An "open source" Powered Air-Purifying Respirator (PAPR) designed for times when access to industrially-produced designs are unavailable or in low supply. Inspired by the COVID-19 pandemic.
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Hygieia: the goddess of health, cleanliness, and sanitation
Concept Design
A Powered Air-Purifying Respirator (PAPR) is used to safeguard workers against contaminated air by pumping filtered air across the wearer's face. It provides both a physical barrier and constant positive pressure of purified air to ensure the safety of the wearer.
3D-Printed Parts
Assembly
3D Printed Parts
Hygieia Helmet
Hygieia Power Pack
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Thingiverse is glitching at the moment. Download individual files by clicking "6 Thing Files"
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For smaller print beds check out this remix by Bird2Brain
Required Hardware
Shower Caps
Plastic shower cap x2, design is personal choice.
Specifically, not a vacuum filter. Do not want to filter with fiber glass
This is the hard one. Filters are selling out
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Filtrete Advanced Allergen, Bacteria & Virus True HEPA Room Air Purifier Filter, Replaces size A/D/H sizes
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Can be found at Walmart
8 1/2 x 11 clear plastic sheet
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thickness is dealer's choice (we chose 7 mil, which is probably minimum desired thickness)
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Order online, office supply store
~40 inches of 1" diameter corrugated tubing
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can be found in AMBU bag kit
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can be purchased at home improvement store
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any home improvement store
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would not recommend Gorilla CA glue, takes too long to cure
No particular brand
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any home improvement store
50mm wide
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inexpensive work belt from home improvement store
Required Electrical Components
1 80mm x 80mm x 25mm 12V DC fan
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found in most computers
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can be ordered online
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most computer repair shops have too many
22-16 gauge Male spade connector
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found in any home improvement/electrical store
Rechargeable 12V battery pack (x2)
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found in home improvement stores, ordered online
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found on drills/drivers & other hand-held power tools
Motor speed Controller 3V 6V 12V 24V 35V DC 5A 90W
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Order online through electronics shop
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Local electronic/repair shops
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24 gauge wire at minimum, 22 gauge is probably best
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wires attached to fan are likely 24, no need to change, just use 22 gauge for other connections
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any home goods electronic store
Prototype #1
The Head Piece
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3D printed Head Piece
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3D printed Jaw Piece
- 3D printed Top Cover​
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Loctite Glue​
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7 mil 8 1/2 x 11" PVC clear sheet
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Foam
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2 shower caps
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Hot glue gun
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Cut clear PVC sheet (see template)
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Cut 23mm off 8 1/2in side (should now be ~7.6")
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cut off corners to match angle of jaw-chin piece junction (2 corners will be cut)​
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Fit into seam of head piece/jaw bars
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apply Loctite glue in corners and along edges for security​
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Cut 1 shower cap
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cut down center about 1/2 way
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hot glue two sides to where jaw meets headpiece
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Carefully continue to separate cap down center so that you can hot glue the sides down the jaw piece
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Try to only split cap enough so that you have a relatively flat section to glue to the bottom jaw piece
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Cut 8" of foam and apply to front rim​
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​Fit two Top Cover pieces together and glue to top of helmet.
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Tie desired elastic to bloat-cleat hooks ​
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Prototype Helmet #2
The Power Box
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2 clam shell pieces
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battery side​
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filter side
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3M HEPA Room Air Purifier Filter
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DC Fan 80mm 12V fan
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2 Milwaukee 12V Batteries
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DC Motor PWN Speed Controller
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Spade Connectors
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22 gauge Wire
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Utility Belt
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Hose
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Battery Side: Align 12V blower fan with indices, use hot glue gun to apply ring of glue around air-inlet to seal
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gently press and hold for 30 sec​
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Connect 4 spade connectors to 4 wires
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2 longer wires (travel the length of box)​
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2 shorter wires
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Thread wires through the battery holder slots (see images)​
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Use hot glue to secure and seal wires and spade connector at bottom
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Complete battery, fan, and controller circuit
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see electrical diagram
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Place speed controller in slot​​
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remove dial head, nut, and washer​
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fit through hole and replace
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Plug 12V Batteries into holders
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Filter Side: Remove adhesive strips from HEPA filter and carefully align and press in​​​
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Align 2 clam shell pieces ​and press together
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Fit utility belt through slots on filter side
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adjust to comfortable length​
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Connect hose to Head piece and ​Power box.
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Electrical Diagram
Disclaimer: Please note, this device has not yet been tested for official use or approved by the FDA. We cannot guarantee the safety of the wearer and should not replace N95 masks. This should only be used in emergency circumstances. This device in not endorsed by Tulane or UNO. Wearer uses at own risk.
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Hose DiameterWe initially chose the hose included with an AMBU bag. However, upon assembly, we realized the 1" diameter was creating too much resistance. We will widen outlet on the Hygieia Power Box, use wider corrugated tubing, and increase diameter of Hygieia Head Piece inlet and canal.
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Hygieia Power Box blower fan placementWe decided to put the fan on the unfiltered-side as we did not want any chance of the fan contaminating the air. However, this does not allow for optimal airflow. Our next design will likely remove the blower fan housing and just use the blades and motor on the filtered side. We will be sure to clean the blades carefully before closing case.
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Hygieia Power Box ClipsWe will modify surrounding support so the box clips together more firmly and creates a better seal.
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Hygieia Power Box battery placementThe batteries were placed on the sides for both wire placement and printability. However, it is too wide and the batteries could be placed in the bottom or closer to the belt-side.
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Alternate Power SourceThe batteries work well but are the most expensive part of the unit if you do not already own them. We would like to provide designs for alternate power sources, including the most common brands of 12V rechargable battery packs.
Creators
&
Collaborators
Jorge Nagel, Electrical/Biomedical Engineer, Tulane Medical Student
Catherine Gilbert, Tulane Medical Student
Matt Owen, Engineer, Lusher High School
Michael Ceraso, Electrical Engineer University of New Orleans
Charlie Miller, Mechanical Engineer
Jay Saksena, Tulane BME PhD candidate
Gnome Computers, New Orleans
What else are we working on....
We have collaborated with makers all over New Orleans to design, produce, and distribute 3D printed and laser cut face shields to local hospitals and beyond! (Feel free to message us for .stl and designs)
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Matt Owen twitter #makered: https://twitter.com/_mattowen_/media