Thought Control Via Handwriting

May 16, 2021 by Al Williams 12 Comments

Computers haven’t done much for the quality of our already poor handwriting. However, a man paralyzed by an accident can now feed input into a computer by simply thinking about handwriting, thanks to work by Stanford University researchers. Compared to more cumbersome systems based on eye motion or breath, the handwriting technique enables entry at up to 90 characters a minute.

Currently, the feat requires a lab’s worth of equipment, but it could be made practical for everyday use with some additional work and — hopefully — less invasive sensors. In particular, the sensor used two microelectrode arrays in the precentral gyrus portion of the brain. When the subject thinks about writing, recognizable patterns appear in the collected data. The rest is just math and classification using a neural network.

If you want to try your hand at processing this kind of data and don’t have a set of electrodes to implant, you can download nearly eleven hours of data already recorded. The code is out there, too. What we’d really like to see is some easier way to grab the data to start with. That could be a real game-changer.

More traditional input methods using your mouth have been around for a long time. We’ve also looked at work that involves moving your head.

Seeing-Eye Shoes Pair Computer Vision With Haptic Feedback

May 12, 2021 by Kristina Panos 21 Comments

Over the years, we’ve seen plenty of projects that use ultrasonic or time-of-flight sensors as object detection methods for the visually impaired. Ultrasonic sensors detect objects like sonar — they send sound pulses and measure the time it takes for the signal to bounce off the object and come back. Time-of-flight sensors do essentially the same thing, but with infrared light. In either case, the notifications often come as haptic feedback on the wrist or head or whatever limb the ultrasonic module is attached to. We often wonder why there aren’t commercially-made shoes that do this, but it turns out there are, and they’re about to get even better.

The shoe’s view — safe walking space is delimited with color. Image via TU Graz

Today, Tec-Innovation makes shoes with ultrasonic sensors on the toes that can detect objects up to four meters away. The wearer is notified of obstacles through haptic feedback in the shoes as well as an audible phone notification via Bluetooth. The company teamed up with the Graz University of Technology in Austria to give the shoes robot vision that provides even better detail.

Ultrasonic is a great help, but it can’t detect the topography of the obstacle and tell a pothole from a rock from a wall. But if you have a camera on both feet, you can use the data to determine obstacle types and notify the user accordingly. These new models will still have the ultrasonic sensors to do the initial object detection, and use the cameras for analysis.

Whenever they do come out, the sensors will all be connected through the app, which paves the way for crowdsourced obstacle maps of various cities. The shoes will also be quite expensive. Can you do the same thing for less? Consider the gauntlet thrown!

We could all use some navigational help sometimes. Don’t want to look like a tourist? Get turn-by-turn directions in the corner of your eye.

Thanks for the tip, [Qes]!

Building An Oxygen Concentrator: It Isn’t Rocket Science

May 10, 2021 by Jenny List 40 Comments

Back at the start of the pandemic, a variety of hacker designs for life-saving machinery may have pushed the boundaries of patient safety. There are good reasons that a ventilator must pass extensive safety testing and certification before it can be attached to a patient, because were it to in some way fail, the patient would die. A year later, we have many much safer and more realistic ways to use our skills as part of the effort.

Probably one of the most ambitious projects comes from a coalition of Indian hackerspaces who are adapting a proven oxygen concentrator for local manufacture. Among them is Hackaday’s own [Anool Mahidharia], who hosts a Maker’s Asylum video (embedded below) explaining how the oxygen concentrator works and how they can be made safely.

The team have proven their ability in manufacturing over the past year, here showing off the M19 motorised air purifying respirator.

An oxygen concentrator is both surprisingly simple and imbued with a touch of magic. At its center are two columns of zeolite, a highly porous aluminosilicate mineral that performs the task of a molecular sieve. When air is pumped into the column, the zeolite traps nitrogen, leaving the oxygen-enriched remnant to be supplied onwards. There are two such columns to allow each to be on an alternate cycle of enrichment or purging to remove the accumulated nitrogen.

