Eye-Controlled Wheelchair Advances from Talented Teenage Hackers

[Myrijam Stoetzer] and her friend [Paul Foltin], 14 and 15 years old kids from Duisburg, Germany are working on a eye movement controller wheel chair. They were inspired by the Eyewriter Project which we’ve been following for a long time. Eyewriter was built for Tony Quan a.k.a Tempt1 by his friends. In 2003, Tempt1 was diagnosed with the degenerative nerve disorder ALS  and is now fully paralyzed except for his eyes, but has been able to use the EyeWriter to continue his art.

This is their first big leap moving up from Lego Mindstorms. The eye tracker part consists of a safety glass frame, a regular webcam, and IR SMD LEDs. They removed the IR blocking filter from the webcam to make it work in all lighting conditions. The image processing is handled by an Odroid U3 – a compact, low cost ARM Quad Core SBC capable of running Ubuntu, Android, and other Linux OS systems. They initially tried the Raspberry Pi which managed to do just about 3fps, compared to 13~15fps from the Odroid. The code is written in Python and uses OpenCV libraries. They are learning Python on the go. An Arduino is used to control the motor via an H-bridge controller, and also to calibrate the eye tracker. Potentiometers connected to the Arduino’s analog ports allow adjusting the tracker to individual requirements.

The web cam video stream is filtered to obtain the pupil position, and this is compared to four presets for forward, reverse, left and right. The presets can be adjusted using the potentiometers. An enable switch, manually activated at present is used to ensure the wheel chair moves only when commanded. Their plan is to later replace this switch with tongue activation or maybe cheek muscle twitch detection.

First tests were on a small mockup robotic platform. After winning a local competition, they bought a second-hand wheel chair and started all over again. This time, they tried the Raspberry Pi 2 model B, and it was able to work at about 8~9fps. Not as well as the Odroid, but at half the cost, it seemed like a workable solution since their aim is to make it as cheap as possible. They would appreciate receiving any help to improve the performance – maybe improving their code or utilising all the four cores more efficiently. For the bigger wheelchair, they used recycled car windshield wiper motors and some relays to switch them. They also used a 3D printer to print an enclosure for the camera and wheels to help turn the wheelchair. Further details are also available on [Myrijam]’s blog. They documented their build (German, pdf) and have their sights set on the German National Science Fair. The team is working on English translation of the documentation and will release all design files and source code under a CC by NC license soon.

Printing Puppy Prosthetics

When [aimzzz] met this puppy born without arms, the need for some assistive hardware was obvious. We love it that rapid prototyping techniques have become so accessible that something like building a wheelchair for a puppy is not just affordable, but a lot of fun too!

The main part of the projects is a cradle which will be comfortable for the dog. 3D printing is a great choice here because it can be customized to suit the needs of a particular dog. We remember seeing another dog named Derby who has 3D printed legs that make room for the biological legs that aren’t functioning correctly. In the case of this wheelchair, the cradle could be altered make room for legs.

The rest of the build is purely mechanical. Aluminum tubing, tubing connectors, and wheels combine with the printed cradle (and some padding material) to make for one sweet ride. It takes a bit of training to get used to, but as you can see after the break this makes mobility quite easy and intuitive for the pup.

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Hackaday Links: April 20, 2014

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[Josh] hit the same issue we’ve faced before: cable modems don’t match a form factor and usually don’t make themselves easy to mount on something. We could complain about routers as well, but at least most of those have keyhole slots so you can hang them on some screws. Inspiration struck and he fabricated his own rack-mount adapter for it. Velcro holds it in place, with a cutout bezel to see the status lights and an added fan to keep things cool.

Here’s a pair of strange but possibly interesting ones that were sent in separately. The first is an analysis of how much energy short-run CNC prototyping consumes versus traditional manufacturing. The other is an article that [Liz] wrote about getting started with CNC mill bits. She says she compiled all that she learned as she was getting started in the field and wants to save others the effort.

This one goes back several years, but who doesn’t love to hear about a voice-controlled wheelchair?

So you can solder QFN parts but you can’t hammer a nail straight into a piece of wood? The answer, friend, is a laser guided hammer. Someone hire this [Andybot] person, because the solution to the problem shows the ability to out-think an interesting dilemma: how do you put a laser in a hammer head and still use it to hit things?

We’ve seen a lot of these long-range WiFi hacks over the years. This one is worth looking at because of the work done to create an outdoor mount that will stand the test of time.

