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Pandemic Ventilator Project

panvent.blogspot.com

31–40 of 111 posts

Re: Pandemic Ventilator Project

#31
post #27
post #14

Earlier quoted context omitted.

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 carbo…

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]…

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.

Re: Pandemic Ventilator Project

#32
post #20
post #3

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

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... ). This is very bad. I could sense his unease, these are machines you don't come by easily. His ITU is preparing for wa…

> and the conservative's austerity program has put the NHS to breaking point.

No such austerity has happened, and now is not the time for this petty bickering.

Re: Pandemic Ventilator Project

#34
post #26

Earlier quoted context omitted.

As others have commented above, reducing the rate of spread (social distancing and hygiene, and convincing others to do likewise) so that this is a more smeared out event with a lower peak need for equipment and staff is the most important intervention. It's also very hard to do; not sure if there is a technological lever that will move the needle on this (advertising?)

I'm a semi-retired Ph.D. scientist, and have already been doing Social Distancing for some time. My (frequently washed ;-) ) idle hands want to contribute something more! Since you are a professional in the field, I am asking your help for brainstorming useful, contributory things for people like me (and others) who are feeling the need to DO something. If hacking up ventilators (like in the OP) is not a great idea f…

First order of business is put in your call to action with your political representatives and tell everyone you know to practice distancing and hygiene.

Once that is done...

If your Ph.D. was in the life sciences, or you can find others with that expertise, I'm curiously exploring a tech tree and precursors breakdown of what I need to actually carry out my own Covid-19/RT-PCR testing, notwithstanding the significant hurdles to do so pointed out by others [1]. That led me to a fellow HN'r pointing out the OpenCovid19 group [2], which has tons of links to other similar hacking initiatives.

It looks like some baseline logistical equipment is required, medical grade freezer, refrigerator, autoclave and centrifuge, along with some glassware. Someone did some work on that [3] earlier, at the moment I'm scrounging my local area to see what pre-owned gear I can pick up for myself (I've always wanted a bio-hacking section in my workshop), and comparing against what I think it would take for example, to fabricate centrifuge parts with a lathe, drill press, soldering iron, and scrounged second-hand shop items like a blender motor, for underserved communities like in the poor sections of the US and in the Third World.

Based upon what I can understand from the CDC testing protocol [4] for example, I need molecular grade water as a precursor. In my position in the US, I'm fortunate enough that I can simply purchase this. But were I to create a procedure for people who have more smarts and time than money, apparently making your own molecular grade water is quite the undertaking, especially if you undertake making your own DEPC. If my tech tree starts at "common 21st century household items, urban community scrounged second-hand equipment, access to trades or Maker shop, and Internet access with modest ($1000 USD) funding for online ordering", even getting the logistical precursors in place looks pretty daunting. The more money I allow into the picture, the easier it gets.

I'm currently researching what logistical train I need after I get a Bento Lab and primers (not necessarily Covid-19, likely not enough time to do that) to conduct my own RT-PCR tests.

I'm fully aware it sounds like I'm asking the equivalent of "teach me to program in 30 days". I have patience, I understand that what I do now likely won't pay off to help with Covid-19. What I really want is the pointers to resources that lets me read and understand how to breakdown the CDC protocol by tech and procedure layer. It sounds like RT-PCR testing could be a really useful general technology to have on hand in the future. So I want to put together the write up on say Hackaday that could drive this kind of conversation.

"First you need a centrifuge, of this minimum rpm, this many slots per patient, etc."

"Oh, you have to source a second-hand one? Link here to a list of characteristics to look for to find a good one. This is a list of good brands."

"Oh, you can't source pre-owned ones? Here is a way to use common machine shop tooling to fab one, link here to the kind of electric motor you want to find, here is how to test the motor."

This has piqued my curiosity, I'm feeding it to see where it leads me.

[1] https://news.ycombinator.com/item?id=22570801

[2] https://app.jogl.io/project/118#about

[3] https://makezine.com/2017/04/11/how-to-set-up-your-own-lab/

[4] https://www.fda.gov/media/134922/download

Re: Pandemic Ventilator Project

#35
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

Re: Pandemic Ventilator Project

#36
post #14

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…

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 carbo…

FWIW: in the kind of disaster these kind of home brew devices are targetted at, they're unlikely to be used on sedated patients.

I read this as "how to save a life with a vaccuum cleaner in extremis", and not "here's a good ventilator design". Is it a good idea? I dunno. I'll check on the vaccuum today just in case.

Also FWIW: the air path doesn't seem like the critical piece here. My (amateur) intuition tells me that the number of lives saved by amateur ventilators will be rather less than the number killed by amateur intubation devices.

Re: Pandemic Ventilator Project

#37

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

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

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.

Re: Pandemic Ventilator Project

#38
post #31
post #27

Earlier quoted context omitted.

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]…

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.

Bagging is hard to do for extended periods.

Re: Pandemic Ventilator Project

#39
post #22

Earlier quoted context omitted.

- COVID-19 seems to be mainly hypoxic respiratory failure, not hypercapnic respiratory failure - NIV (Non invasive ventilation, CPAP is essentially a form of this) doesn't typically perform well (on a patient outcomes, mortality basis) for pneumonia with hypoxia compared with invasive ventilation. However, this is thought to partly be because NIV delays the decision to proceed with intubation and ventilation. If ther…

Ok, so what is the best way, in your opinion, for a still healthy hacker/maker geek to contribute something (anything?) to helping our local ICUs from being overwhelmed with patients? Edited to add: Spoken as the Dad of a 28 week premie who spent 8 weeks on a ventilator in a NICU.

There is a manufacturer of emergency ventilators. Why they aren't working triple shifts to make millions is beyond me.
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