Teardown: Orthofix SpinalStim

August 5, 2020 by Tom Nardi 55 Comments

If you’ve ever had a particularly nasty fracture, your doctor may have prescribed the use of an electronic bone growth stimulator. These wearable devices produce a pulsed electromagnetic field (PEMF) around the bone, which has been shown to speed up the natural healing process in a statistically significant number of patients. That’s not to say there isn’t a debate about how effective they actually are, but studies haven’t shown any downsides to the therapy, so it’s worth trying at least.

When you receive one of these devices, it will be programmed to only operate for a certain amount of time or number of sessions. Once you’ve “used up” the bone stimulator, it’s functionally worthless. As you might imagine, there’s no technical reason this has to be the case. The cynic would say the only reason these devices have an expiration date on them is because the manufacturer wants to keep them from hitting the second hand market, but such a debate is perhaps outside the scope of these pages.

The Orthofix SpinalStim you’re seeing here was given to me by a friend after their doctor said the therapy could be cut short. This provided a somewhat rare opportunity to observe the device before it deactivated itself, which I’d hoped would let me take a closer look at how it actually operated.

As you’ll soon see, things unfortunately didn’t work out that way. But that doesn’t mean the effort was fruitless, and there may yet be hope for hacking these devices should anyone feel like taking up the challenge.

Continue reading “Teardown: Orthofix SpinalStim” →

COVID Tracing Apps: What Europe Has Done Right, And Wrong

August 3, 2020 by Elliot Williams 63 Comments

Europe has been in COVID-containment mode for the last month, in contrast to the prior three months of serious lockdown. Kids went back to school, in shifts, and people went on vacation to countries with similarly low infection rates. Legoland and the zoo opened back up, capped at 1/3 capacity. Hardware stores and post offices are running “normally” once you’ve accommodated mandatory masks and 1.5 meter separations while standing in line as “normal”. To make up for the fact that half of the tables have to be left empty, most restaurants have sprawled out onto their terraces. It’s not really normal, but it’s also no longer horrible.

But even a country that’s doing very well like Germany, where I live, has a few hundred to a thousand new cases per day. If these are left to spread unchecked as before, the possibility of a second wave is very real, hence the mask-and-distance routine. The various European COVID-tracing apps were rolled out with this backdrop of a looming pandemic that’s tenuously under control. While nobody expects the apps to replace public distancing, they also stand to help if they can catch new and asymptomatic cases before they get passed on.

When Google and Apple introduced their frameworks for tracing apps, I took a technical look at them. My conclusion was that the infrastructure was sound, but that the implementation details would be where all of the dragons lay in wait. Not surprisingly, I was right!

Here’s an update on what’s happened in the first month of Europe’s experience with COVID-tracing apps. The good news is that the apps seem to be well written and based on the aforementioned solid foundation. Many, many people have installed at least one of the apps, and despite some quite serious growing pains, they seem to be mostly functioning as they should. The bad news is that, due to its privacy-preserving nature, nobody knows how many people have received warnings, or what effect, if any, the app is having on the infection rate. You certainly can’t see an “app effect” in the new daily cases rate. After a month of hard coding work and extreme public goodwill, it may be that cellphone apps just aren’t the panacea some had hoped.

Continue reading “COVID Tracing Apps: What Europe Has Done Right, And Wrong” →

Folding@Home And Rosetta, For ARM

August 2, 2020 by Jenny List 19 Comments

Most readers will be aware of the various distributed computing projects that provide supercomputer-level resources to researchers by farming out the computing tasks across a multitude of distributed CPUs and GPUs. The best known of these are probably Folding@Home and Rosetta, which have both this year been performing sterling service in the quest to understand the mechanisms of the SARS COVID-19 virus. So far these two platforms have remained available nearly exclusively for Intel-derived architectures, leaving the vast number of ARM-based devices out in the cold. It’s something the commercial distributed-computing-on-your-phone company Neocortix have addressed, as they have successfully produced ARM64 clients for both platforms that will be incorporated into the official clients in due course.

So it seems that mundane devices such as mobile phones and the more capable Raspberry Pi boards will now be able to fold proteins like a boss, and the overall efforts to deliver computational research will receive a welcome boost. But will there be any other benefits? It’s a Received Opinion that ARM chips are more power-efficient than their Intel-derived cousins, but will this deliver more energy-efficient distributed computing? The answer is “probably”, but the jury’s out on that one as computationally intensive tasks are said to erode the advantage significantly.

Folding@Home was catapulted by the influx of COVID-19 volunteers into first place as the world’s largest supercomputer earlier this year, and we’re pleased to say that Hackaday readers have played their part in that story. As this is being written the July 2020 stats show our team ranked at #39 worldwide, having racked up 14,005,664,882 points across 824,842 work units. Well done everybody, and we look forward to your ARM phones and other devices boosting that figure. If you haven’t done so yet, download the client and join us..

Via HPCwire. Thanks to our colleague [Sophi] for the tip.

Sanitizer Dispenser Does It Hands-Free

July 31, 2020 by Lewin Day 11 Comments

Hand sanitizer is the hot product of 2020, and it seems nobody can get enough. In the same way that touching a dirty tap takes the shine off washing your hands in a public bathroom, one wishes to avoid touching the hand sanitizer bottle entirely. To get around this, [makendo] whipped up a quick solution.

