Table 3. Mean bias [Douglas bag (DB) minus K5], lower (LL) and upper (UL) 95% prediction interval, and number (n) of participants that were within 10% of the measured DB value.
| K5 Mixing Chamber | K5 Breath-by-Breath | |||
|---|---|---|---|---|
| Mean Bias (LL, UL) | n≤10% of DB (%) | Mean Bias (LL, UL) | n≤10% of DB (%) | |
| VE (BTPS, L/min) | ||||
| Rest (n = 15) | 0.54 (-4.95, 3.34) | 6 (40.0) | 0.79 (-4.78, 3.63) | 6 (40.0) |
| 50 W (n = 14) | 0.29 (-5.58, 3.28) | 10 (71.4) | -0.65 (-6.77, 2.48) | 9 (64.3) |
| 100 W (n = 14) | 0.7 (-7.9, 5.09) | 10 (71.4) | 0.48 (-6.99, 4.29) | 11 (78.6) |
| 150 W (n = 13) | -0.34 (-7.45, 3.28) | 11 (84.6) | 0.12 (-7.71, 4.11) | 11 (84.6) |
| 200 W (n = 13) | -1.51 (-12.53, 4.11) | 10 (76.9) | -2.14 (-10.53, 2.14) | 11 (84.6) |
| 250 W (n = 8) | 1.25 (-12.91, 8.48) | 5 (62.5) | 1.38 (-9.42, 6.89) | 8 (100.0) |
| VO2 (STPD, L/min) | ||||
| Rest | -0.05 (-0.15, 0) | 7 (46.7) | -0.03 (-0.13, 0.02) | 6 (40.0) |
| 50 W | -0.03 (-0.27, 0.1) | 6 (42.9) | -0.06 (-0.31, 0.06) | 7 (50.0) |
| 100 W | -0.02 (-0.27, 0.11) | 9 (64.3) | -0.08 (-0.27, 0.02) | 11 (78.6) |
| 150 W | 0.02 (-0.33, 0.2) | 11 (84.6) | -0.05 (-0.36, 0.1) | 10 (76.9) |
| 200 W | 0.02 (-0.39, 0.23) | 11 (84.6) | -0.08 (-0.43, 0.1) | 11 (84.6) |
| 250 W | 0.12 (-0.17, 0.26) | 7 (87.5) | 0.07 (-0.46, 0.34) | 6 (75.0) |
| VCO2 (STPD, L/min) | ||||
| Rest | -0.02 (-0.13, 0.03) | 3 (20.0) | -0.01 (-0.12, 0.05) | 7 (46.7) |
| 50 W | 0 (-0.23, 0.12) | 9 (64.3) | -0.03 (-0.26, 0.08) | 8 (57.1) |
| 100 W | 0.06 (-0.18, 0.18) | 11 (78.6) | 0.03 (-0.1, 0.1) | 12 (85.7) |
| 150 W | 0.1 (-0.21, 0.26) | 9 (69.2) | 0.11 (-0.15, 0.25) | 10 (76.9) |
| 200 W | 0.12 (-0.24, 0.3) | 11 (84.6) | 0.14 (0, 0.22) | 12 (82.3) |
| 250 W | 0.31 (-0.09, 0.51) | 4 (50.0) | 0.28 (-0.1, 0.48) | 5 (62.5) |
| FEO2 | ||||
| Rest | 0.0043 (-0.0057, 0.0093) | 14 (93.3) | 0.0032 (-0.0072, 0.0085) | 15 (100.0) |
| 50 W | 0.0004 (-0.0053, 0.0033) | 14 (100.0) | 0.0004 (-0.0065, 0.0039) | 14 (100.0) |
| 100 W | 0.0001 (-0.0047, 0.0025) | 14 (100.0) | 0.0015 (-0.0034, 0.0039) | 14 (100.0) |
| 150 W | -0.0018 (-0.0068, 0.0007) | 13 (100.0) | -0.0002 (-0.0032, 0.0012) | 13 (100.0) |
| 200 W | -0.0024 (-0.0067, -0.0001) | 13 (100.0) | -0.0012 (-0.0051, 0.0008) | 13 (100.0) |
| 250 W | -0.0017 (-0.0057, 0.0003) | 8 (100.0) | -0.0009 (-0.0054, 0.0014) | 8 (100.0) |
| FECO2 | ||||
| Rest | -0.0033 (-0.009, -0.0004) | 9 (60.0) | -0.0034 (-0.0121, 0.001) | 9 (60.0) |
| 50 W | -0.0006 (-0.0052, 0.0017) | 13 (92.9) | -0.0007 (-0.0063, 0.0021) | 12 (85.7) |
| 100 W | 0.0008 (-0.0045, 0.0036) | 11 (78.6) | 0.0003 (-0.0045, 0.0027) | 14 (100.0) |
| 150 W | 0.0023 (-0.0029, 0.0049) | 10 (76.9) | 0.0023 (-0.0016, 0.0042) | 11 (84.6) |
| 200 W | 0.0028 (-0.0014, 0.0049) | 10 (76.9) | 0.0034 (-0.0011, 0.0056) | 18 (61.5) |
| 250 W | 0.0033 (-0.0022, 0.0061) | 5 (62.5) | 0.0027 (-0.0035, 0.0058) | 4 (50.0) |
| RER | ||||
| Rest | 0.05 (-0.12, 0.13) | 12 (80.0) | 0.04 (-0.12, 0.12) | 13 (86.7) |
| 50 W | 0.02 (-0.04, 0.05) | 13 (92.9) | 0.02 (-0.05, 0.05) | 13 (92.9) |
| 100 W | 0.05 (-0.02, 0.08) | 13 (92.9) | 0.06 (0, 0.09) | 12 (85.7) |
| 150 W | 0.04 (-0.03, 0.07) | 12 (92.3) | 0.07 (0, 0.11) | 9 (69.2) |
| 200 W | 0.03 (-0.04, 0.07) | 12 (92.3) | 0.08 (-0.01, 0.12) | 8 (61.5) |
| 250 W | 0.06 (0, 0.09) | 8 (100.0) | 0.06 (-0.04, 0.12) | 6 (75.0) |
BTPS, body temperature pressure saturated; STPD, standard temperature pressure dry; VE, minute ventilation; VO2, oxygen uptake; VCO2, carbon dioxide production; FEO2, fraction of oxygen in expired air; FECO2, fraction of carbon dioxide in expired air; RER, respiratory exchange ratio.