.1 Definition of Terms.- 4.2 Measurement of Relevant Functional Properties.- 5 Conclusions.- References.- Corrosion Resistance and Biocompatibility of Passivated NiTi.- 1 Introduction.- 2 Active Corrosion Testing.- 3 Passive Corrosion Behavior.- 4 Effect of Surface Layer on Corrosion Resistance.- 5 Nickel Release and Biocompatibility.- 6 Conclusions.- References.- The High Damping Capacity of Shape-Memory Alloys.- 1 Introduction.- 2 Internal Friction Behaviour of Shape-Memory Alloys.- 2.1 Internal Friction during Martensitic Transformation.- 2.2 Internal Friction in the Martensitic Phase.- 2.2.1 Frequency.- 2.2.2 The Temperature Rate.- 2.2.3 The Amplitude.- 2.2.4 Time Dependence.- 2.2.5 Relaxation Peaks in Ni-Ti and Cu-Based Martensites.- 2.2.6 How Large is the Damping Capacity?.- 2.3 Specific Results on Ni-Ti Shape-Memory Alloys.- 2.4 Energy Loss during Pseudoelastic Loading.- 2.5 Some Remarks on the Fatigue Life of SMA Devices.- 3 Conclusions.- References.- Physical and Biochemical Principles of the Application of TiNi-Based Alloys as Shape-Memory Implants.- 1 Introduction.- 2 Shape-Memory Effect and Pseudoelasticity in TiNi-Based Alloys.- 2.1 Role of the Chemical Composition.- 2.2 Role of the Phase Composition and the Thermomechanical Treatment.- 2.3 Pseudoelastic Behavior of TiNi-Based Alloys.- 2.3.1 Shape-Memory Effect.- 2.3.2 Ail-Round Shape-Memory Effects.- 2.3.3 Superelasticity.- 3 Corrosion Properties and Electrochemical Behavior of TiNi-Based Alloys.- References.- Porous NiTi as a Material for Bone Engineering.- 1 Introduction.- 2 Porous Biomaterials in Craniomaxillofacial Applications.- 3 NiTi Biocompatibility.- 3.1 Mechanisms of NiTi Biocompatibility.- 4 Authors’Experience with NiTi.- 5 NiTi Versus Other Biomaterials.- 5.1 Mechanical Considerations.- 5.2 Formation Considerations.- 5.3 Machining.- 5.4 Biocompatibility.- 6 Present and Future Advantages of Porous NiTi.- 7 Future Work.- 8 Conclusions.- References.- Ti-Ni-Mo Shape-Memory Alloys for Medical Applications.- 1 Introduction.- 2 Phase Transformation Behaviors of Ti-Ni-Mo Alloys.- 3 Deformation Characteristics of Ti-Ni-Mo Alloys.- 4 Shape-Memory Characteristics of Ti-Ni-Mo Alloys.- 5 Summary.- References.- Orthopaedic Applications.- Ti-Ni-Mo Shape-Memory Alloys for Medical Applications.- 1 Introduction.- 2 The Basic Principles and Requirements.- 2.1 Biocompatibility and Mechanical Properties.- 2.2 Transformation and Recovery Temperatures.- 2.3 The Recovery Force.- 3 Shape-Memory Implants in the Treatment of Transarticular Fracture.- 3.1 Compression Staples.- 3.2 Patellar Fixator Ill.- 3.3 The Shape-Memory Screw Ill.- 4 Shape-Memory Implants in the Treatment of Long-Bone Shaft Fractures.- 4.1 Shape-Memory Sawtooth-Arm Embracing Internal Fixator.- 4.2 Fork-Like Shape-Memory Intramedullar Nail and Bow-Shaped Compressive Osteo-Connector.- 5 Hand Surgery.- 5.1 Shape-Memory Compression Plate.- 5.2 Clamping Plate.- 6 Spinal Surgery.- 6.1 O-Shaped Intravertebral Artificial Joint.- 6.2 Shape-Memory Expansion Clamp.- 6.3 Shape-Memory Device Used in Scoliosis.- 7 Arthroplasty.- 7.1 Shape-Memory Double-Cup Prosthesis of Hip.- 7.2 Other Applications.- 8 Future Studies.- References.- The Surgical Correction of Scoliosis with Shape-Memory Metal.