Okay, thank you everybody for being here.
I know it's the end of the day, it's been a long day.
So thank you.
I'd like to talk about the Polyvent Free Libre Open Source ventilator.
This is hardware in a little different sense than is used in this room.
Normally when you say hardware at this conference, you mean chips and VLSI stuff, but this is
an electromechanical hardware device.
This talk is co-authored with Dr. Victor Sutrin.
Victor, can you raise your hand?
And Antal Zeiderwick is our chief mechanical engineer for the chassis part.
If you meet us after the talk, we'll be happy to answer questions for you.
And we are trying to recruit software engineers and electrical and mechanical engineers to
work on the project as well.
So I am Robert Reed.
I'm the founder of Public Invention, which is a US 501C3 public charity.
Our motto is to invent in the public for the public.
I think this conference will appreciate that we're trying to take the principles of open
source software development and apply it not only to chip design, but to actual hardware
inventions.
So I'd like to create a setting in the spring of 2020 in the United States.
So many people had died of COVID-19 so quickly in New York that they had to use refrigerated
trucks as temporary morts for that purpose.
At that time, there was a genuine belief that the Western world might need a million mechanical
ventilators to try to keep people alive.
That turned out not to be true, but it wasn't erroneous at the time based on what we knew
from the disease progression in northern Italy.
What we didn't know at the time was that social distancing and lockdowns would work,
and also doctors decided they didn't need to ventilate paper people as early with COVID
as they had previously thought.
Nonetheless, a very large number of humanitarian engineering teams all over the world attempted
to make emergency ventilators to solve this problem.
It was kind of a global effort, and Victor and a young man who was 16 at the time started
working on their own ventilator in the same effort.
Now they started with a bellows-based design, we're going to talk about that.
The thing they designed, the polyvent, was specifically designed to talk about fragile
supply chains.
So it was designed to be constructable within a low and middle income country, and that's
one reason they went with bellows in the initial design.
Originally, they weren't necessarily embracing open-source licensing because they didn't know
that much about it, and everyone sort of believed, well, we're going to need large firms to
make a lot of money, and if you have an open-source license on it, they won't want to use your
product.
Now, how do we know that 100 humanitarian engineering teams started?
Because public invention evaluated all of them.
So we made a spreadsheet which evaluated all of the open-source ventilators along a wide
variety of dimensions here.
Now at the time, and still today, what we're trying to do is to create open-source medical
devices.
That is harder than making open-source hardware, which is harder than making open-source software,
which is harder than copywriting text, both from a legal point of view and from an intellectual
point of view.
The cost of development for medical things goes up because you're attempting to produce
regulated devices.
Now originally, the Polyvent team was attempting to do that, but at that time in the United
States, there was an emergency youth authorization.
So there was a belief that we might not need to do all the things that the FDA would normally
require.
So while this was going on, public invention published the Open Medical Technology Manifesto,
which is that open, shareable, repairable medical technology will make us all healthier.
The Polyvent ventilator is aligned with that, and I invite you all to find this and sign
it if you agree with it.
So the Polyvent team began working on a ventilator, and they had some success in Lens, and they
designed a very extensible system that we're going to talk about.
But the global pandemic urgency was dissipating by about six months from that spring.
So by October of that first year, people were no longer excited about the idea.
So the thing that I'm most proud of perhaps of this team is that they just kept going
and continued to develop the ventilator.
So at that time, they joined public invention basically in exchange for making it fully
open source, public invention began to start paying for parts and manual labor to support
the development of the ventilator.
It's also the case that I'm mostly a software guy, another non-profit helpful engineering
had the VentOS software, which we're going to talk about, and the existing team didn't
have any software.
So it was a nice alliance.
This is their original system.
This is a fully functional ventilator.
It uses dual bellows here.
Bellows can be manufactured with 3D printers.
So they can presumably be made in any country was the idea.
However, there were some problems.
The bearings to drive the bellows up and down tended to wear out.
And there were some other improvements possible.
We started to make those improvements.
The big switch we made was to switch to a proportional valve based system that used pressurized air
and pressurized oxygen.
This was inspired by Smith College in the United States, which is probably the premier
of women's college in the United States.
They had made an award-winning ventilator called the Smith Vent.
They stopped.
I don't know why, but we continued and have used the same basic technology.
