Carbon dioxide-sensing airway products and technique for using the same
AssigneeNellcor Puritan Bennett LLC
InventorsClark R. Baker, Roger Mecca, Michael P. O'Neil, Rafael Ostrowski
Life of this patent
Estimating the term…
Abstract
An airway device is provided that may track the flow of respiratory gases through the device with sensing elements at a plurality of locations along the gas flow path of the device. Such a device may be useful for assessing a variety of clinical states, for adjusting patient ventilator settings, or for determining whether or not an airway device has been properly inserted into a patient airway.
Claims20
A method of determining a change in a non-gas-exchanging physiologic volume in a ventilated patient comprising:
- determining a concentration of carbon dioxide gas over time at a first location in a patient breathing circuit;
- determining a concentration of carbon dioxide gas over time at a second location in the patient breathing circuit;
- determining the transit time of the carbon dioxide gas between the two locations;
- determining the volume of the breathing circuit between the first and second locations based on the cross-sectional area of the breathing circuit and the distance between the two locations;
- and
- determining the flow rate over time of the carbon dioxide gas between the first location and the second location in the patient breathing circuit based on the determined volume and transit time, wherein a change in non-gas-exchanging physiologic volume is indicated by a change in the total volume exhaled while the carbon dioxide gas is increasing at the start of exhalation.
A computer readable medium with instructions for determining a change in a non-gas-exchanging physiologic volume in a ventilated patient comprising:
- code for receiving signals from a plurality of carbon dioxide sensors disposed on a patient breathing circuit;
- code for determining a concentration of carbon dioxide gas over time at a first location in a patient breathing circuit;
- code for determining a concentration of carbon dioxide gas over time at a second location in the patient breathing circuit;
- code for determining the transit time of the carbon dioxide gas between the two locations;
- code for determining the volume of the breathing circuit between the first and second locations based on the cross-sectional area of the breathing circuit and the distance between the two locations;
- and
- code for determining the flow rate over time of the carbon dioxide gas between the first location and the second location in the patient breathing circuit based on the determined volume and transit time, wherein a change in non-gas-exchanging physiologic volume is indicated by a change in the total volume exhaled while the carbon dioxide gas is increasing at the start of exhalation.
A medical system adapted to determine a change in a non-gas-exchanging physiologic volume in a ventilated patient comprising:
- a processor adapted to:
- receive signals from a plurality of carbon dioxide sensors disposed on a patient breathing circuit;
- determine a concentration of carbon dioxide gas over time at a first location in a patient breathing circuit;
- determine a concentration of carbon dioxide gas over time at a second location in the patient breathing circuit;
- determine the transit time of the carbon dioxide gas between the two locations;
- determine the volume of the breathing circuit between the first and second locations based on the cross-sectional area of the breathing circuit and the distance between the two locations;
- and
- determine the flow rate over time of the carbon dioxide gas between the first location and the second location in the patient breathing circuit based on the determined volume and transit time, wherein a change in non-gas-exchanging physiologic volume is indicated by a change in the total volume exhaled while the carbon dioxide gas is increasing at the start of exhalation.
Dependencies are inferred from the claim text.