Hypoxaemia SpO_{2} <85% | Hyperoxaemia SpO_{2} >96% in oxygen | Posthypoxaemia overshoot | |||
---|---|---|---|---|---|

30 s episodes per 24 hours | 60 s episodes per 24 hours | 30 s episodes per 24 hours | 60 s episodes per 24 hours | Episodes per 24 hours* | |

Manual control (original recordings) | 30 (12–55) | 8.0 (5.7–18) | 23 (17–30) | 10 (6.5–14) | 0.71 |

Core PID | 0 (0–1.2)^{h} | 0 (0–0.82) | 5.0 (3.1–6.8)^{b,c,h} | 2.2 (0.84–3.4)^{b,h} | 0.90 |

Core PID+SC | 0 (0–1.2) | 0 (0–0.21) | 0 (0–0.62)^{a} | 0 (0–0)^{a} | 0.19 |

Core PID+adaptive K_{p} | 0 (0–1.4) | 0 (0–0) | 6.5 (5.5–11)^{b,d} | 2.7 (1.7–5.4)^{b} | 0.90 |

Core PID+TRA | 0 (0–1.2) | 0 (0–0.20) | 5.5 (3.1–6.2)^{b} | 1.7 (0.84–3.4)^{b} | 0.84 |

Enhanced PID−SC | 0 (0–1.9) | 0 (0–0) | 6.5 (5.5–11)^{e} | 2.3 (1.7–5.4)^{e} | 1.0 |

Enhanced PID−adaptive K_{p} | 0 (0–0.053) | 0 (0–0.0086) | 0 (0–0.026)^{f} | 0 (0–0)^{f} | 0.19 |

Enhanced PID−TRA | 0 (0–2.1) | 0 (0–0) | 1.1 (0.62–1.2)^{f} | 0 (0–0)^{f} | 0.13 |

Enhanced PID | 0 (0–1.9)^{h} | 0 (0–0)^{h} | 1.0 (0–1.6)^{f,g} | 0 (0–0)^{f,g} | 0.19 |

Enhanced PID 30 s lockout* | 0.47 (0–2.2) | 0 (0–0)^{h} | 2.4 (1.8–5.6) | 0 (0–0.14)^{g} | 0.45 |

PD control* | 4.8 (2.2–17)^{g} | 2 (0–4.2)^{g} | 12 (0–110)^{h} | 5.5 (0–54)^{h} | 0.13 |

Comparison of frequency of continuous hypoxaemic and hyperoxaemic episodes (≥30 and ≥60 s duration) and of overshoot. Within-column statistical comparisons (Friedman analysis of variance with Dunn's post hoc test):

^{a}differs from^{b}, p<0.05;^{c}differs from^{d};^{e}differs from^{f};^{g}differs from^{h}.See the Methods section for definition of overshoot.

*Data for overshoot episodes pooled for all 16 recordings.

Kp, proportional coefficient; PD, proportional–derivative; PID, proportional–integral–derivative; SC, Severinghaus compensation; TRA, target range attenuation.