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Welsh inventor crafts 3D printed hydraulic arm for his son and hopes to help others

5 min read

Better Society
Welsh inventor crafts 3D printed hydraulic arm for his son and hopes to help others
Source: None

A Welsh father has invented a 3D printed hydraulic arm for his toddler and hopes to revolutionise National Health Service (NHS) child prosthetics.

Welsh father invents prosthetics to help infants and toddlers develop crucial motor functions

Ben Ryan, 40, is a former psychology lecturer from Anglesey, Wales. He has been developing prosthetics for children born with malformed arms or who have had to undergo amputation. This approach will help them develop crucial motor functions, making it easier for the children to transition to prosthetics in later life.

Inventor's son lost most of his left arm when he was born with an undetected clot A Welsh father has invented hydraulic 3D printed arm technology to improve prosthetics for infants and young children, as well as training their brains from birth to get used to wearing the devices. Source: Facebook/NowThisNews

The needs of his own son inspired the initiative

The need arose because Ryan’s own son, Sol, who is now almost two, lost most of his left arm when he was born with an undetected blood clot. Part of the arm had to be amputated, and Ryan and his partner Kate Smith were told that no further medical assistance could be offered by the NHS until Sol was at least a year old, and even then, options are limited for infants and toddlers. The NHS can only provide a very small silicone hand on a fibreglass socket that is mostly based on Victorian technology. First the child would have to sit for a plasticast to be made of their body, and then wait several more weeks for the plasticast to be turned into a prosthetic. Some of Ryan’s early prototypes below.

Source: IBTimes

The body-powered hook is a spring-activated hand connected via a cable from the shoulder to the opposite hip that requires the child to wear a full body harness. As the child extends the arm forward, the cable will tighten and open the hand.
Extend the arm forward, the cable tightens and opens the hand The body-powered hook is a spring-activated hand connected via a cable from the shoulder to the opposite hip that requires the child to wear a full body harness. As the child extends the arm forward, the cable will tighten and open the hand. Source: IBTimes

The problem with existing prosthetics for small children

"To go from nothing to suddenly have to wear this rigid thing on your body is hit and miss. There’s no guarantee the child will accept it at one-year-old. Even that passive arm has a function in a way. The research I’ve read suggests that function is the critical thing, from the point of the child, they need to use the arm to grab and interact with the world, not just for balance," Ryan, the founder of the startup Ambionics told Mary-Ann Russon, of The International Business Times.

NHS doctors warn the parents of children who require prosthetics that the journey will not be easy. Once they have been fitted with the first, mostly cosmetic arm, and even when they receive a more functional prosthetic arm at the age of 3, most children don’t want to wear it. Getting the child to wear the device for 15 minutes a day is a big achievement. The problem with this is the fact that the first two and a half years of a child’s life are crucial for strengthening neural pathways, and the brain starts to figure out which nerves are needed, and which nerves are not.

If the child is not prepared from birth to use the motor functions in what is left of their arm, they could lose it as they get older, especially if they are unwilling to wear and practice with a clunky, uncomfortable prosthetic. Parents could of course choose to get a prosthetic made privately, but it will set them back by between $5,000-$10,000

Source: IBTimes

The hydraulic arm prosthetic was made entirely on a Stratasys Connex 3 printer using a rubber-like polymer invented by Stratasys called Tango Black Plus. The design of the device was developed by Ryan using Fusion 360 3D modelling software from Autodesk, who provided training on the software and are helping him to develop the first prototypes and other new features.
The hydraulic arm prosthetic was made entirely on a 3D printer The hydraulic arm prosthetic was made entirely on a Stratasys Connex 3 printer using a rubber-like polymer invented by Stratasys called Tango Black Plus. The design of the device was developed by Ryan using Fusion 360 3D modelling software from Autodesk, who provided training on the software and are helping him to develop the first prototypes and other new features. Source: Facebook/Ambionics

To solve this problem Ryan created tiny foam arms for Sol

The IBTimes article continues –

To solve this, Ryan created tiny foam arms for his child which he fitted onto Sol from the age of five weeks. The foam arms had Velcro so that Sol could grab onto soft toys. The foam arms worked so well that when the time came for Sol’s appointment to have a plasticast made at the age of one, he was so used to holding his arm out that he didn’t fidget at all. When the first prosthetic was fitted, he wore it for an entire day. 

