Patient Specific Modelling

Hiii Sir,
I want to reduce the joint spacing between Tibiofemoral joint of the left leg in a GAIT model, so that i can make my model patient specific. Will you please tell me the section whic is to be altered in order to do so…For Eg in order to change the body weight i followed the path like
1.“Model/Kinematics.any”
2.“HumanModel.any”
3."<ANYBODY_PATH_BODY>\Scaling\ScalingLengthMassFat.any"
4. “…/BodyModels/GenericBodyModel/BodyModel.StandardParameters.any”
5."…\Include\BodyParameters.any"
And here i altered the paitent’s weight and height will you please tell the path to change the gap spacing in same way…

Hi,

Could you please upload a snapshot of the model and draw a line to measure which distance you would like to reduce? It will help us to understand your question better.

Best regards,
Moonki

Hlo sir.
Attached with this reply is the snapshort

Hi,

First, I’m not sure why you would like to change that space.

But if you want to do that, you should modify the sRel value of ‘KneeJoint’ AnyRefNode in the Thigh and Shank segments.

But if you open the ‘AMMR\Body\AAUHuman\LegTLEM\Seg.any’ file, the definition of sRel of KneeJoint node is based on the equations.

So please be careful when you try to change the code.

Best regards,
Moonki

Hii Sir,
Thank you for your guidance. I want to analyse the Gait cycle of an Osteoarthritic Patient using anybody… As i am unable to import other stl of tibia and femur of the patient so i wanted to convert already existing model to an osteoarthritic one by reducing the joint space. Could you please tell me any other better way than this one??

Dear Deepa Sharma,

changing the joint space is very tricky and will not give you any more information. You would need a detailed model with soft tissue like meniscus, cartilage etc.

Hiii Sir ,
Could you please help me out in doing that as i don’t know how to manipulate the cartilage and meniscus which segment i need to make changes in order to do so.

Dear Deepa,

Amir is correct, you will need a detailed model with meniscus, cartilage, ligaments etc. to do what you are aiming for.

If you change the joint space in the knee model with the revolute joint very sligthly it will not change much in the model since the moments arm will only change very little.

Basically if you are looking into details of the knee joint you will need to run a FDK based model, please review the tutorial on this subject.

The model which comes closest to this in the repository is the TKR knee bend model, it has an instrumented knee though. This model is in principle what you need but with a natural knee.

Building a natural knee model is not trival and will require you to have good data availble for it and the bone surfaces in the AMMR model is not suitable for this purpose.

Best regards
Søren

Thank you sir.
I will have a look upon TKR model too.

Hiii Sir…
There is some issue with TKR model loading in my system it is continously showing error as :
WARNING(SYS6) : C:/U…s/csio/A…a/R…g/A…y/A…5/Body/A…n/T…k/JointsLumbar.any(65) : Measure.OutDim : Changed usage : initialization of OutDim was previously (v.5.x) not needed in all cases, but its value is now required.
Currently, it has an implicit value of ‘1’ if not set, but it is strongly recommended to specify it anyway. Obligatory initialization requirement will come in future versions.
Configuring model…
ERROR(OBJ1) : C:/U…s/csio/A…a/R…g/A…y/A…5/Body/A…n/T…k/JointsLumbar.any(81) : SpineRhythmDrv.Reaction.Type : Number of elements in type specification must match number of elements in force vector (num. elem = 1)
Model loading skipped.

I am not able to understand this will you please help me understanding this ??

This has been answered several times on the forum and there is a section in the wiki. Please try to search the forum.

Forum

Wiki

Regards,
Pavel