Hacklet 56 – Brain Hacks

The brain is the most powerful – and least understood computer known to man. For these very reasons, working with the mind has long been an attraction for hackers, makers, and engineers. Everything from EEG to magnetic stimulus to actual implants have found their way into projects. This week’s Hacklet is about some of the best brain hacks on Hackaday.io!

teensy-bio[Paul Stoffregen], father of the Teensy, is hard at work on Biopotential Signal Library, his entry in the 2015 Hackaday Prize. [Paul] isn’t just hacking his own mind, he’s creating a library and reference design using the Teensy 3.1. This library will allow anyone to read electroencephalogram (EEG) signals without having to worry about line noise filtering, signal processing, and all the other details that make recording EEG signals hard. [Paul] is making this happen by having the Teensy’s cortex M4 processor perform interrupt driven acquisition and filtering in the background. This leaves the user’s Arduino sketch free to actually work with the data, rather than acquiring it. The initial hardware design will collect data from TI ADS129x chips, which are 24 bit ADCs with 4 or 8 simultaneous channels. [Paul] plans to add more chips to the library in the future.

 

bioxNext up is [Jae Choi] with Lucid Dream Communication Link. [Jae] hopes to create a link between the dream world and the real world. To do this, they are utilizing BioEXG, a device [Jae] designed to collect several types of biological signals. Data enters the system through several active probes. These probes use common pogo pins to make contact with the wearer’s skin. [Jae] says the active probes were able to read EEG signals even through their thick hair! Communication between dreams and the real world will be accomplished with eye movements. We haven’t heard from [Jae] in awhile – so we hope they aren’t caught in limbo!

bioloop[Qquuiinn] is working from a different angle to build bioloop, their entry in the 2015 Hackaday Prize. Rather than using EEG signals, [Qquuiinn] is going with Galvanic Skin Response (GSR). GSR is easy to measure compared to EEG signals. [Qquuiinn] is using an Arduino Pro Mini to perform all their signal acquisition and processing. This biofeedback signal has been used for decades by devices like polygraph “lie detector” machines. GSR values change as the sweat glands become active. It provides a window into a person’s psychological or physiological stress levels. [Qquuiinn] hopes bioloop will be useful both to individuals and to mental health professionals.

biomonitorFinally we have [Marcin Byczuk] with Biomonitor. Biomonitor can read both EEG and electrocardiogram (EKG) signals. Unlike the other projects on today’s Hacklet, Biomonitor is wireless. It uses a Bluetooth radio to transmit data to a nearby PC or smartphone. The main processor in Biomonitor is an 8 bit ATmega8L. Since the 8L isn’t up to a lot of signal processing, [Marcin] does much of his filtering the old fashioned way – in hardware. Carefully designed op-amp based active filters provide more than enough performance when measuring these types of signals. Biomonitor has already found it’s way into academia, being used in both the PalCom project, and brain-computer interface research.

If you want more brain hacking goodness, check out our brain hacking project list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Muse EEG Headset Teardown

[Lady Ada] over at Adafruit just did a delightful tear down of the Muse EEG headset.

The Muse headset is a rather expensive consumer-grade EEG headset that promises better meditation with the ability to track your brainwaves in order to go into a deeper trance. We’re not much for meditating here at Hackaday, but the EEG sensors really do work. It’s pretty cool to see the insides of this without forking out $300 ourselves for one we might break.

Like most EEG headsets, they weren’t really designed to be worn while sleeping. Two bulky pods over the ears hold the battery and charging circuit on one side, and the brains on the other. The neat part about it is a little adjustable metal piece which allows for adjustment on the strap while maintaining all the electrical connections. A flexible circuit houses forehead electrodes which go along the length of the band.

In the past we’ve seen work done on the Lucid Scribe project, using a modified Neurosky Mindwave EEG (at $99 it’s much cheaper to hack). The idea is to be able to monitor your sleep cycles accordingly, and then give audible cues to the dreamer in order to “wake up” inside the dream. Think of the Inception music.

Unfortunately it doesn’t look like the Muse will be any better for lucid dreaming. If you were able to decouple the electrodes from the rest of the headset,  then it might just work.

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Hackaday Prize Entry: Biopotential Signal Library

With prosthetics, EEG, and all the other builds focused on the body and medicine for this year’s Hackaday Prize, it might be a good idea to take a look at what it takes to measure the tiny electrical signals that come from the human body. Measuring brain waves or heartbeats indoors is hard; AC power frequencies easily couple to the high impedance inputs for these measurements, and the signals themselves are very, very weak. For his entry to The Hackaday Prize, [Paul Stoffregen] is building the tools to make EEG, ECG, and EMG measurements easy with cheap tools.

If the name [Stoffregen] sounds familiar, it’s because he’s the guy behind the Teensy family of microcontroller boards and several dozen extremely popular libraries for everything from displays to real time clocks. The biopotential signal library continues in [Paul]’s tradition of building very cool stuff with just code.

The hardware used in this project is TI’s ADS1294, a 24-bit ADC with either 4 or 8 channels. This chip is marketed as a medical analog front end with a little bit of ECG thrown in for good measure. [Paul] is only using the ADS1294 initially; more analog chips can be added later. It’s a great project in its own right, and when you include the potential applications of this library – everything from prosthetics to body sensors – it makes for an awesome Hackaday Prize entry.