Typically, when the child reaches the age of three, the parent can choose from two options – either a myoelectrical battery-powered prosthetic where sensors read nerves through the skin and translate that into signals that can be processed by the device to make the hand work, or a body-powered hook.

The body-powered hook is a spring-activated hand connected via a cable from the shoulder to the opposite hip that requires the child to wear a full body harness. As the child extends the arm forward, the cable will tighten and open the hand.

The myoelectrical device is not safe to be used near water and it doesn’t work well with infants as there are too many layers of fat, so it can’t receive the signal from the skin. In older children, there is risk of muscles wasting away over time as the device doesn’t make use of the biceps or triceps. The body-powered hook, although it works well to prepare children for later prosthetics, is clunky and children become self-conscious about wearing it as they get older.

In addition to being part of the mechanism, the fluid-filled sacs also act as a cushion for the child's arm. The device is body-powered, but if you want more power for grabbing motion, you can use compressed air, a hydraulic pump and reservoir, or battery power.
The Ambionics Arm In addition to being part of the mechanism, the fluid-filled sacs also act as a cushion for the child’s arm. The device is body-powered, but if you want more power for grabbing motion, you can use compressed air, a hydraulic pump and reservoir, or battery power. Source: Facebook/AmbionicsUK

What is the Ambionics Arm?

So Ryan developed a new prosthetic which is suitable to be worn by children from the age of 10 months up to age 3. The hydraulic arm contains two 3D printed fluid-filled sacs in two chambers in the socket, known as the Double Acting Helical Bellow (DAHB). When the user presses on the sacs, they become displaced and bellows are used to operate a simple grabbing mechanism.In addition to being part of the mechanism, the fluid-filled sacs also act as a cushion for the child’s arm. The device is body-powered, but if you want more power for grabbing motion, you can use compressed air, a hydraulic pump and reservoir, or battery power.

His startup, Ambionicswas also selected in November by Life Sciences Wales as one of six startups who will receive dedicated business advice from successful entrepreneurs. He also has a medical advisory board featuring numerous NHS and academic paediatricians from various academic institutions in the UK, helping him with the project.

Ryan is now looking to take his prototype hydraulic arms (for infants and eventually older children) to clinical trial in both the UK and the US, and to that end he has launched a crowdfunding campaign on Indiegogo. He is seeking £150,000 in total for prototyping, CE certification and FDA approval, as well as patenting costs. 

"The NHS see fit to have two arms a year, we’re going to go for three arms [as the child grows]. We can create this with a 76% cost saving and 90% faster, so you will receive the 3D printed prosthetic arm in five days instead of six to 10 weeks on the NHS," said Ryan

"I want to make this affordable for low income families. There’s very few man hours needed as you don’t have to construct any materials, it’s totally 3D printed and if anything happens to the prosthetic, we have the digital file and you can get a new one printed in five days."

Source: IBTimes

The hydraulic arm prosthetic was made entirely on a Stratasys Connex 3 printer using a rubber-like polymer invented by Stratasys called Tango Black Plus. The design of the device was developed by Ryan using Fusion 360 3D modelling software from Autodesk, who provided training on the software and are helping him to develop the first prototypes and other new features.
The arm is entirely 3D printed in a fraction of the time of conventional prosthetics The hydraulic arm prosthetic was made entirely on a Stratasys Connex 3 printer using a rubber-like polymer invented by Stratasys called Tango Black Plus. The design of the device was developed by Ryan using Fusion 360 3D modelling software from Autodesk, who provided training on the software and are helping him to develop the first prototypes and other new features. Source: IBTimes
Make an Impact

If you wish to contribute to this fantastic initiative CLICK to be taken straight to Ryan's Indigogo page

Ryan is now looking to take his prototype hydraulic arms (for infants and eventually older children) to clinical trial in both the UK and the US, and to that end he has launched a crowdfunding campaign on Indiegogo. He is seeking £150,000 in total for prototyping, CE certification and FDA approval, as well as patenting costs. Find out more.