Inhalation/exhalation respiratory phase detection circuit
AssigneePuritan-Bennett Corporation
InventorSteven L. Phillips
Life of this patent
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Abstract
An apparatus (10) for controlling the pressure of a respiratory gas delivered to a patient includes a phase detection circuit (24) for determining the inhalation and exhalation phases of the patient's respiratory cycle. More particularly, a flow signal representative of the respiratory flow is compared to second signal, offset in time and scaled in magnitude relative to the flow signal, in order to determine the transition from one phase to the next.
Claims27
An apparatus for detecting the inhalation and exhalation phases of a respiratory cycle having associated respiratory gas flow, said apparatus comprising:
- signal production means for producing first and second signals representative of the respiratory gas flow with said signal production means further including means for delaying one of said signals in time relative to the other of said signals;
- and said signals having respective amplitudes so that one of said signals presents the greater amplitude during at least a portion of one of the phases and so that the other of said signals presents the greater amplitude during at least a portion of the other of said phases;
- and
- processing means for processing said signals for determining therefrom the occurrence of said respective phases and for producing outputs representative of said phases.
An apparatus for facilitating the respiration of a patient having respiratory cycle with associated respiratory gas flow and exhibiting inhalation and exhalation phases, said apparatus comprising:
- supply means for supplying a respiratory gas under pressure from a source thereof to a patient;
- means for producing first and second signals representative of the respiratory gas flow with said signal production means further including means for delaying one of said signals in time relative to the other of said signals;
- and said signals having respective amplitudes so that one of said signals presents the greater amplitude during at least a portion of one of the phases and so that the other of said signals presents the greater amplitude during at least a portion of the other of said phases;
- processing means for processing said signals for determining therefrom the occurrence of said respective phases and for producing outputs representative of said phases;
- and
- control means coupled with said supply means and said processing means for receiving said outputs and responsive thereto for controlling said respiratory gas pressure to the patient in a predetermined manner correlated with said phases.
A method for detecting the inhalation and exhalation phases of a respiratory cycle having associated respiratory gas flow, said method comprising:
- producing first and second signals representative of the respiratory gas flow from a signal production means, delaying one of said signal in time relative to the other of said signals, said signals having respective amplitudes, said first signal presents the greater amplitude during at least a portion of the inhalation phase, said second signal presents the greater amplitude during at least a portion of the exhalation phase;
- and
- processing said signals for determining therefrom the occurrence of said inhalation and exhalation phases and for producing a first output corresponding to the inhalation phase and a second output corresponding to the exhalation phase.
Dependencies are inferred from the claim text.