Now we already had a spirometer, the VentMon, which was made by public invention.
We used that as part of our system, and eventually we started to redesign for education.
We started with the proportional valve on the left, which is a Birket proportional valve.
It was really kind of an engineering mistake because it was larger than what we needed
and the airflow was not as precise as what we needed.
The valve on the right is difficult to source, it's made in the United States by IQ valve.
It's a very precisely controlled proportional valve.
Like all projects, we learned as we went along.
This was what we called the Polyvent One, even though it's after the Velo's module.
This was, again, fully functional.
We performed some tests with professors of education in biomedical engineering.
This system worked, but we decided to redesign it for education.
So while this was going on, the COVID pandemic continues.
In India, around this time, there was a terrible, terrible spike of death.
Now this was not due to a lack of ventilators.
People say it was due to a lack of oxygen.
We have also, public invention have also worked on an oxygen concentrate.
The reason I bring it up is that what we're attempting to do and what many of you are
attempting to do in the software that you produce is to make the world better for a
lot of people.
Making open source medical devices is a new way, a new avenue for open source philosophy
to make the world better for a very large number of people.
It's quite a technical challenge, but that's why we're doing it.
So based on educator feedback, we made a lighter single deck design.
We made a transparent case.
We made the inside spacious and modular so that students could look at it and you could
also repair it more easily.
You didn't have to take the whole thing apart.
That is very different than the way professionally designed medical equipment is made.
It's not made to be easy to repair.
It's not made to be easy to understand.
So it's quite a departure from what you would see in a normal for profit sort of made device.
We also, Nathaniel did a really good job designing a modular card based electronic control system.
And this actually paid off when a second public invention team created a card that we were
able to put into the device to control a general purpose alarm device, which we're working
on.
So that team did that with no interaction with Victor's team just based on the documentation
that we have.
So this is the timeline and we've been getting better and better as we go along like most
projects.
In October, we did a classroom evaluation with 12 biomedical engineering students at
Rice University in Houston, Texas in the United States.
This is the device as it stands today.
This is the Polyvent 2.
That's what the students looked used.
As you can see, it actually uses an acrylic case so you can see all of the components.
And I don't have a good layout diagram, but it's laid out in a way where it's physically
modular as well as being electronically modular.
The software is too, of course, because we learned a lot from the open source software
community on how to do this.
So it's now our intention with the Polyvent to continue to eventually make a design basis
that can be used for a medical ventilator.
But we believe that by sort of infiltrating the research and education community, we have
a better shot of eventually accomplishing that.
So the Polyvent platform right now is for medical and veterinary doctors, but really
it's for biomedical engineering students, even you can teach business school classes
on it.
You can certainly do mechanical electrical engineering software engineering.
And we consider ourselves firmly part of the emerging discipline of humanitarian engineering.
So what we did to make the classroom instructor, I am not a teacher.
I'm mostly a computer programmer, is we made fake broken parts and we asked the students
to turn their backs and we would install a fake broken part and then they would attempt
to find it.
Now this class they were taking is in fact a troubleshooting class.
So it worked rather well and of the 12 students who were there, they really strongly believe
that this would be useful in other universities.
So it's our hope to sort of sell this at cost, even though it's completely open source.
We could make it if they wanted to, all the physical designs, all the software designs
are completely open, but making things like this in hardware requires, as one of the gentlemen
in the previous talk, a certain amount of tooling and so forth.
So people like a graduate school may find it easier to pay us $5,000 for one of these,
which is sort of the hardware costs are about $2,000 and it takes some labor to put it together.
It's kind of the cost for us to make it rather than build one themselves.
But they could, they can build it and modify it themselves based on licenses that I'm
sure you're all familiar with.
So this is kind of a schematic of the design that you saw there physically and the thing
that's most important is Nathaniel did a really good job designing an electronic extensible
card system.
And this is based on an IEEE standard I'm not familiar with, but basically you plug
slots into it and it exposes pins of the ESP32.
So if you have a device that you would like to add to the ventilator, like a humidifier,
a nebulizer, a heater, an additional set of instrumentation, you can just design a card
and stick it in there.
And that's what the general purpose alarm device team of public convention did.
This is a physical photograph of how those things slide in there.
This card right here is a card with a bunch of power transistors which control the solenoid
valves which are in the system.
Because obviously it takes 24 volts to do that.
