MIMICS is a highly integrated and easy-to-use 3D image generation and editing software that can input various scanned data (CT, MRI), create 3D models for editing, and then output in common CAD (Computer Aided Design), FEA (Finite Element Analysis), and RP (Rapid Prototyping) formats, allowing large-scale data conversion and processing on a PC. MIMICS FEA module MIMICS.
The FEA module can quickly process the scan input data and output the corresponding file format for FEA (finite element analysis) and CFD (computer simulated fluid dynamics), the user can use the scan data to build a 3D model and then mesh the surface for application in FEA analysis. Optimization, based on the Heinz units of the scan data, allows material assignment to the body mesh. A 3D model is created in MIMICS from the point cloud data. Bin Liu, Department of Bone Oncology, Affiliated Cancer Hospital, Guangxi Medical University
In the FEA module, the 3D model mesh is redistributed using the mesh redistribution function of MIMICS.
Export to Patran under FEA module
Neutral,Ansys and Abaqus
surface and other FEA software.
Conversion of surface meshes to body meshes for pre-processing (e.g. MSC, Marc, …)
Input Patran, Ansys, Abaqus body mesh files in FEA module.
Assign material to the body mesh based on the scan data in the FEA module.
Export the material assigned body mesh to FEA software such as Patran, Ansys, or Abaqus in the FEA module.
MIMICS mesh redraw function.
MIMICS mesh redrawing function can significantly improve the quality and processing speed of STL models, and can easily transform irregular triangular pieces into triangular pieces that tend to be equilateral. In the further automatic redrawing function, more professional semi-automatic or manual delineation can be performed for better FEA analysis.
Additional quality control parameters.
MIMICS mesh redraw function provides up to 14 general quality control parameters, the user can choose the appropriate method to calculate the quality of triangular pieces.
Convenient automatic grid redraw function.
The grid redraw function automatically improves the quality of triangles by searching for all bad triangles below a pre-set quality level and converting them to an acceptable shape.
Manual grid redraw.
In individual cases where the quality of the triangles is still below the required level after automatic mesh redrawing, then we can perform the mesh redrawing manually. The mesh redrawing feature provides a unique toolbox to modify their shape manually.
Improving reliability and accuracy in FEA analysis.
The MIMICS mesh redraw feature provides a highly automated interface to all FEA software, which can significantly improve the reliability and accuracy of FEA analysis results for STL models. Most FEA tools cannot perform optimization work after mesh redrawing, which will certainly make the accuracy of the final results greatly reduced, using the MIMICS mesh redrawing function will get the most optimized file, and then the optimized results will be exported to the FEA software.
Saving computing time.
Generally speaking, the time required to carry out optimization will be longer, but the MIMICS mesh redraw function will greatly reduce this time.
Material assignment.
After loading the body mesh data, the FEA function calculates the gray value in Hensel units for each cell of the mesh based on the scanned image data, and then the corresponding material can be defined according to different gray ranges, or by density, or E modulus and Poisson’s coefficient. The body mesh with the assigned material is then exported to Patran
neutral, Ansys and Abaqus files.
Assigning materials in a homogeneous way.
The Heinz units in the bulk mesh are divided into equal areas, each area corresponding to a different material, and an empirical formula is used to convert the Heinz units into density values, which are then assigned to the corresponding bulk mesh, followed by the definition of the E modulus and Poisson’s coefficient for each material.
Assigning materials by look-up table.
Assign the corresponding density values to grayscale values in an XML file, then enter this XML file in the FEA module, assign materials to each body mesh as defined in the XML file, and then define the E modulus and Poisson’s coefficient for each material.
Surgical Simulation Module The MIMICS Surgical Simulation Module is a platform for surgical simulation applications. The anthropometric analysis template can be used to perform detailed data analysis, and it is very helpful to simulate osteotomy and separation procedures as well as implantation procedures, or to explain implantation procedures.
Anthropometric analysis.
To perform anthropometric analysis, first select a template and pre-set the required markers, reference planes and measurement methods. After the required marker points for planes and measurement methods are determined, the planes and measurement methods are also determined, or customize the template if no suitable template is available.
Marker list.
You can create, copy, edit and delete marker points. Each marker point has its own default properties before the above operations are performed, and the properties that can be edited include: marker name, color and description.
Flat List;
The second list allows the user to easily define one or more planes available for analysis. To define an analysis surface you must first define the marker point or base it on a plane in a pre-generated template.
Measurement list.
There are various ways to choose to measure angles or distances. For distance measurements, either between two points or between a point and a plane can be measured, for angle measurements, the three-point method and the two-line method (each line is determined by two points) can be used. Note: Measurements can only be made in the points and planes defined in the template.
Surgical procedure simulation.
MIMICS surgical simulation function provides a powerful 3D toolkit for surgical simulation, a variety of tools to simulate osteotomy and separation surgery and STL file operations are available.
Cutting.
Two cutting tools are available: polyline cutting and polyline cutting with cutting surface. In polyline cutting, the user defines a cutting curve by drawing a line with the cutting surface perpendicular to the view plane, and this cut will be invalid if the cutting depth is not cut through. polyline cutting with cutting surface is a free cutting tool that can be dragged and cut in 3D and 2D, and the cutting trajectory will be displayed in 2 D and 3D in real time.
Splitting.
This feature allows to divide an object into 3D models that are independent of each other, and then create several different local 3D models.
Fusion.