- 1 Introduction.- 1.1 Scoliosis.- 1.2 The Current Surgical Treatment of Scoliosis.- 2 Biomechanical Aspects of the Correction of Scoliosis with Shape-Memory Metal.- 2.1 The Force System in the Scoliotic Spine.- 2.2 Force-Controlled Correction of Scoliosis with Shape- Memory Metal.- 3 Biocompatibility Aspects of the Shape-Memory Metal Scoliosis-Correction Device.- 3.1 The in Vitro Biocompatibility of Shape-Memory Metal.- 3.2 Animal Experience with Shape-Memory Metal Scoliosis Correction Device.- 4 Conclusions.- References.- Shape-Memory Implants in Spinal Surgery: Long-Term Results (Experimental and Clinical Studies).- 1 TiNi Device for the Anterior Fusion of the Spine.- 1.1 Introduction.- 1.2 Material, Method and Experimental Results.- 1.3 Clinical Results.- 1.4 Complications.- 1.5 Discussion.- 1.6 Conclusion.- 2 Porous TiNi Implants.- 2.1 Introduction.- 2.2 Material, Method and Experimental Results.- 2.3 Clinical Results.- 2.4 Conclusions.- References.- The Use of a Memory-Shape Staple in Cervical Anterior Fusion (about 100 Human Implantations).- 1 Introduction.- 2 Nitinol: Properties, Biocompatibility.- 3 Device Description.- 4 Surgical Technique.- 5 Material and Methods.- 6 Results.- 7 Other Complications.- 8 Discussion.- 9 Conclusions.- References.- The Double Compressive Nickel-Titanium Shape-Memory Staple in Foot Surgery.- 1 Introduction.- 2 The Doubly Compressive Nickel-Titanium Shape-Memory Staple.- 2.1 Description.- 2.2 Working Principles.- 3 Material and Methods.- Orthodontic Applications.- Corrosion Behavior of Ni-Ti Alloys in a Physiological Saline Solution.- 1 Introduction.- 2 Anodic Corrosion Behavior of the NiTi Alloy and Other Implant Alloys.- 3 Dissolution of Ni Ions from the NiTi Alloy.- 4 Characterization of the Surface Oxide Film on a Ni-Ti Alloy.- 5 Surface Structure and Corrosion Characteristics of the NiTi Alloy.- 6 Factors Affecting the Corrosion Behavior of the NiTi Alloys.- 6.1 Effects of Alloying.- 6.2 Effects of Surface Texture.- 6.3 Effect of Contact between Dissimilar Metals.- 6.4 Effect of Amino Acids and Serum Proteins.- 7 Surface Treatments for Improving the Corrosion Resistance of the NiTi Alloy.- 8 Summary.- References.- NiTi Alloys in Orthodontics.- 1 Introduction.- 2 Conventional Wires and their Problems.- 2.1 The High-Elasticity Module.- 2.2 The High Load/Deflection Rate.- 3 NiTi Wires.- 4 Thermal NiTi Wires.- 5 Clinical Application of Thermal NiTi Wires.- 6 Properties of NiTi Alloys in Orthodontics.- 6.1 The Great Ability to Deflect (Shape Memory).- 6.2 Small Load/Deflection Ratio.- 6.3 Superelasticity.- 6.4 Memory.- 7 Advantages of NiTi Wires in Orthodontics.- 8 Temperature Treatment of Orthodontic NiTi Wires.- 9 Memory Maker.- 10 Heat-Treated Archwires and Clinical Application.- 11 NiTi-Stainless Steel Combinations.- References.- Clinical Application of Shape-Memory Alloys in Orthodontics.- 1 Introduction.- 2 History.- 3 Basic Application Principles.- 4 When are Orthodontic Wires Superelastic?.- 5 Limiting the Force.- 6 Different Force Requirements for Different Teeth.- 7 Other Superelastic Elements in Orthodontics.- 8 Conclusions and Outlook.- References.- Orthodontic application of NiTi Shape-Memory Alloy in China.- 1 Introduction.- 2 Superelastic Archwire (SE Type).