I have an interesting blog post working where I am going right for the cool and looking at upper limb prostheses that operate with mind-control. There’s wireless technology, algorithms that translate nerve impulses into motion, and nerves implanted onto the chest from the lost arm that the brain still translates as the phantom limb. Whoa! But you are going to have to wait. A little nugget hit the web yesterday and it is too good to delay in posting.
The Eames Inspired Prosthetic Leg
Design Buzz, a site dedicated to everything design, put out a set of 10 prosthetic leg designs that are in their words, “not only highly functional but aesthetically pleasant as well”. Some are part of The Proaesthetics Project like the Outfeet Prosthetic Leg and the Eames Inspired Prosthetic Leg. Some are award-winning designs already in at least limited use like the Cadence Prosthetic Leg for cyclists and Tillmann Beuscher’s affordable leg for victims of landmines. Others are pure design concept and even branded by the likes of Nike, Adidas, Tag Heuer, and Ecko Unltd. Check them all out here.
From an IT and design standpoint, many incorporate the same thing: a 3D scan of the existing leg resulting in point cloud data that is then manipulated in design software to create a mirror image prosthetic or at least a biomorphic outline. This accomplishes one overarching goal: To create a prosthetic that is customized to the shape and size of the person using the device.
Color-corrected point cloud from Eames inspired prosthetic leg
How? We first begin with the 3D scan. 3D scanning is a broad term referring to several different methods of obtaining an image based on distance. In simple terms, scanners are similar to cameras but instead of capturing color, they capture distance data. There are two general classifications of scanners: contact and non-contact. Non-contact scanners are further classified as active or passive. Details of 3D scanning are beyond the scope of this blog but you can find excellent information here and of course here. 3D scans for prostheses are made with hand-held laser scanners that use triangulation to generate the point cloud of geometric samples based on the surface of the subject’s existing leg.
That is not enough! These point clouds are not usable in their raw form for the prosthetic design. The clouds are used to extrapolate the shape of the leg through a process generally called reconstruction or surface reconstruction. There are software packages for this. One used by Bespoke Innovations, an artisan company of customized prosthetic fairings, is called Geomagic. After reconstruction, many designers chose to use Autodesk Inventor 3D (a CAD-based file) to manipulate and refine their designs.
At this point, the standardized parts of the prosthetic can be married with the customized shape and size. Furthermore, the data for each patient can be stored and used for future devices. What is even more amazing is that 3D printers now have the capability to print pieces of the prosthetic right in the design studio or office. In fact, Bespoke Innovations uses 3D printed objects as final product depending on the materials chosen by their customers!
“When I wear the Fairing it looks perfect…it looks better than the bare pylon, not just a little bit better, a lot better – like I’m wearing a piece of art. It’s custom engineering!”
What does this mean for the prosthetic industry? As I mentioned before the process creates a prosthetic that is customized to the shape and size of the person using the device. The technology also opens up prostheses for personalization and corporate branding. But what about cost and access? It is unlikely payors (insurance companies both private and public) will approve custom prostheses unless they cost the same as mass-produced varieties or somehow generate better “daily life” functionality. Access is also a concern. At the minimum, the customer must physically be present for a 3D scan. Lastly, this technology assumes that form is tied to the existing leg. What happens when technology enables form to break free and be tied only to function? That is a topic for another post.
At this point, it is clear these wondrous designs have a limited audience. However, the best technological advances for the masses have started with niche markets. I say, keep the designs coming.
