Van Der Smissen, B., Claessens, T., Verdonck, P., Van Ransbeeck, P., and Segers, P.
IRBM; Jun2013, Vol. 34 Issue 3, p226-234, 9p
RAPID prototyping, BIOMECHANICS, LEFT heart ventricle, HYDRAULIC engineering, PROTOTYPES, and MECHATRONICS
Abstract: Biomechanical research of left ventricular function involves the assessment and understanding of both ventricular wall mechanics and deformation and intraventricular flow patterns, as well as how they interact. Experimental research using hydraulic bench models should therefore aim for an as realistic as possible simulation of both. In previous experimental investigations, wall deformation was studied by means of thin-walled passive experimental models, consisting of a silicone membrane in a closed box, which is squeezed passively by an externally connected piston pump. Although the pump function of these models has already been well established, the membrane deformation remains unpredictable and the effect of muscle contraction – and hence natural wall deformation – cannot be simulated. In this study, we propose a new design of an experimental hydraulic left ventricular model in which left ventricular wall deformation can be controlled. We built this model by a combination of rapid prototyping techniques and tested it to demonstrate its wall deformation and pump function. Our experiments show that circumferential and longitudinal contraction can be attained and that this model can generate fairly normal values of pressure and flow. [Copyright &y& Elsevier]
Rapid prototyping (RP) is a technique which produce 3D model of a part from the CAD model using the additive manufacturing technology. Unlike the traditional method of manufacturing, in this technique small layers are added on top of one another to form the final part. This allows rapid prototyping to create very complex parts in relatively less time period. In recent years this technique has been applied to medical field. Common RP techniques used in the medical field are Selective Laser Sintering, Fused Deposition Modeling, Multi-Jet Modeling and Stereolithography. But for most of the above methods, the working principle remains the same. The input data for model generation is obtained from Magnetic Resonance Imaging (MRI) or Computer Tomography (CT) scan which is converted to a 3D model by image processing software. This 3D model is converted to STL format which is read by the RP machine by creating thin slices of the model. Clubfoot, a challenging foot deformity generally occurs at birth, is caused by the abnormal posturing of the foot which becomes twisted so that the sole cannot be placed flat on the ground. The treatment for clubfoot should begin immediately, preferably in the first week of birth since the tissues, tendons, ligaments and bones of the new born's foot will yield to gentle pressure over time. The treatment involves manipulations and serial casting for correction and orthosis for maintenance. This paper focuses on the applications of rapid prototyping in designing a corrective orthosis which will replace serial casting in the treatment of Clubfoot in children. Rapid prototyping has proven to facilitate, speed up and improve the quality of procedures and products. [ABSTRACT FROM AUTHOR]
Methods in Oceanography; Dec2016, Vol. 17, p97-117, 21p
3D printers allow researchers to produce parts and concept models rapidly at low-cost and allow rapid prototyping of many designs from the comfort of their desk. 3D printing technologies have been explored for a wide range of applications including robotics, automobile components, firearms, medicine, space, etc. Owing to lower costs and increased capabilities of 3D printing technologies, unprecedented opportunities in the world of oceanography research are being created. Some examples include 3D printed components being employed in autonomous underwater (or surface) vehicles; 3D printed replicas of marine organisms being used to study biomechanics, hydrodynamics, and locomotion; and 3D printed coral reef replicas being used to restore damaged coral reefs. To the author’s knowledge, currently there is no review covering the different 3D printing technologies applied in oceanography studies. Therefore, this review presents a summary of the different 3D printing technologies that have been used in fundamental studies or real-life applications related to oceanography. The diverse range of 3D printing applications in oceanography covered in this review has been categorized under the following sub-topics: Ecological Monitoring & Sample Collection, Hydrodynamics, Biomechanics & Locomotion, Tracking & Surface Studies, and Tangible Coral Props & Coral Reef Restoration. A detailed overview of the 3D printing technologies referred to within this review has been presented, and categorized under the following four general topics: Material Extrusion, Photopolymerization, Powder Bed Fusion, and Construction Printing. The broad impact of plastics on oceans and the specific impact of 3D printing materials on ocean life are also discussed. It is anticipated that this review will further promote the 3D printing technologies to oceanographers for a better understanding and restoration of fragile marine ecosystems. [ABSTRACT FROM AUTHOR]
MANDIBLE surgery, BONE grafting, METALS in surgery, AUTOGRAFTS, COMPUTER-aided design, RADIOISOTOPE scanning, and BIOMECHANICS
To esthetically and functionally restore a 40-mm canine mandibular discontinuity defect using a custom-made titanium bone-grafting plate in combination with autologous iliac bone grafts. Individualized titanium bone-grafting plates were manufactured using a series of techniques, including reverse engineering, computer aided design, rapid prototyping and titanium casting. A 40-mm discontinuous defect in the right mandibular body was created in 9 hybrid dogs. The defect was restored immediately using the customized plate in combination with autologous cancellous iliac blocks. Sequential radionuclide bone imaging was performed to evaluate the bone metabolism and reconstitution of the grafts. The specimens were evaluated by biomechanical testing, 3-dimensional microcomputed tomographic scanning, and histological examination. The results revealed that the symmetry of the mandibles was reconstructed using the customized grafting plate, and the bony continuity of the mandibles was restored. By 12 weeks after the operation, the cancellous iliac grafts became a hard bone block, which was of comparable strength to native mandibles. A fibrous tissue intermediate was found between the remodelled bone graft and the titanium plate. The results indicate that the prototyped grafting plate can be used to restore mandibular discontinuous defects, and satisfactory aesthetical and functional reconstruction can be achieved. [ABSTRACT FROM AUTHOR]
Wong, R.C.W., Tideman, H., Merkx, M.A.W., Jansen, J., Goh, S.M., and Liao, K.
International Journal of Oral & Maxillofacial Surgery; Apr2011, Vol. 40 Issue 4, p393-400, 8p
MANDIBLE surgery, BIOMECHANICS, FINITE element method, BONE fractures, DATABASES, and SYSTEMATIC reviews (Medical research)
Abstract: This study looked at computer and physical biomodels used to study the biomechanical performance of mandibular reconstruction, reviews the literature and explains the strengths and limitations of the models. Electronic databases (Pubmed, Medline) were searched. 17 articles were selected. Computer biomodels can be divided into virtual biomodels (mainly used for clinical diagnosis and treatment planning) and computational models (e.g. finite element analysis), they can predict areas most likely to fail based on internal stress distribution and areas of maximum stress concentration. Physical biomodels include: rapid prototyping, animal bone, human cadaveric bone, and bone substitute models. Physical models allow testing on a gross level to give fatigue performance and fracture strength. The use of bone substitutes allows a more consistent specimen size and a reduction in sample size. Some commercially available products can replicate the material properties of bone. The use of any biomodel depends on the question being asked: the bending strength of a reconstruction plate would necessitate a three point bending test; the biomechanical performance of a new method of reconstruction (e.g. the mandibular modular endoprosthesis) would necessitate finite element analysis to predict areas of likely failure and also a physical biomodel to look at fatigue failure. [Copyright &y& Elsevier]