CPAP Firmware Hack Enables BiPAP Mode; Envisions Use As Temporary Ventilator

April 15, 2020 by Tom Nardi 14 Comments

Operating under the idea that a Constant Positive Airway Pressure (CPAP) machine isn’t very far removed electrically or mechanically from a proper ventilator, [Trammell Hudson] has performed some fascinating research into how these widely available machines could be used as life support devices in an emergency situation. While the documentation makes it clear the project is a proof of concept and is absolutely not intended for human use in its current state, the findings so far are certainly very promising.

For the purposes of this research, [Trammell] has focused on the Airsense S10 which currently retails for around $600 USD. Normally the machine is used to treat sleep apnea and other disorders by providing a constant pressure on the lungs, but as this project shows, it’s also possible for the S10 to function in what’s known as Bi-level Positive Airway Pressure (BiPAP) mode. Essentially this means that the machine detects when the user is attempting to inhale, and increases the air pressure to support their natural breathing.

Critically, this change is made entirely through modifications to the S10 firmware. No additional hardware is required, and outside of opening up the device to attach an STM32 programmer (a process which [Trammell] has carefully documented), there’s nothing mechanically that needs to be done to the machine for it to operate in this breathing support function. It seems at least some of the functionality was already included via hidden diagnostic menus which can be enabled through a firmware patch.

As many of these CPAP machines feature cellular data connections for monitoring and over-the-air updates, [Trammell] believes it should be possible for manufacturers to push out a similarly modified firmware on supported devices. Of course, the FDA would have to approve of something like that before the machines could actually be used as emergency, non-invasive ventilators. They would also need to have viral filters installed and some facility for remote control added, but those would be relatively minor modifications.

Learn more about the efforts being put into ventilators right now. Start with this excellent hardware overview called Ventilators 101 and then take a look at some of the issues with trying to build a ventilator from scratch.

Printed Brain Implants Give New Meaning To Neuroplasticity

April 14, 2020 by Kristina Panos 4 Comments

3D printing has opened up a world of possibilities in plastic, food, concrete, and other materials. Now, MIT engineers have found a way to add brain implants to the list. This technology has the potential to replace electrodes used for monitoring and implants that stimulate brain tissue in order to ease the effects of epilepsy, Parkinson’s disease, and severe depression.

Existing brain implants are rigid and abrade the grey matter, which creates scar tissue over time. This new material is soft and flexible, so it hugs the wrinkles and curves. It’s a conductive polymer that’s been thickened into a viscous, printable paste.

The team took a conductive liquid polymer (water plus nanofibers of a polystyrene sulfonate) and combined it with a solvent they made for a previous project to form a conductive, printable hydrogel.

In addition to printing out a sheet of micro blinky circuits, they tested out the material by printing a flexible electrode, which they implanted into a mouse. Amazingly, the electrode was able to detect the signal coming from a single neuron. They also printed arrays of electrodes topped with little wells for holding neurons so they can study the neurons’ signals using the electrode net underneath.

This particular medical printing hack is pretty far out of reach for most of us, but not all of them are. Fire up that printer and check out this NIH-approved face shield design.

So What Is Protein Folding, Anyway?

April 14, 2020 by Dan Maloney 26 Comments

The current COVID-19 pandemic is rife with problems that hackers have attacked with gusto. From 3D printed face shields and homebrew face masks to replacements for full-fledged mechanical ventilators, the outpouring of ideas has been inspirational and heartwarming. At the same time there have been many efforts in a different area: research aimed at fighting the virus itself.

Getting to the root of the problem seems to have the most potential for ending this pandemic and getting ahead of future ones, and that’s the “know your enemy” problem that the distributed computing effort known as Folding@Home aims to address. Millions of people have signed up to donate cycles from spare PCs and GPUs, and in the process have created the largest supercomputer in history.

But what exactly are all these exaFLOPS being used for? Why is protein folding something to direct so much computational might toward? What’s the biochemistry behind this, and why do proteins need to fold in the first place? Here’s a brief look at protein folding: what it is, how it happens, and why it’s important.

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Disinfect PPE On The Cheap With This Hardware Store UV-C Cabinet

April 12, 2020 by Dan Maloney 91 Comments

The current situation has given closet germaphobes the world over a chance to get out there and clean the hell out of everything. Some of it may be overdone; we ourselves can cop to a certain excess as we wipe down cans and boxes when returning from a run to the grocery store. But sometimes disinfection is clearly indicated, and having an easy way to kill the bugs on things like face masks can make a big difference by extending the life of something that would normally be disposable. That’s where this quick and easy UV-C germicidal cabinet really shines.

