
Pandemic Ventilator Project - mhb
https://panvent.blogspot.com/
======
semi-extrinsic
I've been looking over the designs being put forward in the various places
now, and I cannot understand why people aren't just planning to copy the
Manley ventilator.

This was the standard ventilator in Europe for decades. It is simple to
design, does not even require electricity (mechanical solution driven by air
from central compressed air system) so all parts can be sourced locally, and
the design has a clinically proven track record.

Here is a video with schematic showing how it works:

[https://youtube.com/watch?v=CrUfblki6Zs](https://youtube.com/watch?v=CrUfblki6Zs)

~~~
kokey
The issue is that with the kind of ventilation required you need to sedate the
patient with gasses and you need to recycle those gasses and unused oxygen.
With the length of time patients have to be on this you don't want to lose
those gasses and also pump it out into the atmosphere. The Manley design could
be a good starting point I suppose, you just have to replace the weight system
with controllers and add a carbon scrubbing stage to feed back the gasses. The
carbon scrubbing stage is the tricky one, it's something that requires good
chemistry and not mechanics and electronics.

~~~
semenko
Physician here; this isn't true for the ventilation of COVID patients, or ICU
patients in general.

There's a difference between simple ventilator [1], and an anesthesia machine
[2] that adds gas mixing, scavenging, etc.

ICU patients are anesthetized using IV sedation (a common regimen in the US is
fentanyl/propofol), not inhalational anesthetics. Most vents only have simple
inline filters to reduce contamination.

[1] A classic vent in the US is the Puritan Bennett 840. Here's its manual
showing filters:
[https://www.medtronic.com/content/dam/covidien/library/us/en...](https://www.medtronic.com/content/dam/covidien/library/us/en/product/acute-
care-ventilation/PB840_Technical_Reference_Manual_EN_10067720D00.pdf)

[2]
[https://en.wikipedia.org/wiki/Anaesthetic_machine](https://en.wikipedia.org/wiki/Anaesthetic_machine)

~~~
kokey
I suppose that's good news then for potential emergency use of unapproved
makeshift alternatives to ventilators, I guess it also makes hand ventilation
viable if you have enough volunteers available to do the bagging.

~~~
wbl
Bagging is hard to do for extended periods.

~~~
DataDrivenMD
Anesthesiologist here - true, I was a Stanford medical student on an ICU
rotation when a Tesla employee crashed his plane into high voltage power lines
while attempting to land at San Carlos airport. Electrical power on the
peninsula was out for an extended period of time. Battery backups eventually
failed, then gas powered generators started failing so everyone with a pair of
hands took turns manually ventilating the patients. If push comes to shove, we
could get by with a Jackson-Reese circuit and a pair of hands. Obviously we
don’t want to find ourselves in this situation.

~~~
93po
Why is it relevant he was a Tesla employee?

------
DataDrivenMD
As an anesthesiologist and hacker, I love the enthusiasm here. I’m less
concerned about the hospital use-case. It would be helpful to crowdsource
solutions to address the need for ventilators _after_ patients leave the ICU.
Based on current practice patterns, some patients will undergo tracheostomy
tube placement, and then need to be discharged to respiratory rehab
facilities. We will need to increase capacity in this setting, and I’m not
seeing or hearing anyone address this area. If we don’t solve this problem, we
will find ourselves with a backlog of patients who could be discharged from
the ICU, but with nowhere to go.

~~~
rectang
Anecdotally:

My mother is a retired RN with an "inactive" license in Washington state. She
does elder care as a side gig for individual clients.

She recently had to turn someone down because the patient was intubated; it's
not legal for her to care for such a patient. If anything went wrong she could
be both at risk of a lawsuit and in trouble with the state for practicing
medicine without a license.

(She's also in her seventies herself, putting her in the high-risk category,
but that's a different issue.)

I'm at a loss as to how our legal and licensing institutions can be adapted to
allow for a quick increase in the number of personnel who can care for
intubated patients.

~~~
DataDrivenMD
You raise a related issue, which is critical to address as well. That is, we
need people to help manage patients before, during, and after their hospital
stay. I’m less concerned about the licensing issues because public health
emergency declarations make it possible for state officials to clear the way
for someone like your mom.

