The splints are a world first and a clinical trial is set to begin shortly, supported by four universities.
The process will be patented and commercialised with the aim of eventually using the same technology to print prosthetic legs for amputees worldwide.
Starship Hospital paediatric neurologist Dr Rakesh Patel and Auckland University civil engineer Dr Doug Wilson came up with the idea 18 months ago to aid Dr Wilson's disabled son James.
"We were talking about the splints that he had and how expensive they are and how long it takes to fabricate them," Dr Patel said.
A timely lecture by a visiting speaker on 3D printing prompted the duo and another engineer, Professor Xun Xu, to look into the feasibility of making such a brace.
Four smaller prototypes were created as a proof of concept for children with cerebral palsy, muscular dystrophy and other disabilities that leave them with weakened muscles and what is known as drop foot.
"With cerebral palsy, because of their neurological problem their feet go in odd shapes because the muscles pull in different directions," Dr Patel said.
"It means they can't walk properly so what we try to do is correct the position. It improves the chances of walking and getting them upright and more mobile."
The splints can also be used to help people with stroke, spinal cord injury, polio, multiple sclerosis, peripheral neuropathy, arthritis and even broken bones.
The team scanned photos of the limbs into 3D printers at Massey and Auckland University of Technology and tested the prototypes on engineering student Ella Meisel.
She and project partner Phillip Daw joined the team and spent a year developing the process before unveiling it last November.
Miss Meisel said the pair chose the project because "we wanted to do something that would make a real difference to the lives of people".
The clinical trial will be undertaken by more engineering undergraduate students with results expected in six months so the orthotics can be put into practice.
Traditional splints are made by pulling a child's foot into the correct position, plastercasting it, taking a negative mould of the cast and sending that to the United States where a splint is fitted and sent back to New Zealand.
The process is time-consuming and expensive, and often when the hard, heavy splints return the child's feet have grown and they don't fit properly.
By contrast the new splints are turned around in a day for a fraction of the cost, and they're lighter, more comfortable and easier to wear.
Once the design is proven, Dr Patel plans to make similar orthotics for arms and other parts of the body.
His dream is to evolve the process to printing prosthetic legs, cheaply, for Kiwis and for export to countries such as India, Africa and the Middle East.
"That's where we're heading," Dr Patel said.
Making Smart Splint
• Electronically scan or photograph the limb.
• Mould an exact fit digital splint to the limb.
• Print the digital splint using a 3D printer.
Son's summer frustration leads to engineering solution
James Wilson must wear orthotic moulds on his feet to help him walk, but until now they have been hot and uncomfortable to wear.
The 14-year-old suffers from Lennox-Gastaut syndrome, a severe form of epilepsy that left him disabled.
Dad Doug Wilson, a senior lecturer and head of Auckland University's transportation engineering group, said James had worn splints for 10 years but in summer the foam inserts in long socks make the teen unbearably hot. But without them James would never walk, albeit aided by a sling and standing frame.
Dr Wilson said it was this frustration, together with the fact the splints take three months to be specially made in the United States and cost $1000 for a pair, that prompted him to discuss a solution with James' doctor, Starship paediatric neurologist Rakesh Patel.
His long-standing interest in helping the disabled sector spurred the idea to come up with a better process to develop the splints and a low-cost option.
Dr Wilson said James would be in line for the new splints once they were available to other children.
