With the gradual advancement of digital fabrication tools and methods, along with medical enhancements in our modern era, prosthetics have come increasingly closer to mimicking the limbs they are built to replace.
Prosthetics have come a long way, with the first recorded mentions dating back thousands of years. Starting out with wood and iron implements that function almost more as placeholders for the missing body part, materials such as aluminium, steel plastics and plaster have allowed for prosthetics to become body powered mechanisms that restore some degree of motion in missing limbs.
Today, with 3D printing become an increasingly accessible and sophisticated fabrication technology that is more readily available to makers and consumers, prosthetics are moving into closer and closer to fully articulating machines that interface with the human body seamlessly.
3D printing allows for easier beautification of prosthetics into more recognisable and elegant forms, such as with Will Root’ Exo Prosthetic Leg. It has also allowed for a global community of engineers, designers and makers to come together to create free STL (stereolithography) files for various 3D printable prosthetics at Enabling the Future. One member of this community is Mat Bowtell, owner of Free 3D Hands, a charity that that designs and manufactures their 3D printed prosthetics and other assistive devices completely for free. For just eight dollars, a hand can be printed and assembled to fit appropriately. This enables prosthetics to be much more accessible, especially with growing children where a refit of prosthetics for comfort and proper use needs to be done almost yearly. Where traditional thermoplastic body powered prosthetics can cost tens of thousands of dollars, these open sourced hand can be recreated for a tiny fraction of the price.
Computer Aided Drawing and Machining has enabled prosthetics that are stronger and more durable as well. Biodapt’s line of sports oriented leg prosthetics is one such example, manufactured out of machined parts fit for weightlifting, hiking and even skiing. Shock dampening hydraulic parts, roller track systems and interchangeable soles are made possible with digital fabrication.
Digital sensors are another way in which the nature of prosthetics have changed to become far more functional than their predecessors. Myoelectric prosthesis such as the ones offered by Bebionic use highly sensitive electrodes atatched to the end of the user’s limb to detect muscle movements, which are translated by a control unit into commands for the mechanical wrist to activate, allowing hands to open and close to grab objects in specific ways on the go.
These higher end products do cost upwards of forty thousand dollars however, and companies such as Open Bionics have made use of 3D printing to reduce such costs as well as create customisable casings that move further into being more aesthetic pieces that prosthetics users are more confident of wearing. Their line offers a range from ten to fifteen thousand dollars instead, with an emphasis on customisability.
Artificial Intelligence paired with newer experimental technologies are becoming an increasingly viable tool in improving the accuracy and function of sensors as well. The ‘Skywalker’ hand prototype created by a team at Georgia Tech University uses ultrasound sensors as a minimally invasive method of mapping the minute muscle movements at the end of an amputated limb, which is then fed to an AI that learn each minute movement and translates it into precise finger movements. This completely changes the way prosthetic hands function. Where myoelectric sensors decode specific muscle flexes and understand those patterns as commands (requiring the user to learn to flex said muscles in certain ways to control the limb), this new method only requires the user only to think of the finger’s movement, and the AI and sensors do the rest.
Another team from the University of Minnesota and University of Texas Southwestern Medical Center have made progress in this ‘thought’ based control as well, applying a slightly more invasive method of attaching a peripheral nerve interface to the end of the limb, allowing for an even more responsive feedback.
With rapidly advancing digital fabrication methods that are slowly becoming more integrated with artificial intelligence, one must wonder; how far away is human technology from achieving a machine with a seamless connection that replicates a body part, or better yet, out performs it?