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53 Articles

Universal Bio-Electrical Signal Amplifier Makes Reading Body Signals Easy

August 26, 2021 by 18 Comments

The electrical signals emitted by the human body tell us a lot about what’s going on inside. But getting those signals inside your microcontroller is not straightforward: the voltages are too small for most ADCs, and the ever-present 50 or 60 Hz mains frequency makes it hard to discern subtle changes. Over at Upside Down Labs, [Deepak Kathri] developed a universal biosensor interface called the BioAmp EXG Pill to make all this a lot easier.

Its name refers to the fact that it can be used for several different bio-electrical sensing applications: ECG, EMG, EOG and EEG, which deal with signals coming from the heart, muscles, eyes and brain, respectively. To enable such flexibility, the board has connectors for two or three electrodes, as well as solder pads to mount resistors and capacitors to adjust the gain and bandwidth. An instrumentation amplifier increases the strength of the desired signal while rejecting noise and interference.

The form factor allows easy connection to electrodes on one side and a data acquisition system on the other. Measuring just 25.4 mm long and 10 mm wide, it should be easy to integrate into any type of biosensing gizmo you can come up with. [Deepak] has made several demo setups, showing him using the Pill with an Arduino to measure his heart rate, detect eye blinks, and even control a robot arm using his own arm muscles!

The EXG Pill is an evolution of an earlier EMG-only project. We’ve seen several great ECG and EEG projects before, but is the first time we’ve seen one amplifier that can do them all.

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Hearing Aid Reads Your Mind

March 13, 2020 by 16 Comments

If you’ve ever seen an experienced radio operator pull a signal out of the noise, or talked to someone in a crowded noisy restaurant, you know the human brain is excellent at focusing on a particular sound. This is sometimes called the cocktail party effect and if you wear a hearing aid, this doesn’t work as well because the device amplifies everything the same. A German company, Fraunhofer, aims to change that. They’ve demonstrated a hearing aid that uses EEG sensors to determine what you are trying to hear. Then it uses that information to configure beamforming microphone arrays to focus in on the sound you want to hear.

In addition to electronically focusing sound, the device stimulates your brain using transcranial electrostimulation. A low-level electrical signal tied to the audio input directly stimulates the auditory cortex of your brain and reportedly improves intelligibility.

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Brain Hacking With Entrainment

April 8, 2019 by 16 Comments

Can you electronically enhance your brain? I’m not talking about surgically turning into a Borg. But are there electronic methods that can improve various functions of your brain? Fans of brainwave entrainment say yes.

There was an old recruiting ad for electrical engineers that started with the headline: The best electronic brains are still human. While it is true that even a toddler can do things our best computers struggle with, it is easy to feel a little inadequate compared to some of our modern electronic brains. Then again, your brain is an electronic device of sorts. While we don’t understand everything about how it works, there are definitely electric signals going between neurons. And where there are electric signals there are ways to measure them.

The tool for measuring electric signals in the brain is an EEG (electroencephalograph). While you can’t use an EEG to read your mind, exactly, it can tell you some pretty interesting information, such as when you are relaxed or concentrating. At its most basic we’ve seen toys and simple hobby projects that purport to be “mind controlled” but only at an incredibly rudimentary level.

Brainwave entrainment is a hypothesis that sending low frequency waves to your brain can give your mind a nudge and sync up brain activity with the equipment measuring it. The ability to synchronize with the brain could yield much better measurements for a meaningful interface between modern electronics and electric storm of thought happening in your head.

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Turning A Fitness Tracker Into An EEG

August 30, 2018 by 11 Comments

Several years ago, a company called Neurosky came out with an interesting chipset meant to be put in an EEG headset. This chipset would track your brainwaves, do some fancy math, and output a few numbers based on the Delta, Gamma, Alpha, and Beta waves in your brain. Of course, the senseable thing to do with this technology would be to put it in a Star Wars-branded toy where you pretend to be a Jedi. All was good with the world, and a few people hacked these Jedi Mind Trainers for some interesting builds.

But the Neurosky chip was still a black box. No one knew how it worked. The ‘concentration’ number had no relation to anything, except how hard you were apparently concentrating. In an effort to break this black box and build upon years worth of EEG hacks, [Curt White] is hacking a fitness tracker for EEG analysis for his entry into the Hackaday Prize.

The hardware in question for this build is a B20 Fitness Tracker, an ungodly cheap piece of hardware that contains an ADS1292 bioimpedance sensor that can be used for ECG, EMG, and EEG. There’s also an nRF microcontroller with Bluetooth that’s easily programmed with an Arduino. All the building blocks are there.

Right now, [Curt] has successfully opened up one of these fitness trackers and has done enough of a teardown to get the data off of the bioimpedence sensor. The trick now is to emulate the ‘concentration’ and ‘relaxation’ values the Neurosky chip puts out. This is fairly difficult, as what these values actually mean in terms of brainwaves is a bit opaque, but [Curt] has some filters and some tools to pull data from the brain and output something. Now it’s just a question of outputting the right values.

It’s a fantastic hack, that is sure to be a lot more affordable than buying some old Star Wars toys or paying a licensing fee to Neurosky. This is commodity hardware hacked to do something it was never intended to do, and an excellent entry to this year’s Hackaday Prize.

