MakAir — Covid-19 Ventilator

Mass-producible open-source Covid-19 ARDS ventilator. Aims at helping hospitals cope with a possible shortage of professional ventilators during the outbreak. Worldwide.

We are a distributed team of 200+ contributors, mostly spread through France. Makers, developers, university teachers, researchers and medical teams collaborated on this project. Our testing & assembly operations are located in France.

As to ensure international outreach, we made sure that contents required to build your own MakAir ventilator are available in English.

If you're new there, please read the explanations below. Your contributions are much welcome!

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Quick introduction video:

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Abstract

Roughly, the idea is as follows: as of April 2020 and due to the Covid-19 pandemic, hospitals will soon start lacking mechanical artificial ventilators. We built a pump, and a valve system (controlled by electronics). This way, the breathing cycle can be enforced by proper air routing through the valve system.

Our ventilator is able to handle pressure-controlled breathing, stabilized using a PID controller in the software.

In order to ensure a proper breathing cycle (inhale + exhale), multiple valves need to be connected together to form a circuit. The motors needs to be controlled in harmony so that the air routing between each valve unit is consistent.

This project provides all the parts required to build a good-enough ARDS ventilator from mass-produced components. We provide all the required mechanical parts, electronics designs & boards, and firmwares. This ventilator can be 3D-printed and ran on an Arduino board (the maker way), though we highly advise that you work with industrial processes as to mold medical-grade plastic parts and assemble the whole ventilator (this would be required for the built ventilator to pass all medical certifications).

We target a per-unit cost well under 500 EUR, which could easily be shrunk down to 200 EUR or even 100 EUR per ventilator given proper economies of scale, as well as choices of cheaper on-the-shelf components (eg. servomotors).

Mechanically-speaking, the overall system is composed of sub-components that can be plugged together and wired to form an air circuit, namely:

• Air pump (called "Blower");
• Air pump casing fit (called "Blower Holder");
• Valve system (called "Pressure Valve");
• Oxygen Mixer valve (called "Oxygen Mixer");
• Air filter casing (patient variant) (called "Patient Filter Box");
• Air filter casing (machine variant) (called "Machine Filter Box"; intake + outtake);
• Connectors (called "Pneumatic Connectors");
• Fan support (called "Fan Holder");

All those components are fitted in box (ie. a container) that we designed:

• Housing container (called "Container");

⚠️ Warning Notices

A few important words before you start:

1. Though 3D-printing (FDM and SLA) can be used to build your own ventilator — this will definitely not scale well to mass-produce MakAir ventilators, and parts might be brittle or leak air. Please work with proper industrial methods and processes if you want to build your own MakAir ventilators.

2. As ARDS patients are sedated, their breathing cycle is forced by mechanical ventilation, while they are intubated. A failing ventilator (due to bad mechanics, pneumatics or software) could kill the patient (O2 desaturation), or permanently damage their lung alveoli (overpressure). It is critical that any self-built MakAir ventilator is tested against a lung simulator system (eg. ASL 5000), and validated by medical experts.

3. Medical-grade plastic should be used to produce ventilators, and any kind of grease or adhesive chemicals must be avoided in the ventilator. The ventilators should be produced in a cleanroom as to avoid dust & germ contaminations.

4. The pneumatic circuit should be thoroughly tested for leaks and its ability to withstand elevated positive air pressure. Joints should be used where relevant, and medical-grade flexible pipes should be used between components.

5. While the MakAir ventilators produced on-site in France were validated by a medical & engineering board, you should independantly seek validation of the MakAir ventilators that you produce; as your assembly methods or parts may vary with ours.

MakAir and Makers For Life should not be held resposible — at any time, for harm caused to human life (eg. lung damage or loss of life). By building your own MakAir, you are held responsible for its safety validations & use.

How To Build?

This section aims at introducing you on how to manufacture your own MakAir — the 3D-printed way. In other words, we will explain there how to build a DIY MakAir using on-the-shelf parts and 3D printers.

1️⃣ Print all the parts

In order to 3D-print your MakAir, please first ensure you have access to a SLS 3D printer at best (eg. HP Multi Jet Fusion), or otherwise a SLA printer (eg. Formlabs Form 3). If you want to use a FDM printer (eg. MakerBot Method), please note that some precise parts have been optimized for SLA or SLS printing. Some parts may not print well using FDM printers, even on decent hardware.

👉 To sum up: at best, use a SLS metal printer, else, use a SLA resin printer. If you do not have access to either of these, you may fallback on a FDM filament printer (using PLA or ABS filaments).

1. Parts

You can find a list of all parts that should be 3D-printed, as well as the number of parts that should be printed for each one (pick the last active version for each part):

• 1 x Blower — Print all STL parts using the same printer (SLA or SLS; FDM discouraged; 50 microns minimum);
• 2 x Pressure Valve — Print all STL parts using the same printer (SLA, SLS or FDM; 200 microns minimum);
• 1 x Oxygen Mixer — Print the STL part (SLA or SLS; FDM discouraged; 100 microns minimum);
• 1 x Patient Filter Box — Print all STL parts using the same printer (SLA, SLS or FDM; 100 microns minimum);
• 1 x Machine Filter Box (Intake) — Print all STL parts using the same printer, make sure that you pick the proper sub-part (SLA or SLS; FDM discouraged; 100 microns minimum);
• 1 x Machine Filter Box (Outtake) — Print all STL parts using the same printer, make sure that you pick the proper sub-part (SLA or SLS; FDM discouraged; 100 microns minimum);
• 1 x Pneumatic Connectors (Blower) — Print the STL part using the same printer, make sure that you pick the proper sub-part (SLA or SLS; FDM discouraged; 100 microns minimum);
• 1 x Pneumatic Connectors (O2) — Print the STL part using the same printer, make sure that you pick the proper sub-part (SLA or SLS; FDM discouraged; 100 microns minimum);
• 1 x Pneumatic Connectors (No Pressure) — Print the STL part using the same printer, make sure that you pick the proper sub-part (SLA or SLS; FDM discouraged; 100 microns minimum);
• 1 x Pneumatic Connectors (Pressure) — Print the STL part using the same printer, make sure that you pick the proper sub-part (SLA or SLS; FDM discouraged; 100 microns minimum);

