Table 6. Simulations and time to failure (TTF, in hours), defined as 90% volume loss.

Intervention	Cw condition	Variable γ	Simulation	TTF, hours
				constant f	variable f	variable f + AE
None	Low	No	1	2.49	2.53	2.51
		Yes	2	2.25	2.28	2.26
	High	No	3	0.30	0.32	0.30
		Yes	4	0.27	0.29	0.27
Increased Ru	Low	No	5	24.7	24.7	24.5
		Yes	6	22.2	22.2	21.9
	High	No	7	18.5	18.4	17.3
		Yes	8	16.6	16.5	15.0
CPAP, 10% loss	Low	No	9	2.56	2.61	2.60
		Yes	10	2.32	2.36	2.34
	Yes	No	11	0.83	0.79	0.76
		Yes	12	0.83	0.80	0.77
CPAP, 5% loss	High	No	13	2.94	2.50	2.46
1-1 4-7 CPAP, 3% loss			14	8.57	6.89	6.83

Increased R_u: A 10-fold increase in R_u was applied during expiration. CPAP: Simulated administration of P_ao = 5 occurred when recruited fraction was down 10%, then again at 5% and 3% with constant γ. AE: A single 20 second apneic event occurred at the 2 minute mark of the simulation.