Issue tracking

Hi friends,

As you may know, right now Madrid Hospitals are in a really hard situation without the necessary stock of some Individual Protection Equipment.

My best friend that works in a hospital has been attending COVID patients since 5 days ago with almost non stop. I asked her which element is she missing, and she has specified me the next list, which aligns perfectly with our meeting yesterday:

FFP2 masks
FFP3 masks
Face Shields (we are in a good way here)
Goggles
Waterproof Medical Coats

Also, they are missing some equipment as:

Respirators
Vacuometers / Tachometers
Flowmeters

Flowmeters seems the second easiest to achieve due to its a straight forward system composed by a tube, a valve and a calibrated ball. Totally passive. What do you think? I am gonna explore this field to make it Fablable.

I know some of them are the same we talked yesterday and that's great. Hope it serves as an inspiration to anyone and happy to add to possible future meetings Madrid doctors in the loop if just if necessary.

PS: Ive got my tiny CBA at home.

Hi team,

I sympathize with the hardships that your friend is experiencing.

I can help with the flow meter technical specification. The pressure in the hospital from the liquid oxygen tanks coming out of the walls is approximately 4 atmospheres. The flowmeters in the hospitals are designed to deliver up to 30 LPM. With this patient population there is a need for up to 80 LPM of oxygen. Industrial rotometers are designed for 280 LPM. The hospitals can begin to order the industrial equipment or we could help with a medical design that fits the niche.

Also, we need to humidify this flow from preventing mucus from hardening in the airway. If we can keep the viscosity of the mucus low enough the elevator system in the airway will transport the mucus upward and the patient can recover. (Incidentally they started to ventilate patients upside down in Italy to help). The bubble humidifiers used in hospitals are unfortunately under-designed for this higher flow.

I leave you only problems because I trust you smart people will have solutions.

Bill

@alfonso, there's a good network of fab labs in Spain ready to help. It sounds like the shields could be the first thing to start deploying, if @zfredin can prototype and @sclarsic can test with her local ER doctor, then I can pull in those labs.

If a flowmeter is a recurring need that sounds like a good one for you to work on.

@zfredin did an amazing job getting a prototype face shield made already and it's been given to the ER doc. She is trying it out tonight on her next shift. We will give her some other prototypes to try too, and report back.

A quick note: she is very appreciative of what we are doing to help, and it sounds like it is really needed as the hospital is already rationing PPE.

@sclarsic @zfredin great -- as soon as anything looks promising I can start queuing up labs for production, sounds like shields will be first out

@schaudhuri:

@Tourlomousis is our electrospinning guru, do discuss with him filter media production.
Rather than injection molding, quickest thing we could turn on is machineable wax+soft tooling for short-run molding-and-casting. If you pick a part to go through that pipeline we could do a test. Smooth-On has medical-grade resins. If promising, we could then automate that process.

On Wed, Mar 18, 2020 at 1:19 PM Chaudhuri, Santanu schaudhuri@anl.gov wrote:

Thanks, Neil. I will add further detail. The concept I'm running up the chain is distributed development and reuse of medical grade plastic for locally making PCR testing kits at the point of delivery of service. DOE leaders are meeting later today and will coordinate the effort for getting specs out. For now, I shared local injection molding capacity in the Chicago area. In line with thoughts you shared yesterday, we will see if an inexpensive tooling and injection molding system design can be put forward as a solution. Government is trying to repurpose industries using war-time defense production act. However, that's an old solution for the current need for empowering frontline workers. I will report back if our ideas are getting traction.

Also, we have a 56 nozzle electrospinning system printing on moving substrate. We will look into new kinds fibers for filters in masks. You guys had a great discussion on this yesterday. Let us know if we need to connect the engineers from our side into this discussion.

Hi all,

Just added a kirigami shield able to make a shield only cutting material. It could be done even manually. link to kirimask

Please express your concerns / issues in the issue tracker of the page.

Thanks a lot.

Hi all, I need feedback from the doctor side.

Could be interesting a box (around 1m^3 vol) in which you introduce medical equipment and IPEs and pulverize any cleaning agent like Isopropyl Alcohol to remove viruses?

I don't really know if accelerating the cleaning process is something critical right now but it could be a faster way to mass clean all this equipment.

Thanks

@alfonso I'm not a doctor, but I have a lot of experience in disenfection practices for ventilators. There is only one machine on Earth that has been approved for this and it's only available in Germany. It's called Keredusy.

https://www.medizinservice-sachsen.de/en/files/KR2000-brochure_en.pdf

We never tried bathing a device in IPA, but we've tested many other techniques that only ended in damaging the ventilator. e.g. SoClean, Sterrad, Autoclaving.