Where you, and fellow hackers can help, is by offering tech solutions that
solve the issue of coordinating/figuring out _where_ your mom’s skills could
be most helpful. We will also need to collect information, such as _when_ your
mom is available to help. Could be a good time to revisit the concept of an
Uber-like platform for healthcare delivery, assuming that it can be up an
running in a few days. Hack-a-thon, anyone?

~~~
rectang
Count me in!

> _revisit the concept of an Uber-like platform for healthcare delivery_

Where has this been discussed before? There are lots of referral services,
some of them charities, some of them private businesses. For example, in
Washington state there's the Korean Women's Association:
[https://www.kwacares.org/](https://www.kwacares.org/)

~~~
DataDrivenMD
Sweet. Looked into the KWA's site, seems like a clear use-case. If we were to
break down the build into achievable chunks we may have more success, and have
a bigger impact along the way.

There's an immediate need for a single source of truth for all the locations
where COVID-19 testing is available. Trump said Google was building it, but
turns out they are weeks away from an MVP that would only cover the SF Bay
Area. I propose we start by solving that problem.

Building on this, we can answer the question: what is the scope of the
problem? Today, the CDC doesn't have an accurate count of the # of COVID-19
tests that have been performed because they don't have a way to collect that
info from the growing number of labs that are performing the tests. Moreover,
there's no way for anybody to know how many _people_ have actually been
tested, because the same person can be tested multiple times. We could solve
this problem by crowdsourcing that information directly from individuals.

Building on this, we need to know where the sickest people are _right now_ ,
and predict where they _could be_ in the near future. This is crucial
information for healthcare providers (like me) and public health officials
alike. Without this information in hand, it's virtually impossible to know
where to direct resources (like doctors, nurses, ventilators, medical
supplies, testing equipment, etc.). We need to be able to track demand _AND_
supply in real-time --> this is the point at which the project starts shaping
itself into an Uber-like platform.

Building on this, we could enable individuals to post offers to help and for
others to request assistance. This would allow people like your mom to lend a
hand where it is a) safe for her and b) most needed.

The ultimate goal would be to build an open-source platform that could be used
by communities around the world with little-to-no deployment overhead.
Ideally, it would be possible to clone the repo, customize a few parameters,
and deploy instances in less than an hour.

I'll flesh this out a bit more, and submit the idea as an Ask HN topic.

~~~
rectang
> _There 's an immediate need for a single source of truth for all the
> locations where COVID-19 testing is available._

Seems like that could be achieved with a static HTML website, possibly
augmented with a REST API.

I doubt that information is changing very quickly. It could theoretically even
be committed to a Git repo in a CSV file. However, although that would work
for generating a website, it wouldn't be clone-able. So perhaps consider some
canonical datastore in the cloud somewhere.

Also: I propose Apache/MIT licensing to minimize the friction of collaboration
with both commercial entities and charities.

Technology wise, I don't care: it should just be something mainstream, popular
and easy.

> _Moreover, there 's no way for anybody to know how many people have actually
> been tested, because the same person can be tested multiple times._

That seems like a harder problem because of patient privacy issues.

~~~
DataDrivenMD
> _That seems like a harder problem because of patient privacy issues._

Agreed, but even a simple honor system would be better than the current
situation. Perhaps verified via a simple browser-based cookie?

Separately: just dawned on me that HN has no obvious way for users to
communicate directly. Any suggestions on how to share contact info without
begging for spam/bots?

------
Peradine
I'm an anaesthetics and intensive care trainee, so I know something about
ventilation. The reason COVID-19 patients need to get ventilated is due to a
failure of oxygenation - the infection causes direct lung injury (ARDS) which
impairs oxygen absorption in the lung tissue. Normally we breathe room air,
which is 21% oxygen, this drops to around 10% oxygen in the arterial blood due
to inefficiencies in the absorption in the lungs. In a normal healthy patient
breathing 100% Oxygen, their arterial oxygen content would be around 90%. ARDS
significantly impairs oxygen uptake by the lungs, in severe cases patients
breathing 100% oxygen may have arterial oxygen concentrations of just 8-10%.

