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Dealing with importing complicated Biological models (bone, etc) as point cloud

Question asked by David Ng on Sep 19, 2012
Latest reply on Sep 19, 2012 by 1-4EQZK9

Hi guys

 

I am a final year mech student doing his dissertation. I've encountered a problem here I need some help with

 

To cut a long story short, I have used MIMICS medical imaging software to create a 3D model of a human femur( thigh bone) . I am investigating the mechanical failure of knee implants using FEA analysis (Abaqus.)

 

so basically, I need to:

1) create a bone model with CT scan images in MIMICS

2) export to solidworks, perform some cutting of the bone to fit the implant

3) laser scan the implant and fit it into the model

4) fit it all together back in MIMICS, then export it to Abaqus and mesh it.

5) export it back to mimcis to assign node properties ( I need to do this in mimics because mimics has a handy way of segmenting tissue types that Abaqus doesnt)

6) export it out to Abaqus to run the FEA analysis.

 

Right now, I am stuck at part 2.

I have created a trial bone model (my real CT scans arent out yet) based on older CT scans and have tried to use scanto3D to import it as a point cloud . this works suitably okay for small pieces of bone but it is piss poor for larger, more complicated surfaces. I am losing large amounts of data in the meshing and surfacing of the point cloud. I have no idea how I will turn the surface into a solid even! Would appreciate any help as to how I should go about doing this.

 

I have also tried other ways of getting the bone model into solidworks, such as DXF, ASCII stl, Binary stl, but they do not work for such a large model. solidworks refuses to build a solid from ascii data as there are too many surfaces.

 

I understand that polygonal modeling is one of the weaknesses of solidworks and that there are better programs equipped to handle this, such as rhino, but I am obviously limited by what my school is able to provide me.

 

I have attatched the point cloud and ASCII data for people to have a look, as well as some pictures of what I have been able to experiment so far. do note that the bone model is right now just a rough model and not the final piece.

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