Losing a limb often means getting fitted for a prosthetic. Although there have been some scientific and engineering advances (compare a pirate’s peg leg to “blade runner” Oscar Pistorius’ legs), they still are just inert attachments to your body. Researchers at Johns Hopkins hope to change all that. In the Journal of Neural Engineering, they announced a proof of concept design that allowed a person to control prosthetic fingers using mind control.
One of the greatest uses we’ve seen for 3D printing is prosthetics; even today, a professionally made prosthetic would cost thousands and thousands of dollars. For his entry to the Hackaday Prize, [Martin] is building a low-cost 3D printed hand that works just like a natural hand, but with motors instead of muscles and tendons.
There are a lot of 3D printed finger mechanisms around that use string and wires to move a finger around. This has its advantages: it’s extremely similar to the arrangement of tendons in a normal hand, but [Martin] wanted to see if there was a better way. He’s using a four-bar linkage instead of strings, and is driving each finger with a threaded rod and servo motor. It’s relatively strong; just the motor and drive screw system was able to lift 1kg, and this mechanical arrangement has the added bonus of using the servo’s potentiometer to provide feedback of the position of the finger to the drive electronics.
This is far from the only prosthetic hand project in the running for The Hackaday Prize. [OpenBionics] is working on a very novel mechanism to emulate the function of the human hand in their project, and [Amadon Faul] is going all out and casting metacarpals and phalanges out of aluminum in his NeoLimb project. They’re all amazing projects, and they’re all making great use of 3D printing technology, and by no means are there too many prosthetic projects entered in The Hackaday Prize.
The 2015 Hackaday Prize is sponsored by:
For the last few years now, the 3D printing community has been searching for a groundbreaking application for out little boxes of plastic squirting goodness. On of the most interesting applications the community has stumbled upon is prosthetics.
There have been a lot of people warming up their 3D printers and laser cutters to make prosthetic limbs in recent years. For [OpenBionics]’ entry for The Hackaday Prize, they’re building a prosthetic hand that costs less than $200, weighs less than 300 grams, and can be easily fabricated with 3D printers and laser cutters.
The human hand is the most complex end-effector on the planet, and emulating its range of motion is a difficult task. Still, the [OpenBionics] team is working hard to properly emulate a thumb with three degrees of freedom, putting 144 different grasps on the hand, and making their hand useful with soft fingertips.
Even with all this capability, [OpenBionic]’s robotic hand – motors and all – is about the same size as a normal human hand. That’s incredible, especially when you consider the motors for your hand – muscles – are all in your arm.
The team has put together a video demoing the capabilities of their hand. It’s somewhat remarkable, and able to do everything from lift a coffee cup to holding a pen. You can check that video out below.
The 2015 Hackaday Prize is sponsored by:
Throughout human history, mankind has worked to enable those with disabilities. This applies especially to those who have missing limbs, either from injury or since birth. Every time technology improves, prosthetics improve along with the way. Unfortunately this now means prosthetics have become expensive systems. Hackers, makers, and engineers are working to make prosthetics more affordable, and more available to everyone. This week’s Hacklet focuses on some of the best prosthetics projects on Hackaday.io!
We start with [Open Bionics] and Affordable Bionic Hands For Amputees. The [Open Bionics] team are using 3D printers to bring the cost of a prosthetic arm and hand down from up to $100,000 USD to just $1000 USD. They’ve also reduced the time to create a custom device from weeks to just 5 days. The team’s current hand has five degrees of freedom, uses electromyography (EMG) for control, and weighs just 268 grams. [Open Bionics] discovered that many amputees are willing to trade off functions for a lighter weight device. Having a sensor and motor studded hand won’t help much if the wearer is worn out after just a couple of hours!
Next up is [yash.gajra56] and RE-ARM. RE-ARM is a prosthetic arm project which aims to help both those who have lost limbs, and those with full or partial paralysis of a limb. Movement is provided by radio control style servos. Control is via voice commands and Bluetooth from a cell phone. [Yash] has incorporated feedback into RE-ARM by using flex sensors. Processing is handled by an Arduino. We like the low-cost, low tech approach RE-ARM uses. We’d love to see everyone have access to a 3D printer, but unfortunately the world isn’t there quite yet. RE-ARM uses readily available components to build a functional prosthetic. Nice work [yash]!