The purpose of ventilation in these severe ARDS patients is to augment
oxygenation of the blood, using a combination of techniques including end-
expiatory positive pressure and inverse-ratio ventilation, among others, and
support the fatiguing respiratory muscles. Because the lungs of COVID-19
patients are already injured by the infection, they are very prone to further
ventilator-associated injury. Modern intensive care ventilators have
complicated computer-controlled 'modes', which allow precise regulation of
ventilatory volumes, pressures, rates, timing, and gas blending. The ARDSnet
trials in the early 2000s demonstrated the importance of carefully managed
'lung protective' ventilation, poor quality ventilation is likely to cause
further lung injury and make the patient worse, not better. Therefore amateur
ventilators are unlikely to be beneficial in COVID-19 unless they can provide
similar lung protective ventilation, which would make them quite complicated.

Additionally, ventilation is just one component of the management of sick
COVID-19 patients. First you need to pass a breathing tube into their trachea,
which is a challenging and risky procedure when performed by a skilled
operative in a otherwise well patient, let alone someone on the brink of
respiratory failure. Once intubated you will need to keep them deeply sedated,
otherwise they will strain against the ventilator and make effective
ventilatory care impossible. This requires equipment, drugs, and skilled
staff, all of which are going to be in short supply.

~~~
jmccorm
Any thoughts as to the early treatment with a medical BiPAP when full-function
respirator therapy is not available?

~~~
Peradine
Doesn't seem to be very helpful - In a multicenter cohort of 302 patients with
MERS coronavirus, 92% of patients treated with BiPAP failed this modality and
required intubation (Alraddadi 2019)

------
_red
Great idea. Simultaneous to these types of home-brew projects...we also need
someone (President? eCelebs? etc) to promote and organize fund raising efforts
to simply buy and distribute cheap but effective ventilators.

Imagine a WWII style "war bonds" effort, but instead to build and distribute
say 5M ventilators over the next 6 weeks.

In addition to this, we must re-purpose closed schools (gyms, cafeterias, etc)
into make-shift CoVid19 triage centers where affected patients can be put on
cots with saline drip, drugs, and ventilation. This is doable, but we need to
do it.

~~~
squarefoot
"we also need someone (President? eCelebs? etc) to promote and organize fund
raising"

Fund raising won't help if too many people get infected. What you need right
now is for those in charge to stop playing Rambo and pretend they have it in
control (they don't) then grow up, tell people to stop behaving like there is
nothing going on. Schools, stadiums, all non vital businesses should close and
people should stay home. This virus propagates at very high speed; as for now
there is no cure, and I'm sorry for believers but prayers won't work
(ironically, "healing" pools at Lourdes are already closed since days). This
is serious, folks. We can only slow infections to a level in which people
recover at faster pace than those who get infected, otherwise ICU numbers
won't be enough and a lot more people will die.

~~~
sneak
Plan for the big peak, hope for the small one. There is no indication that
leadership in the US is going to suddenly start behaving sensibly.

------
tommaho
I posted directly via the contact form on the blog, not sure if it made it
through.

I'm way out of my lane even commenting on this, but maybe you can dramatically
simplify the air delivery side of this design, if you're willing to under-
engineer. A single air chamber with an inlet (blower in) and two outlets
(patient out and return out). Low rpm motor slow rotating a sealed disc with
holes in it balancing outflow between feed-to-patient and return. Put a
blowoff mechanism inline around the flow meter. If the capacity is there and
there's such a thing as a common or global delivery 'frequency', maybe it
could support more than one person.

Again, I might as well be from another planet in terms of knowledge in this
domain. I'm just confused at the apparent complexity around the servo,
linkage, and waste-gating. I DO get that delivery can be tailored nearly
entirely in software with this design. That's cool.

~~~
derefr
Not by any means an expert here either, but my impression is that, to call
something a “ventilator” in a medical context, it has to have a software-
controlled rate of flow. “Ventilator” is to “air pump” as “CNC router” is to
“regular router.” It needs to be integrated as part of a control system,
feeding out forced air-pressure (thrust?) data, and getting fed back a PWM
control signal. (Sort of like a CPU fan, but with air pressure in place of on-
die temperature.)

Keep in mind, the use of these things is that you hook this up to a patient
and then leave them in a room while you go handle other emergencies. _It_
needs to tell _you_ if it’s having a problem (through hookups to monitoring
equipment.)

I _think_ it also needs to not try to force air into a blocked airway (i.e. to
blow open the patient’s larynx the moment they try to swallow), and/or needs
to let up on the air pressure in a sinusoid pattern so the patient can
exhale—though I might be wrong about either/both of those, given that they’re
not really problems doctors encounter with hand-pumped ventilation. But either
of those, in combination with the flywheel-like momentum of a big blower fan,
would explain the waste gate.

------
dang
Some related submissions:

[https://news.ycombinator.com/item?id=22573926](https://news.ycombinator.com/item?id=22573926)
"Low-cost portable ventilator (2010)"

[https://news.ycombinator.com/item?id=22573656](https://news.ycombinator.com/item?id=22573656)
"Low-cost ventilator wins Sloan health care prize (2019)"

