CARDIAC OUTPUT MONITORING SYSTEM AND CARDIAC OUTPUT MEASUREMENT METHOD
First Claim
1. A cardiac output monitoring system comprising:
- a flow velocity peak value detection section that detects a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section;
an ejection time calculation section that calculates an ejection time from a temporal change in diameter of an artery, the diameter of the artery being a diameter of a second artery that has been measured from a body surface using a second sensor section;
a cross-sectional area estimation section that estimates a cross-sectional area of the first artery from the diameter of the second artery using a relationship between the diameter of the second artery and the cross-sectional area of the first artery that has been specified in advance;
a stroke volume calculation section that calculates a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and
a cardiac output calculation section that calculates a cardiac output using the stroke volume and a given heart rate.
1 Assignment
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Accused Products
Abstract
A processing device included in a cardiac output monitoring system includes an arterial diameter measurement ultrasonic probe that is attached to a neck of a subject, and measures the diameter of the carotid artery, and an arterial diameter measurement control section. A carotid artery diameter control section analyzes an ultrasonic echo to calculate the diameter of the artery (DOA), and outputs the diameter of the artery (DOA) to an ejection time/mean arterial pressure calculation section. The ejection time/mean arterial pressure calculation section calculates the ejection time (ET) from a temporal change in the diameter of the artery (DOA), and calculates the cardiac output. The temporal change waveform of the diameter of the artery (DOA) is clearer than the waveform of the blood flow velocity in the aorta or the ventricular outflow tract measured using an ultrasonic Doppler method, and the ejection time (ET) can be automatically calculated with high accuracy.
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Citations
16 Claims
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1. A cardiac output monitoring system comprising:
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a flow velocity peak value detection section that detects a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section; an ejection time calculation section that calculates an ejection time from a temporal change in diameter of an artery, the diameter of the artery being a diameter of a second artery that has been measured from a body surface using a second sensor section; a cross-sectional area estimation section that estimates a cross-sectional area of the first artery from the diameter of the second artery using a relationship between the diameter of the second artery and the cross-sectional area of the first artery that has been specified in advance; a stroke volume calculation section that calculates a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and a cardiac output calculation section that calculates a cardiac output using the stroke volume and a given heart rate. - View Dependent Claims (4, 7, 9, 10)
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2. A cardiac output monitoring system comprising:
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a flow velocity peak value detection section that detects a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section; an ejection time calculation section that calculates an ejection time from a temporal change in arterial pressure, the arterial pressure being a pressure of a third artery using a third sensor section, the third artery being an artery that is palpable from a body surface; a cross-sectional area estimation section that estimates a cross-sectional area of the first artery from the arterial pressure of the third artery using a relationship between the arterial pressure of the third artery and the cross-sectional area of the first artery that has been specified in advance; a stroke volume calculation section that calculates a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and a cardiac output calculation section that calculates a cardiac output using the stroke volume and a given heart rate. - View Dependent Claims (5)
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3. A cardiac output monitoring system comprising:
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a flow velocity peak value detection section that detects a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section; a cross-sectional area estimation section that estimates a cross-sectional area of the first artery from a diameter of a second artery using a relationship between the diameter of the second artery and the cross-sectional area of the first artery that has been specified in advance, the diameter of the second artery being a diameter that has been measured from a body surface using a second sensor section; an ejection time calculation section that calculates an ejection time from a temporal change in arterial pressure, the arterial pressure being a pressure of a third artery using a third sensor section, the third artery being an artery that is palpable from a body surface; a stroke volume calculation section that calculates a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and a cardiac output calculation section that calculates a cardiac output using the stroke volume and a given heart rate. - View Dependent Claims (6, 8)
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11. A cardiac output measurement method comprising:
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detecting a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section; calculating an ejection time from a temporal change in diameter of an artery, the diameter of the artery being a diameter of a second artery that has been measured from a body surface using a second sensor section; estimating a cross-sectional area of the first artery from the diameter of the second artery using a relationship between the diameter of the second artery and the cross-sectional area of the first artery that has been specified in advance; calculating a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and calculating a cardiac output using the stroke volume and a given heart rate. - View Dependent Claims (14)
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12. A cardiac output measurement method comprising:
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detecting a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section; calculating an ejection time from a temporal change in arterial pressure, the arterial pressure being a pressure of a third artery using a third sensor section, the third artery being an artery that is palpable from a body surface; estimating a cross-sectional area of the first artery from the arterial pressure of the third artery using a relationship between the arterial pressure of the third artery and the cross-sectional area of the first artery that has been specified in advance; calculating a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and calculating a cardiac output using the stroke volume and a given heart rate. - View Dependent Claims (16)
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13. A cardiac output measurement method comprising:
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detecting a flow velocity peak value, the flow velocity peak value being a peak value of a flow velocity in a first artery or a ventricular outflow tract that has been measured from a body surface using a first sensor section; estimating a cross-sectional area of the first artery from a diameter of a second artery using a relationship between the diameter of the second artery and the cross-sectional area of the first artery that has been specified in advance, the diameter of the second artery being a diameter that has been measured from a body surface using a second sensor section; calculating an ejection time from a temporal change in arterial pressure, the arterial pressure being a pressure of a third artery using a third sensor section, the third artery being an artery that is palpable from a body surface; calculating a stroke volume using the flow velocity peak value, the ejection time, and the cross-sectional area; and calculating a cardiac output using the stroke volume and a given heart rate. - View Dependent Claims (15)
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Specification