The choice, style and shape of the cosmetic finish of most children’s prostheses is limited.

Initial funding demonstrated the feasibility of producing customized 3D printed cosmetic covers which clip over the external dimensions of the existing prosthetic exoskeletal limb. Individual designs were produced and covers fitted to a sample of children in a single center trial. Pilot feedback on the design process and covers themselves was obtained by using a non- validated questionnaire and the feasibility of the process evaluated.

In the follow up study it is proposed that ethical permission will be gained to produce and evaluate up to 60 covers in a multi centre trial in the UK. Covers will be made available to users free of charge throughout the NHS in centres managed by Ability Matters. In addition, the project aims to establish an appropriate pathway from selection to delivery of customized covers which fits in with the current NHS patient pathway to maximize process efficiency.

Our project aims to teach children how to control a robotic hand by playing an immersive computer game. Learning novel ways to control forearm muscles is a core part of the gameplay. The goal is for children to understand how to use a modern robotic hand before they are provided with one.

Our initial work for Starworks Two has focussed on building and testing new, child-appropriate, hardware for learning to control forearm muscles. These devices will allow us to control our game without having to use any messy wires or gels. This will make it easier for use to make games that can be easily setup and played at home, either on a pc or on a phone or tablet.

Going forward we are continuing to improve the game we prototyped during Starworks One. We are getting help from rehabilitation experts to ensure our game control is clinically relevant, and from and game designers to make things more fun. The overall game design is updated based on children’s feedback and we are always looking for new players.

Residual limbs of children grow non-uniformly and experience volumetric changes throughout a day, therefore, need frequent replacements of the rigid socket. A socket’s lifespan is further reduced due to the necessary high rigidity of the used materials; support, via a secure fit, takes precedence over comfort, therefore little room is given to accommodate growth cycles.

This project aimed to increase the lifespan of children’s prosthetic sockets by incorporating auxetic structures into a novel design, whilst utilising the potentials of digital manufacturing methods. As children’s limbs typically grow longer faster than in circumference, a combination of auxetic structures were selected where each was fit for purpose. A bow tie structure was used to support areas along the longitudinal axis, whereas a 3D star honeycomb structure was used for a base component at the distal end. Both low and high frequency limb volume changes may be compensated for, subject to user trials, by maintaining contact between adjacent components and the user throughout a day. Auxetic structures, therefore, may provide a prosthetic wearer with increased comfort and safety in comparison to conventional alternatives. In this application, the natural channels of the structures also increase air circulation to the skin, which may reduce perspiration by the wearer.

Modularity of our socket design also allows for multiple materials to be used within or between structural components. Combining with the benefit of additive manufacturing, it is therefore, possible to create a fully customisable socket design with different geometries and/or materials selection for bespoke fit. In addition, a low stiffness, biocompatible polymer was developed for the liner component, with tailorable skin-like property, whereas a high stiffness nylon, pre-impregnated with short carbon fibres, was chosen for the socket shell.

Geometries of the novel design components are further driven by 3D scan data of a residual limb, to provide a secure fit. A fully parametrised design and manufacturing workflow was developed to provide editable design and easy to use solution for the end users, reducing the need for reforming at a subsequent clinic visit.

The Starworks-2 project aims to continue our development in producing functional and personalised prototype sockets that is comfortable and adaptable to limb growth. The current focus is to validate our design and manufacturing processes. To date, the team has made considerable progress on optimising the build quality of the 3D printed prototype socket via multiple experimental tests and computational simulations. A custom-built testing rig has also been developed to further exam the integrity of the prototype socket based on industrial standard. Next, the team is intended to conduct further laboratory verifications on the prototype socket, leading towards an in-lab case study.

Our Starworks project focuses on the reduction of problematic signal artifacts, which are false signals that can disrupt control and limit the usability of the latest myoelectric upper limb prostheses. To this end, we have developed a novel electrode housing, which is designed to significantly reduce the production of problematic artifacts, and has produced some encouraging results so far, which we highlighted within the first Starworks project.

During this first Starworks project, we identified how our new electrode housing design could potentially improve prosthesis control for adults, but we were keen to see how our device would work with child prosthesis users, as this was of course the focus of the research. Finding suitable willing participants is not easy, but once we had the ethical approval in place, we travelled down southwards to see a child prosthesis user and their family who had agreed to help us, so we could start work with them. They were absolutely lovely, and it was great to chat with them about their experiences with prostheses, and of course to take some plaster casts of the child’s residual limb, so that we could test our device on our next visit. We will be seeing them again for device testing and data collection on March 5th, and we are hoping to get some useful data which shows how our device can (we hope) reduce artifacts and potentially improve prosthesis control in children as well as adults.

We have also successfully filed a patent for our new device, and we have worked with the team at Southampton University, integrating their pressure sensors within our new prosthesis electrode housing. These can help us to identify and record any correlations between the myoelectric signal and prosthesis control and the amount of pressure at the electrode surface.

So all in all, things are going according to plan thus far. I will of course keep you updated on how our assessments go, but would like to take this opportunity to once again thank you for supporting this work, and most importantly, for helping us to help children with upper limb absence.

Cambridge Prosthetics is a collaboration between an experienced materials scientist and lifelong prosthesis user, a leading rehabilitation consultant and a social impact specialist. We are developing a new generation of prosthetic limbs that are more versatile, reliable, affordable and available worldwide.

Natural legs are very good at absorbing impacts when running, jumping and rapidly changing direction. Current prostheses are rigid, heavy and cumbersome – they are poorly suited to children. With Starworks funding, Cambridge Prosthetics is developing a child-focused artificial knee joint that facilitates children’s active play alongside their peers.

With earlier Starworks funding, the team have already produced a prototype knee which is lightweight, easily maintained and waterproof. Follow-on Starworks funding is enabling us to optimise the design and produce pre-production samples which can undergo the trials and approvals needed to make them widely available. Thanks to the Starworks network, we are also collaborating with LimbPower to ensure the needs of children feed into the design process.