The 2015 Hackaday Prize is sponsored by:

Brains Controlling Labyrinths Without Hands

[Daniel], [Gal] and [Maxim] attended a hackathon last weekend – Brainihack 2015 – that focused on neuroscience-themed builds in a day and a half long build off. The trio are communications systems engineering and computer science students with no background in neuroscience whatsoever. You can’t build an FMRI in a day and a half, so they ended up winning the best project in the open source category with a brain-controlled labyrinth game.

The labyrinth itself is entirely 3D printed and much, much simpler than the usual, ‘wooden maze with holes’ that’s generally associated with labyrinth puzzles. It’s really just a plastic spiral for a ball to follow. There’s a reason for this simplicity. The team is using EEG to detect brain waves and move the labyrinth on the X and Y axes.

The team is using OpenBCI for the interface between their brains and a pair of servos. This is actually an interesting piece of tech; unlike a few toys like the NeuroSky MindWave and the Star Wars Force Trainer, the OpenBCI gives you eight input channels that attach to anywhere on the scalp. The team used these inputs to measure Alpha waves and Steady State Visually Evoked Potential to control the pair of servos on the labyrinth frame.

It’s a great build, a wonderful demonstration of a device that outputs real EEG signals, and the team on a prize. What’s not to like?

Use the Force, Luke…to Turn Off Your TV

Have you ever wanted to turn on or off your TV just by thinking about it? We love this hack mainly because it uses an old Star Wars Force Trainer game. You can still buy them for about $40-$80 USD online. This cool little toy was introduced in 2009 and uses a headset with electrodes, and an electroencephalography (EEG) chip. It transmits the EEG data to control a fan that blows air into a tube to “levitate” a ball, all the while being coached on by the voice of Yoda. (Geesh! Kids these days have the best toys!)

[Tinkernut] started by cracking open the headset, where he found the EEG chip made by a company called NeuroSky (talk about a frightening sounding company name). The PCB designer was kind enough to label the Tx/Rx pins on the board, so hooking it up to an Arduino was a snap. After scavenging an IR LED and receiver from an old VCR, the hardware was just about done. After a bit of coding, you can now control your TV by using the force! (Ok, by ‘force’ I mean brainwaves.)  Video after the break.

Note: [Tinkernut’s] blog page should have more information available soon. In the meantime if you can find his Arduino Brain Library on github.

This isn’t the first EEG to TV interface we’ve featured. Way back in 2010 we featured a project that used an Emotiv EPOC EEG headset to turn on and off a TV. But at $400 for the headset, it was a little too expensive for the average Jedi.

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Your New Winter Hat Should Express Your Brain Waves Like a Neon Sign… Just Saying

We’ve seen a few cool hacks for mainstream commercial EEG headsets, but these are all a tad spendy for leisurely play or experimentation. The illumino project by [io] however, has a relatively short and affordable list of materials for creating your own EEG sensor. It’s even built into a beanie that maps your mental status to a colorful LED pompom! Now that winter is around the corner, this project is perfect for those of us who want to try on the mad scientist’s hat and look awesome while we’re wearing it.

How does all the neuro-magic happen? At the heart of [io’s] EEG project is a retired Thinkgear ASIC PC board by Neurosky. It comes loaded with fancy algorithms which amplify and process the different types of noise coming from the surface of our brain. A few small electrodes made from sheets of copper and placed in contact with the forehead are responsible for picking up this noise. The bridge between the electrodes and the Thinkgear is an arduino running the illumino project code. For [io’s] tutorial, a Tinylilly Arduino is used to mesh with the wearable medium, since all of these parts are concealed in the folded brim of the beanie.

eegBeanie3

In addition, a neat processing sketch is included which illustrates the alpha, beta, gamma, and other wave types associated with brain activity as a morphing ball of changing size and color. This offers a nice visual sense of what the Neurosky is actually reading.

If all of your hats lack pompoms and you can’t find one out in the ether that comes equipped, fear not… there is even a side tutorial on how to make a proper puff-ball from yarn. Sporting glowing headwear might be a little ostentatious for some of us, but the circuit in this project by itself is a neat point of departure for those who want to poke around at the EEG technology. Details and code can be found on the illumino Instructable.

Thanks Zack, for showing us this neat tutorial!

Continue reading “Your New Winter Hat Should Express Your Brain Waves Like a Neon Sign… Just Saying”

An Open Hardware Platform for ECG, EEG and Other Measurements

[Eric] tipped us about the OpenHarwareExG project which goal is to build a device that allows the creation of electrophysiological signal processing applications. By the latter they mean electrocardiography (ECG, activity of the heart), electroencephalography (EEG, signals on the scalp), electromyography (EMG, skeletal muscles activity), electronystagmography and electrooculography (ENG & EOG, eye movements) monitoring projects. As you can guess these signals are particularly hard to measure due to their small amplitude and therefore susceptibility to electrical noise.

The ADS1299 8-channel 24-bit analog front end used in this platform is actually electrically isolated from the rest of the circuit so the USB connection wouldn’t perturb measurements. An Arduino-compatible ATSAM3X microcontroller is used and all the board is “DIY compatible” as all parts can be sourced in small quantities and soldered by hand. Even the case is open source, being laser cut from acrylic.

Head to the project’s website to download all the source files and see a quick video of the system in action.

Interested in measuring the body’s potential? Check out an ECG that’s nice enough to let you know you have died, or this Android based wireless setup.