Sol's mother and father had to wait 10 days as his arm slowly decayed before the doctors could amputate it.
"It was a massive relief seeing this hideous thing that was attached to him and dying suddenly gone," Sol's father, Ben Ryan, tells CNN.
But the family from North Wales was told Sol would need to wait a year to be issued a prosthetic arm from the United Kingdom's National Health Service (NHS). What's more, he would likely have received a standard issue prosthetic arm with a rigid socket and a rubber or silicone hand, with no hand movement, Ryan explains.
While there are options for babies to be fitted with such "passive" devices, there are no functioning prosthetic arms on the market for children younger than three, says Ryan. This is owing to the small or electrical parts, as well as the costs involved, because young children regularly outgrow their prostheses.
A new arm for Sol
So Ryan, a former psychology teacher, buried himself in research to find an alternative.
He came up with a basic design for a 3D-printed prosthetic arm that would let his son grip things.
The design includes a bulb of fluid -- or actuator -- under the armpit which, when squeezed, creates fluid pressure to open or close the prosthetic thumb.
"It's only the thumb that moves, so that it can be robust enough to crawl on and put weight on," says Ryan. "It had to be something that could withstand a tantrum."
Although the arm is still to be perfected, Ryan has had inquiries from 160 families to print prosthetics for their children. He has since established an online prosthetics service, Ambionics
, and plans to trial his device by working with 20 families around the world.
Lending hands to children around the world
Ryan uses an Xbox scanner to create digital scans of the residual limb, so that he can 3D print the socket. The families working with Ryan will send him scans that he will use to model and 3D print their prosthetics.
Ryan's beta trial began in October when he fitted his first prosthetic on another child in Wales.
"The trial is really to test that basic assumption -- can a family send me a scan from Ecuador, Australia or Africa and then can I model a socket that will fit?"