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Nasopharyngeal swabs

World-wide there is a shortage of nasopharyngeal swabs, with which samples are gathered to check patients for COVID-19. These swabs are also used for testing for influenza and other respiratory infections. Locally in Sweden Kalmar has reported using swabs intended for Chlamydia.

NP swabs are flexible sticks with a bristled end that are inserted into the nose to the back of the nasal cavity and swept around to collect material that sticks to or wicks up the bristles. The swab is then placed into a vial that contains a culture medium. Swab sticks have an intentionally weak point 7-8cm from the bristled tip, which allows the stick to be broken to the correct length so that the vial can be capped before it is transported to a laboratory for testing. There is a comprehensive GIT-hub page for swabs available Covidswab.

Current status

A bunch of test swabs have been printed and delivered. The pins are packaged and autoclaved in 134 degrees. We are currently printing on a Formlabs Form3 printer and in SG resin. Printing on Form 3B printer takes about 24 hours for 300 pins, and the print time on a Form2 printer is about 13 hours. We have also printed parts to facilitate handling such as stands for curating. Basically all SLA printers with some kind of surgical resin should work as long as the build volume is sufficient.

Test results

2020-04-16 First test to autoclave. Initial results looks good. More comprehensive tests will be performed. 2020-04-17 Tested on volunteers and patients. Awaiting for the results to come in.

nasopharyngealswabs.txt · Last modified: 2020/04/17 19:26 by