Import an implant into Anybody for simulation

[ngoctt (Thanh Ngoc Tran)]

Hello everyone,

I have just started to work with Anybody. For our research, we need to measure contact forces and kinematics of the knee after a total knee replacement. For this purpose, we need to create a knee model, including the bones, the implant, muscles and ligaments in Anybody. For this I would have 2 questions as follows:

1. Is this possible just to import the implant into Anybody and adap/modify the knee joint that are available in Anybody? I mean that can we cut the bones and mount the implant into the joint with Anybody, or we have to use other CAD software, like Catia or Solidworks?
2. How can we import our knee model and/or the implant into Anybody? We have the software Mimics and Catia, but don't have Solidworks.

Many thanks for your help in advance.

Best regards
Ngoc

[pgalibarov]

Hi Ngoc,

You can load any STL file to represent your implant surface.

   AnySurfSTL Surf = {
     FileName = DATA_PATH+"\Implants\ImplantArticularSurface.stl";
     ScaleXYZ={1,1,1}*..UnitConversion;
     AnyDrawSurf DrwSurf = {
       FileName = .FileName;
       ScaleXYZ = .ScaleXYZ;
       Opacity = 0.3;
     };
   };

By default it would not do anything except being drawn through AnyDrawSurf. But you can define contacts with AnyForceSurfaceContact class. Please check KneeSimulator example.

SolidWorks converter is great for complex mechanisms with a lot of joints and sophisticated kinematics. If you have a simpler implant, behaving more like a rigid body - you can just use STL import and set up proper behavior.

For visualization, you can disable drawing of the bone surface and add a new one (representing resection). It needs to be drawn in exactly the same way as the original one, using the same scaling functions and added in exactly the same reference frame.

Kind regards,
Pavel

[ngoctt (Thanh Ngoc Tran)]

Hi Pavel,

Many thanks for your information. That would help me alot at the beginning of my work with Anybody. I will first follow your instructions.

Best regards

Ngoc