We gave up testing and now we just recommend that a filter always be used on the inlet and outlet of the device. If you suspect a device is contaminated, there is nothing to be done other than quarantine it. You've touched on a real problem, especially the speed issue.

any science on UV light in combination with mechanical filtration?

I've added colleagues from:

https://www.3ds.com/
https://www.moog.com/
https://www.airbus.com/

interested in helping this work with their great engineering resources, along with a super fab lab in India working on the response there.

Reminder, this project group and tracking project:

https://gitlab.cba.mit.edu/pub/coronavirus
https://gitlab.cba.mit.edu/pub/coronavirus/tracking

is for the work we're doing based at CBA, and this project group and tracking project is for the larger development and deployment effort in the fab lab network:

https://gitlab.fabcloud.org/pub/project/coronavirus
https://gitlab.fabcloud.org/pub/project/coronavirus/tracking

I'm separating those to buffer traffic on the latter from the core group working on the former, but expect them to connect as work progresses, and you're welcome to join there.

@sclarsic, any update on the mask shields from your ER colleague? Should we look ahead to ramping up production of those? Or are those still waiting on materials?

@jakeread, do you need anything sent to you to start looking at pumps?

Hi @neilg , @zfredin gave Dr#1 (can we use this name to maintain confidentiality?) the first prototype and is going to give her a few more different models soon (within about 24 hours I think). He ordered enough material to make 2k-4k masks, the material arrives mid-next week. We will put into production whichever design is best at that point.

@sclarsic, if shields are promising there are ~5 fab labs I could pull in locally to help produce. Unless they need the Zund, in which case I'd reach out to them.

@alfonso is going to be doing a shift on prototyping.

The designs are still annealing; it looks like there may be at least one part that needs to be milled out of HDPE or other ~1/4" sheet stock which is a great job for a ShopBot. The thin clear film can be laser-cut or Zunded, with the latter being more efficient (as the machine can take full 4x8 sheets, and works faster) and produces cleaner results with less discoloration. I think it will make sense to do a good bit of the production in-house, but also send out material kits to FabLabs to parallelize effort and keep them involved.

I'm skeptical that 3D printing is a good fit since it's a huge time drag and there are concerns about cleanability, but that might end up being an option if we need to go 'all-of-the-above' due to demand.

OK, I think we have enough people with access to rotate in to keep short-run production going in-house for testing.

@neilg just settled and setting up the bunker lab this morning, am going to start doodling positive pressure helmets and modular breathing / filtering / pumping circuits for PPE as well as CPAP

the breathing circuit ISO standard is $140 to buy, unless we can find connector spec somewhere else

@jakeread @neilg If you need an ISO standard, Philips will supply it.

breathing_tubes_ISO5367_2014_.pdf

@bill.truschel thanks !

@bill.truschel I think I also need https://www.iso.org/standard/54851.html - the actual socket drawing.

additionally, if you have information on 'standard' lung volumes, breath periods and peak flow rates that would be spectacular. I will hunt online myself, but I imagine you have been through this data before... I recall 1 litre/second was mentioned in our earlier call, and 30 breaths / minute being an upper bound for distressed patients... tidal volume ~ 0.5 - 3 litres?

ISO_5356-1__2015_.PDF

To estimate tidal volume in patients with acute respiratory syndrome (ARDS), you will find that the volumes will range from 4 to 6 ml per kg ideal body weight(IBW).

You can calculate IBW by

IBW Estimated ideal body weight in (kg) Males: IBW = 50 kg + 2.3 kg for each inch over 5 feet. Females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet.

Tidal Volumes will range in the clinic from 250 ml to 600 ml.

The breath rates will be 13 to 30 Breaths per minute (BPM) depending on many factors. The slower breath rates will show an inspiration to expiration time ratio (I:E ratio) of 1:3, the faster rates will exhibit 1:1 I:E ratio. The ideal I:E ratio is 1:2.

The peak flows will typically be around 60 Liters/min (LPM) or 1 liter/sec (lps)

Hey everyone, for my biomedical engineering capstone, my team worked with ALUNG technologies to design a low-cost controller and partial redesign of their already FDA-approved Hemolung Cartridge, project video link here. It is a respiratory dialysis system that removes CO2 from the blood and partially reoxygenates it. The function is essentially the same as ECMO/mechanical ventilators, but more effective and less physically taxing. As you guys have probably heard, Italian doctors now need to decide who is getting a ventilator due to shortages. CBA has the machines necessary to produce the cartridge and controller, so I am thinking of reaching out to my contacts there to see if there is any way to help. Let me know what you think. @neilg

Interested with a handful of caveats. Can you give more details on exactly what we'd be building? We're not exactly set up to do USP-rated manufacturing at CBA, etc.

