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.
As with so many devices, it’s easier for the manufacturer to make one base model, nerf most of the features, then charge more to un-nerf them. Multimeters, oscilliscopes, and now cpap machines.
For the medical corporation CEOs out there working on how to sell life supporting gizmos, bear in mind that ‘Repo: the Genetic Opera’ was an entertaining bit of fiction, not a business model. Failing to pay more for the same device should not result in living your life with nerfed lifesaving functions.
Whilst that’s true, it’s also common for devices which fail some QA or which have bad tolerance to be sold as lower spec. So check before you make accusations on a particular device. Or before you reflash something to enable the feature that was disabled because it was unsafe.
It may well also be that devices which do one thing are safer in a medical setting, rather than the device reporting it’s working correctly but being in the wrong mode.
nice — but sorry. the damn boards are identical. I’m looking at 4 samples and they’re the same damn boards. same MCUs, same sensors, same everything down to the last resistor. So stop trying to protect your company from the inevitable fall that is coming from the DoJ.
Yeah, not going to put alcohol into the tank of my CPAP. The air doesn’t go through the water, there is a heater under the tank that heats the water to raise the humidity of the air going into the mask.
Yeah, my comment was, “tongue in cheek”.
But, the UV-C lamp posting has me wondering about building a germicidal lamp enclosure at the air intake…
And breathe ozone?
The Aircurve 10S is the same design as the unit mentioned in the article, but operates in bipap mode.
This is nice, but it’s being way over egged by the blog. This modification doesn’t take the model anywhere close to being a useful ventilator and hardware modification would be required which of course as the manufactorer says will be difficult.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/879382/RMVS001_v4.pdf
This supports up to 30mmH2O, Not the minimum upper end of 40mmH2O as required by UK guideance on rapid veniltators for COVID.
Not too mention BiPAP is a “should” requirement so it wouldn’t even be classed as a ventilator by the requirements issued.
No doubt CPAP might be handy especially as these low pressure compressor CPAPs take the strain off hospital O2 supply.
But they also flood the air with virus which is pretty scary.
The question then is – is this poor man’s BiPAP more useful than the original intended CPAP? And does that benefit justify the risk of this rushed modification (talking about a manufactorer mod subbmited by FDA even).
I think the feeling at the moment is No. It’s not.
Some research has been published that address the excessive pressure of the current ventilators is too high for the lungs to take with the amount of capacity for the cells to have to absorbe. The capacity of the lung cells in CV patients has been decreased by 50 % or so. Using the standard pressure settings may damage the cells more than help. Non medical person but a CPAP user.
Every arrow in your bow is great I suppose, but like you say covid patients require delicate titration that’s why the the F1 CPAP machines were rejected don’t know if this would be most useful.
The idea that a software guru understands the hardware or medical licensing requirements and testing is rich to me.
Could CPAP machines be used to help surveilance for covid19/influenza like illness?
Makers of a smart thermometer found that by mapping anonymous data on elevated temperature they could predict influenza infection levels, and they observed atypical levels which seem to correlate with covid19. Researchers are looking at fitness tracker data to see if they could detect covid19. Some have proposed using smart speakers to detect cough frequency.
There are a few million CPAP machines measuring people’s breathing nightly.
Could these machines be used to detect coughs?
Could patterns of changes in respiration (increased rate, coughs, etc.) be detected,
and gathered by cell network to help detect ILI/covid outbreaks?
(Directing to areas where additional viral testing might be beneficial.)
My experience is with my Adaptive PAP machine that automatically adjusts to my breathing during the night. This type of service may be easily adapted to ventalation usage.
The housings are plastic with a filtered air intake port that can easily be able to accept the mounting brackets for an O2 line.
Far to many people are diying with out the PROPER equipment so maybe some Field Expedite modafications may be in order.
https://www.leeds.ac.uk/news/article/4573/simple_fix_creates_coronavirus_breathing_aids