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Anouk Wipprecht: Robotic Dresses And Human Interfaces

November 21, 2017 by 11 Comments

Anouk Wipprecht‘s hackerly interests are hard to summarize, so bear with us. She works primarily on technological dresses, making fashion with themes inspired by nature, but making it interactive. If that sounds a little bit vague, consider that she’s made over 40 pieces of clothing, from a spider dress that attacks when someone enters your personal space too quickly to a suit with plasma balls that lets her get hit by Arc Attack’s giant musical Tesla coils in style. She gave an inspiring talk at the 2017 Hackaday Superconference, embedded below, that you should really go watch.

Anouk has some neat insights about how the world of fashion and technology interact. Technology, and her series of spider dresses in particular, tends to evolve over related versions, while fashion tends to seek the brand-new and the now. Managing these two impulses can’t be easy.

For instance, her first spider was made with servos and laser-cut acrylic, in a construction that probably seems familiar to most Hackaday readers. But hard edges, brittle plastic, and screws that work themselves slowly loose are no match for human-borne designs. Her most recent version is stunningly beautiful, made of 3D printed nylon for flexibility, and really nails the “bones of a human-spider hybrid” aesthetic that she’s going for.

The multiple iterations of her drink-dispensing “cocktail dress” (get it?!) show the same progression. We appreciate the simple, press-button-get-drink version that she designed for a fancy restaurant in Ibiza, but we really love the idea of being a human ice-breaker at parties that another version brings to the mix: to get a drink, you have to play “truth or dare” with questions randomly chosen and displayed on a screen on the wearer’s arm.

Playfulness runs through nearly everything that Anouk creates. She starts out with a “what if?” and runs with it. But she’s not just playing around. She’s also a very dedicated documenter of her projects, because she believes in paying the inspiration forward to the next generation. And her latest project does something really brilliant: merging fashion, technology, and medical diagnostics.

It’s a stripped-down EEG that kids with ADHD can wear around in their daily lives that triggers a camera when their brains get stimulated in particular ways. Instead of a full EEG that requires a child to have 30 gel electrodes installed, and which can only be run in a medical lab, stripping down the system allows the child to go about their normal life. This approach may collect limited data in comparison to the full setup, but since it’s collected under less intimidating circumstances, the little data that it does collect may be more “real”. This project is currently in progress, so we’ll just have to wait and see what comes out. We’re excited.

There’s so much more going on in Anouk’s presentation, but don’t take our word for it. Go watch Anouk’s talk right now and you’ll find she inspires you to adds a little bit more of the human element into your projects. Be playful, awkward, or experimental. But above all, be awesome!

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Hackaday Prize Entry: Seizure Detection By EEG

May 2, 2017 by 13 Comments

For those that suffer them, seizures are a dangerous thing. Outside the neurological effects, there is always the possibility of injury from the surrounding environment as well – consider the dangers of having a seizure near a busy road, or even simply a glass table. Some detection methods exist for seizure sufferers, but they are primarily based on detecting the jerking motion of the patient. [akhil2001us] thinks it’s possible to do better – by measuring brainwaves to detect the onset of seizures.

The build is centered around the Neurosky Mindwave headset. This is an off-the-shelf product designed specifically for capturing EEG data. It outputs raw brainwave data which is key for doing proper analysis. The project then uses an Arduino Mega to tie everything together, along with some Sparkfun Bluetooth modules to talk to a cell phone to send an SMS for help in the event of a seizure.

The real difficulty in a project like this comes from developing an algorithm that can reliably detect seizures, as well as a unit robust enough to work in the real world. It’s no use if your headset is detecting a seizure in progress, but the help message is never sent because a wire fell out of your breadboard. It’s considerations like this, combined with the threat of litigation, behind why medical devices are so rigorously engineered and certified. For a proof of concept, however, such concerns are not as important.

We’ve seen Mindwave builds before – brainwave research is an exciting field!

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How To Telepathically Tell A Robot It Screwed Up

March 6, 2017 by 3 Comments

Training machines to effectively complete tasks is an ongoing area of research. This can be done in a variety of ways, from complex programming interfaces, to systems that understand commands in natural langauge. A team from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) wanted to see if it was possible for humans to communicate more directly when training a robot. Their system allows a user to correct a robot’s actions using only their brain.

The concept is simple – using an EEG cap to detect brainwaves, the system measures a special type of brain signals called “error-related potentials”. Simply noticing the robot making a mistake allows the robot to correct itself, and for a nice extra touch – blush in embarassment.

This interface allows for a very intuitive way of working with a robot – upon noticing a mistake, the robot is able to automatically stop or correct its behaviour. Currently the system is only capable of being used for very simple tasks – the video shows the robot sorting objects of two types into corresponding bins. The robot knows that if the human has detected an error, it must simply place the object in the other bin. Further research seeks to expand the possibilities of using this automatic brainwave feedback to train robots for more complex tasks. You can read the research paper here.

MIT’s CSAIL work on lots of exciting projects – their video microphone technology is truly astounding.

[Thanks to Adam Connor-Simmons for the tip!]