This is a ventilator system concept that I think solves several of the major challenges presented (especially cost and material availability), but will need a lot of prototyping to determine if it's viable. DISCLAIMER: I have no medical, engineering (except the software kind), or manufacturing experience and am simply presenting this concept for your consideration.
This project was an interesting exploration into the world of medical device design, but is nowhere near sophisticated enough to meet even the lowest requirements for safe mechanical ventilation. Additionally, my assumptions about using OTS parts and widely available plastics were wrong and introducing this level of complexity on a rapid timescale is simply not feasible.
Please direct input / feedback for this concept to the github issues tab. For Chat with people around the world working on the Agorize ventilator challenge check out this Discord room: https://discord.gg/4T2EGjh
This ventilator concept is designed to regulate approximately 3.6L of air (IPPV) to two patients. It includes only two components:
(see also Component B Rotating Valves.png and Component B manifold base.png)
In this concept I've sized the canister to use readily available 6in PVC pipe (with minimally modified end caps) and a free-floating chamber separation plug / seal (not sure the proper name). I arbitrarily chose 2cm diameter tubes for my concept, but any size should be possible with minimal adaptation. The valve manifold is designed to be CNC machined from a single piece of stock material (reductive manufacturing), but has additional parts for each valve. Rotating half-circle valves are actuated by a small electric motor (that should have speed controls!). These valves may not work at all as I have no experience with pneumatic valves, but the real concept here is to 1) centralize parts requiring precision to as few parts as possible and 2) synchronize the four one-way valves (V1-4) so that air is flowing through V1 and V4 at the same time, then V2 and V3, and back to V1 and V3, such that the free-floating plug alternates back and forth in the cylinder.
A few dimensions I baked into this design that will definitely need to be reviewed by a medical professional:
I don't know enough to dictate what materials should be used for any parts in this contraption, but from my limited knowledge of plastics:
Air supply may be delivered via any compressed air source, and filter either pre-ventilator or post-ventilator. I imagine that, in a pinch, portable air compressors (the kind that run air tools) could be used, perhaps in a bank of multiple compressors to provide redundancy / overcome duty cycle limitations. I read somewhere that 50PSI was required for inspiration, which sounds high to me, but regardless this concept should be able to be used for any pressure given the right materials.
This ventilator concept is only concerned with providing positive pressure for inspiration, relying on natural lung elasticity and pressure differential for expiration.
I don't have any plans to attempt to build this ventilator myself, but offer it up to the world in the hope that it inspires (pun intended) someone out there. Please use it in your hackathon or however! If you have any questions please open an issue on this repository.
Copyright 2020 jwilson8767 on GitHub
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