Cranioplasty Mold

IMPLANT_3D_T_02.3dm (547.3 KB)

Hello,
i need to make a mold for a cranioplasty implant, but i dunno how !

If any one can help with a video tutorial, because am stuck !

Thanks

Hi , that is kind of vague. That’s like saying I need a car. What type? Is it going to be big ,small?
More info would help. What is the end goal to look like? —-Mark

1 Like

thanks for your reply, like the one in this video https://youtu.be/VplByCOK62k from 0:12 second

I guess the tricky part is to make the partition line for the mould. you could try with RibbonOffset

Hi Ahmed,

Is something like this what you are after?

I created a mold with two pieces divided at the cranial plate center (but you can adjust the mold piece size offset)

Essentially the cranial plate is “stamped” into the mold and the extra pieces that would get lost between the halves are added to each opposite side, creating a tight fit but allowing (hopefully) easy separation.

You could 3D print these mold pieces, make molds from the 3D prints, and then cast the cranial plate from the mold.

20230520_IMPLANT_Response_01a.gh (448.1 KB)


4 Likes

Hello and big thanks Michael for your help ! Awesome !
Can you make a video tutorial :smiling_face_with_tear: coz am not familiar yet with RHINO.
Have a good day Sir !

1 Like

Are you curious to learn the grasshopper logic involved or how to manipulate the rhino model resulting from the grasshopper script?

EDIT: I noticed the mold doesn’t account for the small edge loop of the cranial plate thickness. I will add that little bit in and send an update when I am at my computer next

1 Like

in the case of the mold, i think i’m interrested in both grasshopper logic and how to manipulate the rhino model resulting from the grasshopper script, because one cannot function without the other ?
Anyway, thanks again for your time Sir ! I appreciate.

Hi again, i found a method https://rhino3dmedical.com/2021/03/02/cranioplasty-implant-mould/#6_Second_half_of_the_mould but in the step 4 " Trim and jon with lines", i don’t understund the process " We run command Line to join the duplicated edge curve with the offset curve, and another time to join the offset curve with the projected curve."
also all the step 5…

So they are just saying that you need to draw two lines in step 4:

The purple highlighted line connects the flattened left geometry to the right geometry and the green circled line connects the offset of the right geometry to the geometry.

A1 is the start point of the first line and A2 the end. B1 & B2 are the respective points of the second line.

Essentially in this step you are setting up a section profile that will be swept around the booundary curves in the next step 5.

Does that help?

1 Like

am gonna try your explanation and get back to you asap ! Thanks.

Hello again, i manage to make it work, and this is the result !
IMPLANT_3D_MOLD.3dm (2.7 MB)

But i dunno, it’s not like is gonna be a good mold !
especially if i wanna make something like in the link shared above.

What do you think Sir ? Thanks.

Could you perhaps share what you would consider to be a “good” mold?

-reuseability?
-rigidity?
-flexibility?
-detail of result?

If you need very accurate detail you may need to leverage a photogrammetry scan of the patients or an example patients skull and then use that as a baseline so you can get finer and higher quality details (such as the growth plate lines, indentations, scars, etc.)

I mean I want a mold like the proposal you made to me.

The solution I found is certainly not bad, but a mold apart from the shape of the implant that centered in the mold, so that the doctor can make the implant, it is also the volume of the mold (example in the video I shared, the mold is simple and effective, not too bulky).

Knowing that this mold will be used during an operation for a patient. I hope you understood me.

I see, well the good news is that you can right click on the green dot (in the grasshopper script I shared) and choose Bake.

This will turn the mold into actual rhino geometry that you can save, export, print, etc.

Once I have a chance to update the script for that last little edge loop detail of the cranial plate I will also bake the result for you so you can have the .3dm but in the meantime give it a shot on your end with the right click bake method and you can then pull apart the mold pieces in Rhino and look at them more easily.

And the method I shared in the script should work with a variety of different cranial plate shapes/sizes as long as the models of said plates are in good overall condition such as the one you provided.

Cheers!

2 Likes

You are helpfull man !

I appriciate your effort, your time and your patience. Am so gratefull to you Sir !

Thank you.

Happy to help!

Here’s the updated script with user exposed controls.
You can show the Remote Control Panel by turning on the Grasshopper Panel after right clicking the gear icon to the upper right of the snip view.

By default dynamic baking is turned on, meaning that when the grasshopper script is open it will bake the mold creation into Rhino in real-time and if you adjust the slider parameters it will update the Rhino geometry as well.

You can “pull” the mold apart, offset the “slice plain”, adjust the cutter depth (shouldn’t need to mess with this setting hopefully), and set the display color.

By default it bakes to a new layer called “IMPLANT_MOLD_3D” and names the two halves of the mold “MOLD - SIDE A” and “MOLD - SIDE B”

I’m attaching the grasshopper and rhino files.
-Keep in mind the Rhino file will have geometry in it but won’t update in real-time unless the grasshopper script is open.
-However, since the Grasshopper script actually creates the Rhino geometry you don’t need the Rhino file I attached to this post for the Grasshopper script to work.

I only attached the rhino file here in case you just want the mold result and not the GH script.

Also this uses new Rhino 8 Grasshopper nodes, if that is a deal breaker for you and you absolutely need to stay in Rhino 7, I can help you by updating the script to leverage Elefront plugin to create the same result for Rhino 7.

Result:

Cheers, hope this helps!

20230522_IMPLANT_Response_01b.3dm (1.6 MB)
20230522_IMPLANT_Response_01b.gh (455.7 KB)

2 Likes

You are Hero Michael ! again thank you for your time and effort.

Cheers.

1 Like

You’re welcome! Let me know if you come across any issues working with it.

Have a good one!

1 Like