US3556082A
Expired / Lapsed
US
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Method and apparatus for measurement of cardiac output
Assignee: Columbia Scientific Industries Corp
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Filing: 1965-08-19
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Granted: 1971-01-19
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Expires: 1985-08-19
Abstract
Abstract A method and apparatus for determining the true cardiac output from a detected dilution curve having an exponential decay by integrating the area under the curve up to a predetermined point approximately where the detected equilibrium level differs from the true level; detecting the level and the slope of the natural logarithm of the curve at that point; combining the level and slope at the point to obtain a value equal to the area under an exponential curve representative of an extrapolated ''''true'''' curve; adding the two area signals to obtain the total area under the curve representing the true dilution and combining the total area signal with signals representative of the equilibrium level and blood volume to obtain the desired signal.
Inventors
- 👤 Charles E Mccullough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:30
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/026; A61B5/0275
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
186 words
Apparatus suitable for permitting determination of cardiac output from an electrical source which produces a first electrical output representing a dilution curve with respect to time; said apparatus comprising input means connectable with said source; integrating means associated with the input means through switch means to permit integration of said first electricAl output until the switch means breaks the association with the input means; differentiating means including amplifying means associated with the input means to produce a second electrical output related to the exponential slope of the first electrical output at least near the time the association of the input means with the integrating means is broken; means for providing a third electrical output related to the magnitude of the first electrical output at the time association of the input means with the integrating means is broken; means responsive to the second and third electrical outputs to produce a fourth electrical output directly related to the third and means inversely related to the second electrical output; and means for combining the output of the integrating means with said fourth electrical output to provide a combined output.
Claim 2
Dependent Claim
186 words
Apparatus suitable for permitting determination of cardiac output from an electrical source which produces a first electrical output representing a dilution curve with respect to time; said apparatus comprising input means connectable with said source; integrating means associated with the input means through switch means to permit integration of said first electricAl output until the switch means breaks the association with the input means; differentiating means including amplifying means associated with the input means to produce a second electrical output related to the exponential slope of the first electrical output at least near the time the association of the input means with the integrating means is broken; means for providing a third electrical output related to the magnitude of the first electrical output at the time association of the input means with the integrating means is broken; means responsive to the second and third electrical outputs to produce a fourth electrical output directly related to the third and means inversely related to the second electrical output; and means for combining the output of the integrating means with said fourth electrical output to provide a combined output.
Claim 3
Dependent Claim
15 words
The apparatus defined in claim 1 wherein said integrating means comprises an operational amplifier integrator.
Claim 4
Dependent Claim
27 words
The apparatus defined in claim 1 wherein a potential storage means is associated with the output of the differentiating means for retention of the second electrical output.
Claim 5
Dependent Claim
36 words
The apparatus defined in claim 1 wherein the means responsive to the second and third electrical outputs comprises ganged potentiometers, one of which has an output proportional to the quotient of two inputs to the other.
Claim 6
Dependent Claim
69 words
The apparatus defined in claim 1 wherein said apparatus includes potential storage means associated with the input means through a switch to permit retention of the first electrical output at the time the association of the input means with the integrating means is broken, and to permit supply of this potential to the means responsive to the second and third electrical outputs, this potential being the third electrical output.
Claim 7
Dependent Claim
54 words
The apparatus defined in claim 5 wherein the associations of the input means with the integrating means and with the potential storage means are broken by at least one relay set to break the associations of the input means with the integrating means and with the potential storage means at virtually the same time.
Claim 8
Dependent Claim
15 words
The apparatus defined in claim 6 wherein said potential storage a means comprises a capacitance.
Claim 9
Dependent Claim
34 words
The apparatus defined in claim 6 wherein said relay is responsive to deviation of the second electrical output of the differentiating means from that produced during an exponential decay portion of the dilution curve.
Claim 10
Dependent Claim
24 words
The apparatus defined in claim 6 wherein said relay is responsive to a predetermined percentage decrease from the maximum amplitude of the dilution curve.
Claim 11
Dependent Claim
73 words
The apparatus defined in claim 1 wherein said apparatus includes means for measuring an equilibrium value of the dilution curve, means for providing a potential which may be representative of blood volume in cardiac output determination, and means for multiplying and dividing to obtain an output proportional to the equilibrium value of the dilution curve times the potential which may be representative of blood volume divided by the output of the combining means.
Claim 12
Dependent Claim
14 words
The apparatus defined in claim 1 wherein said electrical source comprises a radioactivity detector.