~~~
0xWTF
Is there some way HN can bend to support the pandemic? A flag or something?

------
opendomain
I am working on one now.

The problem is that ventilators require tubes to be inserted into the patients
lung. This requires a very skilled doctor and has a risk of infection and
injury.

So I am making an wooden lung - like an iron lung but made from plywood. I can
share the plans and sourcing for the parts if you want

~~~
burfog
Make it like a turtle shell, hooked up to something like this:

[https://en.wikipedia.org/wiki/Rotary_woofer](https://en.wikipedia.org/wiki/Rotary_woofer)

That lets you use both positive and negative pressure. You could even support
fast pulses for clearing out gunk from the lungs.

------
trevyn
Any thoughts about using a regular sleep apnea CPAP device for this type of
situation, where one has access to the pressure settings?

~~~
pujjad
Someone dear to me needs a ventilator per tracheostomy (Trilogy 100). Her
Consultant Aenesthesist who was in Italy four weeks ago and works on an
Intensive Care Unit told me that 6 out 10 Covid-19 affected ITU patients
require an ECMO
([https://en.m.wikipedia.org/wiki/Extracorporeal_membrane_oxyg...](https://en.m.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation)).
This is very bad. I could sense his unease, these are machines you don't come
by easily. His ITU is preparing for war, Brexit and the conservative's
austerity program has put the NHS to breaking point.

~~~
ozi
Most hospitals have just a handful of ECMO machines, if any. And most of them
are talking about not providing ECMO to COViD-19 patients because of this.

~~~
klipt
This article says an ECMO machine costs less than $50k:
[https://www.chicagotribune.com/news/ct-
xpm-2000-03-13-000314...](https://www.chicagotribune.com/news/ct-
xpm-2000-03-13-0003140069-story.html)

That seems low relative to US medical costs in general. I'm sure the average
Bay Area software engineer would happily pay that much to save a dying family
member.

------
projektfu
I would imagine an epidemic of ventilator associated lung injury if people
started rolling out homemade ventilators in quantity.

~~~
yourapostasy
Please don't take this as a personal address to your specific comment. Yours
was simply the last drop of water that tipped the scales in me to comment on
an overall trend I'm seeing. What I'm beginning to see in a lot of these types
of discussions is those calling for caution/compliance are missing the term
"in extremis".

I've seen no one is suggesting that these DIY/hacking efforts of all stripes
replace the existing healthcare infrastructure. What I see is concern the
existing infrastructure is not scaled to handle what we anticipate will happen
even in a moderate scenario. We have in this very thread a real MD who
confirms that post-ICU ventilation is not being addressed but still needs to
be, yet that confirmation seems to fly by those who say that DIY isn't
advisable.

My position on the mitigation however, starts from these two premises:

In Extremis, any action is better than no action at all.

In Extremis, don't let perfect be the enemy of good.

When asked, I believe many will opt for a 1% chance of living on a DIY
ventilator intubated by recently-out-of-license nurses emergency-authorized
during the pandemic when no other intubation staff are available in the time
required to attempt saving a life, than a 100% chance of dying with no
ventilation option whatsoever.

What I'm not seeing are any alternative solutions offered by those who want to
stick to the "official" script. Let's in about 6-8 weeks from now our
healthcare infrastructure is overwhelmed by severe respiratory distress cases,
starting in the June timeframe. What do you suggest we do to prepare for that
starting now instead of any of the DIY efforts you deem too risky/non-
compliant?

I'm honestly asking in response your specific post, now. Even an answer like
"triage non-comorbid over comorbid patients, let the comorbid patients die" is
acceptable. Even if your response is, "I'm no domain expert, I'm leaving it
all up to the experts", that works for me, too. I'm just trying to figure out
what your mitigation angle is.

What doesn't help improve our probabilities nor mesh with my personal
philosophy is giving criticisms with either no alternatives or no position
statement of what you believe is an acceptable protocol going forward. It's in
my nature to seek answers and address my curiosity, even if it only leads to a
partial answer. If that's not you, then you live your best life, and thanks
for the note of caution, it is definitely a concern to manage as best as we
can.

