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Pneumask: Reusable Full-Face Snorkel Mask PPE Project - 🟧Sourceful

Repurposing full-face snorkel masks with a 3D printed N95 filter attachment as a reusable stopgap PPE solution for healthcare workers to help address the N95 mask shortage. - 🟧Sourceful

coronavirus, hardware, PPE

Prakash Lab COVID-19 Response Group Working Draft Document

Document #002, rev. 2020-05-10 draft Not an approved medical device

Pneumask: Reusable Full-Face Snorkel Mask PPE Project

Repurposing full-face snorkel masks with a 3D printed N95 filter attachment as a reusable stopgap PPE solution for healthcare workers to help address the N95 respirator shortage.

Created: March 19, 2020

Last Updated: May 5, 2020

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

Short Title: Repurposing of full-face snorkel masks as reusable PPE for healthcare workers

Detailed Title: N95 filter attachment to repurpose full-face snorkel masks as reusable PPE with airborne and splash precautions for healthcare workers.

Technical & Academic Contributors:

- Stanford University Prakash Lab: Prof. Manu Prakash, Laurel Kroo, Anesta Kothari, Thibaut Pollina, George Herring, Ray Chang, Rebecca Konte, Hongquan Li, Hazel Soto-Montoya, Samhita P. Banavar, Elliot Flaum, Grace Zhong, Prakash Lab members

- Melanie Hannebelle, EPFL

- Dominic Peralta, Stellar Design

- Eric Gagner, Boston Scientific

- Olin College of Engineering (Bluetooth App Team): Kyle Combes, Emma Pan, Khang Vu, Kelly Yen

- Deakin University (iOS bluetooth app): James Dale

- Ross Venook, Stanford University Dept. of Bioengineering

- Nicholas Cucinelli, Entrepreneurial Leadership Faculty, U-M

- Rozhin Hajian, Harvard

- Simon Ellgas, Waymo

- Luca Borroni

- Noah Jacobs

- Patrick Gerber, DSPS, EPFL

Clinical Contributors:

- University of Utah School of Medicine: Dr. John Pearson MD, Patrick Kolbay, Dept. of Anesthesiology team

- UCSF Dept. of Anesthesia and Perioperative Care

- Dr. Philip Wagner MD, Hospital for Special Surgery, NYC

- Dr. Roberto Miki, Miami

- Dr. Cristián Muñiz Herrera MD, Chile

- Dr. David Kohn Bitran MD, Chile

- Dr. Peter Baek MD MS, U.S. Anesthesia Partners, Texas

- Nitin Arora M.D., M.P.H, F.A.A.P, Assistant Professor

Children’s of Alabama & University of Alabama at Birmingham

Industry Contributors:

- Boston Scientific: Randy Schiestl, Shannon Abel, Eric Gagner, Darius Mercer, Chase Fetzek, Paul Miller, Martin Plantenberg, Michael Brekke, Tim Dolan, Abigale Bather, Daniel Burgess

- Stellar Design: Dominic Peralta

- Autodesk: CEO Andrew Anagnost

- Wildhorn Outfitters: Gerry Ayala

- Decathlon: Quentin Allinne

- Kober Engineering: Filip Kober

- Dave Kasper, iSnorkel, Inc.

Prototyping, Supply and Manufacturing Partners: FormLabs (Jory Block), PrinterPrezz (Eshaan Gandhi), Origin.IO (Finbarr Watterson), CZ Biohub, Wildhorn Outfitters (Mark Siu and Gerry Ayala), Walmart

Project Leads: Anesta Kothari, Thibaut Pollina and Laurel Kroo

Please write to and if you would like to join our effort.

Project PI: Manu Prakash

Document Steward/Editor: Manu Prakash

Quick Links:

* Executive summary on Prakash Lab website

* Supplementary document for Pneumask Coupler Design (note: this document is temporarily private for a day to allow for reorganization of document contents)

* Directory of other Prakash Lab COVID-19 response projects

Concept and first functional prototypes currently being tested in the clinic.


A full-face snorkel mask has been adapted and evaluated for use as personal protective equipment for health care workers, who lack appropriate alternatives during the COVID-19 crisis in the spring of 2020. The design consists of a custom snorkel-specific adapter that couples the snorkel-port of the mask to a rated filter (either a medical-grade ventilator inline filter or an industrial filter). Our team refers to this combined solution as Pneumask.

This design has been tested for the sealing capability of the mask, filter performance, CO2 buildup and clinical usability. These tests found the Pneumask capable of forming a seal that exceeds the standards required for half-face respirators or N95 respirators. Filter testing indicates a range of options with varying performance depending on the quality of filter selected, but with typical filter performance exceeding or comparable to the N95 standard. CO2 buildup was found to be roughly equivalent to levels found in half-face elastomeric respirators in literature. Clinical usability tests indicate sufficient visibility and, while speaking is somewhat muffled, this can be addressed via amplification (Bluetooth voice relay to cell phone speakers through an app) in noisy environments. We present guidance on the assembly, usage (donning and doffing) and decontamination protocols.

The benefit of the Pneumask as PPE is that it is reusable for longer periods than typical disposable N95 respirators, as the snorkel mask can withstand rigorous decontamination protocols (including autoclaving). With the dire world-wide shortage of PPE for medical personnel, our conclusions on the performance and efficacy of Pneumask as an N95-alternative technology are cautiously optimistic. The FDA has instructed our industry partners to ship these units as “face-masks” (that may be assembled by healthcare workers themselves and categorized as “improvised” PPE) until they can verify and validate the data and conclusions within this report.

Table of Contents:

Description of Innovation


Diversity of Full-Face Snorkel Mask

Inhale/Exhale Pathways for the Snorkel Mask

3D Printed Coupler Parts for the Snorkel Mask

Pneumask-G: Anesthesiologist and General-Use PPE

Pneumask-S: Surgeon-Specific PPE

Testing and Ongoing Clinical Validation

Fit Test & Seal

Qualitative Fit Test

Quantitative Fit Test

Evaluating Potential Leakage from Chin Valve

Exhalation Valve Leakage Test

Valve Closure Times Estimation

Carbon Dioxide level test

Exercise test

Simulation of CO2 Speci

Pneumask: Reusable Full-Face Snorkel Mask PPE Project
Tags Coronavirus, Hardware, PPE
Type Google Doc
Published 17/09/2020, 11:45:05


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