A computational fluid dynamics assessment of 3D printed ventilator splitters and restrictors for differential multi-patient ventilation

Table 1 Summary of microscopy measurements for 3D printed ventilator restrictors with nominal internal diameter of D=2.00 mm, given in both absolute terms and as a ratio of the printer layer thickness

Manufacturer/Model	Type	Material	Layer thickness	True I.D.		Mean internal feature size	I.D. error to layer thickness ratio
				Mean	Peak-peak variation		Mean	Peak-peak
(a) Creality LD-002R	Consumer SLA	Monocure 3D Rapid transparent photopolymer resin	50 µm	1.69 mm	0.06 mm	0.05 mm	2.4	1.0
(b) Prusa i3 Mk3S	Consumer FDM	PLA	50 µm	1.87 mm	0.04 mm	0.05 mm	3.0	0.8
(c) Prusa i3 Mk3S	Consumer FDM	PLA	100 µm	1.94 mm	0.12 mm	0.10 mm	1.2	1.2
(d) Prusa i3 Mk3S	Consumer FDM	PLA	200 µm	1.92 mm	0.15 mm	0.20 mm	0.8	0.8
(e) Stratasys uPrint	Professional FDM	ABS	254 µm	1.38 mm	0.14 mm	0.23 mm	2.7	0.6
(f) Stratasys Connex500	Professional Polyjet	Vero White Plus acrylate photopolymer	32 µm	1.74 mm	0.27 mm	0.43 mm	8.25	8.4
(g) Markforged Mark 2	Professional FDM	Nylon-carbon fibre composite	100 µm	1.78 mm	0.28 mm	0.10 mm	3.6	2.8
(h) Formlabs Form 2	Mid tier (Pro-sumer) SLA	Surgical guide resin	50 µm	1.73 mm	0.06 mm	0.05 mm	12.0	2.4

Microscopy measurement uncertainty is ±0.01 mm. Further details on printer settings may be found in the Appendix

ISSN: 2365-6271