Systems and methods for accurately, substantially noninvasively determining pulmonary capillary blood flow or cardiac output

摘要

Methods for noninvasively determining a pulmonary capillary blood flow or a cardiac output of a subject include determining data of the amount of gas exchanged between blood and gas in lungs of the subject, as well as data of an indicator of the content of the gas in blood of the subject. Such a determination may be made during two or more different states of ventilation. A geometric relationship is identified between data points, with any data points outlying the geometric relationship being disregarded. The remaining data points may be used to estimate or calculate a measure of pulmonary capillary blood flow or cardiac output. Systems that include elements that are configured to effect such methods are also disclosed.

主权项

1. A system for substantially non-invasively determining at least one of a pulmonary capillary blood flow and a cardiac output of a subject, comprising:
a breathing conduit; a flow sensor in communication with the breathing conduit; a gas sensor in communication with the breathing conduit; and at least one processing element for receiving signals including measured data points from the flow sensor and the gas sensor, the at least one processing element being configured to:
retain data points of the measured data points when a number of the data points within a location is equal or greater than a specified threshold; anddiscard data points of the measured data points when the number of the data points within the location is less than the specified threshold.