Table 1.

Parameters of the model in units from clinical practice converted to S.I. units.

parameter	clinical units	S.I. Units	references
ventilator parameters
PEEP	5 cmH2O	490 Pa	[17,18]
PIP (reference value)	15 cmH2O	1471 Pa	[17,18]
RR	15 breaths/min		[17,18]
I : E ratio	1 : 2		[17,18]
splitter parameters
RI	0.06 cmH2O/L/s	5670 Pa s m−3a	derived
RV	variable	variable	N/A
RE	0.06 cmH2O/L/s	5670 Pa s m−3a	derived
patient parameters
RL	2 cmH2O/L/s	196133 Pa s m−3	[19]
CL (reference value)	0.054 L/cmH2O	5.5 × 10−7 m3 Pa−1	[17]
RETT	8.0 cmH2O/L/s	784000 Pa s m−3	[19]

^aResistance (R) derived from Poiseuille law for straight laminar pipe, R = (128 µL)/(πD⁴), assuming diameter D = 22 mm, viscosity of air µ = 18.13 × 10⁻⁶ Pa s, length L = 1.8 m. PEEP, positive end-expiratory pressure; PIP, positive inspiratory pressure; RR, respiratory rate; I : E ratio, inspiratory/expiratory ratio. Reference values represent healthy patients and are used for Lung Model A, defined below.