- 3 Memory Archwire (RTF Type).- 4 Rocking-Chair Archwire.- 5 Superelastic Orthodontic Springs.- References.- Progressive Damage Assessment of TiNi Endodontic Files.- 1 Introduction.- 2 Materials and Methods.- 3 Results and Discussion.- 4 Conclusions.- References.- Endovascular Applications.- Effects of Surface Modification Induced by Sterilization Processes on theThrombogenicity of Nickel-Titanium Stents.- 1 Introduction.- 2 Materials.- 3 Methods.- 3.1 Animal Preparation.- 3.2 Isolation and Labeling.- 3.3 Stent Insertion.- 3.4 Extracorporeal AV Shunt.- 3.5 Auger-Electron Spectroscopy.- 3.6 Scanning Electron Microscopy.- 4 Results.- 4.1 Surface Analyses of Electropolished NiTi Stents.- 4.2 Effect of Sterilization on Thrombogenicity of Electropolished NiTi Stents.- 4.3 Effect of Blood Flow on Platelet Adhesion of Electropolished NiTi Stents in Comparison to Stainless teel.- 4.4 Morphological Analyses of the Stents Post-Perfusion.- 5 Discussion.- 6 Conclusions.- References.- X-Ray Endostenting Surgery of Vessels and Hollow Organs.- 1 X-Ray Endovascular Stent Surgery.- 2 Stenting Surgery on Bile Ducts.- 3 Stenting Surgery on Oesophagus.- 4 The Endostenting Surgery on Trachea by NiTi Spiral.- 5 The Stenting Surgery on Cervical Canal of Uterus.- References.- Device for Extravasal Correction of the Function of Vein Valves Based on Nitinol Shape Memory and Its Clinical Application.- 1 Introduction.- 2 Anatomic Examination of Main Vein Valves and Grounds for Corrector Shape Selection.- 2.1 Methods of Anatomic Examination.- 2.2 Results of Anatomic Examinations and Discussion.- 3 Shape-Memory Nitinol Extravasal Correctors.- 4 Clinical Approving and Effectivity of the Nitinol Shape-Memory Extravasal Correctors.- References.- Large-Caliber NiTi SMA Stents and Stent Grafts.- 1 Introduction.- 2 Design Constraints.- 3 Review of NiTi SMA Stent Designs.- 4 Test Requirements.- 5 Clinical Applications.- 6 Future Development.- References.- Shape-Memory Alloy for Interventional Stenting in View of Its Development in China.- 1 Introduction.- 2 Structural and Material Considerations for the Stent Design.- 3 SMA Stent and Its Application in China.- 3.1 Nonvascular Applications.- 3.2 Vascular Applications.- 4 Discussion and Comments.- 4.1 Systematic Clinical Investigations.- 4.2 Stent Manufacture.- 4.2.1 Geometric Considerations.- 4.2.2 Mechanical Performance.- 4.3 Stent-Material Preparation.- 4.3.1 Bulk-Material Production.- 4.3.2 Surface Preparation.- 5 Summary.- References.- Other Medical Applications.- An Implantable Drug Delivery System Based on Shape-Memory Alloys.- 1 Introduction.- 2 Design of a Delivery System for Solid Drugs.- 2.1 Introduction.- 2.2 Design of a Drug-Delivery Device for Solid Drugs.- 2.3 Conclusion on Solid Drug Delivery.- 3 Design of a System for Delivery of Liquid Drugs.- 3.1 Introduction.- 3.2 Mechanical Design.- 3.2.1 First Prototype.- 3.2.2 Tube Characteristics.- 3.2.3 Valve Finite-Element Model.- 3.3 First Prototype Building.- 3.3.1 Introduction.- 3.3.2 Electrical Characteristics.- 3.3.3 Design of the Reservoirs and Refill Port.- 3.3.4 Prototype Drug Delivery System.- 4 Operational Tests.- 4.1 System Components.- 4.2 Total System.- 5 Possible Improvements.- 6 Conclusion.- References.