And finally, we’re still really fond of this 2-bit paper processor that helps you wrap your brain around what’s going on with those silicon wafers that rule our everyday lives. [glomCo] liked it as well, and actually coded an emulator so that you can play with it without printing anything out on paper. We think it takes away some of the fun, but what an excellent programming exercise!

Wheelchair hack lets two-year-old explore on his own

[Shea’s] son [Alejandro] was born with Spinal Muscular Atrophy which limits his ability to move. The ability to explore one’s environment as a toddler is really important to development so [Shea] and his wife have been looking into assistive technology. Their health insurance paid for a medical stroller when he was nine-months old and has told the family they need to wait five years for a powered wheelchair. Rather than wait, [Shea] took it upon himself to hack a wheelchair his son could control.

He found a used adult-sized motorized wheelchair on eBay for about $800. Not cheap, but way more affordable than a brand new unit. This type of chair is made to be controlled with a joystick, an option not available to his son at this point. Foot control was an option if he could figure out how to build an interface.

After unsuccessfully trying to repair a broken digital kitchen scale [Shea] was inspired to reuse the sensors as pedal inputs. [Alejandro] has limited foot strength and the sensitive strain gauges are perfect for picking it up. Above you can see the sandal-based interface he built. The two feet working together affect steering as well as forward and reverse. The pedal system is connected to the wheelchair using a Digital to Analog converter chip to stand-in for the original analog joystick. After the break we’ve embedded a video of [Alejandro] exploring the outdoors in the finished chair.

In this case it’s fortunate that [Shea] has the skills to build something like this for his son. We hope this will inspire you to donate your time an know-how to help those in your own community who are in a similar situation. This really takes the concept of The Controller Project to the next level.

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Motorized wheelchair built from LEGO pieces

You’re certainly not going to sneak up on anyone if using this LEGO motorized wheelchair. The high-pitched whine of all those tiny motors sounds like an army of robotic mosquitoes out for blood.

Six of the LEGO Mindstorm bricks are used to drive the motors, with a seventh acting as the master. It’s not pictured above, but there is a joystick on the right hand side which allows the rider to navigate. The master brick monitors the four sensors on that joystick. It then uses a pair of motors to actuate switches monitored by the slave bricks. Each slave has one switch for forward, and another for backward and drives two motors. To get around problems with angular velocities dues to turning, all of the wheels are multidirectional.

The plan is to add Bluetooth control in the near future. The master/slave setup should make that relatively easy as it only affects one of the bricks. The idea is to facilitate Android control to the chair like we’ve seen in other Mindstorm builds.

Don’t miss the demo embedded after the break.

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Robotic assist helps paraplegic stand and move around

Seeing this device help a man get up out of his wheelchair makes us wonder why this hasn’t been around for ages. The design principles behind the Tek RMD greatly benefit those without use of their legs. But it’s not just to help him stand, it also serves as motorized transport that makes bulky electric wheelchairs look so last century.

Instead of having the support structure beneath the rider, the RMD (Robotic Mobilization Device) uses a sling-like method to hang from the hinged arm. A folding handlebar can be raised up, allowing the rider to move from sitting to standing with a bit of help from the machine. Whether upright or sitting, the device can travel using its electric motors. In fact, this tip was sent in because it looks very much like riding a Segway.

The video demonstration after the break really hits home the functionality provided. This is an instant quality of life improvement, breaking down some of the barriers of moving around in confined quarters with a motorized wheelchair. There is also a lot to be said for having the option to stand. The demo shows several circumstances like shopping at the market, going through the checkout, and grilling out. What an amazing use of technology.

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Ignored disabled man builds his own damn elevator

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There’s an old saying that goes something like, “When the going gets tough, the tough builds their own 5-story wheelchair lift.”

Actually we’re pretty sure that’s not even close to how the saying goes, but when his local council turned their backs on [Dmitry Bibikow’s] request for wheelchair access to his apartment, that’s exactly what he did.

[Dmitry], an avid mountaineer, was injured in a climbing accident that left him without the use of his legs. Unfortunately for him, he and his family reside on the 5th floor of an apartment building that was not handicap accessible. Rather than move out, he asked the local council to install an elevator, which they agreed to.

Time passed, and as the project sank deeper and deeper into a mire of bureaucracy, [Dmitry] began to lose hope of ever seeing an elevator installed. After six years of relying on friends to help him get in and out of his apartment, he took matters into his own hands and installed a chair lift just off the side of his balcony.

According to [Dmitry] it works great, and he can get from the front door to his apartment well before his more able neighbors make it up the stairs. So far, the city council has not said anything about the lift, and he hopes it stays that way.