| 摘要 |
A method and apparatus in an apnea detector monitor impedance pneumographic respiratory signals and heart rate of a patient. Magnitudes of excursions of the respiratory signals are monitored to resolve respiratory events, i.e. breaths, inhalations and exhalations. A counter will reach a threshold count and trigger an alarm if a selected interval lapses without a respiratory eve nt being detected. If a respiratory event is detected, as by detecting successi ve peaks, a peak or a valley of the respiratory signal, the timer is reset. The method and apparatus reject artifact that would otherwise appear as breathin g cycles in order to prevent false negative indications of apnea. Cyclically occuring peaks are rejected as being indicative of a breath if they are in a selected magnitude range compared to that of a normal breath and they approximate the patient's heart rate. Successive peaks due to sighs or of a baseline change are measured for average rate of change over the period it takes for the waveform to decrease from the second peak by of a selected lev el generally corresponding to of a normal inhalation or exhalation. They are rejected as artifact if the change is too slow. Consequently, sighs are not misinterpreted as breaths.
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