A team of ten students from the School of Mechanical and Manufacturing Engineering at UNSW are collaborating with AbilityMade for their thesis project to develop a fatigue testing model for 3D printed, lower limb, ankle foot orthoses (AFOs) for people with disabilities and sports injuries.

The team aims to develop a device that will test the endurance of orthoses to ensure that it can handle the weight and distance that is required of the wearer. AbilityMade is a mission-driven company that uses 3D printing to develop paediatric orthoses to give children with disabilities access to orthoses they need to make their life easier. This is done by applying engineering expertise from AbilityMade and knowledge from Orthotists (healthcare professionals that specialize in the provision of orthoses) to develop orthoses designs.

As AbilityMade developed their product and testing, they have been able to expand their range to fit adult clients as well.

The project was chosen by the students as their first preference in their Thesis course (Thesis A MMAN4010 / Thesis B MMAN4020 / Project A MMAN9001 / Project B MMAN9002) headed by course coordinators: Dr Shaun ChanDr Wade Smith and Professor Tracie Barber in 2022. During the planning and execution of the fatigue testing system, the team is being mentored by Ye Wang, a third year PhD student at UNSW specialising in finite-element-method (FEA) simulation and from AbilityMade: Hugo Marchant, Quality, Production & Development Engineer and Josiah Jagelman, Systems Engineer.

3D printing is more scalable than traditional methods of creating AFOs, and also yields better accuracy and repeatability, which helps with first time fitments. much faster than traditional methods of producing casts. Since 3D printing is a relatively new application in the field of prosthetics and orthotics, rigorous testing of the AFOs must be conducted to ensure they will perform well for the clients.

‘’We need to test them to ensure that they'll survive approximately 2 years’ worth of walking, which is a lot of steps, especially if you've got a really mobile kid who just wants to play soccer, and this is the device that gives them the ability to do that,” said Hugo Marchant. 

The Group consists of ten students divided across three teams: the rig team, the transmission team, and the software team. The rig team develops the rig which is the machine that will conduct the fatigue testing. It consists of four members: Rosa Ji Yoon Pak, Mohammad Iramul Hoque, Jianyu Guo and Adam Schuman. The transmission team is responsible for selecting the appropriate motor and attaching the motor to the rig so that it drives the machine to do the fatigue testing. This team includes Jiajian Shang, Kailin He and Chiranjive Manivasagam. The software team works on data transmission, sensor data acquisition, developing the website and setting up the controllers. This team is incorporated of the final members of the group, Darcy Owen Slevin, Baasim Ullah and Luke Banicevic.

 

Prototype of the fatigue testing model

 

“We are making a machine that you can attach one of these AFOs and it will apply a constant force to it to simulate the damage that walking will do about 2 million times, record any data, and let us observe what happens during the cycles.

“This means that either the cost comes out fine at the other end, which is great, but if it comes out damaged, it'd be good to see what the anomalies are in the data relative to the other ones that are fine.

 “That will help with design and will also be good to ensure customers that their product is up to spec,” says the leader of the team, Darcy Owen.

The ultimate goal is to create a user-friendly interface on the fatigue testing model, apply 2 million step cycles to an  record all the data that is created and have it available for multiple cycles or test runs. Other sensor senses would be measured such as motor temperature when testing the casts. 

"We find it really rewarding to work with students as it gives them like real world experience of industry projects, it also helps us develop and progress our research and research in the field of prosthetics and orthotics,” said Hugo Marchant.

The Australian orthotics industry is currently unable to provide enough orthoses for the population as the number of practitioners is less than the recommended rate for the population. With projected population growth, it is vital to find more ways to increase testing and production of orthoses.

 

 

Through the use of fatigue testing model, finding suitable products that can fulfil the needs of clients would be able to reduce this issue. The team meets up regularly once a week and will undertake the testing of the machine in the Makerspace at UNSW and at AbilityMade.