Further Adventures in CT Scan 3D Ego Printing

 

 

After a long series of manipulations, the CT scan derived  face was successfully used to make a pencil holder (of all things!).  It is about 100mm high and took about 9 hours to print.  You can find files that you can use to make your own mash-ups of my face on thingiverse: http://www.thingiverse.com/thing:203856

3 face cup 2

Successful CT scan processing into 3D printable file

Today was spent researching all the manipulations involved in getting a CT scan into printable form and I managed to get a print out of it.  The process starts with DeVide where the dicom data from the CT scan is processed using a dual threshold, decimation filter, and stl writer.  The stl file contains a lot of unwanted stuff, in this case, soft tissues inside my head that add triangles but won’t be seen in the print, so those are removed by applying ambient occlusion followed by selecting and deleting vertices by “quality” (which will be very low values for vertices on the interior of the object).  This process invariably blows small holes in the desired surface, so you apply a “close holes” filter to fix that (which closed up the nostrils very nicely).  Next you open the stl file in netfabb and rotate and clip unwanted external stuff and apply repairs as necessary.  Finally, drag it into slicer and scale it. slice and print.

First successful ego print!

First successful ego print!

CT Scan Processing into 3D printable STL files

CT Scan with lower threshold swept

CT Scan with lower threshold swept

While investigating software to extract bone data from CT scans and turn it into 3D printable STL files, I played with a CT scan of my own head that was used to treatment plan orthodontics.  I have been using DeVide to process the data and finding it is not only easy to use, but a lot of fun!

The animated gif was made by sweeping the lower threshold of a dual threshold module from -800 to 900 in steps of 100 with the upper threshold fixed at 1400.  The effect is to strip away the lower density tissues leaving only dense bone at the end of the sweep.  I saved the result of each run as a png file then converted to an animated gif using an on-line service.