Makers

We have received many emails from people asking how they can help as a maker, with certain 3D printing resources. With many of you coming from many different geographical locations and with variety of skills and tools/resources, we would like to outline a few key points to keep in mind. We caution the community that these adapters are not a great project for hobbyists -- while it is possible to use 3D printing to make certain PPE, there are technical challenges that have to be overcome to be effective enough, such as making sure the fit and tolerances of the parts are excellent in mechanical fit, material, and are extensively quality controlled. Therefore we really encourage the community to supply these adapters from verified partners who are doing high-quality injection molded adapters, rather than printing them yourself. 

However, we do understand that in times of great need, these adapters may be hard to acquire, especially internationally. We have outlined some files and some notes on materials below to help guide your efforts, if you choose to take on this liability of manufacturing and distribution of these systems. It is possible that you will need to adapt these parts, especially on the side of tweaking tolerances on the snorkel port for use with your specific printer. Proceed with extreme caution, knowing that we cannot speak to the safety of anything that you design, print or test yourself. The FDA has also released a series of FAQs on 3D printing medical devices.

Please always keep in mind the goal of this alternative PPE is to keep healthcare workers safe rather than create a false sense of security.

 

Download our Adapter Models

If you’d like to download the adapter models that we have prepared for the Dolfino Frontier and Decathalon Subea V1, please refer to the links below. Please see notes below for additional details.

Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)

 
 

Design/Fit

There are multiple brands and models of snorkel masks available. If the ones you or your community have access to are outside of the main two models we have shown (Dolfino Frontier and Decathlon Subea V1), please take the time to work with an engineer and CAD modeler to edit one end of the adapter that engages with the masks’ ventilation ports. It is critical to get a tight fit between the adapter and the mask. 

  • For the main Dolfino mask design, this is the latest adapter design (latest version by Boston Scientific) that connects the Snorkel Mask to an ISO 22mm port (to engage with the bacterial/viral filter). 

  • As an an additional modular component of the design, we have also have a separate ISO 22mm to ¼ turn cartridge filter adapter, which allows standard industrial filters that are NIOSH-approved to be mounted to the snorkel adapter listed above. It is CRITICAL that the proper gaskets are used if using these industrial-grade filters are mounted instead of the medical-grade filters. The fit-tests with the industrial filters require the use of these gaskets. The medical filters with the simple adapter part do not require the use of these gaskets. 

For each design, please produce a few initial prototypes that can be tested for fit at your local institutions. Refer to the fit test protocol

 

Dangers of Monofilament Printing

Material/Tool

Please note the fidelity of 3D printed parts vary with the printer and associated materials. 

  • Always TEST any printed parts for fit. Fit protocols are standard at most hospitals Health and Safety sectors (protocols such as Saccharin Fit Testing). It may be necessary to print a range of parts with different tolerances on the part for good fit, depending on your printer. Specifically the for on the adapter-to-snorkel side may need to be tweaked depending on the printer you use. Substantial CAD proficiency necessary. Of course, we recommend printing these adapters yourself ONLY if in dire emergency need where no other safe PPE is available, AND if you cannot source the injection-molded adapter (independently fit-tested) from our partners.

Bio-compatibility and withstanding decontamination protocol:

  • We suggest using materials  that will hold up to multiple decontamination cycles (submersion in 99-100% alcohol for several minutes, followed by drying; or one of the other decontamination procedures that can be found in our live google doc). We have had good experiences with several kinds of resins on this project: 

    • Carbon RPU-70 is one material that we have worked with extensively in our lab.  It is a polyethylene resin and it has a spec sheet on biocompatibility. Printerprezz is a company we have been working with locally in the Bay area; they have the resin (and the Carbon3d printers that use it) and have been printing prototypes for us in this, primarily. It is just slightly more compliant than most of the other materials we’ve been looking at, which helps with seal/fit. Spec sheets on carbon RPU are here: https://www.carbon3d.com/materials/rpu-rigid-polyurethane/ 

    • Formlabs resins of pro-grey and high-temp resin appear to work from a mechanical perspective, too. The tolerances on these printers tend to run a little tighter than some; so the adapters should be checked for fit very carefully. 

    • Boston Scientific has built steel molds; they are doing injection-molded adapters out of polypropylene (PP). It’s quite non-compliant, but the tolerances are excellent.