Table 5.

Modeling of wash-in phase.

Breath	Horse Xe%—FeXe	Cumulative Xe volume required (L)	Horse O2%—FeO2	System O2%—FiO2
1	0.00	1.67	67.00	63.01
2	1.70	3.33	65.86	59.87
3	4.27	5.00	64.15	57.22
4	7.25	6.67	62.17	54.88
5	10.41	8.33	60.09	52.73
6	13.59	10.00	57.98	50.72
7	16.75	11.67	55.91	48.81
8	19.83	13.33	53.88	46.99
9	22.81	15.00	51.91	45.25
10	25.71	16.67	50.01	43.57
11	28.49	18.33	48.17	41.97
12	31.18	20.00	46.40	40.42
13	33.77	21.67	44.69	38.93
14	36.26	23.33	43.04	37.49
15	38.66	25.00	41.46	36.11
16	40.97	26.67	39.93	34.78
17	43.20	28.33	38.46	33.50
18	45.34	30.00	37.04	32.26
19	47.40	31.67	35.67	31.07
20	49.38	33.33	34.36	29.93
21	51.28	35.00	33.09	28.82
22	53.12	36.67	31.87	27.76
23	54.88	38.33	30.70	26.74
24	56.58	40.00	29.57	25.75
25	58.22	41.67	28.48	24.80
26	59.79	43.33	27.43	23.89
27	61.31	45.00	26.42	23.01
28	62.76	46.67	25.44	22.16
29	64.17	48.33	24.51	21.35
30	65.52	50.00	23.60	20.56
31	66.82	51.67	22.73	19.80
32	68.07	53.33	21.90	19.07
33	69.27	55.00	21.09	18.37
34	70.43	56.67	20.31	17.69
35	71.54	58.33	19.56	17.04
36	72.61	60.00	18.84	16.41
37	73.64	61.67	18.15	15.81
38	74.64	63.33	17.48	15.22
39	75.59	65.00	16.83	14.66
40	76.51	66.67	16.21	14.12

Immediately after the denitrogenation phase, the spreadsheet starts with a FeO₂ of 67% and a xenon flow of 10 L min⁻¹. Calculations used to model gas movements, considering a FRC of 15 L, a tidal volume of 6 L, and f_R of six breaths min⁻¹, indicated that FiO₂ reached 30% after 20 breaths (3 min and 20 s) and FeXe achieved 70% after 34 breaths (5 min and 40 s).