Identifying medical equipment in potential short supply
During the first 2 weeks of the pandemic in Spain (March 2020), our team worked with pulmonologists, intensive care physicians, and hospital purchasing managers to identify potentially unavailable medical equipment that could be manufactured using 3D printing. To determine the health system’s needs, we also considered news, other online information, and proposals from other health centers. Items that could not be validated in terms of knowledge or available facilities were excluded.
After the identification phase, two reengineering strategies were used to design items: 1) optical scanning and 2) de novo design referencing the dimensions of the original item.
For optical scanning, we used a hand-held 3D scanner (HandySCAN BlackTM Elite, Creaform Inc.; Lévis, Canada) with dedicated software for reverse engineering and metrology (Geomagic® Design X, 3D Systems Inc.; Rock Hill, SC, USA or VxModelTM, Creaform Inc.; Lévis, Canada). For de novo design, we used computer-aided design software (SOLIDWORKS®, Dassault Systèmes; Vélizy-Villacoublay, France).
When optical scanning could not detect specific areas of the product, we combined the two strategies.
All digital designs were exported as STL files (the most common file type for 3D printing).
Validation was based on the ISO13485 quality standard for customized medical device manufacturing.(13)(15)
In the validation phase, we used 3D modeling software (Materialise 3-matic; Leuven, Belgium) for mesh analysis, optimization, and correction of the STL file. We printed small quantities of the items with polylactic acid on 3D printers (Ultimaker 3 or Ultimaker S5; Ultimaker B.V.; Utrecht, the Netherlands or MakerBot Replicator+; MakerBot Industries, LLC; New York, NY, USA), ensuring the dimensions of 3D-printed pieces with certified vernier calipers. Afterward, pieces were tested in real clinical scenarios (Figure 1). Devices that needed additional considerations or calibrations (3DPT21, 3DPT22, 3DPT23, and 3DPT33: see the Supplementary Appendix) were tested in an experimental model using a polygraph (PowerLab 16 SP; ADInstruments, Dunedin, NZ) equipped with an S300 pneumotachograph (dead space, 80 ml) and a pressure transducer.(18)
Once the design was validated, a technical documentation form was completed for each item, including information regarding its use, technical design, and manufacturing specifications as well as schematic diagrams and pictures of the products.
To ensure the items’ functionality, we asked manufacturers to supply units for testing made with different 3D-printing technologies and different materials (only biocompatible materials fulfilling the ISO 10993 / USP class VI quality standards for at least skin and mucous contact).
Specific cleaning procedures were defined for each material to prevent thermal deformation and alteration of chemical properties.
Validated items were included with their STL files and technical documentation in an online catalogue on our institution’s open website.(19)
Local manufacture and distribution
In parallel with the publication of the catalogue, we designed a system to supply the items to health centers in our region. Orders were placed through a form on our institutional website(20) and transmitted to COMB and EIC, who coordinated the manufacture, storage, and distribution (Figure 2).
Manufacturing companies from different sectors willing to collaborate in the context of the COVID-19 crisis were grouped and organized through a citizens’ initiative platform.(21) Companies received no financial compensation for these actions.
Items for which full details about manufacture were unavailable were excluded from centralized distribution channels. All items were washed, disinfected, and dried before distribution.
The 3D-printed items produced are consumables or disposable components necessary for the proper function of electromedical equipment, but not considered critical by manufacturers. Given the manufacturers’ inability to supply these products during the COVID-19 pandemic health emergency, European in-house manufacturing regulations allow them to be manufactured as custom medical devices with appropriate safety guarantees by 3D printing for hospitals’ exclusive use, waiving the need for CE marking(22) and assigning the responsibility for the use of these products to the health centers. Hospital executives accepted the responsibility for using the products.
Data regarding the number of individual visitors and the total number of visits to the catalogue were extracted from Google Analytics.
The number of deaths due to COVID19 and number of infections in each Spanish region were extracted from the Spanish Ministry of Health’s website.(23)
Information regarding orders, manufacturers, and 3D-printed items was collected in a dedicated database.
We compiled descriptive statistics, reporting frequencies and percentages. To evaluate the relationship between visits to the online catalogue and incidence of COVID-19 in Spain, we used Pearson correlation, considering P<0·05 significant.