[OpenBionics] brings us Affordable Prosthetic Hands. No, you didn’t read that name wrong. There are two “Open Bionics” on Hackaday.io! This [OpenBionics] team has no space, and is based in Athens, Greece. The other [Open Bionics] team does have a space between the words, and is based in Bristol in the United Kingdom. We’re hoping the two groups can come together and collaborate now that they’re both using Hackaday.io. This [OpenBionics] team is working on prosthetic hands, in the sub $200 USD price range. The team has come up with a novel thumb design which provides nearly full functionality with only one rotating joint. [OpenBionics] also allows their users to selectively lock digits, which allows for up to 144 different grasping postures.
Finally we have [Daniel Mead] with Third World Medical Equipment (Arm). [Daniel] created this project as an independent study back in high school. The idea is create a simple arm with a gripper out of cheap or freely available items. The gripper is fashioned from a bicycle brake. The fitting system is especially novel. [Daniel] used an old soda bottle to create a custom mold for the amputee’s residual limb. Plastic bottles are generally made of polyethylene terephthalate, or PET, a thermoplastic. [Daniel] placed a wet sock over his arm, and a plastic bottle over the sock. Holding the plastic bottle above a fire created enough heat to shrink the bottle to his arm. the sock provided room for padding, and insulated him from getting burned during the molding process.
Not satisfied? Want more prosthetics? Check out the Prosthetics list over on Hackaday.io! If any of these projects inspire you, don’t forget that prosthetics are a great starting point for an entry in The Hackaday Prize!
That’s about all the time we have for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!
Here’s a heartwarming story for the day. Introducing [Shea], a little 9-year-old girl with a prosthetic hand made possible from a community of internet strangers!
She was born with only the palm of her right hand and a two-digit thumb — no fingers. Despite this day and age, prosthetics aren’t generally that good, or affordable — especially for a quickly growing young girl. So when [Shea] asked for a new hand from Santa before Christmas, her mom, [Ranee], started doing some research online. She had seen 3D printed prosthetics through Facebook posts and managed to track down the E-Nable group, which is a community of maker’s dedicated to lending a hand — quite literally.
The group got her in touch with [Nick Parker], a high school student and robotics enthusiast from California eager to help, who then introduced her (online) to his local Makerspace — from there they connected with the Milwaukee Makerspace (closer to home), and [Frankie Flood], an associate professor at the University of Wisconsin-Milwaukee.
[Joseph] and [Ian] have been working on a project that turns physical objects into bendable, snake-like controllers
This build is the culmination of an earlier project that digitally modeled a flexible object with accelerometers, gyroscopes, and IMUs. When we first saw this build, we wondered what it could actually be used for, but it seems [Joseph] and [Ian] came up with a pretty cool use for it: turning prosthetic spines and ribs into musical instruments.
These flexible devices are loaded up with sensors along their joints and are connected to a microcontroller with a Zigbee radio transceiver. The positioning data from these devices is transmitted to a computer where it’s turned into audio, effectively turning a dancer into a musical instrument.
For an art piece, it’s pretty cool, but as a new means of interacting with a computer, we’re thinking this might be a game changer. Imagine a gauntlet loaded up with IMUs being turned into a waldo, or precisely controlling virtual objects naturally with your hand.
We know that there are already 3D printed hips and knees in use in the medical field, but it takes a story like this one to really bring home the idea of how this technology changes lives. 5-year-old [Liam] is missing parts of his right hand, and this open-source prosthetic hand has given him a jolt of increased function. The video clip after the break shows him on the third day with the device. He’s practicing picking up coins from a stack using the hand. Just $150 in parts, combined with the hard work and good nature of the developers, made this possible.
The design is available on Thingiverse. In addition to the 3D printed parts the prosthesis uses off-the-shelf hardware store items like bungee cord and fasteners. The tips of each finger and the thumb are given some flex and grip by covering each with a rubber thimble.
We love seeing this life-changing technology wielded by basement and garage hackers. Another great example is this scratch-built leg from last May.