War has sadly been an easy answer to the world’s simplest problems. The outcome of humanity’s oldest instinct poses a difficult question for many: the loss of life and property. Luckily, a part of that question has been eased only recently by the advent of additive manufacturing. This technology, commonly known as 3D printing, can’t bring back the dead, but it has the ability to restore amputated limbs that too cheaply.
In fact, there once was a time when getting prosthetic limbs required numerous appointments with the doctor. Wait times would span months or even years, not to forget hospital bills scaling up to $80,000 plus taxes for a non-myoelectric appendage. Before we dive into the ‘whys’ and ‘how’s,’ let’s look at how prostheses have evolved over the years.
A Brief History of Prostheses
Almost 3,000 years ago, an ancient Egyptian noblewoman for reasons unknown lost the big toe of her right leg. The replacement for her amputation was found in a Cairo excavation, entirely made of wood. Archaeologists and consulting prosthetists reckon the fake toe helped her wear flip-flops, a must-have against the semi-desert Egyptian climate.
Second Punic War General— Marcus Sergius is known to have worn a prosthetic limb. The appendage was metal-constructed and it helped him hold his shield against Carthaginian warriors. Marcus was famous for his metal arm, and according to Pliny the Elder, he used to “wage war with the prosthetic bound to his arm, he sieged Cremona, saved Placentia (modern-day Piacenza), and captured twelve enemy camps in Gaul (modern-day France). Fast forward to European Renaissance, 16th century French Surgeon Ambroise Paré made several accomplishments in this field. It was this doctor who introduced the hinged prosthetic hand and a leg, with the added advantage of latching joints. His inventions are still applied. modern-day. More recently, Mexican-American inventor Ysidro M. Martinez upgraded lower-limb prostheses designs that allowed improved gait.
The Gamechanger: 3D Printed Prostheses
There are still miles to go as even the latest prostheses lack specific parameters. The primary issue is cost, then customizability, followed by inadequate performance. 3D Printed prostheses managed to solve all three of these problems.
First of all, the cost has been driven down by additive manufacturing to one-twelfth of what a standard prosthetic arm or leg costs (and in some cases, one-thirtieth). Unlimited Tomorrow, a Colorado-based company is offering TrueLimbTM , 3D printed prosthetics that can be delivered all over the globe for as low as $8,000. All You have to do is fill in their questionnaire, follow their due process and they’ll 3D-print the appropriate appendage for you.
Limbitless Solution’s Albert Manero, championed the industry with his team by creating a bionic arm for six-year-old Alex Pring. Using CAD, the team designed the nitty-gritties of Alex’s replacement limb. The design was printed using acrylonitrile butadiene styrene plastic resin, the same thing Legos are made of. Parts included the forearm, fingers, palm, and hinges made of NinjaFlex thermoplastic elastomer (TPE). A servomotor coupled with a sensor was used to read Alex’s electrical impulses and in turn manipulate Kevlar cords attached to the motor to move the fingers of the bionic arm. This all costed $350!
Simply put, 3D Printed bionic limbs can cost at most $10,000 as additive manufacturing eliminates the need of expensive hinge components, building material, and metal molds.
3D printed prostheses are highly customisable. The process of customisation usually follows with the prosthetist taking measurements of the area where the additive-manufactured limb has to be applied. Customisable variables include the weight of the patient, type of amputation, motion of the amputation, surface area, and the material the patient would like his/her prosthetic to be made of. Relevant details are adjusted to specifications in 3D printing software like FreeCAD or 3D Builder.
An open access research conducted by Christopher Copeland, Claudia Cortes Reyes, et al., found that the use of the 3D printed arm culminated in improved gross manual dexterity. It also increased performance in bimanual coordination. In most of the cases, independent thumb rotation enabled strong grasp power of objects and the 3D printed prostheses were several grams lighter than their conventional counterparts. 3D printed legs have corrected the gait of amputated patients, who otherwise found conventional prosthetic leg ‘stumpy’.
Roadblocks in the 3D Printed Prosthetics Industry
It’s the dawn of 3D Printed Prosthetics Industry, so naturally the horizon looks slightly bleak. Electronic components still make mechanisation of 3D printed limbs a costly affair, especially myoelectric sensors. Durability isn’t the strongest suit of 3D printed limbs as regular alloy limbs are unbreakable. This is why 3D printed legs are uncommon as they can’t support the weight of the patient properly.
Jonathan Raines, a mechanical engineer at Open Bionics deems 3D file format of the designed limbs an issue. He explains that STL offers a great layout for printing but it’s not editing-friendly. There is no consensus among designers about which software is best for this purpose. A proper format for the communication of 3D printed limb details is also lacking, making the whole idea sparsely distributable.
Most of the 3D printed prostheses designers are not trained medical professionals. What adds fuel to fire is the fact that these independent visionaries do not get FDA approval for their products. Market ResearchTM forecasts the prosthetics market to be worth $13.12 billion. Lobbies will not tolerate a new revolution in the prosthetic industry that brings the costs down.
The future of 3D printed prosthetics will be illuminated by the light of technological advancements. If Moore’s law has taught us anything, it’s that the development and growth of microprocessors is exponential, while the cost of computers and electronic items is halved.
Microprocessors, nanotechnology, and intelligent algorithms are bound to make 3D printed prosthetics cheaper, faster, and durable in the future. Who knows, maybe Alex Pring will have an Anakin Skywalker-esque 3D printed metal arm that’s let loose on a mere thought.