So now I'd like to talk about software.
The software system is called Vint OS.
I didn't name it, really it's not an operating system.
But we kind of think of it that way.
It runs on an ESP32 and it was created by a different non-profit, which I'm a board
member, helpful at engineering, and some other people worked on it, in particular Ben Coons.
Now interestingly, this was forked to make an oxygen concentrator, which we have since
quit working on, called the AUX.
But that was forked to be used by me for NASA, the U.S. National Aeronautics and Space Administration,
to make a control system for a high-tech ceramic oxygen generator.
So a lot of times, as I'm sure you guys understand, open source code lives even if its initial
purpose is not met.
If you write good code that's documented with a good license, you can use it for some
other purpose and we're trying to do that.
In fact, Ben made a number of improvements that really need to come back into Vint OS
and I kind of need a volunteer to help me do that because there's always more software
work to be done.
So the Vint OS architecture, and this is where we're really talking about an embedded system
that you guys will understand, is a simple Arduino platform compiled with PlatformIO.
Configuration modes in PlatformIO set pre-processed with compile time switches, which give us
a wide variety of hardware architectures we can compile into, although the PolyVent is
effectively the only machine on which it really runs today, but we could support other architectures.
It almost doesn't run on an Arduino Uno because it's too big, but technically it will run
on an Uno.
We use an ESP32.
We have a pretty good hardware abstraction layer.
The basic architecture is what's called a superloop or simple loop architecture and
we believe that's appropriate for a life-critical medical device like the one that we're designing.
So Vint OS claims to be a operating system that is universal.
It's a universal platform for mechanical human ventilation.
How is that possible?
Well it's possible because all ventilators do almost exactly the same thing.
They're relatively straightforward.
They're simple devices.
Simple doesn't mean easy because if you do something wrong the patient dies, but they
are still relatively simple devices.
Thank you.
In particular, doctors normally want to vary the breasts per minute.
As you become sicker you require more breasts per minute.
You hope that doesn't happen.
The inhalation time and the exhalation time ratio is varied for the comfort of the patient.
If you are approaching death they may have to make that what would be very uncomfortable
for a healthy person to try to keep you alive.
Pressure control ventilation keeps constant pressure through the inhalation.
You want that pressure to be low because high pressure can cause damage to your lungs.
But as you approach death that pressure may have to go up to try to keep you alive.
Doctors, I'm not a medical doctor, Victor is a physiologist, not a medical doctor.
Clinicians know how to balance these things.
It's our desire to give them the power to do that.
Basically you just blow air into the patient's lungs and then you stop and the lungs deflate
on their own.
That's the way positive pressure ventilation works.
It's simple but you have to control all these things.
This is sort of a diagram of a universal ventilator.
All ventilators are sort of the same in this sense.
There's an air drive which produces air in one way or another and that's the most mechanical
system that's part of it.
There's a sense module and ours is completely separated in the sense that we use the Ventmon
which is a separate device that we would like to productize.
We gave a bunch away because we had a grant to give them away but it's basically a spirometer.
It measures everything about human breath and if you connect it to the ventilator it
allows you to see what the ventilator is doing.
A controller is what this room would think of as the embedded system.
That's where VentOS runs.
Our interface is we use a Internet of Things based public data cloud and we're still working
on aspects of the clinical interface.
If we think about philosophy, the Unix way, and of course I didn't write this, this is
on Wikipedia you can find us, is to write programs that do one thing and do it well,
write programs to work together, and write programs to handle text streams because they're
a universal interface.
This is from the 70s.
This is very old philosophy which has served the world in good stead because Linux and
open source software is eating the world.
How do you apply the same things to the kinds of electromechanical devices that we're building?
There aren't even chips.
They're moving air around.
Well, you attempt to do the same thing.
You build machines that do one thing and do it well.
That is not the way Johnson and Johnson would build a ventilator.
They would put everything in the same case but we're not Johnson to Johnson, right?
We can do something different.
We make a physically separated device where physical components handle one component at
a time and then they're integrated in a soft way.
By using digital control, we make them all roboticizable or controllable by a controller
so that we can use them and they can be reused in that way.
In my experience, instead of handling text streams, the modern way to do this is you
handle JSON objects that are communicated either via SPI or I squared C and that's kind
of a universal control language that's easy for both programmers and the hardware devices
to understand.
