Medical device company Medtronic released designs for one of their ventilators to open source for use in the COVID-19 pandemic. This is a laudable action, and there is plenty to glean from the specs (notable is that the planned release is incomplete as of this writing, so more info is on the way). Some initial reactions: medical devices are complicated, requirements specifications are enormous, the bill of materials (BOM) is gigantic, and component sourcing, supply chain, assembly, and testing are just as vital as the design itself.
The pessimist in me says that this design was open sourced for two reasons; to capitalize on an opportunity to get some good press, and to flex in front of the DIY community and convince them that the big boys should be the ones solving the ventilator shortage. The likelihood of anyone actually taking these specs and building it as designed are essentially zero for a variety of reasons, but let’s assume their intent is to give a good starting point for newer changes. The optimist in me says that after what happened to California over the weekend with 170 ventilators arriving broken, it might be nice to have open designs to aid in repair of existing non-functioning ventilators.
The design details released today are for their PB560 model, which was originally launched in 2010 by a company called Covidien, before it merged with Medtronic, so we’re already starting with a device design that’s a decade old. But it’s also a design that has proven itself through widespread use, and this data dump gives us a great look at what actually goes into one of these machines. Let’s take a look.
Treating the most serious cases of COVID-19 calls for the use of ventilators. We’ve all heard this, and also that there is a shortage of these devices. But there is not one single type of ventilator, and that type of machine is not the only option when it comes to assisted breathing being used in treatment. Information is power and having better grasp on this topic will help us all better understand the situation.
We recently wrote about a Facebook group focused on open source ventilators and other technology that could assist in the COVID-19 pandemic. There was an outpouring of support, and while the community is great when it comes to building things, it’s clear we all need more information about the problems doctors are currently dealing with, and how existing equipment was designed to address them.
It’s a long and complicated topic, though, so go get what’s left of your quarantine snacks and let’s dig in.
In January 2019 I gave a presentation at Nerd Nite about my experience selling Wacky Dancers on Amazon. There’s no video, but someone recorded audio. I finally got around to syncing it with my slides, so if you didn’t get to see it then, here’s as close a chance as you’ll get. Also, an update since then; we’ve sold over 450 dancers, and are no longer offering our product for sale since we have no more inventory.
Technology frequently looks at nature to make improvements in efficiency, and we may be nearing a new breakthrough in copying how nature stores data. Maybe some day your thumb drive will be your actual thumb. The entire works of Shakespeare could be stored in an infinite number of monkeys. DNA could become a data storage mechanism! With all the sensationalism surrounding this frontier, it seems like a dose of reality is in order.
The human genome, with 3 billion base pairs can store up to 750MB of data. In reality every cell has two sets of chromosomes, so nearly every human cell has 1.5GB of data shoved inside. You could pack 165 billion cells into the volume of a microSD card, which equates to 165 exobytes, and that’s if you keep all the overhead of the rest of the cell and not just the DNA. That’s without any kind of optimizing for data storage, too.
This kind of data density is far beyond our current digital storage capabilities. Storing nearly infinite data onto extremely small cells could change everything. Beyond the volume, there’s also the promise of longevity and replication, maintaining a permanent record that can’t get lost and is easily transferred (like medical records), and even an element of subterfuge or data transportation, as well as the ability to design self-replicating machines whose purpose is to disseminate information broadly.
So, where is the state of the art in DNA data storage? There’s plenty of promise, but does it actually work?
2020 is a year of reflection and avoiding regret, and one of the biggest practices we all know we should do better is back up our data. Inevitably there will be a corruption or accident, and we mourn the loss of some valuable data and vow to never let it happen again, and then promptly forget about good data retention practices.
I believe life is about acquiring memories, so it makes sense to me to try to archive and store those memories so that I can reflect on them later, but data storage and management is a huge pain. There’s got to be a better way (cue black and white video of clumsy person throwing up arms in disgust).
Assembly lines for electronics products are complicated beasts, often composed of many custom tools and fixtures. Typically a microcontroller must be programmed with firmware, and the circuit board tested before assembly into the enclosure, followed by functional testing afterwards before putting it in a box. These test platforms can be very expensive, easily into the tens of thousands of dollars. Instead, this project uses a set of 12 Raspberry Pi Zero Ws in parallel to program, test, and configure up to 12 units at once before moving on to the next stage in assembly.
There’s a newish development in the world of keyboards; the optical switch. It’s been around for a couple years in desktop keyboards, and recently became available on a laptop keyboard as well. These are not replacements for your standard $7 keyboard with rubber membrane switches intended for puttering around on your raspberry pi. Their goal is the gamer market.
The question, though, is are these the equivalent of Monster Cables for audiophiles: overpriced status symbols? Betteridge would be proud; the short answer is that no, there is a legitimate advantage, and for certain types of use, it makes a lot of sense.
If you came here from an internet search because your battery just blew up and you don’t know how to put out the fire, then use a regular fire extinguisher if it’s plugged in to an outlet, or a fire extinguisher or water if it is not plugged in. Get out if there is a lot of smoke. For everyone else, keep reading.
I recently developed a product that used three 18650 cells. This battery pack had its own overvoltage, undervoltage, and overcurrent protection circuitry. On top of that my design incorporated a PTC fuse, and on top of that I had a current sensing circuit monitored by the microcontroller that controlled the board. When it comes to Li-Ion batteries, you don’t want to mess around. They pack a lot of energy, and if something goes wrong, they can experience thermal runaway, which is another word for blowing up and spreading fire and toxic gasses all over. So how do you take care of them, and what do you do when things go poorly?