Dentist's Chair Respirator Adapter - 3D printable.

This is to protect you from the aerosols emitted by the client/patient before you in the same dentist's chair, given #COVIDisAirborne (as might be Flu, RSV, Polio, TB, and others). 

Dentist's Chair Respirator Adapter (DCRA henceforth) is a gizmo that you'd use for adapting a vertical fold KN95, FFP2, N95 respirator for nose use only.  You'd use staples and duct tape.  there would be a range of sizes with the key component being the distance between the centers of your own flared nostrils (23 mm is the distance between the two nostril centers now).  You'd hold it in one hand on the opposite side to where the dentist is working.  If you can close off your airway from your mouth, and hold it like that for the duration of the dental inspection or teeth cleaning you can use this thing. Well, if you've not been injected with injected or gassed for a procedure you can.

This is 3D printable. It is also injection moldable in two mirror-image halves (welded or glued after).

GPL 3.0 license -> https://www.gnu.org/licenses/gpl-3.0.html. 

Version 2.0 (Dec 18th 2022)

  • Better nose fit?
  • Grip added
  • Respirator fixing part now closer to cheek to make it easier to hold


3D model for examination in your browser

Design files:

If making your own:


  1. Look in a mirror and fully flare your nostrils. 
  2. Measure the center to center distance with a ruler, and take off maybe 1 mm.
  3. Noting the 3D design linked to in  this page is 23 mm (measured in #2), adjust your 3D print up or down proportionally.  Perhaps use https://www.treatstock.com for a one-off printing - very easy.

Using:



The gizmo can work with the respirator over your left or right cheek. You'd work out which side is correct based on the dentist, the chair and you THEN you tape it all shut.

head looking up at 45 degrees

There's a few ways you can hold it and still be out of the way of the dentist. If you get a bit claustrophobic and suddenly decide the risk is zero and you need a big breath, you can just lift it off as it is not attached in any way. Someone else can think of straps. Heck, someone else can make something that goes over the nose with straps that is more like this -  https://www.thecpapshop.com/resmed-airfit-n30-nasal-cpap-mask-with-headgear


You'd enter the room in a regular N95 (etc), then swap over to this one as you sit in the chair.  Practice using it first. 



The SolidWorks design was made via UpWorker E.M. for a fee.

if you choose to use a big elastic band and no hands



This polystyrene head is 85% adult head size (despite what it said on Amazon). 
With mouth open and in the dentist chair there is plenty of room for them to work, I promise.


Tests



With a GVS FFP3 mask snipped, 
stapled and duct-taped
Portacount port and 'grip' on the other side.
Mask taped for being held in left-handed 


Ex 1: 99.4781%, Fit-Factor 192.0

Ex 2: 99.4038%, Fit-Factor 168.0


That's with some pressure applied to nostrils, it has to be said.

Testing the fit for yourself


Tape over the open end with duct tape where you would normally affix the mask. You're trying to completely close it.  


In front of the mirror put the two tubes into your nostrils and try multiple positions until you can't inhale or exhale at all.  

Be careful to still draw breaths, as you're trying to determine how best to hold it with the mask attached and not suffocate or end up injured somehow.

If this works and you can hold it like that, you should match the best filtration performance of the N95-ish respirator that you can duct-tape on.



Older first 3D print version


I tested the prototype on a vintage PortaCount 8020a with a generic FFP2 centerfold respirator and it hit 98% particle filtration efficiency.



3D model for examination in your browser (Scroll to bottom for latest!!!!!)


V1 Design files:

Scroll to bottom for latest!!!!!

Dec 16th update: 3D printed item received next to MacGyvered prototype:



Dec 5th update:  the end that the mask fixes to should turn by 30 degrees to make the ask closer to the user's cheek and make more room for the hand that holds it.


Results: 


Ex 1: 97.3217%, Fit-Factor 37.3

Ex 2: 97.6907%, Fit-Factor 43.3



Small leaks at the nose inserts. A redesign needed.

Dec 17th, more epoxy putty and I'm chatting to E.M again about new SolidWorks modeling,

if you choose to hold with a hand




















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