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CONVERTING PATIENT-SPECIFIC SCANS INTO HIGHLY ACCURATE COMPUTATIONAL MODELS
Poster P-126
Modelling
S499
CONVERTING PATIENT-SPECIFIC SCANS INTO HIGHLY ACCURATE COMPUTATIONAL MODELS Rajab Said (1), Daniel Thomas (2), Richard Curtis (3) and Philippe Young (4)
1. Simpleware Ltd, UK; 2. University of Kentucky, KY, USA; 3. King’s College London, UK; 4. SECaM, University of Exeter, UK;
Introduction
SPF for patient-specific prostheses
Computational simulation technology has become an indispensable tool for researchers across the biomechanics discipline. Crucial to the effectiveness of such a tool is its ability to efficiently simulate patient-specific problems. This paper will present a unique and exceptionally efficient approach that converts 3D digital images (provided typically by CT, Ultrasound or MRI scanners) directly into highly accurate computational models.
Superplastic Forming (SPF) of titanium alloy sheet has been shown to be a viable means to create dental and maxillofacial prostheses. SPF opens up the possibilities of creating prostheses of lower cost and with more complex shapes than current cold forming processes. However, SPF has yet to be successfully integrated into an efficient patientspecific manufacturing process. An on-going collaboration project is investigating the use Computed Tomography (CT) scanning technology in association with image-based mesh generation tools (such as these developed by Simpleware) to efficiently and accurately construct an appropriate geometrical representation of every prosthesis. Such a 3D surface and/or solid representation can be used for both Rapid Prototyping and/or Computational Simulation purposes both of which are essential parts in fully automated SPF manufacturing process of patient-specific prostheses
Image-based mesh generation A mesh generation technique based on a unique inhouse developed multi-part marching cubes algorithm with specifically designed multi-part smoothing algorithms will be presented. Uniquely this technique allows the user to: straightforwardly generate meshes of excellent quality (low element distortions) regardless of complexity; will mesh any number of structures simultaneously (handles multi-part junctions); and allow the user to seamlessly apply signal strength to material property mapping functions (e.g. Young’s Modulus to Hounsfield Number mapping functions). Important concepts in smoothing of meshes such as topological preservation of data (for example to ensure preservation of connectivity), volume neutral smoothing (to prevent shrinkage of convex hulls) and convergence to geometry will be discussed; a typical example is illustrated in Figure 1. The approach has been applied to a very wide range of problems for both Finite Element Analysis, CFD analysis and FSI problems [1, 2].
Figure 2: Example of constructing 3D SPF Die of maxillofacial prosthesis using Simpleware tools.
References Figure 1: Segmentation of multi-part scan: brain, CSF, skull, mandible, soft tissue, spine, spinal cord, and intervertebral discs.
16th ESB Congress, Posters
1- Johnson, E.A.C., Young, P.G., 2005. Journal of Biomechanics, 38, 39-45 2- Tabor, G., Tame, D., Pierron, F., Young, P.G., et al, 2006. ECCOMAS CFD 2006, 5-8 September 2006 Egmond aan Zee. Journal of Biomechanics 41(S1)
Modelling
S499
CONVERTING PATIENT-SPECIFIC SCANS INTO HIGHLY ACCURATE COMPUTATIONAL MODELS Rajab Said (1), Daniel Thomas (2), Richard Curtis (3) and Philippe Young (4)
1. Simpleware Ltd, UK; 2. University of Kentucky, KY, USA; 3. King’s College London, UK; 4. SECaM, University of Exeter, UK;
Introduction
SPF for patient-specific prostheses
Computational simulation technology has become an indispensable tool for researchers across the biomechanics discipline. Crucial to the effectiveness of such a tool is its ability to efficiently simulate patient-specific problems. This paper will present a unique and exceptionally efficient approach that converts 3D digital images (provided typically by CT, Ultrasound or MRI scanners) directly into highly accurate computational models.
Superplastic Forming (SPF) of titanium alloy sheet has been shown to be a viable means to create dental and maxillofacial prostheses. SPF opens up the possibilities of creating prostheses of lower cost and with more complex shapes than current cold forming processes. However, SPF has yet to be successfully integrated into an efficient patientspecific manufacturing process. An on-going collaboration project is investigating the use Computed Tomography (CT) scanning technology in association with image-based mesh generation tools (such as these developed by Simpleware) to efficiently and accurately construct an appropriate geometrical representation of every prosthesis. Such a 3D surface and/or solid representation can be used for both Rapid Prototyping and/or Computational Simulation purposes both of which are essential parts in fully automated SPF manufacturing process of patient-specific prostheses
Image-based mesh generation A mesh generation technique based on a unique inhouse developed multi-part marching cubes algorithm with specifically designed multi-part smoothing algorithms will be presented. Uniquely this technique allows the user to: straightforwardly generate meshes of excellent quality (low element distortions) regardless of complexity; will mesh any number of structures simultaneously (handles multi-part junctions); and allow the user to seamlessly apply signal strength to material property mapping functions (e.g. Young’s Modulus to Hounsfield Number mapping functions). Important concepts in smoothing of meshes such as topological preservation of data (for example to ensure preservation of connectivity), volume neutral smoothing (to prevent shrinkage of convex hulls) and convergence to geometry will be discussed; a typical example is illustrated in Figure 1. The approach has been applied to a very wide range of problems for both Finite Element Analysis, CFD analysis and FSI problems [1, 2].
Figure 2: Example of constructing 3D SPF Die of maxillofacial prosthesis using Simpleware tools.
References Figure 1: Segmentation of multi-part scan: brain, CSF, skull, mandible, soft tissue, spine, spinal cord, and intervertebral discs.
16th ESB Congress, Posters
1- Johnson, E.A.C., Young, P.G., 2005. Journal of Biomechanics, 38, 39-45 2- Tabor, G., Tame, D., Pierron, F., Young, P.G., et al, 2006. ECCOMAS CFD 2006, 5-8 September 2006 Egmond aan Zee. Journal of Biomechanics 41(S1)