TITLE: 3D Printed Nasopharyngeal Swabs with Wrapped Rayon Fibers Developed and validated by SCREEN (San Diego Covid19 Research Enterprise Network)
AUTHORS: Justin Ryan, Nicole Coufal, Sage Aronson, Kelsey Ladt, Catelyn Andersen, Mark Zeller, Stephen Rawlings, Denise Malicki, Gene Yeo

[DESCRIPTION]
<div class = "text-blocks"><div class = "text-block"><div class = "justify" style = "text-align:justify">The global pandemic due to SARS-CoV2 virus, also known as COVID-19, has drastically increased the need for nasopharyngeal-swab-based testing resulting in shortages of commercially available nasopharyngeal (NP) swabs. One solution to overcome the national deficit of swabs is for medical device manufacturers and hospitals to generate NP swabs. Numerous entities are attempting to manufacture a direct from 3D printing NP swab but presented here is a validated two-part swab manufacturing protocol utilizing 3D printing and manual intervention (wrapping of nylon fibers). We recommend material extrusion or powder bed fusion technologies utilizing materials that can be sterilized using high level heat decontamination. Through the application of 3D printing and manual fabrication, we present an NP swab that can be created in a controlled environment. Coupled with CDC published viral transport media, the following swab can be used for COVID-19 testing or for testing for other respiratory viruses (eg, influenza, respiratory syncytial virus). The CDC viral transport medium has only four reagents which are readily available. </div><style>
							  .justify:after {
							    content: "";
							    display:inline-block;
							    width: 100%;
							  }
							</style></div></div>

[STEPS]
?. [3D Printing]
Print the SCREEN design in a nylon-based media and ensure additional adhesives or binding agents are not used unless additional validation is performed.
?. [Swab Procedure]
While wearing gloves, open the supplied 3D print file.
Note the following: The file was designed to not need support structures in the case of material extrusionSpecific printers may still benefit from added support structuresAdhesives should not be used on the build bed unless further validations with the adhesive have taken place
?. [Swab Procedure]
Send the job to print.
?. [Swab Procedure]
After printing, inspect print for deviations in the print process such as delamination and burrs.
?. [Swab Procedure]
Take a quarter-sized amount of rayon fibers.
?. [Swab Procedure]
Tightly wrap the fibers onto the tip of the swab.
?. [Swab Procedure]
Extra care should be given to ensure the end of the tip is covered.
?. [Swab Procedure]
The swab tip should be 3-4mm in diameter following the tight wrapping procedure.
?. [Swab Procedure]
Perform non-radial motions to help the fibers intertwine and reduce the chances of the fibers becoming unwound.
?. [Swab Procedure]
Pull on the collective rayon fibers to ensure that the fibers do not become dislodged from the swab.
?. [Swab Procedure]
Sterilize the swabs utilizing hospital grade high level decontamination at  for  in individual packages, preferably with a temperature indicator to indicate appropriate temperature has been attained. Prototypes were autoclaved at  for  without complications.
270 °F
121 °C
?. [Swab Procedure]
Validation of the effectiveness of printed nasal swabs can be found in the Guidelines Section.