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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Hackaday Prize Entry: Robotic Prosthetic Leg Is Open Source And 3D-Printable

May 25, 2016 by Moritz Walter 19 Comments

We’ve been 3D-printing parts for self-replicating machines before, but we’ve been working on the wrong machines. Software and robotics engineer [David Sanchez Falero] is about to set it right with his Hackaday Prize entry, a 3D-printable, open source, robotic prosthetic leg for humans.

[David] could not find a suitable, 3D-printable and customizable prosthetic leg out there, and given the high price of commercial ones he started his own prosthesis project named Drakkar. The “bones” of his design are made of M8 steel threaded rods, which help to keep the cost low, but are also highly available all over the world. The knee is actively bent by a DC-motor and, according to the source code, a potentiometer reads back the position of the knee to a PID loop.

While working on his first prototype, [David] quickly found that replicating the shape and complex mechanics of a human foot would be too fragile when replicated from 3D-printed parts. Instead, he looked at how goat hooves managed to adapt to uneven terrain with only two larger toes. All results and learnings then went into a second version, which now also adapts to the user’s height. The design, which has been done entirely in FreeCAD, indeed looks promising and might one day compete with the high-priced commercial prosthesis.

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Hackaday Prize Entry: Sniffing Defibrillator Data

May 22, 2016 by Brian Benchoff 46 Comments

There’s a lot of implantable medical technology that is effectively a black box. Insulin pumps monitor blood sugar and deliver insulin, but you can’t exactly plug in a USB cable and download the data. Pacemakers and cardiac defibrillators are the same way. For these patients, data is usually transmitted to a base station, then sent over the Internet to help doctors make decisions. The patient never gets to see this data, but with a little work and a software defined radio, a team on Hackaday.io is cracking the code to listen in on these implanted medical devices.

The team behind ICeeData was assembled at a Health Tech Hackathon held in Latvia last April. One of the team members has an implanted defibrillator keeping her ticker in shape, and brought along her implant’s base station. The implant communicates via 402-405MHz radio, a region of the spectrum that is easily accessible by a cheap RTL-SDR TV Tuner dongle.

Right now the plan is to intercept the communications between the implant and the base station, decode the packets, decipher the protocol, and understand what the data means. It’s a classic reverse engineering task that would be the same for any radio protocol, only with this ones, the transmissions are coming from inside a human.

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DIY Vein Finder Shows You Where To Stick It

May 19, 2016 by Adam Fabio 73 Comments

Everyone who’s donated blood, gotten an intravenous (IV) line put in, or has taken a blood test knows that little bit of anxiety before the needle goes in. Will this be a one stick operation, or will the phlebotomist do their impression of drilling for oil while trying to find a vein? Some of us are blessed with easy to find blood vessels. Others end up walking out looking like they’ve been in a fight with a needle.

[Alex’s] ~~wife~~ girlfriend is a nurse who’s had trouble finding veins in the past. [Alex] is an automotive engineer by trade, more acquainted with oil lines than veins and arteries. While he couldn’t help her himself, [Alex] designed this 3D printed vein finder to help his ~~wife~~ girlfriend out at work. He started by studying devices on the market. Products like Veinlite use LEDs to illuminate the skin. Essentially these products are a string of LEDs and a battery. They are patented, FDA approved, and will set you back between $188 and $549 USD. [Alex] and his ~~wife~~ girlfriend couldn’t afford that kind of cost, so he built his own. Continue reading “DIY Vein Finder Shows You Where To Stick It” →

To See Within: Making Medical X-rays

May 12, 2016 by Dan Maloney 47 Comments

I was a bit of a lost soul after high school. I dabbled with electrical engineering for a semester but decided that it wasn’t for me – what I wouldn’t give for a do-over on that one. In my search for a way to make money, I stumbled upon radiologic technology – learning how to take X-rays. I figured it was a good way to combine my interests in medicine, electronics, and photography, so after a two-year course of study I got my Associates Degree, passed my boards, and earned the right to put “R.T.(R) (ARRT)” after my name.

That was about as far as that career went. There are certain realities of being in the health care business, and chief among them is that you really have to like dealing with the patients. I found that I liked the technology much more than the people, so I quickly moved on to bigger and better things. But the love of the technology never went away, so I thought I’d take a look at exactly what it takes to produce medical X-rays, and see how it’s changed from my time in the Radiology Department.

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3D Printing Bone

May 9, 2016 by Al Williams 11 Comments

What do you print with your 3D printer? Key chains? More printer parts (our favorite)? Enclosures for PC boards? At Johns Hopkins, they want to print bones. Not Halloween skeletons, either. Actual bones for use in bodies.

According to Johns Hopkins, over 200,000 people a year need head or face bone replacements due to birth defects, trauma, or surgery. Traditionally, surgeons cut part of your leg bone that doesn’t bear much weight out and shape it to meet the patient’s need. However, this has a few problems. The cut in the leg isn’t pleasant. In addition, it is difficult to create subtle curved shapes for a face out of a relatively straight leg bone.

This is an obvious application for 3D printing if you could find a suitable material to produce faux bones. The FDA allows polycaprolactate (PCL) plastic for other clinical uses and it is attractive because it has a relatively low melting point. That’s important because mixing in biological additives is difficult to do at high temperatures.

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Hackaday Prize Entry: Raimi’s Bionic Arm

May 8, 2016 by Moritz Walter 9 Comments

Sometimes, the most amazing teams make the most wonderful things happen, and yet, there is just not enough time to finish all the features before the product ships. This is what happened to Raimi, who came to this world missing a right hand and half of her right forearm. Raimi is now 9 years old, and commercial mechatronic prostheses are still only available to those who can afford them. When Raimi’s father approached [Patrick Joyce] to ask him for help in building an affordable prosthesis, he knew it would matter, and went right to work.

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