~~~
01100011
Yeah but there is a non-zero portion of the population that may choose to use
a home-brew solution instead of seeking proper medical care. Sure, we want to
give people tools to be self-sufficient, but we don't want billybob hooking
grandma up to the vacuum cleaner to save money.

~~~
MockObject
> What doesn't help improve our probabilities nor mesh with my personal
> philosophy is giving criticisms with either no alternatives or no position
> statement of what you believe is an acceptable protocol going forward.

------
gentleman11
My parents both have lung conditions. If this were Italy, and they got
infected and needed ICU, they would not get treatment at the moment.

What is the most promising home made gear I might be able to scrap together in
the worst case scenario?

------
nx20593
This whole sticking a tube down someone's throat without proper qualifications
or equipment seems pretty dicey. Would an old fashion wooden iron lung work
better? It's pretty primitive technology that doesn't seem too difficult to
build. [https://blog.sciencemuseum.org.uk/a-wooden-iron-
lung/](https://blog.sciencemuseum.org.uk/a-wooden-iron-lung/)

------
niutech
There is a working open source ventilator prototype called VentilAid made in
Poland: [http://www.ventilaid.org](http://www.ventilaid.org)

------
pcj-github
I'm surprised we haven't seen anything detailing the supply chain involving
O2. This is as important than the actual machine.

~~~
DataDrivenMD
Anesthesiologist here: yes and no. It depends on whether the patient is having
difficulty clearing CO2, in which case ventilation is more important. If the
patient’s lungs are unable to extract sufficient oxygen from the air such that
the blood oxygen levels drop below a certain threshold, then supplemental
oxygen becomes important. In fact, excessively high oxygen concentrations in
inhaled gas has the potential to damage lung tissue. Hopefully this helps to
explain why the ability to titrate oxygen flows is important. If we can do
that effectively, we can conserve our oxygen supply for those who need it.

~~~
duckymcduckface
Where do hospitals get their O2 supply from out of curiosity? Do they buy it
from one of the major gas suppliers like praxair or airliquide and store it in
the back as GOX/LOX or can it also be produced on site?

~~~
khwerou098
In the past they had large tanks of liquid O2.

More recently, many have a large oxygen concentrator machine on site which
just takes it from the air.

------
sigmaprimus
Good idea using a large AC blower. I would think a small brand new or very
clean wet dry shop, vac using the blower attachment might be even better.

It would be noisy but would allow the design to incorporate negative pressure
of the vacuum side to assist with exhaling.

Maybe the shop vac could be plugged into a speed controller to improve duty
cycle and reduce noise but controlling an AC motors speed is quite a bit more
complicated(expensive) than controlling a DC one.

~~~
mhb
What about using an air compressor? These should still be readily available
and is an off-the-shelf air pressure solution. The air couldn't be used
directly (oil in it) - there would need to be an isolation bellows or
something similar.

~~~
sigmaprimus
Thats a good idea too, and they do make oil-less compressors they are
typically smaller but years ago I came across many of these attached to dry
sprinkler systems in small parkades.

