Patent ID: 6675797
Filing Date: 2004-01-13
Classification: A61B,A61F,A61M

Abstract:
A method for determining patency of the airway of a patient to distinguish central from obstructive apnea events, the method comprising the steps of:delivering an approximately constant level of pressure support above atmospheric to the patient during at least one respiratory cycle of the patient, the respiratory cycle having an inspiratory portion and an expiratory portion; measuring respiratory air flow from the patient; determining an occurrence of apnea from said respiratory air flow during delivery of the constant level of pressure support; and if an apnea is determined then determining patency by (a) applying an oscillatory pressure waveform of known frequency to the patient's airway; and (b) determining if the airway is patent from a component of said air flow at said known frequency induced by said oscillatory pressure waveform, wherein a central obstructive apnea event is distinguished.