Let me send them an email and ask if they have specific needs. I can't speak on USP-rating stuff, but I know they fabricate their devices through a community Fab Lab in Pittsburgh.

Sounds good. I'd love to help -- I just want to make sure we help, rather than hurt. Dealing with blood that gets sent back into a person is a pretty high level of danger.

Sounds good, I just sent the email. I totally agree with you. I think even just milling the parts and sending them to ALUNG for sterilization and assembly may be useful. Let's see what they say, glad you are interested though!

The Alung is a great device. Extracorporal CO2, ECCO2, is typically indicated for Chronic Obstructive Pulmonary Disease, but like ECMO, these machines could be used in a pandemic.

I took a look at making CPAP-helmet type devices, and pumps (turns out these are just blowers) - as reusable, more effective and comfortable PPE. My thoughts are here:

https://gitlab.cba.mit.edu/pub/coronavirus/pph-ppe

I'm not sure if this is a good idea, input appreciated.

@jake interesting -- do you have access to tools for prototyping there? Do you want to do that by remote-control at CBA? Any orders to get into the lead time pipeline?

Jake this looks neat and definitely worthwhile, but I defer to an MD for the safety/efficacy questions. Happy to assist with remote prototyping. If it's helpful, we have a ton of 0.020 PETG arriving next week; might be too thick but I think it can be heat-bonded and is great for thermoforming.

I can plan on prototyping one unit, there is a decent amount of CAD to sort out. I think I can do this with the 3D printer I have and some hand-cut PET film (@zfredin I'll get thinner ~ 6 mil film for this) but if we ramped production, I would send design files to CBA to use the Zund / Prusa farm there.

@jakeread @neilg

I'm so glad you took this up, I was going to ask you guys about developing a solution for PPE. But I still don't know how to start an issue on this site.

Please consider safe ways of doffing when you design PPE. The best guidance I've seen on PPE was from the days of the Ebola outbreak from the CDC. https://www.cdc.gov/vhf/ebola/healthcare-us/ppe/guidance.html

The Chinese in Shenzhen, have had zero health care workers infected, so we could also learn from them.

Lastly, I have a recent success story from China in the treatment of a patient who was severely ill, but recovered with simple treatments. I sub acute ventilator, Oxygen, and chest percussions. (We make a vest that can be worn that does this without caregiver labor)

You can view the PPE in these images.

@bill.truschel if you go to the tracking project issue page:

https://gitlab.cba.mit.edu/pub/coronavirus/tracking/issues

you should see a link to start a new issue.

As we start adding sub-projects:

https://gitlab.cba.mit.edu/pub/coronavirus
https://gitlab.cba.mit.edu/groups/pub/coronavirus/-/shared

each also has its own issue tracker (this one is for managing the overall projects).

Two important additions today to this project, Jan Vandenbrande (@jan.vandenbrande) who is coordinating DARPA's rapid-prototyping response, and Alexander Piontkovski (@apiontkovski) who is doing the same for MGH.

Jan's immediate interest is ventilators; I mentioned the guidance that more CPAPs are likely to be needed, and are more accessible. @jakeread has been looking at that with @bill.truschel.

And Alex's immediate interest is masks, I'll start an issue on that.

Re: ventilators, the GO2VENT design comes up quite a bit in various discussions: https://www.vortran.com/go2vent

It doesn't cover all circumstances and requires 10 LPM air or O2 flow, but is otherwise ideal for scaling disaster response. My concern with this, and frankly anything that directly interacts with patients (vs PPE for healthcare providers), is safety. If we, for example, reverse-engineered and remade GO2VENTs out of 3D printed PLA, would they be accepted in the field? Would the devices do more harm than good? I think there is a bright line between making PPE and support supplies, and making invasive life-critical patient support equipment; at the minimum, we need someone with expertise to validate our ideas, and some base-level understanding of liability.

Thoughts, from experts and others?

This primary issue has gotten so long, please do start issues on topics like @zfredin's Vortran question (which came up in the first video). Let's use this issue for overall care-and-feeding rather than particular projects. Hopefully as we ramp up we'll be able to close as many issues as we open.

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