The idea behind [Deeplocal]’s “YouVee” is to be something that can be quickly cobbled together from parts that can be picked up at any big-box home store, thereby limiting the number of trips out. You might even have everything needed already, which would make this a super simple build. The business end is a UV-C germicidal fluorescent lamp, of the kind used in clarifiers for backyard ponds. A fluorescent droplight is modified to accept the lamp by snipping off a bit of plastic, and the lamp is attached to the inside of the lid of a sturdy black plastic tote. The interior of the tote is lined with aluminum tape and a stand for items to be disinfected is made from a paint roller screen. The clever bit is the safety interlock; to prevent exposure to UV, the lamp needs to be unplugged before removing the lid. Check out the full build tutorial for details.

We can’t vouch for YouVee’s germicidal efficacy, but it seems like a solid design. If you have doubts, you could always measure the UV-C flux easily, or you could build a smaller version of this peroxide vapor PPE sterilizer, just to be sure.

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What Does A Dependable Open Source Ventilator Look Like?

April 9, 2020 by Mike Szczys 61 Comments

Ventilators are key in the treating the most dire cases of coronavirus. The exponential growth of infections, and the number of patients in respiratory distress, has outpaced the number of available ventilators. In times of crisis, everyone looks for ways they can help, and one of the ways the hardware community has responded is in work toward a ventilator design that can be rapidly manufactured to meet the need.

The difficult truth is that the complexity of ventilator features needed to treat the sickest patients makes a bootstrapped design incredibly difficult, and I believe impossible to achieve in quantity on this timeline. Still, a well-engineered and clinically approved open source ventilator might deliver many benefits beyond the current crisis. Let’s take a look at some of the efforts we’ve been seeing recently and what it would take to pull together a complete design.

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Real Engineering Behind Ventilators

April 7, 2020 by Al Williams 40 Comments

Experts on cognition tell us that most people think they know more than they really do. One particular indicator for that is if someone is an expert in one field and they feel like all other fields relate to theirs (everything boils down to math or chemistry or physics, for example). This causes them to be overconfident on things they don’t actually know about. When it became clear that the current virus crisis might lead to a shortage of ventilators, many electronic experts set about to design low-cost easy to replicate ventilators. How hard is it, after all, to squeeze a bag once every few seconds? But it turns out, there are a lot of details you need to know to do it right. [Real Engineering] and [Real Science] joined to create an excellent video that covers a lot of what you need to know. You can see the video below. The video shows a few designs that — while motivated by altruism — would probably do more harm than good if used on real patients.

The video’s creator is a biomedical engineer who worked in the past for Medtronic — a maker of ventilators who, by the way, recently open-sourced one of their designs. They also had [Dr. Rohin Francis], who has a medical YouTube channel, fact check the video. and provide some on-screen background We learned a few new medical terms and found that a high-end ventilator made in one factory gets built at about 225 per week. They think they can increase to 500.

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Reliability Check: Consumer And Research-Grade Wrist-Worn Heart Rate Monitors

April 7, 2020 by Orlando Hoilett 12 Comments

Wearables are ubiquitous in today’s society. Such devices have evolved in their capabilities from step counters to devices that measure calories burnt, sleep, and heart rate. It’s pretty common to meet people using a wearable or two to track their fitness goals. However, a big question remains unanswered. How accurate are these wearable devices? Researchers from the Big Ideas Lab evaluated a group of wearables to assess their accuracy in measuring heart rate.

Unlike other studies with similar intentions, the Big Ideas Lab specifically wanted to address whether skin color had an effect on the accuracy of the heart rate measurements, and an FDA-cleared Bittium Faros 180 electrocardiogram was used as the benchmark. Overall, the researchers found that there was no difference in accuracy across skin tones, meaning that the same wearable will measure heart rate on a darker skin-toned individual the same as it would on a lighter skin-toned. Phew!

However, that may be the only good news for those wanting to use their wearable to accurately monitor their heart rate. The researchers found the overall accuracy of the devices relative to ECG was a bit variable with average errors of 7.2 beats per minute (BPM) in the consumer-grade wearables and 13.9 BPM in the research-grade wearables at rest. During activity, errors in the consumer-grade wearables climbed to an average of 10.2 BPM and 15.9 in the research-grade wearables. It’s interesting to see that the research-grade devices actually performed worse than the consumer devices.

And there’s a silver lining if you’re an Apple user. The Apple Watch performed consistently better than all other devices with mean errors between 4-5 BPM during rest and during activity, unless you’re breathing deeply, which threw the Apple for a loop.

So, it seems as if wrist-worn heart rate monitors still have some work to do where accuracy is concerned. Although skin tone isn’t a worry, they all become less accurate when the subject is moving around.

If you’d like to try your own hand with fitness trackers, have a look at this completely open project, or go for the gold standard with a wearable DIY ECG.