The fusion function turns the selected different models into one model.
Mirroring.
The mirroring function mirrors the selected object along a set plane or an existing plane (from human data analysis or MEDCAD) to generate a new object, and multiple objects can be selected for mirroring operations.
Placement traction:
After the cutting operation, a suitable tractor can be selected from the database and placed on the 3D model for comparison. Since the cutting operation cannot be automatic, the operator must know the correct way to use the selected tractor.
Adjustment of the retractor position.
To simulate the positioning and adjustment of the retractor, an analysis view of the retractor movement is available for reference.
Positioning functions.
The object can be moved or rotated, and any of the operation methods can be used to achieve the user’s purpose. Several modifications of the object are available: moving along the axis, moving in-plane or rotating along the axis, rotating along the point, and of course operations without these restrictions are also an option. The registration function allows easy adjustment of objects with marker points and also with mouse movements.
Additional features.
The loaded STL file can be added to the project manager, and the buttons under the STL tab in the project manager can be used to rotate, move, etc. the STL file. A neural tool is available: draw in 2D first, then add the neural tab in the project manager.
MEDCAD module The MEDCAD module is a bridge between medical imaging data and CAD, communicating through a two-way interaction mode to achieve interconversion of scan data and CAD data.
There are two ways to create CAD projects in MIMICS projects.
Contour line modeling.
In the segmentation function state, MIMICS automatically generates contour lines on the separated mask. MEDCAD is able to automatically generate a local contour line model with a given error, which in turn is used in the CAD model of medical geometry.
Possible methods of the created CAD model.
-B spline curves and surfaces
-points, lines, circles, surfaces, spheres, cylinders, etc.
All these entities can be exported to CAD software in iges format to make implants. Another typical use is to use the MEDCAD module for statistical analysis, e.g. to measure the data of many different femoral heads for reference when creating standard femoral head implants.
Parametric or interactive CAD modeling
CAD objects can be created directly in 2D or 3D view, or in a parametric way (e.g. defining the center and radius of a circle to create a circle), and after creation they can be edited interactively with the mouse.
Easy design validation.
To validate the design of CAD implants, MIMICS input STL file format is displayed in 2D view and standard view, or in 3D view, showing anatomical relationships in a transparent way, using this method to quickly implement medical images in the CAD software call.
RP-SLICE module The Rp-slice module creates an interface between MIMICS and most RP machines in SLICE format, and the RP-Slice
module automatically generates the support structures needed for RP models.
Fast and accurate data conversion for RP machines.
With RP
Slice technology allows the processing of large files and maintains a high resolution of the RP model when creating slice files, which is improved with a cubic interpolation algorithm.
Supported Hole Forming Technology – a patented technology from materialise that not only speeds up the molding process four times, but also saves more material and facilitates cleanup.
Slicing.
Rp-slice provides the best and most accurate data conversion in a very short time, outputting SLI, SLC format
to 3D System, CLI format to EOS.
High-order interpolation algorithms enable the scanned data to be turned into 3D solid models with perfect surfaces.
Rp-slice supports colored photosensitive materials: teeth, roots, glands, nerve ducts, etc. can be shaded in the mold.
Coloring.
The model is prominently marked with a new reference dimension, and patient information can also be marked with embedded or colored labels.
Parameters.
RP-slice allows the setting of parameters such as layer thickness, resolution, scaling, etc. A variety of filters are available, such as: minimum segment length filter, minimum contour length, linear deviation correction. Slicing data can be saved in various formats: *.CLI, *.SLI, *.SLC.
Support for generation.
The support generation function automatically generates the structure of the support required in rapid prototyping and outputs it automatically in the corresponding file format (SLI, SLC, and CLI formats), which not only provides a faster way to prepare data before prototyping, but also the patented hole formation technology can shorten the whole process by more than four times and save material.
Support generation parameter selection.
Several support generation parameters are available. RP-slice makes it possible to define supports in the X and Y coordinate planes, to define the length and hole formation angle of supports, the maximum inclination angle without supports and the starting and ending height of supports.
Mimics STL+ Module Mimics
The STL+ module interacts between MIMICS and RP rapid prototyping technologies through a triangular slice file format, with binary and intermediate interpolation algorithms to ensure the final accuracy of the rapid prototype.
Output Formats.
Standard 3D file output formats such as STL or VRML (Virtual Reality File Format), STL file format can be used on any RP machine, powerful adaptive filtering can significantly reduce the file size, can output from mask, 3D map and 3DD file format, output file formats include: ASCII STL, Binay
STL, DXF, VRML2.0, PointClouds.
Parameter setting.
Several parameters can be selected. The STL+ module can reduce the number of triangular pieces in the output file, and the 3D model can be smoothly processed by interpolating the image.
There are two ways to reduce the number of triangles: matrix reduction and triangle reduction, matrix reduction can be used to combine voxels (or image points) to calculate triangles, triangle reduction can be used to reduce the number of triangles in the mesh division process. Reducing the number of triangles facilitates the manipulation of the file.
There are also two ways to generate 3D meshes by interpolating images: grayscale interpolation and contour line interpolation, which is 2D interpolation in the image plane so that these images can be expanded in the height direction. Grayscale interpolation is 3D interpolation in the true sense of the word. When we need an image display quality better than 3D reconstruction and STL file accuracy, we can apply the continuous algorithm function, and vice versa with the exact algorithm.
Smooth algorithm can make the rough surface smoother.