The point of the video is to show that such a device can be constructed from readily available parts and with common tools; as the title says it isn’t rocket science. Concentrators produced by the hackerspace coalition won’t save the world on their own, but as a part of the combined effort they can provide a useful and reliable source of oxygen that will make a significant difference in a country whose oxygen distribution network is under severe strain.

We previously covered the Indian oxygen concentrator effort when they launched the project. Their website can be found on the Maker’s Asylum website, and their crowdfunding campaign can be found on the Indian crowdfunding platform, Ketto. They have already proved their ability to coordinate large-scale manufacturing with their previous PPE and respirator projects, so please consider supporting them if you can. Meanwhile, we can’t help a twinge of space envy, from the fleeting glimpse of Maker’s Asylum in the video.

Continue reading “Building An Oxygen Concentrator: It Isn’t Rocket Science” →

ECG Project With All The Messy Safety Details

May 3, 2021 by Orlando Hoilett 11 Comments

We’ve seen a number of heart rate monitoring projects on Hackaday, but [Peter’s] electrocardiography (ECG) Instructable really caught out attention.

If you’ve followed Hackaday for any period of time, you’re probably already somewhat familiar with the hardware needed to record the ECG. First, you need a high input impedance instrumentation amplifier to pick up the millivolt signal from electrical leads carefully placed on the willing subject’s body. To accomplish this, he used an AD8232 single-lead ECG module (we’ve actually seen this part used to make a soundcard-based ECG). This chip has a built-in instrumentation amplifier as well as an optional secondary amplifier for additional gain and low-pass filtering. The ECG signal is riddled with noise from mains that can be partially attenuated with a simple low-pass filter. Then, [Peter] uses an Arduino Nano to sample the output of the AD8232, implement a digital notch filter for added mains noise reduction, and display the output on a 2.8″ TFT display.

Other than the circuit itself, two things about his project really caught our attention. [Peter] walks the reader through all the different safety considerations for a commercial ECG device and applies these principles to his simple DIY setup to ensure his own safety. As [Peter] put it, professional medical electronics should follow IEC 60601. It’s a pretty bulky document, but the main tenets quoted from [Peter’s] write-up are:

limiting how much current can pass through the patient
how much current can I pass through the patient?
what electrical isolation is required?
what happens if a “component” fails?
how much electromagnetic interference can I produce?
what about a defibrillator?

[Peter] mentions that his circuit itself does not fully conform to the standard (though he makes some honest attempts), but lays out a crude plan for doing so. These include using high-valued input resistors for the connections to the electrodes and also adding a few protection diodes to the electrode inputs so that the device can withstand a defibrillator. And of course, two simple strategies you always want to follow are using battery power and placing the device in a properly shielded enclosure.

[Peter] also does a great job breaking down the electrophysiology of the heart and relates it to terms maybe a bit more familiar to non-medical professionals. Understanding the human heart might be a little less intimidating if we relate the heart to a simple voltage source like a battery or maybe even a function generator. You can imagine the ions in our cells as charger carriers that generate electrical potential energy and nerve fibers as electrical wires along which electrical pulses travel through the body.

Honestly, [Peter] has a wealth of information and tools presented in his project that are sure to help you in your next build. You might also find his ECG simulator code really handy and his low-memory display driver code helpful as well. Cool project, [Peter]!

Measuring ECG is something that is near and dear to my heart (sorry, couldn’t resist). Two of my own projects that were featured on Hackaday before I became a writer here include a biomedical sensor suite in Arduino shield form factor, and a simple ECG built around an AD623 instrumentation amplifier.

An LED Heartbeat Display You Can Wear On Your Sleeve

April 30, 2021 by Lewin Day 3 Comments

There are a few different ways to take a person’s pulse, with varying utility depending on the categories said patient fits in to. [Nitin Nair]’s method doesn’t really have a medical application, but it’s certainly a neat example of what you can do with modern sensors.