The solution consists of a 3D printed caddy which holds a typical bottle of hand sanitizer. This is affixed to a wall with either screws or double sided tape. A long string is then attached to the dispenser nozzle, and passes down to a foot pedal. By depressing the pedal, it pulls on the string, pulling down the dispenser nozzle and delivering the required sanitizer to the hands.

It’s by no means an advanced hack, but one that can be whipped up in a short time to make sanitizing one’s hands just that little bit more pain-free. If you’re still short on sanitizer, you might want to make your own. If you do, let us know how it goes. Otherwise, consider alternate methods of automating the delivery!

Microwave Modified For Disinfecting

July 24, 2020 by Bryan Cockfield 29 Comments

We’re all hopefully a little more concerned about health these days, but with that concern comes a growing demand for products like hand sanitizer, disinfectant, and masks. Some masks are supposed to be single-use only, but with the shortage [Bob] thought it would be good if there were a way to sanitize things like masks without ruining them. He was able to modify a microwave oven to do just that.

His microwave doesn’t have a magnetron anymore, which is the part that actually produces the microwaves for cooking. In its place is an ultraviolet light which has been shown to be effective at neutralizing viruses. The mask is simply placed in the microwave and sterilized with the light. He did have to make some other modifications as well since the magnetron isn’t always powered up when cooking, so instead he wired the light into the circuit for the turntable so that it’s always powered on.

Since UV can be harmful, placing it in the microwave’s enclosure like this certainly limits risks. However, we’d like to point out that the mesh on the microwave door is specifically designed to block microwaves rather than light of any kind, and that you probably shouldn’t put your face up to the door while this thing is operating. Some other similar builds have addressed this issue. Still, it’s a great way to get some extra use out of your PPE.

DIY Dongle Breathes Life Into Broken Ventilators

July 15, 2020 by Kristina Panos 51 Comments

We have a new hero in the COVID-19 saga, and it’s some hacker in Poland. Whoever this person is, they are making bootleg dongles that let ventilator refurbishers circumvent lockdown software so they can repair broken ventilators bought from the secondhand market.

The dongle is a DIY copy of one that Medtronic makes, which of course they don’t sell to anyone. It makes a three-way connection between the patient’s monitor, a breath delivery system, and a computer, and lets technicians sync software between two broken machines so they can be Frankensteined into a single working ventilator. The company open-sourced an older model at the end of March, but this was widely viewed as a PR stunt.

This is not just the latest chapter in the right-to-repair saga. What began with locked-down tractors and phones has taken a serious turn as hospitals are filled to capacity with COVID-19 patients, many of whom will die without access to a ventilator. Not only is there a shortage of ventilators, but many of the companies that make them are refusing outside repair techs’ access to manuals and parts.

These companies insist that their own in-house technicians be the only ones who touch the machines, and many are not afraid to admit that they consider the ventilators to be their property long after the sale has been made. The ridiculousness of that aside, they don’t have the manpower to fix all the broken ventilators, and the people don’t have the time to wait on them.

We wish we could share the dongle schematic with our readers, but alas we do not have it. Hopefully it will show up on iFixit soon alongside all the ventilator manuals and schematics that have been compiled and centralized since the pandemic took off. In the meantime, you can take Ventilators 101 from our own [Bob Baddeley], and then find out what kind of engineering goes into them.

DIY Filtered Positive Pressure Suit Shows Fine Workmanship

July 3, 2020 by Donald Papp 19 Comments

[Andrew]’s Air filtering unit & positive pressure supply might look like something off the set of Ghostbusters, but it’s an experiment in making a makeshift (but feasible) positive pressure suit. The idea is to provide an excess of filtered air to what is essentially an inflatable soft helmet. The wearer can breathe filtered air while the positive pressure means nothing else gets in. It’s definitely an involved build that uses some specific hardware he had on hand, but the workmanship is great and shows some thoughtful design elements.

The unit has three stacked filters that can be easily swapped. The first stage is medical mask material, intended to catch most large particles, which is supported by a honeycomb frame. The next filter is an off-the-shelf HEPA filter sealed with a gasket; these are available in a wide variety of sizes and shapes so [Andrew] selected one that was a good fit. The third and final stage is an activated carbon filter that, like the first stage, is supported by a honeycomb frame. The idea is that air that makes it through all three filters is safe (or at least safer) to breathe. There isn’t any need for the helmet part to be leakproof, because the positive pressure relative to the environment means nothing gets in.

Air is sucked through the filters and moved to the helmet by an HP BLc7000 server fan unit, which he had on hand but are also readily available on eBay. These fan units are capable of shoveling a surprising amount of air, if one doesn’t mind a surprising amount of noise in the process, so while stacked filter stages certainly impede airflow, the fan unit handles it easily. The BLc7000 isn’t a simple DC motor and requires a driver, so for reference [Andrew] has a short YouTube video of how the fan works and acts.

All the 3D models and design files are available online should anyone wish to take a closer look. It’s certainly a neat experiment in making a filtered positive pressure supply and head cover with materials that are fairly common. If [Andrew] ever wants to move to a whole-body suit, maybe repurpose an old Halloween costume into a serviceable positive pressure suit.