How realistic is this?
That's debatable because we're nowhere close to having an FDA-based ventilator at the moment.
However, we have done a lot with very little money.
We built the Ventmon which is kind of our most realized device because it's much easier
than a ventilator, right?
VentOS is an existing operating system, Polyvent is a ventilator.
I'm very proud that we've defined two data standards based on JSON, the public invention
respiratory data standard and the public invention respiratory control standard.
Now, as you guys, I'm going to come back to this but as you guys know, progress is often
made through defining standards.
It's often not very glamorous to do so but the work of defining the standards is really
what allows other people to take your work and utilize it in a standard way.
In this case, we've done work that has not been recognized.
No one else is using these standards yet but I hope that will change.
We tried to build an oxygen concentrator.
We sort of stopped working on that.
We also have vent display which gives a complete dynamic display of breath plots and the things
that clinicians need to do.
So if we map that to our diagram here, what we find is that the device that we're calling
the ventilator really could be thought of as an air drive.
It's the part that makes the air.
We have a separate device, the Ventmon, which can be used as a sense module and we have
a separate set of programs which happens to be an IoT defined public lake and some JavaScript
that runs in a browser to do the clinical GUI aspects of the system.
We're also designing a general purpose alarm device as I'm sure you understand in any
intensive care unit, thank you, situation you have to produce alarms when the patient
needs care.
Now, that can occur because your machine has broken or the battery has failed or you've
run out of power or someone has tripped over a hose but then that happens a lot but it
also can occur simply because the patient's condition is deteriorating.
In any case, you have to be able to produce a device which can generically alert people
to the fact that something has to be done.
While following the UNIX way adopted the hardware, our idea is to make a separately packageable
device that could be used for a cap door or a burglar alarm or all kinds of other devices
in hopes that we can build a community of practice using that which will strengthen
the use for medical alerts.
This is the software that I was talking about.
This runs in a browser.
This is what is produced by the Ventmon.
I probably should be showing a video but this is actually dynamic as the machine breeze
or the patient breeze, you're seeing the pressure flow and various events like the measurement
of the humidity and temperature, the end of the breath, the beginning of the breath.
What you have on the right here is what a doctor in an ICU would typically compute about
the breath traces.
This is not super sophisticated but the thing that I really like about it is it runs in
a browser so it's distributed generally and then secondly the software functionality
of doing all those computations completely separated from the ventilator.
In most devices this is built into the panel of the ventilator and cannot be reused in
any other way.
Lots of the things we've been talking about, VentOS can claim to be a universal system
because it implements a hardware abstraction layer that lets you interface to turbines,
fans, in our case proportional valves, bellows, other ways of producing gas.
Following the open source methodology, it's not so much a machine as an ecosystem.
We're trying to build a respiration ecosystem.
As we've said, we've already seen that one piece of functionality has been added as a
PCB that's put into the control module and that is an SPI interface to the general purpose
alarm device which I mentioned previously.
You might say, well why on earth would we ever have a respiration ecosystem?
Well, there's a good reason from kind of a patient point of view which is all of these
devices which accomplish various medical purposes, a ventilator, an O2 concentrator, a by level
positive pressure air wave machine, a CPAP machine, a PAPR, a bag valve mass monitor,
all of those essentially need standards of respiration data exchange which we have developed
but nobody else has used and many of them need the same sense module that we've been
talking about in the Vintmont.
In that sense, if you think of the way open source software has made components that work
together really effectively, what we're trying to do is to create hardware and software components
integrated which work together as effectively in the realm of human respiration.
In a sense, we're trying to democratize the field of medical respiration and education
around it.
Open source software has already shown us the way.
We're just taking things that were developed by open source software and attempting to
apply them to hardware.
In particular, as I'm sure you guys know, the development of standards like HTTP, HTML,
JSON, etc. are absolutely critical to the progress and interaction of multiple components
in the embedded architecture world but open source software more generally.
We're trying to accomplish the same thing by producing respiration standards.
These of course exist in GitHub repos.
Thank you very much.
In short, we built the most open, extensible ecosystem for a classroom.
It's the most open, best documented system.
I can claim that because I evaluated all of the other ones.
There are other open source ventilators but you cannot find their designs online.
They're not really open.
They're just thinking about being open.
That concludes my talk.
Thank you very much.