Application of 3D-Modeling in Medicine in Preparation for 3D-Printing

Abstract

3D-modeling in the medical field can be used to create medical models (eg, tissues and human organs) using 3D-printing or used for digital 3D visualization of the necessary structures.

Medical 3D-printing is used when the work on prostheses that should perfectly match the patient's anatomy is needed. In addition, thanks to 3D-modeling technology, it is possible to develop peculiar medical tools. It is also possible to perform trial surgeries on 3D-models before the actual operation. There is special software for creating medical 3D-models for further printing. 

The purpose of this work is to determine the functions of 3D-modeling in preparation for 3D-printing in the process of creating medical models and comparative analysis of software for 3D-modeling used in the medical field.

There is a common workflow that can be used to convert volumetric medical imaging data (created by computer tomography (CT), or other imaging techniques) into physical models printed on a 3D-printer. This process is divided into three stages: image segmentation, polygon mesh refinement, and 3D-printing.

3D-modeling programs are used at the stage of polygon mesh refinement. They allow almost unlimited manipulations to 
refine the mesh to make the model printable. The main manipulations for post-processing of a segmented model using 3D modeling are: 1) reparation - correction of errors and discrepancies that sometimes occur in the process of segmentation and images export; 2) smoothing - correction of errors that occur during segmentation due to inappropriate resolution of the original medical image via softening by smoothing the surface of the model; 3) adding elements - combining a segmented model with other structures or removing unnecessary parts from the segmentation.

As a result of a comparative analysis of 3D-modeling software used in the medical field, it was found that for 3D-modeling can be used software specifically designed for medical 3D-modeling and regular 3D-modeling software. When using regular software, you need third-party software to get the correct model file format.

The choice of software depends on the goal: to work with implants and create patient-specific devices, it is possible to use specially designed programs for these purposes, such as Within Medical and Medical Design Studio; if high accuracy is  required, it is possible to use D2P created for working with DICOM-images at the image segmentation stage; to achieve fast results, when maintaining of maximum accuracy is not needed, a mobile version of the software, such as Ossa 3D, can be used; common 3D-modeling software, such as Cinema 4D and Blender, can be used to develop peculiar tools and medical equipment.