Hacklet 41 – Prosthetics Projects

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!

bionic1We 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!

bionic2Next 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]!

bionic3[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.

 

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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!

THP Semifinalist: B10N1C Yourself

The Hackaday Prize has had a few medical devices make the semifinalist cut, and of course wearables are on the list. How about implantables? That’s what Bionic Yourself 2.0 (or B10N1C) is doing with an implantable microcontroller, battery, and sensor system.

The hardware in B10N1C includes a electromyography sensor for measuring muscle activity, an accelerometer, a vibration motor, RFID reader/writer, temperature sensor, and – get this – a LED bar graph that will shine a light through the skin. That’s something we’ve never seen before, and if you’re becoming a cyborg, it’s a nice feature to have.

As with anything you would implant in your body, safety is a prime consideration for Bionic.the Lithium battery can be overcharged (yes, through a wireless charging setup) to 10V without a risk of fire or explosion, can be hit with a hammer, and can even be punctured. The enclosure is medical grade silicone, the contacts are medical grade stainless steel, and there’s a humidity sensor inside that will radio a message saying its time to remove the device if the moisture level in the enclosure increases.

Because the device is implanted under the skin, being able to recharge and update the code without a physical connection is the name of the game. There’s a coil for wireless charging, and a lot of work is going into over the air firmware updating. It’s an astonishing project, and while most people probably won’t opt for a cyborg implant, it will look really cool.


SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.

Building a prosthetic leg from scratch

[Radek] from Poland sent in a neat video of a bionic prosthetic leg he made for one of his patients. Even though [Radek] says it’s a ‘prototype of a prototype,’ we’d have to agree with him that it’s a very neat build that could provide inexpensive motorized prosthetic legs to amputees in the future.

[Radek] has been working on his project for about two years now, after building the motor and electronics by hand. The leg is powered by 1.5 kilogram battery pack – no details on the chemistry of the batteries, but [Radek] says it will last 12 hours on one charge. There are also small vibration sensors in the leg for a bit of feedback, and a few switches so the knee joint can be operated by the stump.

If you’re wondering where [Radek] got the proper tools and materials to make a carbon fiber prosthesis, he works for Carbon Prosthetics where builds simple prosthetic devices. His bionic leg creation looks really cool, and he says the final product will be much less expensive than the very high-end bionic prosthetic legs.

[Radek] was kind enough to share some more videos and a few pictures of his robotic prosthetic leg; you can check those out after the break.

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