If you are using your own proprietary blower — in addition to the parts above — please adjust the Blower Holder CAD model and print it as well (this one prints well using a FDM printer at worst).

2. Container

Now that you got all parts printed, you may assemble them in the MakAir container box. We recommend that you build the container using laser-cut acrylic panels. You may find the container CAD model for Fusion 360 or as a STEP file.

Please ensure that you cut your acrylic panels using the same sizes than stated on our models; as those sizes are optimized to contain all required parts and electronics in the minimum amount of space.

2️⃣ Setup the electronics

Electronics are comprised of two parts: the firmware controller board (typically, an Arduino), and the "raw" PCB electronics (LCD, interface buttons, alarm beeper, etc.). Those parts make up the motherboard, on the top of which a rigid panel is mounted, and user instructions are printed (eg. control button bindings).

1. Motherboard

The motherboard electronic schematics and wiring diagrams can be found there. Please pick the last version available.

👋 If you need help on this step, you may open an issue.

3️⃣ Flash the firmware

1. Ventilator Firmware

Now that both mechanical parts and electronics are ready, you may flash the latest MakAir firmware binary on your firmware controller board (Arduino, ST Nucleo, or other).

Firmware release binaries are available for download on our releases page.

👋 If you need help on this step, you may open an issue.

Components

Mechanics

Part	Version	Last Changelog	Ready?	Live CAD Models	Contributors
Blower	V14	Smaller form factor & more powerful	✅	view model	Gabriel Moneyron + Baptiste Jamin + Valerian Saliou
Blower Holder	V3	Differentiate Model A and Model B	✅	view a model, view b model	Gabriel Moneyron + Valerian Saliou
Pressure Valve	V6	General improvements	✅	view model	Clement Niclot
Oxygen Mixer	V4	Updated with correct O2 ID diameter, reinforced O2 nipple.	✅	view model	Yohann Nédélec + Steven Daix
Patient Filter Box	V6	Update input/output mensurations	✅	view model	Martial Medjber + Eliott Vincent
Machine Filter Box (Intake)	V2	Modeling corrections	✅	view model	Valerian Saliou
Machine Filter Box (Outtake)	V2	Modeling corrections	✅	view model	Valerian Saliou
Pneumatic Connectors	V4	Wall-mountable patient connectors	✅	view o2 model, view blower model	Gabriel Moneyron
Fan Holder	V1	Initial version	✅	view model	Eliott Vincent
Container	V2	Update mensurations	✅	view model	Arthur Dagard

Electronics

Board	Version	Major Changes	Ready?	Schematics	Contributors
Motherboard	V2	Working PCB w/ software	✅	view schematic	Vincent Le Cunff + Cherine Kamel + Pierre Papin

Software

Runtime	Version	Major Changes	Ready?	Contributors
Ventilator Firmware	V1.5.x	Initial test working	✅	Emmanuel Feller + Gautier de Saint Martin Lacaze + David Sferruzza + Baptiste Jamin + Gabriel Moneyron
Control Unit	V0.1.x	Project started	❌	Valerian Saliou + Quentin Adam

Schemes

Pneumatic Circuit Scheme

(design by Valerian Saliou)

Container Layout

Top Part: Electronics (Power & Controllers)

(design by Arthur Dagard; drawing by Valerian Saliou)

Bottom Part: Pneumatics

(design by Arthur Dagard; drawing by Valerian Saliou)

News & Contact

Updates

• Live updates on Telegram: join "Newsroom MakAir (Covid-19 Ventilator)"
• Coordination on Slack: request to join "Makers For Life" (open an issue)

Contacts

• Open-source & questions: please open an issue on GitHub
• Press contacts: Grégory Thibord
• Medical contacts: Pierre Antoine Gourraud
• Industry relations: Quentin Adam
• Engineering contacts: Valerian Saliou, Eliott Vincent

Sponsors & Contributors

This project would not have been possible without the support of those companies and organizations, which have put human, real estate and/or financial resources at work on the project:

• Clever Cloud (founding team)
• Crisp (founding team)
• Cooprint (CAD)
• SenX (electronics)
• Tronico (PCB design)
• Renault (manufacturing)
• Le Palace Nantes (team offices)

We are supported by public entities as well, namely:

• Region of Auvergne-Rhône-Alpes (France)
• City of Nantes (France)
• CEA (France)

Adding to that, 200+ individual members of the project who contributed to technical, legal, medical and press subjects (and more).

Renders

Mechanics

The "Pressure Valve"

The "Blower"

🎦 View: Animation of the "Blower"

The "Blower Holder"

The "Oxygen Mixer"

The "Machine Filter Box" (Both Directions)

The "Patient Filter Box"

The "Pneumatic Connectors"

The "Fan Holder"

The "Container"

Electronics

The "Motherboard"