3D Printed Test Swabs for COVID-19 Testing
What are Test Swabs?
There is a worldwide shortage of the nasopharyngeal (NP) swabs needed to collect samples for COVID-19 testing. The shortage is expected to become even more acute as many governments and healthcare institutions around the world consider ramping up testing a prerequisite before lifting restrictions and resuming normal economic activity. The current and impending supply chain shortages are serious enough that clinicians have begun to design and test their own swabs as quickly and safely as possible.
This page describes efforts originating in Spain. Find out more about the development of NP swabs in the US.
NP swabs are typically used for testing for influenza and other respiratory infections. They 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 7–8 cm 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.
How are Test Swabs Made?
After identifying that NP swabs for testing COVID-19 were in high demand and extremely limited in supply, officials from the healthcare system of Cantabria in Spain contacted the Hospital virtual Valdecilla (HvV) and challenged the institution to develop ways to design and manufacture swabs internally in their region.
“What we are facing today, I'm sure in a short period, will be also a situation in many other regions. Before we lift the shelter in place restrictions, we need to test more people, so we need more swabs. But that’s a challenge because the US needs more swabs, Italy, Spain, and many other countries also need more swabs,” said Ignacio Del Moral, MD, PhD, Executive Director at Hospital virtual Valdecilla (HvV).
HvV established a multidisciplinary research group—ear, nose & throat (ENT) specialists, microbiology specialists, nurses, and engineers—to develop an alternative design using Formlabs’ 3D printers and biocompatible, autoclavable resin, and conduct testing. The team designed and tested new iterations every two days until reaching a final design within 10 days—a process that normally takes months for medical devices.
“The latest, fifth version has been used on more than 100 patients. The ENT department is very happy with these swabs because the design is hard, but at the same time, it's very flexible. It allows them to get to the far away point in the nasal cavity to collect the biological specimen”, said Juan Pedraja Vidal, Human Factor Engineer and Leader of the 3D printing and Virtual Reality Lab at HvV.
Using a Formlabs SLA 3D printer, HvV can manufacture 324 swabs in 11 hours, which translates to 650 swabs on a single printer within 24 hours by printing overnight.
The 3D printed swabs have been tested in more than 100 patients in Spain to validate patient safety and usability to ensure that they function as intended and that they don't cause any harm to the patients. HvV has also defined a manufacturing process from the point of 3D printing to cleaning, post-curing, and quality controlling, using sterilized tools to create an aseptic and controlled environment.
The internal clinical validation was performed by clinicians from the Microbiology and ENT departments at Valdecilla University Hospital. After the internal clinical validation, healthcare authorities in the Cantabria region of Spain have approved the clinical use of the 3D printed swabs.
HvV has started to produce swabs and provide them to clinicians in the region and others from hospitals in other regions of the country. With a second 3D printer on the way, they’ll be able to manufacture enough swabs to become one of the first regions in Europe to achieve autonomy in the production of this fundamental piece of equipment for PCR tests.
HvV also worked with a regional technological institute, Centro tecnológico CTC, to conduct mechanical tests to evaluate the behavior of the swabs under stress and to gather data on the maximum flexion of the part before breaking. See the results of the mechanical validation (in Spanish).
The researchers are now planning to collect more data to compare the effectiveness of the 3D printed swabs to standard swabs, and then publish the results in a scientific journal. HvV is also working with other healthcare organizations to submit the information of the swab to get the CE mark, which confirms that the medical device meets certain "essential requirements" of the European Medical Devices Directive (i.e. that it is safe and effective for the intended purpose).
How to Create Test Swabs
The Hospital Virtual Valdecilla made the swab design open-source and publicly available so that other institutions who face shortages of swabs can manufacture their own.
Please note that it is any hospital's or institution’s responsibility to validate the workflow, perform disinfection procedures, confirm the quality of the swabs, and comply with the required local regulatory approvals and clearances.
If you’re interested in producing swabs or purchasing a Formlabs 3D printer and materials for medical use, please contact us directly.
In Partnership With
Formlabs would like to thank our partner Domotek for their contribution to this project.
Formlabs has created this website and has become involved in varying degrees with the projects described here during a global medical crisis. Formlabs is working on many projects to address global healthcare-related supply shortages around the world, but in trying to mitigate these shortages, patient safety is still Formlabs’ top concern. We must remind those who are helping to alleviate these shortages that masks, swabs, face shields, and other 3D printed products intended to prevent or treat COVID-19 are medical devices that these devices must be safe for their intended purpose and anyone considering the manufacturing of these products should consider the following items:
Formlabs is a manufacturer of 3D printing materials capable of fabricating finished devices according to their labeling and any other product manufactured from these materials should be verified and validated according to their intended purpose.
You may be fabricating a device that does not have the required regulatory approvals and clearances. If you are fabricating devices, follow the guidelines on the label for each material. You may seek to obtain reliable regulatory advice.
Please consider local regulations, material safety data sheets, software capabilities, sterilization requirements, and institutional requirements before 3D printing medical devices.
Regulatory agencies (such as the MHRA, BfraM, etc.) may consider an expedited review of manufacturing information and/or premarket submissions.
Formlabs cannot warrant that any products not manufactured by Formlabs are suitable for their intended purpose. Formlabs has not independently verified or validated the specific design parts mentioned in this case study and if they are safe or effective for their intended purpose. Any 3D printed appliances that are subjected to skin contact should meet the biocompatibility requirements stated in ISO 10993-1.