Process and devices for determining the instant of injection and the duration of injection in thermodilution measurements
First Claim
1. A process for determining an instant of injection and a duration of injection in thermodilution measurements, the process comprising the steps of:
- providing an injectate fluid at a temperature deviating from a temperature of a blood of a patient and having a temperature at approximately room temperature;
providing a temperature sensor having a temperature deviation from room temperature;
injecting said injectate fluid at a specific injection site into a blood vessel of said patient;
passing said injectate fluid over said temperature sensor and reading continuously a temperature sensed by said temperature sensor;
measuring a temperature of the blood at a measuring site downstream of said injection site;
determining an instant of a beginning of injection from a change occurring in said temperature sensed by said temperature sensor; and
determining an instant of an end of injection from a subsequently occurring change in direction of said temperature sensed by said temperature sensor.
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Accused Products
Abstract
The present invention relates to a process and devices for determining the instant of injection and the duration of injection in thermodilution measurements in which an injectate fluid at a temperature deviating from the temperature of the blood of a patient is injected at a specific injection site into a blood vessel of the patient and the temperature of the blood is measured at a measuring site downstream of the injection site, the injectate fluid being used at approximately room temperature and, before entry into the blood vessel, passed by a temperature sensor which, before the measurement, has a temperature deviating from room temperature, the temperature determined by the temperature sensor being sensed continuously, the instant of the beginning of injection being determined from a change occurring in the sensed temperature and the instant of the end of injection being determined from a subsequently occurring change in direction of the temperature profile.
41 Citations
7 Claims
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1. A process for determining an instant of injection and a duration of injection in thermodilution measurements, the process comprising the steps of:
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providing an injectate fluid at a temperature deviating from a temperature of a blood of a patient and having a temperature at approximately room temperature;
providing a temperature sensor having a temperature deviation from room temperature;
injecting said injectate fluid at a specific injection site into a blood vessel of said patient;
passing said injectate fluid over said temperature sensor and reading continuously a temperature sensed by said temperature sensor;
measuring a temperature of the blood at a measuring site downstream of said injection site;
determining an instant of a beginning of injection from a change occurring in said temperature sensed by said temperature sensor; and
determining an instant of an end of injection from a subsequently occurring change in direction of said temperature sensed by said temperature sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification