Abstract: A gas concentration monitoring system (100, 600) may include a processor (110, 610) configured to detect a concentration of a selected gas in a sample gas flow obtained from a physical interface (107) to a patient (101); form a dataset including a plurality of data points, each data point corresponding to the detected concentration of the selected gas within the sample gas flow during a sampling time; group the data points according to a frequency of occurrence of the data points within the sampling time; and/or determine at least one of a signal confidence and signal quality based on relative characteristics between the groups of data points.

Abstract: A capnography system (100, 400), comprising: a controller (110, 410) configured to obtain a sample gas flow from a physical interface (107) for a patient (101); determine a change in a characteristic of the sample gas flow during a sampling time interval; determine whether the change in the characteristic of the sample gas flow during the sampling time interval is equal to or greater than a corresponding threshold value; determine that supplemental oxygen is provided when it is determined that the change in the characteristic of the sample gas flow is equal to or greater than the threshold value; and determine that supplemental oxygen is not provided when it is determined that the change in the characteristic of the sample gas flow is less than the threshold value.

Abstract: A capnograph device includes a carbon dioxide measurement component (20) configured to measure respiratory carbon dioxide level, and an electronic processor (30) programmed to generate a capnogram signal (40) and compute an end-tidal carbon dioxide (etCO2) signal (50) by performing a sliding window maximum operation (42, 44) on the capnograph signal. In some embodiments the sliding window maximum operation employs a sliding time window (W) whose duration (Tw) is at least 30 seconds. A smoothing filter may be applied to the capnograph signal before performing the sliding window maximum operation, and/or a smoothing filter (52) may be applied after the sliding window maximum operation to produce a smoothed etCO2 signal (54). The capnograph device may be a sidestream capnograph device (10) or a mainstream capnograph device.

Abstract: Breaths of a subject are identified based on the concentration of carbon dioxide at or near the airway of the subject. Troughs corresponding to inhalation are identified and plateaus corresponding to exhalation are identified. A breath is identified responsive to a trough being followed by a plateau.

Abstract: A system and method are configured to monitor respiratory stability and/or effectiveness. A ventilation index is determined that provides an indication of respiratory stability and/or effectiveness. The ventilation index is determined from one or more metrics that indicate deviation of a breathing parameter of a subject from levels that have been observed to be normal or typical for the subject.

Abstract: Breaths of a subject are identified based on the concentration of carbon dioxide at or near the airway of the subject. Troughs corresponding to inhalation are identified and plateaus corresponding to exhalation are identified. A breath is identified responsive to a trough being followed by a plateau.