Gas delivery method and apparatus
AssigneeThornhill Scientific Inc.
InventorMichael Klein
Life of this patent
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Abstract
An apparatus, method and system for delivering CO2 into an inspiratory gas stream to formulate a blended respiratory gas in a manner that continuously maintains a target CO2 concentration in a volume of the inspired respiratory gas, for example, over the course of a breath or a volumetrically definable part thereof or a series of partial or full breaths.
Claims26
An apparatus for adding a carbon dioxide (DAn) containing gas (Gn) to an inspiratory gas G0, to formulate a respiratory gas (GR) for delivery to a subject, comprising:
- a control system operable to maintain a targeted concentration of carbon dioxide in a volume of the GR, the control system being operatively associated with:
- A) input means configured to:
- (i) obtain input of confirmed incremental volumes of one of G0 and GR flowed to a subject with respect to time points of interest;
- and
- (ii) obtain input of confirmed incremental volumes of one of Gn and pure DAn flowed to the subject with respect to the time points of interest;
- B) a processor configured for computing, for successive respective time intervals between contiguous time points of interest, an error signal (en) representing a volume of Gn to be made available for inspiration with respect to the respective time interval so that a cumulative volume of DAn equals DAnT;
- C) a controller configured for providing an output signal to a gas delivery device (GDn) for the respective time interval based on the en computed for the respective time interval such that the cumulative volume of DAn is controlled to DAnT.
A method for adding at least one added carbon dioxide containing gas (Gn) to an inspiratory gas G0, to formulate a respiratory gas (GR) for delivery to a subject, comprising:
- maintaining a targeted concentration (DAnT) of a carbon dioxide constituent (DAn) of an added gas Gn in a volume of the GR by:
- (a) obtaining input of confirmed incremental volumes of at least one of G0 and GR made available for inspiration by a subject with respect to respective time points of interest;
- (b) obtaining input of confirmed incremental volumes of Gn made available for inspiration by a subject with respect to the respective time points of interest;
- (c) as necessary, obtaining input of the concentration of the at least one of DAn in G0 and GR and Gn with respect to the respective time points of interest;
- wherein the input obtained is cumulatively sufficient to compute, for successive respective time intervals between contiguous points of interest, an e, that represents an incremental volume of Gn that must be delivered to the subject with respect to the respective time interval between successive time points Tcurrent) so that the cumulative volume of DAn equals DAnT;
- d) computing en for each respective time interval between contiguous time points of interest;
- and
- e) providing an output signal to a gas delivery device (GDn) for each respective time interval based on the en computed for the respective time interval such that the cumulative volume of DAn is controlled to target DAnT.
Dependencies are inferred from the claim text.