The problem of comfort in prosthetics

Author: Oscar Rovira (2nd year Integrated Mechanical & Electrical Engineering student) -

There are thousands of amputations per year in war-torn countries due to mines. The current process of multiple castings and weeks of testing for every individual prosthetic limb has remained relatively unchanged for fifty years. This is a time consuming and costly process for a standard prosthetic (prices can range from £4000 to £40,000).

3D printing technology is developing prosthetic technology at a reduced price, but there remains comfort and reliability issues. As part of my first-year project I decided to focus on developing affordable, comfortable prosthetics. In the end, no matter how robust a prosthesis is, if it’s not comfortable to wear, then it won't be used.

Developing a prototype

Once I knew my objective, I started drawing and sketching all the ideas that came to my mind: from developing a fully 3D printed design of a robotic leg that could automatically adapt to the limb, to creating a prosthesis which could be “built” by the customer (imagine Lego pieces constructing and improving their design). After two weeks of crazy designs and research I decided that the quickest way to solve the problem of comfort was to create a tool that could analyse the stiffness of the stump at any point. This would reduce the forces that the socket applies to the hard tissue, thus reducing any soreness due to bad force distribution.

Inspired by the FitSocket from MIT, and with the objective of reducing the cost whilst maintaining reliability, I started writing all the specifications that “Rijido” (the name I gave my project) needed. Once I had all the measurements and data I spent three days doing all the CAD designs that I would later 3D print. Once all the parts were printed, I started troubleshooting with the prototype and assembly until I got a much better result. Then I used a solder to attach all the wires to the prototype and I connected an Arduino with a bit of code in order to retrieve all the data. After one month Rijido’s first prototype was born!

Seeking funding and promoting my project

I would say that there’s nothing more fulfilling than to see hard work, passion and dedication finally paying off, but that's not where the story ends. I posted my project on Instructables and I applied to a seed accelerator named Imagine to receive feedback and promote Rijido. Although I didn't receive funding from the seed accelerator in the end, I still managed to finish third out of two hundred applicants.

A prosthetist from South Carolina noticed my project on Instructables and expressed an interest in using Rijido as a tool in his practice. It was so exciting to see that my project was actually something people were already looking for. This prosthetist got in touch with the MIT Department of Biomechanics, which then contacted Arthur Petron, a postgraduate who holds the patent alongside Hugh Herr (a heavily influential person in the area of biomechanics) of FitSocket. It was amazing to talk on LinkedIn with the person (Arthur) who first inspired me. Rijido was also then selected as a finalist for the TEDxBarcelona Awards 2016.

Passion and perseverance

Fun, stress, excitement, uncertainty…I would say that the whole journey of making Rijido was a combination of these emotions. The fact that I could use 3D printers, get spare parts and work both in the mechanical and electrical workshops at any time, was the most fun part. I felt like a kid in a ball pit.

Thanks to Rijido I have learnt a host of things! In terms of technical skills, I have mastered how to use 3D printers, I have developed my skills at using turning machines, drawing, CAD modelling and project management. The project also introduced me to different business strategies. In terms of personal skills, I have gained more confidence in myself and improved my communication skills. I’ve learnt again that the combination of passion and perseverance can make any idea into reality and verified how errors and mistakes during the design process are key to producing a much better final product.

Definitely only one of the many more projects yet to come…

Find out more about Rijido.