Measurement of cardiac output and blood volume by non-invasive detection of indicator dilution
First Claim
Patent Images
1. A method of measuring in absolute physical units cardiac output of a subject comprising:
- a) administering to a cardiovascular system of the subject a detectable amount of at least one indicator;
b) applying a first wavelength of light for exciting the indicator within the cardiovascular system and causing the indicator to emit a second wavelength of light, wherein the second wavelength of light is fluorescence emitted by the indicator;
c) measuring intensity of fluorescence emitted by the indicator in the cardiovascular system over a period of time using at least one photodetector proximately located to at a detection area of the subject;
d) converting the measured intensity of the fluorescence over the period of time to a measured concentration of the indicator over a period of time using a known calibration curve that defines how the concentration of the indicator in the cardiovascular system varies as a function of the measured value of the intensity of the fluorescence;
e) determining cardiac output of the subject in absolute units of volume over time based on the measured concentration of the indicator over the period of time.
1 Assignment
0 Petitions
Accused Products
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.
-
Citations
33 Claims
-
1. A method of measuring in absolute physical units cardiac output of a subject comprising:
-
a) administering to a cardiovascular system of the subject a detectable amount of at least one indicator; b) applying a first wavelength of light for exciting the indicator within the cardiovascular system and causing the indicator to emit a second wavelength of light, wherein the second wavelength of light is fluorescence emitted by the indicator; c) measuring intensity of fluorescence emitted by the indicator in the cardiovascular system over a period of time using at least one photodetector proximately located to at a detection area of the subject; d) converting the measured intensity of the fluorescence over the period of time to a measured concentration of the indicator over a period of time using a known calibration curve that defines how the concentration of the indicator in the cardiovascular system varies as a function of the measured value of the intensity of the fluorescence; e) determining cardiac output of the subject in absolute units of volume over time based on the measured concentration of the indicator over the period of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A system for measuring the cardiac output of a subject comprising:
-
a) an illumination source configured to be positioned proximately to at least one blood vessel of a cardiovascular system of the subject for providing a first wavelength light for exciting an indicator within the cardiovascular system and causing the indicator to emit a second wavelength of light, wherein the second wavelength of light is fluorescence emitted by the indicator; b) a photodetector configured to be positioned proximate to the blood vessel of the cardiovascular system for detecting a magnitude of intensity of the fluorescence emitted from the indicator in the cardiovascular system and to generate electronic signals indicative of the detected magnitude of intensity of the fluorescence over a period of time; and c) a computing system configured to receive the electronic signals and to compute the cardiac output of the subject in absolute units of volume over time wherein the computer system; i. converts the electronic signals indicative of the detected magnitude of intensity of the fluorescence over the period of time to a measured concentration of the indicator over a period of time using a known calibration curve that defines how the concentration of the indicator in the cardiovascular system varies as a function of the measured value of the intensity of the fluorescence and ii. computes the cardiac output of the subject in absolute units of volume over time based on the measured concentration of the indicator over the period of time. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
-
-
30. A method of measuring blood volume in a subject comprising:
-
a) administering a detectable amount of at least one indicator to a cardiovascular system of a subject; b) applying a first wavelength of light for exciting the indicator within the cardiovascular system and causing the indicator to emit a different second wavelength of light, wherein the second wavelength of light is fluorescence emitted from the indicator; c) measuring intensity of fluorescence emitted from the indicator in the cardiovascular system over a period of time using at least one photodetector proximately located to a detection area of the subject; d) converting the measured intensity of the fluorescence over the period of time to a measured concentration of the indicator over a period of time using a known calibration curve that defines how the concentration of the indicator in the cardiovascular system varies as a function of the measured value of the intensity of the fluorescence; and e) determining a magnitude of the blood volume in absolute units based on the measured concentration of the indicator over the period of time. - View Dependent Claims (31, 32, 33)
-
Specification