Claim 13
Dependent Claim
205 words
Apparatus suitable for permitting determination of the area under a dilution curve which decays according to a given decay curve to a value other than its extrapolated value; said apparatus comprising input means connectable with a source of potential which produces a dilution curve; first integrating means associated with the input means through a switch to permit integration of the potential until the switch breaks the association with the input; potential storage means associated with the input means through a switch to permit retention of the potential at the time the switch breaks the association with the input means; means associated with the input means for measuring the slope of the dilution curve at least near the time the associations of the input means with the first integrating means and with the potential storage means Are broken; second integrating means for integrating the given decay curve from the time the associations of the input with the first integrating means and with the potential storage means are broken, by employing the potential in the potential storage means and the slope along with the characteristics of the given decay curve; and adding means for adding the outputs of the first integrating means and the second integrating means.
Claim 14
Dependent Claim
205 words
Apparatus suitable for permitting determination of the area under a dilution curve which decays according to a given decay curve to a value other than its extrapolated value; said apparatus comprising input means connectable with a source of potential which produces a dilution curve; first integrating means associated with the input means through a switch to permit integration of the potential until the switch breaks the association with the input; potential storage means associated with the input means through a switch to permit retention of the potential at the time the switch breaks the association with the input means; means associated with the input means for measuring the slope of the dilution curve at least near the time the associations of the input means with the first integrating means and with the potential storage means Are broken; second integrating means for integrating the given decay curve from the time the associations of the input with the first integrating means and with the potential storage means are broken, by employing the potential in the potential storage means and the slope along with the characteristics of the given decay curve; and adding means for adding the outputs of the first integrating means and the second integrating means.
Claim 15
Dependent Claim
73 words
The apparatus defined in claim 12 wherein said apparatus includes means for measuring an equilibrium value of the dilution curve, means for providing a potential which may be representative of blood volume in cardiac output determination, and means for multiplying and dividing to obtain an output proportional to the equilibrium value of the dilution curve times the potential which may be representative of blood volume divided by the output of the adding means.
Claim 16
Dependent Claim
247 words
Apparatus suitable for permitting determination of cardiac output from a dilution curve associated with measurement of cardiac output; said apparatus comprising a radioactivity detector which produces potential proportional to radioactivity detected; an input means connectable with the output of the detector; and operational amplifier integrator associated with the input means through a switch to permit integration of the potential until the switch breaks the association with the input means; first potential storage capacitance associated with the input means through a switch to permit retention of the potential at the time the associations of the input means with the integrator and with the capacitance are broken; a logarithmic amplifier associated with the input means to permit logarithmic amplification of the potential at least near the time the associations of the input means with the integrator and with the capacitance are broken; a differentiator associated with the logarithmic amplifier for differentiating the output thereof; second potential storage capacitance for permitting retention of the potential output of the differentiator; a pair of ganged potentiometers, one of which is associated with the first potential storage capacitance and the second potential storage capacitance, the other of which has an output proportional to a quotient of the potential stored in the first potential storage capacitance as the dividend, and the potential stored in the second potential storage capacitance as the divisor; and adding means for adding the of the operational amplifier integrator and the output of the ganged potentiometers proportional to the quotient.
Claim 17
Dependent Claim
247 words
Apparatus suitable for permitting determination of cardiac output from a dilution curve associated with measurement of cardiac output; said apparatus comprising a radioactivity detector which produces potential proportional to radioactivity detected; an input means connectable with the output of the detector; and operational amplifier integrator associated with the input means through a switch to permit integration of the potential until the switch breaks the association with the input means; first potential storage capacitance associated with the input means through a switch to permit retention of the potential at the time the associations of the input means with the integrator and with the capacitance are broken; a logarithmic amplifier associated with the input means to permit logarithmic amplification of the potential at least near the time the associations of the input means with the integrator and with the capacitance are broken; a differentiator associated with the logarithmic amplifier for differentiating the output thereof; second potential storage capacitance for permitting retention of the potential output of the differentiator; a pair of ganged potentiometers, one of which is associated with the first potential storage capacitance and the second potential storage capacitance, the other of which has an output proportional to a quotient of the potential stored in the first potential storage capacitance as the dividend, and the potential stored in the second potential storage capacitance as the divisor; and adding means for adding the of the operational amplifier integrator and the output of the ganged potentiometers proportional to the quotient.
Claim 18
Dependent Claim
73 words
The apparatus defined in claim 14 wherein said apparatus includes means for measuring an equilibrium value of the dilution curve, means for providing a potential which may be representative of blood volume in cardiac output determination, and means for multiplying and dividing to obtain an output proportional to the equilibrium value of the dilution curve times the potential which may be representative of blood volume divided by the output of the adding means.
