Introduction: How to 3D Scan Body Parts for Prosthetic or Any Use
Use these tips and best practices to 3D scan any part of the body for any use.
In this Instructable I'm sharing 3D scanning a limb difference for CAD modeling and making a custom prosthetic device.
I most commonly use three dimensional scan data / reality capture cad geometry of the body for making garments and wearables. Aside from prosthesis, other common uses are for cad modeling, artwork, fashion design, pattern making, fitness and training, portraiture, avatars, figurines, action figures and more.
Before 3D scanning technology was available, I used to make body molds mostly from Alginate/Algiform and vermiculite or out of plaster. This was time consuming, messy and dangerous.... have you ever been under a plaster face mold?! its SCARY! I'm also remembering back to the 200lb+ body mold I made of weightlifter Justin Healy not even a decade ago and am so glad that we have other options now.
Here I share how to 3D scan body parts and limb differences with help from a very special guy Riley Gonzalez and scanning ninja Gabe Patin.
Step 1: Background
I met Riley and his Dad Noelle through Cyborg Superheroes, a workshop for kids to build their own prosthetic devices. It was inspiring to see what the kids made over their 5 day workshop at Pier 9. Check out this article by the Guardian to learn more!
Although Riley made a super fun bow and arrow on his E-nable prosthetic, it had the same problem he often has: the connection point is uncomfortable and its heavy so he doesn't wear it that often. I was surprised to learn that on average, persons with upper limb differences only wear their prosthesis 20% of the time, mostly because they are uncomfortable and heavy. So Riley and I started working together along with mechanical engineer Kyam Krieger to create a more comfortable solution with practical applications (typing, holding his trumpet, holding his drumstick, etc).
E-nable is a non-for profit organization which connects cad modelers, makers, volunteers and funding to provide children with limb differences a low-cost 3D printed prosthetic. Learn more about it in this supersweet video by colleague and friend Charlie Nordstrom:
Riley's silver grey 3D printed arm shown though out this Instructable was made from the Unlimbited Armand and the Phoenix Hand by colleague Andreas Bastian (check out his Instructables, he's awesome!)
The Phoenix hand has no parametric source files. Its precursor, the Raptor Reloaded has native Fusion files (and detailed documentation) like the Unlimbited arm. Everything on Riley's device is welded together with Instamorph, which is available from Amazon, as are the straps. Finally this dovetail unit can be used to modularly secure other things to the device.
Download CAD designs to make or hack your own prosthesis at:
Step 2: Onto 3D Scanning!
Gabe and I used Artec Spider and Eva 3D scanners to scan Riley's arm but the tips I'm sharing here apply to almost all 3D scanners, even homemade 3D scaning devices and photogrammetry.
Start with checking out this fantastic Pier 9 Guide: Artec 3D Scanners by Gabe Patin.
and follow the instructions in this video:
- It helps if the subject is wearing a patterned shirt. Start with a point on the shirt (I started with Riley's shoulder and sleeve), then scan the body from there, returning to that point. That pattern recognition helps the scanner to locate the data in space.
- Scan all around the body part from multiple angles and scan a little beyond the part that you want to capture.
- Go slow, take your time, and make multiple captures.
- You may want to use Memento, a free reality capture program to process your scan data into high definition 3d meshes or quads.
**3D scanning is just one step in creating a well-fitting prosthetic, and I am certain there are ways to better measure Riley's joint, stresses and pressure points through 3D scanning and reality capture, though I don't know what they are at this point. If you have suggestions or ideas, please contact me or include them in the comments!**
Step 3: Take Thorough Measurements
Take thorough measurements of the body part(s) that you are scanning to be sure that you keep proper proportions and sizes when working with the data in your software.
Step 4: Now That You Have Your Scan Data, What Will You Make With It?
If you are making a prosthetic device, check out the first demo on in this reel on how to make a prosthetic using Meshmixer. Meshmixer is free and makes it easy to design solid parts that fit the detailed contours of 3D scans, while also incorporating precise mechanical features.
Learn more about making prosthetics in Meshmixer and the work they are doing in Health and Medical applications, including sharing it with those in need across developing countries at http://www.meshmixer.com/health.html
Please share what you make in the comments or your own Instructable and
watch out for more Instructables as we create prosthetic devices for Riley and friends!