Air Collective Forum

What kind of device should I work on?

One of the most common questions we get from engineers is, “what device should I work on?”

The answer depends on a few factors, which are different in different countries.

To help you navigate this decision, let’s go over them.

Ambubags and BVM automation

These are the most common type of device in the maker communities. They take an existing Ambubag or BVM (Bag-valve-mask) or ambubag, which is a mask connected to a rubber bag that can be squeezed to manually ventilate a patient) and put some kind of robotic apparatus around it so it can be pumped.

Ambubags are usually found in ambulances and first-aid equipment, and in extreme cases like earthquakes and natural disasters, these are used too. When a mechanical ventilator isn’t available, ambubags are used but must be manually pumped by family members and volunteers.

These devices are useful when there are ventilator shortages, but many heathcare workers and regulators are not willing to accept them.

ARDS and lung complience

ARDS is a more sever complication common in COVID cases.

ARDS is a condition where the lungs become swollen and more resistant to expanding. Doctors use a word for how elastic the lungs are: lung compliance. In ARDS cases, the lungs are not complaint, they are swollen and stiff.

This causes 2 problems:

  1. The lungs require a lot more pressure to push air into them.
  2. The alveoli, or little folds in the lungs that move oxygen into the blood, they get swollen shut. (That’s called derecruitment.)


There is a solution to that, which is to put continous pressure into the lungs, especially after breathing out. That way, the alveoli are held open by the pressure. This is called CPAP, or PEEP, and there’s a more sophisticated version called APRS.

Ambubags don’t do CPAP, so aren’t very useful if the patient develops ARDS. But these are often the most critical patients.

Arguably, ARDS patients should get the CPAP ventilators, and the non-ARDS patients should get the ambubags, but doctors have many other factors to consider too, not just about the patients but also about concerns over certified or uncertified devices.


Certification is a big barrier for a lot of projects. Doctors firstly don’t want to harm patients, and non-certified devices can be seen as putting them in harms way.

On top of this, they are constrained by hospital policies and national heathcare laws.

In most countries, doctors will informally tell you that management is not competent, and they are at odds. There are many cases where hospital policy puts the doctors and patients at high risk, and yet the doctors accept that and risk their own lives needlessly, just to do their jobs. (Here are some anonymous interviews from US hospitals.) This tells us two things:

  1. Doctors often don’t get enough protective equipment from management, which is something you might want to help with. More heathy doctors = more healthy patients
  2. Doctors and management often disagree, and in normal circumstances, the doctors are forced to comply to unsafe management decisions. In this crisis, we’ve seen a few countries like Italty suddenly flip, and the doctors mobilize to adopt new equipment.

Some countries, like the US and UK, have announced new regulations for COVID-use ventilators. Spain has approved a 3D printed device, and Colombia is testing one. But most heathcare regulators have been silent.

When we look at countries like Italy, we see that once the situation is very bad, then doctors begin to speak out and take decisions in their own hands.

This creates a tough decision for engineers, to work on a device that will be necessary but possibly not accepted? Or work on a device that’s more complex and less likely to be built on time?

CPAP/sleep apnea and home-use devices

Home use devices, especially those used to treat sleep apnea, are CPAP ventilators. They are not necessarily useful in sever ARDS cases, but they can be used on patients earlier. We have been advised that those machines should help some patients recover to a degree where they would not need to advance to ambubags or certified ventilators with CPAP/PEEP.

The challenge with this strategy is that many more devices would be needed, since they must be employed before the ARDS sets in, to a larger number of patients, in order to save the same number of lives.

The only bad decision is to wait

These factors are likely to remain unclear in most countries, and health institution policies are likely to change as the situation changes, so it’s up to you to decide what to work on based on where you want to help, and in what timeframe. It’s better that you pick anything and start, since that way you make progress that can help other projects or be repurposed later. Having something to offer, even if it has drawbacks, is still better than nothing.

Nobody can predict what’s coming, and the more we all do, the more avenues we have covered.

If the situation changes, you can always jump to a different design and pick it up where others have progressed it.