A disabled mountaineering enthusiast from California, USA has received a new titanium alloy prosthesis designed especially to help with climbing.
The lower-leg amputee, a keen climber, found the specialised shoes difficult to use. They fitted poorly with the generic shape of his standard artificial foot and tended to wear out quickly. His climbing partner, a former mechanical engineer at a major aerospace company in the US, used a CAD package on her laptop to design an aggressive climbing prosthesis with a downturned toe, eliminating the need to use a shoe.
The foot was made from Ti64 titanium alloy powder using an EOS direct metal laser sintering (DMLS) machine at Morris Technologies in Ohio, USA.
Fabricating the approximately 150 x 75 x 50 mm, smooth-edged foot took about 40 hours. The finished 2.25 kg prosthetic was a single-piece construction, of high strength and stiffness, hollow to minimise weight and with no seams or fasteners. It was stress relieved to cure the metal and ensure material strength.
To create the combined foot and shoe, it was coated with a rubber used for the soles of climbing shoes. The artificial leg, a solid titanium rod, connects to a socket on the prosthesis.
While the prosthesis was the first that Morris Technologies hd produced, Tim Warden, vice president of sales and marketing, regards laser sintering as ideal for this kind of application. “A prosthesis should ideally be customised to an individual’s anatomy. After he or she has tried it out, if it doesn’t fit or function quite correctly, we can tweak the CAD file and re-grow the product, adding a little more material in a critical area, for example,” stated Warden.
Posted by: Paul Whittaker, Editor ipmd.net, [email protected]