Rapidly deployable, open-source, low-cost ventilator for COVID-19 patients - 1st prototype idea

As the COVID-19 pandemic continues to ramp up at an alarming rate, the government has called for assistance in solving or mitigating the upcoming shortage of respiratory ventilators.

This ventilator design idea, started by the Medical Devices Center at the University of Minnesota and continued by Teknic engineers over the last day and a half is for an automated bag valve mask (BVM) ventilator.

*PLEASE NOTE* This design has not been sufficiently tested and even once it has been, the machine is meant to be used only by highly trained medical operators in emergency situations. Building and using one of these machines without proper training could cause serious harm or death. DO NOT ATTEMPT TO BUILD AND USE THIS MACHINE ON YOUR OWN.

The BVM is commonly known as an “ambu bag” and they are very readily available. This ventilator design is one that automatically actuates a BVM, which otherwise would require the full attention of a nurse/tech. Obviously, given the current Coronavirus situation, medical staff is in high demand right now. The goals for this device are:

· Open source (so anyone can leverage the design)
· Easy to build
· Reliable
· Inexpensive
· Able to be ramp up production quickly
· Adjustable speed of ventilation
· Adjustable compression/stroke

There are some other ideas floating around the internet but many of them rely on reciprocating motion from the motor and that requires a more complex control system. Teknic motors have the capability of doing reciprocating motion, but to maximize the source of supply (and to minimize complexity), we thought it would be important to create a design that would work with uni-directional motion only.

To that end our design is able to function with any motor that is able to provide consistent (but adjustable) velocity in a single direction. In our concept we used one of our ClearPath-MCVC motors since it is easy to adjust its velocity with a simple dial and no separate electronics other than a power supply. However, any standard NEMA 23 or 34 motor with variable velocity control (and sufficient torque) would work well.

Teknic can provide a good deal of engineering and prototyping support for this project but we need more help. We are not in a position to manufacture, assemble or distribute a complete system like this (all of our manufacturing is specific to motor and drive production).

The help we need is:
· Manufacturers who can build this assembly at the required scale
· Medical professionals' advice on the usability of the concept and any advice on how to deploy this to hospitals
· Anyone that can provide information on any relevant FDA requirements

If you can help in any way, we’d appreciate it. Please comment below.

Stay safe!

[rickdeckard]

You should enter your design in the *Code Life Ventillator Challenge* . A contest open to the world to help combat Covid-19. Best of luck!

[MiloLabradoodle]

This is the right idea. A simpler device with a minimum number of parts.

[hispanicuscorpus]

Student in the Dominican Republic are using Honda windshield washer motor to build similar DIY respirator

[qwertzundefinedapfel]

What about as windshield wiper motor assembly? It's strong enough, the gear is included and it even has a crank added.

[colinellicott]

A nice initial Engineering Breadboard prototype.
I hope they have created the Risk Management Plan, listed all safety issues found from research of all sources, databases, and the competitors equipment safety instructions, created the Customer Requirements Database, initial House of Quality is complete, and validated the Customer Requirements, and System Requirements Specifications (system, hardware, and software) already.
All plans reviewed and approved for Development, Design, Reliability, Configuration Management, Quality Assurance, Verification & Validation, Software, Procurement, Production, Testing, and Quality Control.
Next is the Initial Design review of all output by expert customers and independent experienced engineers.
Then on to design the Engineering Model after repeating and refining everything as well as creating Fault Tree Analysis, Failure Mode Effect analyses for system, hardware, and software and incorporate all the design changes and validate them, and reliability plan and demonstration initiated.
Then comprehensive Design Review again.
Then the Pre-Pilot Run Model repeating and refining everything using production parts and methods but engineers building. Design Review again.
Then the actual Production Pilot Run using production processes and personnel and then clinical trials, and compliance testing.
Then final Design Review.
Then file 510k with FDA and filings with other regulatory bodies, and receive consent to distribute.
Then Production Release with all production processes and supply chain activated. Continuous monitoring of fielded units for data analysis, trending, safety oversight, and CAPA process.

