3D Printed Prosthesis Reads Your Mind, Sees With Its Hand

July 17, 2019 by Erin Pinheiro 4 Comments

Hobbyist electronics and robotics are getting cheaper and easier to build as time moves on, and one advantage of that is the possibility of affordable prosthetics. A great example is this transhumeral prosthesis from [Duy], his entry for this year’s Hackaday Prize.

With ten degrees of freedom, including individual fingers, two axes for the thumb and enough wrist movement for the hand to wave with, this is already a pretty impressive robotics build in and of itself. The features don’t stop there however. The entire prosthesis is modular and can be used in different configurations, and it’s all 3D printed for ease of customization and manufacturing. Along with the myoelectric sensor which is how these prostheses are usually controlled, [Duy] also designed the hand to be controlled with computer vision and brain-controlled interfaces.

The palm of the hand has a camera embedded in it, and by passing that feed through CV software the hand can recognize and track objects the user moves it close to. This makes it easier to grab onto them, since the different gripping patterns required for each object can be programmed into the Raspberry Pi controlling the actuators. Because the alpha-wave BCI may not offer enough discernment for a full range of movement of each finger, this is where computer aid can help the prosthesis feel more natural to the user.

We’ve seen a fair amount of creative custom prostheses here, like this one which uses AI to allow the user to play music with it, and this one which gives its user a tattoo machine for an appendage.

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Rapidly Prototyping Prosthetics, Braille, And Wheelchairs

February 23, 2018 by Anool Mahidharia 4 Comments

We live in an amazing time where the availability of rapid prototyping tools and expertise to use them has expanded faster than at any other time in human history. We now have an amazing ability to quickly bring together creative solutions — perfect examples of this are the designs for specialized arm prosthetics, Braille printing, and custom wheelchair builds that came together last week.

Earlier this month we published details about the S.T.E.A.M. Fabrikarium program taking place at Maker’s Asylum in Mumbai. The five-day event was designed to match up groups of makers with mentors to build assistive devices which help improve the condition of differently-abled people.

The participants were split into eight teams and they came up with some amazing results at the end of the five-day program.

Hands-On: Prosthetic Designs That Go Beyond

Three teams worked on projects based on Bionico – a myoelectric prosthesis

DIY Prosthetic Socket – a Human Machine Interface : [Mahendra Pitav aka Mahen] lost his left arm during the series of train bomb blasts in Mumbai in 2006, which killed 200 and injured over 700 commuters. He uses a prosthetic arm which is essentially a three-pronged claw that is cable activated using his other good arm. While it is useful, the limited functionality restricted him from doing many simple things. The DIY Prosthetic socket team worked with [Mahen] and [Nico Huchet] from MyHumanKit (who lost his right arm in an accident 16 years back), and fabricated a prosthetic forearm for [Mahen] with a modular, 3D printed accessory socket. Embedded within the arm is a rechargeable power source that provides 5V USB output at the socket end to power the devices that are plugged in. It also provides a second port to help recharge mobile phones. Also embedded in the arm was an IR reflective sensor that can be used to sense muscle movements and help trigger specific functions of add-on circuits, for example servos.

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S.T.E.A.M. Fabrikarium Builds Assistive Tech In Mumbai

February 7, 2018 by Anool Mahidharia 3 Comments

Starting this weekend, a group of 65 invited Maker’s from various disciplines, along with 20 awesome Mentors, will gather at the Maker’s Asylum in Mumbai for the five day S.T.E.A.M. Fabrikarium program. The aim is to improve the capabilities of the differently-abled by building and expanding upon existing open source projects. At the same time, the teams will learn more about rapid prototyping techniques.

Among the participants will be at least 15 differently-abled people who will be a part of the whole process of learning as well as providing their inputs on the problems being tackled. Participants have an opportunity to understand how design thinking works and work on improving the existing designs.

Participants will team up and choose from five existing open source projects:

Bionico – a myoelectric prosthesis
Braille rap – using a 3D printer as a braille embosser.
e-Trotti – a low-cost, removable electrical assistance for wheelchair use, made from electric scooter parts.
Project Shiva – customized and beautiful upper limb prosthetics.
Flying Wheelchair – a wheelchair specially adapted for use while paragliding.

The Asylum’s fully-fledged workshop facilities offer a wood shop, a laser cutter, a CNC, several 3D printers, electronics tools and instruments and an infectious environment that will allow the participants to learn a lot during the five short days. While working on prototyping their projects, all teams will have constant access to a team of mentors and industry experts who will help solve their problems and give guidance when necessary.

The Maker’s Asylum includes fully-fledged workshop facilities for the build process, and the team succeeded in bringing onboard a slew of industrial partners and supporters to ensure that the program can be offered to the participants for free. That is a great way to bring makerspaces, makers, and the industry together in a symbiotic program that benefits society. The program was developed in collaboration with My Human Kit, a company from France who selected the five open-source projects mentioned above. The Fabrikarium is made possible via Bonjour-India, which fosters Indo-French partnerships and exchanges.

