Retrograde thermodilution catheter having an injectate thermal effect compensation for blood flow measurement
AssigneeTransonic Systems, Inc.
InventorsNikolai M. Krivitski, Victor V. Kislukhin
Life of this patent
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Abstract
A catheter for retrograde orientation in a blood flow is used to determine the blood flow rate by thermodilution measurements. The determination of the blood flow rate accommodates injectate induced thermal influences on a dilution thermal sensor, wherein the thermal influences can occur prior to introduction of the injectate into the blood flow.
Claims29
A method of determining blood flow in a conduit, comprising compensating for an injectate induced thermal offset of a first thermal dilution sensor connected to a catheter, the injectate induced thermal offset resulting from travel of the injectate through the catheter.
A method of determining a blood flow in a conduit, the method comprising:
- (a) sensing a blood parameter related to blood temperature;
- (b) passing an injectate through a lumen in a catheter, the passing injectate inducing a measurement offset in a blood parameter sensor;
- and
- (b) compensating for the measurement offset of the blood parameter sensor.
A method of thermodilution measurement of a blood flow rate in a conduit, the method comprising compensating for an injectate induced thermal variance of a thermal dilution sensor, the induced thermal variance resulting from an injectate flow through a catheter.
A method of thermodilution measurement of blood flow rate by a retrograde catheter, the method comprising:
- (a) identifying a thermal transfer coefficient for the retrograde catheter;
- and
- (b) adjusting a thermal dilution sensor measurement by an amount corresponding to the thermal transfer coefficient.
A method of determining a blood flow by thermodilution measurement, comprising:
- (a) calculating the blood flow from a measured first dilution curve corresponding to a first injectate volume having a first injectate time and a first injectate temperature, and from a measured second dilution curve corresponding to a second injectate volume having a second injectate temperature and a second injectate time.
A method of determining a blood flow rate by thermodilution measurement, comprising:
- (a) determining the blood flow rate in response to a temperature of the blood flow, a temperature of an injectate, a volume of the injectate, a dilution curve from a proximal thermal dilution sensor and a dilution curve from a distal thermal dilution sensor, wherein at least a portion of the injectate is introduced into the blood flow at a location between the proximal thermal dilution sensor and the distal thermal dilution sensor.
A method of determining a blood flow by thermodilution measurement, the method comprising:
- (a) exposing a first thermal sensor to a first thermal influence of an injectate flowing in an injectate lumen in a catheter and to a first thermal influence of the blood flow diluted by the injectate, and
- (b) exposing a second thermal sensor to a different second thermal influence of one of the injectate flowing in the injectate lumen and the blood flow diluted by the injectate.
A method of determining blood flow by thermodilution measurement, the method comprising:
- (a) passing a first portion of an injectate volume through a first introduction port in a catheter, to combine the first portion of the injectate with the blood flow thereby forming a first diluted flow;
- (b) thermally sensing the first diluted flow with a first thermal dilution sensor;
- (c) passing a balance of the injectate volume through at least a second introduction port to combine with the first diluted flow to form a second diluted flow;
- and
- (d) thermally sensing the second diluted flow with a second thermal dilution sensor.
A method of determining a blood flow rate by thermodilution measurement comprising:
- (a) determining the blood flow rate corresponding to a factor representing an amount of an injectate volume passing through a proximal introduction port, a difference between a blood flow temperature and an injectate temperature, and a difference between an upstream dilution curve obtained upstream of the proximal introduction port and a downstream dilution curve obtained downstream of the proximal introduction port.
A method of determining blood flow rate by thermodilution measurement with a retrograde catheter, comprising:
- (a) determining the blood flow rate corresponding to a first dilution curve from a first thermal sensor having first thermal conductive properties, and a second dilution curve from a second thermal sensor having different second thermal conductive properties, and an injectate volume.
Dependencies are inferred from the claim text.