One response to possible COVID-19 medical device shortages is to try to hack DIY COVID-19 medical devices together. It’s very empowering to see open-source communities come together to try to turn out a workable design to help avoid dire shortages for those in need. However, development of medical devices is far more nuanced than it might seem.

Polymerase chain reaction (PCR) devices

One technology that’s come to the spotlight in the wake of the pandemic are polymerase chain reaction (PCR) devices. These are in-vitro devices used for certain types of COVID-19 tests to amplify small amounts of the virus to levels we can actually detect, making the tests more sensitive. There have been a number of open source projects dedicated to this for at least a decade. As the pandemic picks up momentum, fast access to PCR machines is suddenly in very high demand. PCR devices are fairly reliable, but need to be accurate to avoid false negatives (which could lead to further spread of the virus if people think they are unafflicted when they actually are).

3D printed face-shield holders

Another popular DIY medical device is 3D printed face-shield holders. These are incredibly low risk, and a great way to help out if there is an organization in your area looking for donations. They are usually a simple 3D printed visor with an elastic headband and a letter sized overhead transparency attached. Technically, these should still follow medical device standards for safety (cleanliness) and traceability, but a lot of front-line health providers have been requesting these from the public. Reach out to organizations in your area for opportunities to contribute.

Ventilators

Besides PCR machines and face shields, most of the discussion surrounds ventilators. Ventilators are used to assist patients in breathing where they can’t breathe (or can’t breathe well enough) on their own. They are essentially automatic billows – forcing air into and out of the lungs. Many use venturi geometry (a type of flow control nozzle) to ensure correct pressure, speed and flowrate. Typically, ventilator devices have a reusable pumping portion and a disposable tubing portion that is changed out between patients.

There is worldwide concern that there aren’t enough of either the reusable pumping portions or the disposable elements. Doctors in various hotspots are already preparing to hook up multiple patients to one ventilator where the pumps are short supply, and getting ready to 3D print the disposables if needed. Approved disposables are made from biocompatible materials using specialized moulding equipment and are sterilized in their packaging, so any sort of homemade disposable is quite a departure from the typical methods. The proper disposables might also be washed and reused in desperate times. That may not be effective at all and may end up spreading the disease to the next patient despite best efforts.

One important thing to remember is that ventilators force air into vulnerable patients, so they require a fairly precise control system to ensure they deliver just the right amount of pressure and humidity. Home-made versions that aren’t properly prepared or designed could introduce a significant risk of causing further harm to the patient or spreading disease to others. If a ventilator is being used to keep people alive, it’s also essential they have a fail safe mechanism of some sort, be that a warning alarm should they stop working, or a backup of some kind.

Over the last few days, we have seen medical device manufacturers step up ventilator production and release design details, as well non-medical factories start making them for the first time. This makes sense, as these organizations can deliver safe, effective ventilators that will certainly bring a higher level of care to those who need them. Open source and DIY ventilators are great, but should be treated as a last resort if professionally made ventilators don’t get out in time. I know I’d rather have a loved one take a chance with a homemade ventilator than nothing if there were no other options.

In some ways the risks related to both ventilators and PCR machines are very concerning, but the stakes are also very high if the alternative is not having enough available for everyone to support appropriate testing and treatment. Health care providers worldwide are aware of the risks, and are preparing for a spectrum of shortages from mild to severe with the goal to limit risk as much as possible for each scenario.