Conception of virtual endoscope based on mimics and Matlab

Virtual endoscope based on mimics and Matlab

Virtual endoscopes are an important application of digital medicine. An image similar to an endoscopic image is formed by passing through a model of a channel organ (stomach and intestine) from an endoscopic perspective. Because Virtual endoscopes are non-invasive diagnostic methods based on CT image reconstruction, they are very important. Many large companies, such as GE and Siemens, have virtual endoscopes. At the end of the last century and at the beginning of this century, the National Institutes of Health invested a lot of money here. Many universities studied virtual endoscopes during this period. Here is an example:

Http://groups.csail.mit.edu/vision/medical-vision/virtual-endoscopy/

For the implementation of virtual endoscopes, you can use a visual software Amira with a secondary programming interface. Another simple but not very professional method is to use the virtual reality toolbox of mimics and Matlab. To make a virtual endoscope effect, two problems need to be solved: one is the model problem (3d internal surface of the pipe organ), and the other is the virtual tracking problem (the route of the virtual camera ). Therefore, mimcs provides a good interface. First, mimics supports exporting models in vrml2.0 file format (WRL. Secondly, the medcad module of mimics has the fitcenterline function, and the generated center line can be used as the travel route of the virtual camera. The figure above is an assumption of this workflow.

The center line generated by mimics can be exported as a text file, which contains the positions and vectors of all the points in the center line (positions are used to determine the coordinates of the virtual camera, the normal vector is used to help determine the direction of the virtual vision ). And through MATLABProgramIt is very easy to read such text files. The center line data can be easily imported into the MATLAB matrix. You can also read WRL files generated by mimics In the MATLAB virtual reality toolbox. When these two files are imported, create a virtual camera object (or a virtual car, etc.), and then let it move according to the center line to get the virtual endoscope effect. You can observe the relative position of the endoscope from the global perspective, and simulate the mirror from the endoscopic perspective. We can try it by downloading some of the fault data containing the colon in http://www.volvis.org/raw format.

Another issue that needs to be considered is space matching. The Conversion Relationship Between the coordinate of the center line in the space modeled by mimics and the coordinate of the space in the MATLAB virtual reality must be clear.