So another two days and they'll be satisfying all the needed vents worldwide ;)

Of course any product must meet the minimum requirements outlined in:
ISO 80601-2-72:2015
Medical electrical equipment — Part 2-72: Particular requirements for basic safety and essential performance of home healthcare environment ventilators for ventilator-dependent patients.
And all associated Directives, and national and local standards too.

Oh, almost forgot ...
I assume they have done all the design activities under FDA GMPs and ISO compliances including all the required documented processes, training, and validated systems, successful independent audits, and methods. Because to do otherwise would endanger lives and be foolish. Right?

[scottsutton]

Just ordered 2 ambu bags. I have the Teknic Servo in stock for a future application and I can make the balance of the frame and gear on the CNC router. Thank you for sharing, I have a family member that has cardiac/respiratory difficulties and may not fair well with a Covid-19 infection.

[mohitsingh]

Design will work well but it needs microcontroller based calibrator which pumps air inside the lungs according to its capacity....need all the formula to calculate how much air is needed by patient...and then servo will pump air accordingly

[tyoud]

Also please consider how to make PAPRs, it might be a good approach to save healthcare workers lives; ideally it would be battery packs that are simple, rechargable, hose, a couple of standard 40mm M95 type filters, and a mask, maybe an adapter to a scuba mask (to the snorkel on top) or to other facemask systems.

[christianlandauro]

Very interesting and simple design. Please if you can show us a complete design with the name and size of the gears, axle, shafts, bushing and hubs would be excelent.

[LVXPLR]

Simple design! I see you have a variable radius on the crank to change tidal volumes. If you're using a Clearpath, you could also change tidal volumes by reversing the piston to only give a partial stroke. You should consider a toothed belt, as I think it would last longer than 3D printed gears. Also you could eliminate the crank by putting the equivalent holes in the larger toothed gear. To be simpler yet, I think your even your smaller ClearPaths could directly drive the crank. Single-speed motors prevent the ability to set a inhale to exhale time ratio, which seems to be important.

[hmbini]

Hi, thank you very much for your efforts. It looks very promising.
The air volume could be varied by changing the length of the arm of round last piece. A screwing it in or out.

[richardmccombs]

Great idea, that’s basically a car wiper motor

[NathanielBechard]

to make it even more readily available, you could design it with a nema 23 stepper motor, they're cheaper and in the worst case scenario, the government can take them from cnc machine owners

[OrbPonderingWizard]

can i use this to one of our project study course?

[carterjon]

Great job. Looks like you could print most of it today. Sadly now that Ford is working with the fed, they will spend months on over designing, months on tooling before one is produced. Oh, and then they won’t be needed..we need like now.. or next week.

[shootgp]

Please add a link to the model so those interested can modify it in their choice of CAD. Also, great work, now I'm off to try to find a download link. Thanks

[KCRAS]

I thought of the same thing but mine is based on a cam and can be adjusted for volume or air for child infant

[oswaldomoraleslopez]

Estoy en Colombia y tengo la maquinaria para hacer la fabricación del ensamble, que son los piñones, chasis y guías, por favor que tipo de materiales se utilizan para la fabricación de todos los elementos mecánicos y así poder ayudar a controlar la situación.
I am in Colombia and I have the machinery to manufacture the assembly, which are the sprockets, chassis and guides, please, what type of materials are used to manufacture all the mechanical elements so that I can help control the situation.

[hlw]

Very good, From what I can tell, medics need to be able to set the rate, volume and o2 density. Is it possible to change the compressed volume/pressure with this system?

[constantgardener]

Ok, how about this ; a car windshield wiper switch set to intermittent, to a car blower motor, to a tube to a mask ? You could hook it to a 12 volt converter or a 120 volt converter ?