Method For Determining Hemodynamic Effects Of Positive Pressure Ventilation
First Claim
1. A device for assessing changes in cardiac output and/or stroke volume of a subject receiving airway support from a breathing assistance system, the device comprising:
- a processor;
an airway sensor in communication with the processor, wherein the airway sensor is configured and arranged to sense pressure in the subject'"'"'s airway, lungs, and/or intrapleural space over time;
a blood volume sensor in communication with the processor, wherein the blood volume sensor is configured and arranged to sense pulsatile volume of blood in a tissue of the subject over time; and
a display configured and arranged to display a representative of an airway pressure, a pulsatile blood volume, a photoplethysmogram, a photoplethysmogram ratio, the determined cardiac output and/or stroke volume, or combinations thereof,wherein the processor is configured and arranged to (a) produce a photoplethysmogram, (b) determine a photoplethysmogram ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation, and (c) determine the change in cardiac output and/or stroke volume of the subject using the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation.
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Accused Products
Abstract
The present disclosure relates, in some embodiments, to devices, systems, and/or methods for collecting, processing, and/or displaying stroke volume and/or cardiac output data. For example, a device for assessing changes in cardiac output and/or stroke volume of a subject receiving airway support may comprise a processor; an airway sensor in communication with the processor, wherein the airway sensor is configured and arranged to sense pressure in the subject'"'"'s airway, lungs, and/or intrapleural space over time; a blood volume sensor in communication with the processor, wherein the blood volume sensor is configured and arranged to sense pulsatile volume of blood in a tissue of the subject over time; and a display configured and arranged to display a representative of an airway pressure, a pulsatile blood volume, a photoplethysmogram, a photoplethysmogram ratio, the determined cardiac output and/or stroke volume, or combinations thereof. A method of assessing changes in cardiac output or stroke volume of a subject receiving airway support from a breathing assistance system may comprise sensing pressure in the subject'"'"'s airway as a function of time, sensing pulsatile volume of blood in a tissue of the subject as a function of time, producing a photoplethysmogram from the sensed pulsatile volume, determining the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation, and determining the change in cardiac output or stroke volume of the subject using the determined ratio.
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Citations
28 Claims
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1. A device for assessing changes in cardiac output and/or stroke volume of a subject receiving airway support from a breathing assistance system, the device comprising:
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a processor; an airway sensor in communication with the processor, wherein the airway sensor is configured and arranged to sense pressure in the subject'"'"'s airway, lungs, and/or intrapleural space over time; a blood volume sensor in communication with the processor, wherein the blood volume sensor is configured and arranged to sense pulsatile volume of blood in a tissue of the subject over time; and a display configured and arranged to display a representative of an airway pressure, a pulsatile blood volume, a photoplethysmogram, a photoplethysmogram ratio, the determined cardiac output and/or stroke volume, or combinations thereof, wherein the processor is configured and arranged to (a) produce a photoplethysmogram, (b) determine a photoplethysmogram ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation, and (c) determine the change in cardiac output and/or stroke volume of the subject using the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation.
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2. A device for assessing changes in cardiac output or stroke volume of a subject receiving airway support from a breathing assistance system, the device comprising:
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an airway sensor configured and arranged to sense pressure in the subject'"'"'s airway, lungs, and/or intrapleural space over time; a blood volume sensor configured and arranged to sense pulsatile volume of blood in a tissue of the subject over time; a processor configured and arranged (a) to receive input from the airway sensor and the blood volume sensor, (b) to produce a photoplethysmogram;
(c) to determine a photoplethysmogram ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation, and (d) to determine the change in cardiac output and/or stroke volume of the subject using the determined ratio; anda display configured and arranged to display a representative of a parameter selected from the group consisting of the sensed airway pressure, the sensed pulsatile blood volume, the photoplethysmogram, the determined ratio, the determined cardiac output and/or stroke volume, combinations thereof. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for assessing changes in cardiac output or stroke volume of a subject, the system comprising:
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(a) a breathing assistance system comprising (1) a ventilation system, (2) an airway connection system configured and arranged to link the ventilation system and the subject'"'"'s airway, and (3) an airway pressure sensor configured and arranged to detect pressure in the ventilation system and/or the subject'"'"'s airway; (b) a display system; (c) a pulse oximeter comprising a blood volume sensor; and (d) a processor in communication with the breathing assistance system, the display system, and the pulse oximeter, wherein the processor is configured and arranged to (a) produce a photoplethysmogram, (b) determine the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation, and (c) determine the change in cardiac output or stroke volume of the subject using the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A method of assessing changes in cardiac output or stroke volume of a subject receiving airway support from a breathing assistance system, the method comprising:
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sensing pressure in the subject'"'"'s airway as a function of time; sensing pulsatile volume of blood in a tissue of the subject as a function of time; producing a photoplethysmogram from the sensed pulsatile volume; determining the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation; and determining the change in cardiac output or stroke volume of the subject using the determined ratio. - View Dependent Claims (21, 22, 23, 24, 25)
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26. A method of predicting the effect of changes in ventilation settings on stroke volume of a ventilated subject, the method comprising:
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sensing pressure in the subject'"'"'s airway during at least one breathing cycle comprising an inhalation and an exhalation; producing a photoplethysmogram spanning the at least one breathing cycle; determining the ratio of the amplitude of the photoplethysmogram during inhalation to the amplitude of the photoplethysmogram during exhalation; determining the change in cardiac output or stroke volume of the subject using the determined ratio; referencing the stroke volume to current active ventilation settings of the breathing assistance system, and combinations thereof; and comparing the change in changes in ventilation settings to the current active ventilation settings. - View Dependent Claims (27)
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28. A method of assessing the relative strength of an autonomic neural response of a subject connected to a breathing assistance system, the method comprising:
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determining the cardiac output of the subject at a first airway pressure; changing the subject'"'"'s airway pressure to a second airway pressure; monitoring the cardiac output of the subject at the second airway pressure; comparing the cardiac output of the subject at the second airway pressure with the cardiac output of the subject at the first airway pressure; measuring the time required for the cardiac output of the subject at the second airway pressure to return to the cardiac output of the subject at a first airway pressure; and comparing the required time to a reference time to determine the relative strength of an autonomic neural response of the subject.
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Specification