Claim 19
Dependent Claim
57 words
The apparatus defined in claim 15 wherein the associations of the input means with the operational amplifier integrator and with the first potential storage capacitance are broken by at least one relay set to break the associations of the input with the operational amplifier integrator and with the first potential storage capacitance at virtually the same time.
Claim 20
Dependent Claim
43 words
The apparatus defined in claim 16 wherein said apparatus includes a cathode follower associated with the output of the first potential storage capacitance, and a cathode follower associated with the output of the second potential storage capacitance to minimize discharge of these capacitances.
Claim 21
Independent Claim
161 words
A method suitable for determining the area under a dilution curve which decays according to a given decay curve to a value other than its extrapolated value; which method comprises detecting a potential with respect to time which describes a dilution curve; integrating the potential with resPect to time to obtain a first integral potential po proportional to the integral of the dilution curve until a selected potential on the given decay curve is reached; determining the slope of the decay curve at least near the selected potential; employing the slope, the selected potential, and the characteristics of the known type of decay curve to integrate the potential representative of the given decay curve from the time of the selected potential to infinity to obtain a second integral potential; and adding the first integral potential to the second integral potential to determine a potential proportional to the area under the dilution curve as if it decayed according to its known type.
Claim 22
Independent Claim
161 words
A method suitable for determining the area under a dilution curve which decays according to a given decay curve to a value other than its extrapolated value; which method comprises detecting a potential with respect to time which describes a dilution curve; integrating the potential with resPect to time to obtain a first integral potential po proportional to the integral of the dilution curve until a selected potential on the given decay curve is reached; determining the slope of the decay curve at least near the selected potential; employing the slope, the selected potential, and the characteristics of the known type of decay curve to integrate the potential representative of the given decay curve from the time of the selected potential to infinity to obtain a second integral potential; and adding the first integral potential to the second integral potential to determine a potential proportional to the area under the dilution curve as if it decayed according to its known type.
Claim 23
Independent Claim
214 words
A method suitable for determining the area under a dilution curve associated with a fluid in a fluid flow line, which dilution curve decays according to a given decay curve to a value other than its extrapolated value; which method comprises injecting into the fluid in a fluid flow line a radioactive material; detecting a potential proportional to radioactivity in the fluid flow line, which potential describes a dilution curve with respect to time; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the given decay curve in the dilution curve is reached; storing the selected potential; determining the slope of the decay curve at least near the selected potential; employing the slope, the selected potential, and the characteristics of the given decay curve to integrate the potential representative of the given decay curve from the time of the selected potential to infinity to obtain a second integral potential; and adding the first integral potential to the second integral potential to determine the total integral potential proportional to the area under the dilution curve as if it decayed according to its known type; and employing the total integral potential to indicate the area under the dilution curve.
Claim 24
Independent Claim
214 words
A method suitable for determining the area under a dilution curve associated with a fluid in a fluid flow line, which dilution curve decays according to a given decay curve to a value other than its extrapolated value; which method comprises injecting into the fluid in a fluid flow line a radioactive material; detecting a potential proportional to radioactivity in the fluid flow line, which potential describes a dilution curve with respect to time; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the given decay curve in the dilution curve is reached; storing the selected potential; determining the slope of the decay curve at least near the selected potential; employing the slope, the selected potential, and the characteristics of the given decay curve to integrate the potential representative of the given decay curve from the time of the selected potential to infinity to obtain a second integral potential; and adding the first integral potential to the second integral potential to determine the total integral potential proportional to the area under the dilution curve as if it decayed according to its known type; and employing the total integral potential to indicate the area under the dilution curve.
Claim 25
Independent Claim
198 words
A method suitable for determining the area under a dilution curve which decays exponentially to a value other than the exponentially extrapolated value of the dilution curve to its base line; which method comprises detecting a potential as a function of time which produces a dilution curve; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the exponential decay portion of the dilution curve is reached; storing the selected potential; logarithmically amplifying the decay potential on the exponential decay portion to form a ramp output; differentiating the ramp output to determine a decay slope potential proportional to the decay slope of the exponential decay portion of the dilution curve; dividing the stored selected potential by the decay slope potential to obtain a second integral potential proportional to the integral of the exponential decay portion of the dilution curve from the time of the selected potential to infinity; and adding the first integral potential and the second integral potential to provide a total integral potential proportional to the area under the dilution curve as if it decayed exponentially to its base line.
