Measurement of cardiac output and blood volume by non-invasive detection of indicator dilution
First Claim
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1. A method of measuring a parameter of the cardiovascular system of a subject in absolute physical units comprising:
- a) administering to the cardiovascular system a detectable amount of an indicator that fluoresces when illuminated;
b) illuminating the indicator;
c) measuring the intensity of the illumination that is reflected by or transmitted through a portion of the cardiovascular system;
d) measuring the intensity of the fluorescence of the indicator that was administered while it is illuminated;
e) taking a blood sample from the cardiovascular circulatory system;
f) measuring the concentration of the indicator in the blood sample;
g) waiting a period of time;
h) administering a detectable amount of the indicator to the cardiovascular system for a second time;
i) illuminating the indicator for a second time;
j) measuring the intensity of the illumination for a second time that is reflected by or transmitted through a portion of the cardiovascular system;
k) measuring the intensity of the fluorescence of the indicator that was administered for the second time while it is illuminated;
i) determining the magnitude of the parameter in absolute physical units after the administration of the indicator for a second time based on the measured concentration of the indicator in the blood sample, the first and second measured intensity of the illumination, and the first and second measured intensity of the fluorescence.
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Abstract
A system for evaluating the cardiovascular system parameters using indicator dilution and non-invasive or minimally invasive detection methods is disclosed. Intravascular indicators are stimulated, and emissions patterns detected for computation of cardiac output, cardiac index, blood volume and other indicators of cardiovascular health.
47 Citations
15 Claims
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1. A method of measuring a parameter of the cardiovascular system of a subject in absolute physical units comprising:
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a) administering to the cardiovascular system a detectable amount of an indicator that fluoresces when illuminated; b) illuminating the indicator; c) measuring the intensity of the illumination that is reflected by or transmitted through a portion of the cardiovascular system; d) measuring the intensity of the fluorescence of the indicator that was administered while it is illuminated; e) taking a blood sample from the cardiovascular circulatory system; f) measuring the concentration of the indicator in the blood sample; g) waiting a period of time; h) administering a detectable amount of the indicator to the cardiovascular system for a second time; i) illuminating the indicator for a second time; j) measuring the intensity of the illumination for a second time that is reflected by or transmitted through a portion of the cardiovascular system; k) measuring the intensity of the fluorescence of the indicator that was administered for the second time while it is illuminated; i) determining the magnitude of the parameter in absolute physical units after the administration of the indicator for a second time based on the measured concentration of the indicator in the blood sample, the first and second measured intensity of the illumination, and the first and second measured intensity of the fluorescence. - View Dependent Claims (2)
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3. A method of measuring a parameter of a cardiovascular system in a subject in absolute physical units comprising:
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a) administering to the cardiovascular system a detectable amount of an indicator that fluoresces when illuminated; b) illuminating the indicator; c) measuring the intensity of the fluorescence of the indicator that was administered while it is illuminated; d) taking a blood sample from the cardiovascular circulatory system; e) measuring the concentration of the indicator in the blood sample; f) waiting a period of time; g) administering a detectable amount of the indicator to the cardiovascular system for a second time; h) illuminating the indicator for a second time; i) measuring the intensity of the fluorescence of the indicator that was administered for the second time while it is illuminated; and j) determining the magnitude of the parameter in absolute physical units after the administration of the indicator for the second time based on the first and second measured intensity of the fluorescence and the measured concentration of the indicator. - View Dependent Claims (4, 5, 6)
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7. A system for measuring a parameter of a cardiovascular system in a subject in absolute physical units comprising:
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a) an illumination source configured to illuminate an administered indicator in the cardiovascular system of the subject at a first and a second time, wherein the indicator is administered before the first and the second time; b) a photo detector configured to measure the intensity of fluorescence emitted from the indicator while it is illuminated;
at the first and the second time; andc) a computing system configured to determine the magnitude of the parameter in absolute physical units based on the measured intensity of the fluorescence after at the first and the second time and a measured concentration of the indicator in a blood sample taken from the cardiovascular system after the first administration of the indicator. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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Specification