The build combines an EmotiBit sensor platform with an Adafruit Feather and accompanying Charlieplexed LED module. The EmotiBit packs a PPG, or photoplethysmogram sensor, otherwise known as a pulse oximeter, which uses optical methods to detect changes in blood volume beneath the skin. From this data, a pulse rate can be derived, and the LEDs flashed with a heart graphic in concert with the rhythm of the wearer’s heart. The benefit of the PPG in the EmotiBit is that it can be worn on the wearer’s arm, or other location with suitable vascularization. This allows the wearer to place the sensor on the arm, and thus wear their heart on their sleeve.

It’s a cool concept, and we’d love to see it neatly packaged with a smoothly animated fade as a sports accessory. It’d be an easy way to signal how fast your heart rate recovers on a run with friends – the device could brag about your fitness for you. Alternatively, if pulse oximetry isn’t enough for you, go ahead and build an ECG instead!

Indian Makers Respond To The COVID-19 Pandemic By Producing Oxygen Concentrators

April 26, 2021 by Jenny List 56 Comments

We’ve all spent the last year or more under the shadow of the COVID-19 pandemic, and though some of us may have been vaccinated or come through its various waves it remains far from over. One of the hardest-hit parts of the world at the moment is in India, where health services are struggling to maintain adequate oxygen supply such is the demand for it from sick patients.

India’s hacker and maker community have risen to the challenge and done their bit to supply needed resources, and fresh from last year’s PPE manufacturing efforts a group from the Makers Asylum hackerspace in Goa have launched upon a fresh challenge. They aim to start producing the established open-source OxiKit oxygen concentrator in the Indian hackerspace community using locally manufactured parts, and they’ve launched a crowdfunding effort to cover their development, prototyping, and certification work.

The oxygen concentrator project builds on Makers Asylum’s experience last year as part of an extremely successful network of makerspaces producing PPE, which demonstrates that they have the resources, logistics, and ability to take on a project of this size. The OxiKit is no hare-brained contraption but an established and successful design that is already at work, so we believe that this project has a good chance of success. It’s close to home for Hackaday too, and one of the people involved with it is our colleague [Anool Mahidharia].

In a global pandemic only a global response can overcome the incredible challenges before us. For that reason we’d like to urge you to take a look at the Makers Asylum page wherever you are, and if you can, support it.

Continue reading “Indian Makers Respond To The COVID-19 Pandemic By Producing Oxygen Concentrators” →

Treatment Triggers Teeth To Thrive

April 13, 2021 by Kristina Panos 38 Comments

We humans like to think we’re pretty advanced, but we can’t regrow missing teeth in adulthood like sharks, alligators, and crocodiles. Once those pearly whites are gone, they’re gone for good, and we don’t even have a way to regenerate the protective enamel. However, this may not always be the case, because scientists at Kyoto University and University of Fukui in Japan have discovered a monoclonal antibody treatment that triggers tooth regeneration in laboratory mice.

Image by Katsu Takahashi/Kyoto University via Medical Express

Monoclonal antibodies are lab-fabbed molecules that act as substitute antibodies to enhance the body’s natural defenses against diseases like cancer and arthritis. These antibodies are also used to develop vaccines and treat COVID-19. In the case of cancer, monoclonal antibodies bind to antigens on cancer cells, effectively flagging them for removal, but they also do much more, such as deliver chemo and radioimmunotherapies.

By blocking the gene USAG-1, the scientists saw an increase in Bone Morphogenic Protein (BMP), which is a molecule that dictates the number of teeth a given creature will have in the first place. Because of this increase in BMP, the mice were able to regrow teeth. This proposition was a challenging one — BMP affects other aspects of development, and the early attempts did more harm than good by causing birth defects. The good news is that the treatment also worked in ferrets, whose teeth are much closer to human dentition than mice. Before moving on to human trials, the scientists will test it out on pigs and dogs. If you were given a second shot at a set of teeth, would you treat them better than the first, or even worse because you can just grow new ones again?

Speaking of pigs, it seems that pig-to-human organ transplants are on track for 2021.