Claim 26
Independent Claim
198 words
A method suitable for determining the area under a dilution curve which decays exponentially to a value other than the exponentially extrapolated value of the dilution curve to its base line; which method comprises detecting a potential as a function of time which produces a dilution curve; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the exponential decay portion of the dilution curve is reached; storing the selected potential; logarithmically amplifying the decay potential on the exponential decay portion to form a ramp output; differentiating the ramp output to determine a decay slope potential proportional to the decay slope of the exponential decay portion of the dilution curve; dividing the stored selected potential by the decay slope potential to obtain a second integral potential proportional to the integral of the exponential decay portion of the dilution curve from the time of the selected potential to infinity; and adding the first integral potential and the second integral potential to provide a total integral potential proportional to the area under the dilution curve as if it decayed exponentially to its base line.
Claim 27
Independent Claim
249 words
A method suitable for determining the area under a dilution curve associated with a fluid in a fluid flow line which decays exponentially to a value other than the exponentially extrapolated value of the dilution curve to its base line; which method comprises injecting a radioactive material into the fluid flow line; detecting a potential proportional to the radioactivity passing in the fluid flow line, which potential describes a dilution curve with respect to time; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the exponential decay portion of the dilution curve is reached; storing the selected Potential; logarithmically amplifying the decay potential on the exponential decay portion of the dilution curve to form a ramp output; differentiating the ramp output to determine a decay slope potential proportional to the decay slope of the exponential decay portion of the dilution curve; dividing the stored selected potential by the decay slope potential to obtain a second integral potential proportional to the integral of the exponential decay portion of the dilution curve from the time of the selected potential to infinity; adding the first integral potential and the second integral potential to provide a total integral potential proportional to the area under the dilution curve as if it decayed exponentially to its base line; and employing the total integral potential to indicate the area under the dilution curve associated with the fluid flow line.
Claim 28
Independent Claim
249 words
A method suitable for determining the area under a dilution curve associated with a fluid in a fluid flow line which decays exponentially to a value other than the exponentially extrapolated value of the dilution curve to its base line; which method comprises injecting a radioactive material into the fluid flow line; detecting a potential proportional to the radioactivity passing in the fluid flow line, which potential describes a dilution curve with respect to time; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the exponential decay portion of the dilution curve is reached; storing the selected Potential; logarithmically amplifying the decay potential on the exponential decay portion of the dilution curve to form a ramp output; differentiating the ramp output to determine a decay slope potential proportional to the decay slope of the exponential decay portion of the dilution curve; dividing the stored selected potential by the decay slope potential to obtain a second integral potential proportional to the integral of the exponential decay portion of the dilution curve from the time of the selected potential to infinity; adding the first integral potential and the second integral potential to provide a total integral potential proportional to the area under the dilution curve as if it decayed exponentially to its base line; and employing the total integral potential to indicate the area under the dilution curve associated with the fluid flow line.
Claim 29
Independent Claim
229 words
A method for determining cardiac output by measurement of the dilution curve associated with measurement thereof which decays exponentially to a value other than the extrapolated value to its base line; which method comprises injecting a radioactive material into the blood of the host; detecting a potential proportional to the radioactivity concentration associated with cardiac output, which potential describes a dilution curve with respect to time; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the exponential decay portion of the dilution curve is reached; storing the selected potential; logarithmically amplifying the decay potential on the exponential decay portion of the dilution curve to form a ramp output; differentiating the ramp output to determine a decay slope potential proportional to the decay slope of the exponential decay portion of the dilution curve; dividing the selected potential by the decay slope potential to obtain a second integral potential proportional to the integral of the exponential decay portion of the dilution curve from the time of the selected potential to infinity; adding the first integral potential and the second integral potential to provide a total integral potential proportional to the area under the dilution curve as if it decayed exponentially to its base line; and employing the total integral potential to indicate cardiac output.
Claim 30
Independent Claim
229 words
A method for determining cardiac output by measurement of the dilution curve associated with measurement thereof which decays exponentially to a value other than the extrapolated value to its base line; which method comprises injecting a radioactive material into the blood of the host; detecting a potential proportional to the radioactivity concentration associated with cardiac output, which potential describes a dilution curve with respect to time; integrating the potential with respect to time to obtain a first integral potential proportional to the integral of the dilution curve until a selected potential on the exponential decay portion of the dilution curve is reached; storing the selected potential; logarithmically amplifying the decay potential on the exponential decay portion of the dilution curve to form a ramp output; differentiating the ramp output to determine a decay slope potential proportional to the decay slope of the exponential decay portion of the dilution curve; dividing the selected potential by the decay slope potential to obtain a second integral potential proportional to the integral of the exponential decay portion of the dilution curve from the time of the selected potential to infinity; adding the first integral potential and the second integral potential to provide a total integral potential proportional to the area under the dilution curve as if it decayed exponentially to its base line; and employing the total integral potential to indicate cardiac output.
References Cited (Backward Citations)
US3334788A
Cited
US3313290A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |