Apparatus and method for measuring cardiac output
AssigneeAmerican Hospital Supply Corporation
InventorRob J. Roy
Life of this patent
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Abstract
Updated cardiac output measurements are obtained using a reference value of cardiac output and the natural change in phase of variations in blood temperature. The reference value of cardiac output can be obtained using a thermodilution technique. The variations in blood temperature are sensed at appropriate locations, such as in the right atrium and the pulmonary artery. The temperature information is processed to provide a signal which is related to the velocity of the blood, and the signal and the reference value of cardiac output are used to provide the updated cardiac output measurement.
Claims12
An apparatus for measuring cardiac output using the natural change in phase of variations in blood temperature within the circulatory system, said apparatus comprising:
- means for measuring cardiac output to provide a reference value of cardiac output;
- and
- means responsive to the natural change in phase of variations in blood temperature within the circulatory system and the reference value of cardiac output for providing an updated measurement of cardiac output.
An apparatus for measuring cardiac output using the natural change in phase of variations in blood temperature which occur at first and second locations within the circulatory system, said apparatus comprising:
- a catheter having first and second temperature sensors adapted to be inserted into the circulatory system so that the temperature sensors can sense the temperature at said first and second locations;
- means for measuring cardiac output to provide a reference value of cardiac output;
- and
- processing means responsive to the natural change in phase of variations in the blood temperature at the first and second locations as sensed by the temperature sensors and the reference value of cardiac output for providing an updated measurement of cardiac output.
A method for measuring cardiac output comprising:
- measuring cardiac output to provide a reference value of cardiac output;
- sensing the temperature of the blood at first and second spaced locations within the circulatory system to provide first and second temperature signals, respectively, said first and second locations being locations at which there is a natural change in phase of variations in blood temperature;
- processing the first and second temperature signals to provide a velocity-related signal which is related to the velocity of the blood traveling between the first and second locations;
- and
- processing the reference value of cardiac output and the velocity-related signal to provide an updated measurement of cardiac output.
Dependencies are inferred from the claim text.