------
enchiridion
[https://www.projectopenair.org/](https://www.projectopenair.org/)

~~~
westurner
> _[https://www.projectopenair.org/](https://www.projectopenair.org/) _

From
[https://app.jogl.io/project/121#about](https://app.jogl.io/project/121#about)

>> _Current Status of the project_

>> _The main bottleneck currently (2020-03-13) is organization / management._

>> […] _This is an organization of experts and hobbyists from around the
globe._

~~~
MockObject
The link
[https://app.jogl.io/project/121#about](https://app.jogl.io/project/121#about)
doesn't go anywhere anymore. And there are no results for "ventilator" in the
app.jogl.io search.

~~~
westurner
I see a "Ventilator Project" heading?

(edit) here's the link to their 'Ventilator' document:
[https://docs.google.com/document/d/1RDihfZIOEYs60kPEIVDe7gms...](https://docs.google.com/document/d/1RDihfZIOEYs60kPEIVDe7gmsxdYgUosF9sr45mgFxY8)

------
agumonkey
Do you guys have seen similar devices with embedded sanitizing modules ?
heating wire, UVC led or plasma blade to clean air intake ?

the air version of that
[https://www.youtube.com/watch?v=d1RoEgxax60](https://www.youtube.com/watch?v=d1RoEgxax60)

------
ilan1966
i am an anaesthetist i trained using a manley ventilator covid patients
apparently are easy to ventilate the issue is their gas exchange not their
compliance a manley ventilator will do just fine for many patients, not all i
accept but many

~~~
ilan1966
BTW ICU doenst use volatile anaesthetics to sedate people we tend to use
opioids & benzos to sedate

------
ilan1966
i recon you could build a manley in your shed with some decent mech eng skills
and it could certainly be printed

------
nopinsight
4x resources delay a crisis by 2 doublings.

If a doubling takes 7 days, that’s just 2 weeks.

R0 (reproduction rate) overwhelms everything. The only way out safely is to
greatly reduce R0:

\- social distancing: 6-9 feet away from everyone

\- avoiding crowds

\- Never share utensils; no buffets

\- hygienic routines: wash hands, use wipes, close toilet lid before flushing
(see Amoy Gardens), etc.

And _convince_ others to do the same.

Italy closed schools when they had just 150 confirmed cases but still in a
tragic crisis because people kept socializing.

See a timeline & analysis here: [https://www.luca-dellanna.com/how-
bad/](https://www.luca-dellanna.com/how-bad/)

~~~
chimprich
I've got an idea for a way to reduce R0 with some voluntary people tracking. I
could do with some other developers to plan it.

If anyone's interested, please drop me an email: rls at hwyl.org

~~~
chimprich
Care to explain the downvote? It's a bit depressing trying to do something
positive in the current climate.

~~~
sowbug
I didn't downvote, but I can see why others did.

If you have an idea to share, share it. Don't make people jump through the
hoop of sending email.

If you are concerned about others stealing your idea, then your comment is
essentially spam, because you're using HN as a recruiting tool to build your
team. Only YC companies can do that here.

Your motivation might be something other than either of these possibilities.
It's easier to downvote and stop thinking about it than to figure out your
true intentions.

~~~
chimprich
Thanks for the explanation. Makes sense; I've actually posted the idea a few
times (including as an Ask HN) and I was getting fatigued. I absolutely have
no interest in making money out of this - just potentially saving lives.

Reposted:

Could a voluntary user-tracking app help reduce the R0 level of the COVID-19
virus?

One of the main challenges with this virus is that carriers of the virus
become infectious well before they show symptoms. Consequently, they pass on
the infection before they can be isolated.

Apps such as Google Maps already track users' movements to a high level of
precision. A similar app could be created that tracked users' movements and
notified people they had interacted with if they got infected.

It would work like this:

    
    
      - Users' movements are tracked
      - Upon developing a fever (etc.) the user notifies the app
      - The app checks their movements during the estimated period they could have been infectious
      - Every other user who was in their presence for X minutes gets notified and requested to isolate themselves
      - Recursively check those users' movements to see if they may have passed on the virus
    

Disadvantages I can think of off the top of my head:

    
    
      - Requires simultaneous voluntary use by a large proportion of a regional population
      - Possibility of false positives by bad actors (would an occasional false positive be so bad)?
    

I've had this idea checked with a leading epidemiologist, and he was
enthusiastic.

I see this same or similar idea has been written up as a paper (which I've
just submitted as a separate story):
[https://www.medrxiv.org/content/10.1101/2020.03.08.20032946v...](https://www.medrxiv.org/content/10.1101/2020.03.08.20032946v1)

------
Yuioup
I'm surprised there's no emoji for Corina

