The Impetus

1
Universal Facemask Adapter (UFA) N. Burns, M.
Callahan, L. Flournoy, G. Ramus

• The Impetus
• Widespread flu pandemics crippled the country and
  the world in 1918, 1957, and 1968. There is
  generally acceptance that whether a similar
  pandemic will occur is not a question of, if
  but rather, when. The next strain of influenza
  that may make the jump to pandemic status is
  hypothesized to be H5N1, more commonly known as
  avian influenza or the bird flu. Based on
  consultation with clinical advisors, the original
  intention for this senior design effort was
  design and development of a improved disposable
  particulate respirator that would effectively
  prevent passage of H5N1 virus-containing
  particulates into a healthcare providers airway
  while not impairing their ability to function in
  their particular job. Because it is not known
  what form the virus may take if it becomes
  capable of human-to-human transmission, this
  non-pharmaceutical intervention would likely be a
  highly desirable source of protection. After
  several reviews of possible designs, the concept
  was re-geared toward the creation of a
  gasket-type adaptor that would sit in between the
  users face and a preexisting mask to better seal
  any gaps that naturally exist due to the
  populations differing facial structures. This
  approach would allow existing masksas well as
  any masks that may yet be developed to be
  immediately improved allowing more effective and
  adequate protection from both avian flu and a
  variety of other infectious diseases.

• Testing Methodology
• Qualitative Fit Testing
• The testing used to validate the success of the
  prototypes involved a three stage process
  Bitrex detection with sensitization, testing
  without the adapter, and testing with an adapter.
  
• Initially ten subjects who failed a respirator
  fit test without the use of the UFA was desired
  for testing
• Success of the Phase I prototypes would be based
  on the aforementioned subjects passing the
  qualitative fit test only when using the UFA.

• Results
• Currently, eleven subjects have been tested using
  the Bitrex method, four of which have failed the
  qualitative fit test without the use of the UFA
• Three of the four subjects who failed the fit
  test without the use of the UFA subsequently
  passed the fit test with the use of our product
• One subject who passed the initial fit test
  without the adapter failed the second fit test
  with the UFA
• A table summarizing the results of the Bitrex
  testing can be found below.

• Design Methodology
• Design Development
• The initial design and shape were created in
  SolidWorks 2006 (SolidWorks Corp., Waltham, MA)
• A prototype was created and the SolidWorks model
  was refined several times until the final shape
  and design was determined
• Foam Adapter
• Using the Solidworks models as a guide a
  prototype was created by hand out of Airtex high
  density foam.
• The dimensions of the foam adapter are show in
  Figure 1 below.
• The foam adapter costs approximately 0.60 to
  produce by hand, but with further refinement mass
  production could greatly reduce this cost
• Polyacrylamide Gel Adapter
• The desired shape of the adapter was transferred
  onto thin vinyl (PVC) sheeting, and a second
  sheet was then glued and heat sealed on top of it
• Non-toxic polyacrylamide gel was then injected
  into the space between the two vinyl sheets
• The cost per adapter is approximately 1.80, but
  this would decrease dramatically with larger
  scale production

Without Adapter With Adapter
Pass 7 9
Fail 4 2
Figure 3. Participant of the fit testing
procedure.
Discussion Although further testing must be done,
the preliminary fit testing that was performed
with the use of the Universal Facemask Adapter
indicates the potential for success of the
product. However, the Bitrex testingdue to its
qualitative natureis relatively subjective, and
relies heavily on the perception of the subject
being tested. It is recommended that for further
testing a more quantitative testsuch as
PortaCount testingis used. This would remove any
potential bias that a subject may have, and would
give the exact number of particulates that pass
beyond the respirator. Also, the use of an
adhesive to secure the UFA to both the mask and
the subjects face should be tested for potential
use with a final prototype. Further, to truly
call this product universal, different styles of
particulate respirators that are on the market
must be tested with the adapter. Although only
in a preliminary stage of development, results
suggests the product warrants further pursuit.
The economic benefit that may potentially arise
due to the eventual elimination of fit testing,
as well as the health and safety benefit to the
intended user that the adapter would bring demand
that the development of the Universal Facemask
Adapter be continued.
Acknowledgments Special thanks to the generous
gift of Drs. Hal Wrigley and Linda Baker, the
BioEngineering Department, Andy Holmes, Virginia
Dato, MD, MPHPA Department of Public Heath, and
Eric Toner, MDUPMC Center for Biosecurity