Hackaday is proud to be a part of this program and will be present to help document all of the awesome projects. Participants will share their progress on Hackaday.io, so watch for updates over the coming week. To get an idea of what to expect at the S.T.E.A.M. Fabrikarium 2018, check out the video from an earlier version embedded below.

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Hackaday Prize Entry: Let Your Muscles Do The Work

July 23, 2016 by Brian Benchoff 6 Comments

Electromyography is a technique used to study and record the electrical signals generated when a muscle contracts. It’s used for medical diagnosis, rehab, kinesiological studies, and is the preferred method of control for robotic prosthetics and exoskeletons. There are a few companies out there with myoelectric products, and the use case for those products is flipping the slides on a PowerPoint presentation. Lucky for us, this project in the Hackaday Prize isn’t encumbered by such trivialities. It’s an open, expandable platform to turn muscle contractions into anything.

As you would expect, reading the electrical signals from muscles requires a little more technical expertise than plugging a cable into an Arduino. This project has opamps in spades, and is more than sensitive enough to serve as a useful sensor platform. Already this project is being used to monitor bruxism – inadvertent clenching or grinding of the jaw – and the results are great.

While it’s doubtful this device will ever be used in a medical context, it is a great little board to add muscle control to a robot arm, or build a very cool suit of power armor. All in all, a very cool entry for The Hackaday Prize.

Hackaday Prize Entry: Open-Source Myoelectric Hand Prosthesis

May 26, 2016 by Moritz Walter 9 Comments

Hands can grab things, build things, communicate, and we control them intuitively with nothing more than a thought. To those who miss a hand, a prosthesis can be a life-changing tool for carrying out daily tasks. We are delighted to see that [Alvaro Villoslada] joined the Hackaday Prize with his contribution to advanced prosthesis technology: Dextra, the open-source myoelectric hand prosthesis.

Dextra is an advanced robotic hand, with 4 independently actuated fingers and a thumb with an additional degree of freedom. Because Dextra is designed as a self-contained unit, all actuators had to be embedded into the hand. [Alvaro] achieved the necessary level of miniaturization with five tiny winches, driven by micro gear motors. Each of them pulls a tendon that actuates the corresponding finger. Magnetic encoders on the motor shafts provide position feedback to a Teensy 3.1, which orchestrates all the fingers. The rotational axis of the thumb is actuated by a small RC servo.

In addition to the robotic hand, [Alvaro] is developing his own electromyographic (EMG) interface, the Mumai, which allows a user to control a robotic prosthesis through tiny muscle contractions in the residual limb. Just like Dextra, Mumai is open-source. It consists of a pair of skin electrodes and an acquisition board. The electrodes are attached to the muscle, and the acquisition board translates the electrical activity of the muscle into an analog voltage. This raw EMG signal is then sampled and analyzed by a microcontroller, such as the ESP8266. The microcontroller then determines the intent of the user based on pattern recognition. Eventually this control data is used to control a robotic prosthesis, such as the Dextra. The current progress of both projects is impressive. You can check out a video of Dextra below.

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Thalmic Labs Shuts Down Free Developer Access Update: It’s Back Again

November 18, 2014 by Brian Benchoff 56 Comments

The Thalmic Myo is an electronic arm band with an IMU and myoelectric sensors, able to measure the orientation and muscle movements of an arm. This device has uses ranging from prosthetics to Minority Report-style user interfaces. Thalmic is also a Y Combinator company, with $15 million in funding and tech press gushing over the possible uses of this futuristic device. Truly, a remarkable story for the future of user interfaces and pseudo-medical devices that can get around most FDA regulations.

A few months ago, Thalmic released a firmware update to the Myo that blocks raw access to the myoelectric sensors. Anyone wanting to develop for the Myo now needs to submit an application and pay Thalmic and their investors a pound of flesh – up to $5000 for academic institutions. The current version of the firmware only provides access to IMU data and ‘gestures’ – not the raw muscle data that would be invaluable when researching RSI detection, amputee prosthetics, or a hundred other ideas floating around the Thalmic forums.

Thalmic started their company with the idea that an open SDK would be best for the community, with access to the raw sensor data available in all but the latest version of the firmware. A few firmware revisions ago, Thalmic removed access to this raw data, breaking a number of open source projects that would be used for researchers or anyone experimenting with the Thalmic Myo. Luckily, someone smart enough to look at version numbers has come up with an open library to read the raw sensor data. It works well, and the official position of Thalmic is that raw sensor data will be unavailable in the future. If you want to develop something with the Myo, this library just saved your butt.

Thalmic will have an official statement on access to raw sensor data soon.

Quick aside, but if you want to see how nearly every form of media is crooked, try submitting this to Hacker News and look at the Thalmic investors. Edit: don’t bother, we’re blacklisted or something.

Update: Thalmic has updated their policy, and will be releasing a firmware version that gives access to the raw EMG sensor data later on. The reasons for getting rid of the raw sensor data is twofold:

Battery life. Streaming raw data out of the armband takes a lot of power. Apparently figuring out ‘gestures’ on the uC and sending those saves power.
User experience. EMG data differs from person to person and is hard to interpret.