Placement of new prosthesis on a patient requires measuring the exact dimension of a patients body. Such measurement involves multiple dimensions and hence a precise method is required. Artistic rendering using manual measurements involves considerable time, effort and expense and are also prone to error. Hence conversion of precisely obtained Computed Tomography (CT)
There are various softwares available to perform each of these operations independently but Mimics (Materialise NV, Belgium) provides a one step interface for performing all these operations. It provides a seamless workflow platform and hence conversion from CT and MR data in to 3D models can be performed in less time. It also converts these 3D models in to FEM models and export them to different FEM softwares.
Steps in creation of 3D models
The various steps involved in the conversion of CT and MRI data in to 3D model are
2. Convert the segmented data in to 3D model and
3. Export the model in to various formats as required for FEM or RP.
Mimics has various modules like Mimics base, STL+, FEM, Simulation, ... In this article, we will evaluate the first three modules.
The Mimics base module allows user to read CT and MRI data in DICOM
To edit the mask, Mimics provides mask editors that work in both 2D slices or 3D volumes. The masking involves adding pixels that have not been included in the segmentation process or removing excess pixels which the user judges as not belonging to the part. The masking operation works by painting over pixels that need to be selected and for precise selection, a threshold range can also be set. Similarly, the 3D masking operation performs a 3D erase along a cylindrical axis.
The edited mask can then be converted in to STL
The FEM module converts the 3D mask in to a mesh. The mesh can then be refined both globally and locally by controlling individual mesh elements. The edited mesh can then be stored in different FEM file formats that includes most commonly used FEM formats for packages like Ansys, Abaqus, Patran etc.
Please leave your comments at the bottom and if many users request, I can work on a more detailed tutorial on Mimics and post it in the future.