casting stand, AK brims and 3D scanning

casting stand, AK brims and 3D scanning

Mathieu Sylvain, prosthetist

5/6/2016

I was wondering if anybody out there had the same idea that I had as to use the UC-Berkeley casting stand and brims when scanning an AK patient. I know that some practices involve using the UC-Berkeley kit to improve the precision of the measurements taken and then using them in a CAD/CAM software but what I have in mind is completely different.
 
First, put a 3D tracking target on the casting stand. This device will allow the practicioner to three-dimensionnaly align the 3D models later in the process. After that you would fit the patient in the casting stand as usual and then proceed to scan the limb with the brim on while making sure to capture the tracking target (don't mind the other leg and torso in the scan, those will be trimmed out later). Remove the patient from the casting stand without changing any adjustments. Now, scan the entire fixture (again making sure to correctly catch the tracking target). Once those steps completed, import the two 3D models in a CAD software, make them solid, align the tracking targets and do a simple bolean subtraction of the second from the first (the metal/plastic brim will be remove from the patient scan). You now have an accurate 3D model of your patient's stump with little left to do to make it into a socket.
 
We recently acquired a 3D scanner (Structure Sensor) but we don't have the Berkeley stand and brims. I've looked around the web for them but nobody seems to make them anymore, therefore I can't put my theory to the test. I was able to get my hand on an Ottobock Sit-Cast apparatus but I don't have the stand that goes with it yet. Has anyone ever tried something similar? Does it make sense to you?
 
Thanks,

Mathieu Sylvain, prosthetist
Trois-Rivières, Québec, Canada
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