초록 ▼

The apparatus provides for the determination of the instantaneous phase in the respiratory cycle, subject's average respiration rate and the provision of ventilatory assistance. A microprocessor (16) receives an airflow signal from a pressure transducer (18) coupled to a port (27) at a mask (11). Th

The apparatus provides for the determination of the instantaneous phase in the respiratory cycle, subject's average respiration rate and the provision of ventilatory assistance. A microprocessor (16) receives an airflow signal from a pressure transducer (18) coupled to a port (27) at a mask (11). The microprocessor (16) controls a servo (19), that is turn controls the fan motor (20) and thus the pressure of air delivered by the blower (10). The blower (10) is coupled to a subject's mask (ii) by a conduit (12). The invention seeks to address the following goals: while the subject is awake and making substantial efforts the delivered assistance should be closely matched in phase with the subject's efforts; the machine should automatically adjust the degree of assistance to maintain at least a specified minimum ventilation without relying on the integrity of the subject's chemoreflexes; and it should continue to work correctly in the presence of large leaks.

대표청구항 ▼

1. A method for providing ventilatory assistance in a spontaneously breathing subject, comprising the steps, performed at repeated sampling intervals, of:calculating the instantaneous phase .phi. in the respiratory cycle as a continuous variable from 0 to 1 revolution, selecting a desired pressure m

1. A method for providing ventilatory assistance in a spontaneously breathing subject, comprising the steps, performed at repeated sampling intervals, of:calculating the instantaneous phase .phi. in the respiratory cycle as a continuous variable from 0 to 1 revolution, selecting a desired pressure modulation amplitude A, calculating a desired instantaneous delivery pressure as a function of an end expiratory pressure plus the desired pressure modulation amplitude A multiplied by the value of a waveform template function II(.phi.) at the calculated instantaneous phase .phi., and delivering pressure to said subject at the calculated desired instantaneous delivery pressure.