Calibration solutions useful for analyses of biological fluids and methods employing same
First Claim
1. A method for the calibration of a sensor employed for the detection of CO2 partial pressure in physiological fluid, said method comprisingcontacting a sensor assembly having:
- a fluid passageway and a sensor for CO2 exposed to said fluid passageway, and means to pass physiological fluid or infusible calibrant, or physiological fluid and infusible calibrant over said sensor,with an infusion medium/calibrant comprising;
non-buffered physiological sodium chloride-containing saline, and an amount of sodium bicarbonate effective to provide a concentration of HCO3- in the range of about 1 up to 100 mM/L; and
thereaftercalibrating said sensor.
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Abstract
Novel calibration solutions are provided which are useful, for example, with sensor assemblies used for analysis of CO2, especially in combination infusion fluid delivery/blood chemistry analysis systems which include a sensor assembly with each of the assembly electrodes mounted in an electrode cavity in the assembly. The analysis system used in the practice of the present invention typically includes provision for delivering infusion fluid and measuring blood chemistry during reinfusion of the physiological fluid at approximately the same flow rates. The invention calibration solutions are useful for calibrating an array of sensors capable of simultaneously measuring a number of blood chemistry parameters, including the partial pressures (tensions) of carbon dioxide and oxygen, pH (hydrogen ion), sodium, potassium, ionized calcium, ionized magnesium, chloride, glucose, lactate and hematocrit, in body fluids. More particularly, this invention relates to the use of an infusible intravenous solution to facilitate calibration on a regular basis for every individual sensor in a sensor assembly, which is in constant fluid communication with the body regardless of whether the sensors are ex vivo or in vivo.
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Citations
13 Claims
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1. A method for the calibration of a sensor employed for the detection of CO2 partial pressure in physiological fluid, said method comprising
contacting a sensor assembly having: - a fluid passageway and a sensor for CO2 exposed to said fluid passageway, and means to pass physiological fluid or infusible calibrant, or physiological fluid and infusible calibrant over said sensor,
with an infusion medium/calibrant comprising;
non-buffered physiological sodium chloride-containing saline, and an amount of sodium bicarbonate effective to provide a concentration of HCO3- in the range of about 1 up to 100 mM/L; and
thereaftercalibrating said sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- a fluid passageway and a sensor for CO2 exposed to said fluid passageway, and means to pass physiological fluid or infusible calibrant, or physiological fluid and infusible calibrant over said sensor,
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11. A method for the assay of CO2 partial pressure in physiological fluid, said method comprising
contacting an assembly having: -
a fluid passageway and a sensor for CO2 exposed to said fluid passageway, and means to pass physiological fluid or infusible calibrant, or physiological fluid and infusible calibrant over said sensor, with an infusible calibrant comprising; a non-buffered physiological sodium chloride-containing saline, and an amount of sodium bicarbonate effective to provide a concentration of HCO3- in the range of about 1 up to 100 mM/L; and
calibrating said CO2 sensor; and
thereaftercontacting said assembly with said physiological fluid and measuring the CO2 partial pressure in said physiological fluid.
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12. In a method for the assay of pCO2 in physiological fluid employing a sensor assembly, the improvement comprising using an infusible calibrant comprising:
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a non-buffered physiological sodium chloride-containing saline, and an amount of sodium bicarbonate effective to provide a concentration of HCO3- in the range of about 1 up to 100 mM/L.
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13. In a combination infusion delivery system and chemical analysis system having a pCO2 sensor, wherein physiological saline is employed as the infusion medium, the improvement comprising introducing an effective amount of sodium bicarbonate into said physiological saline to provide a CO2 concentration adequate to calibrate said CO2 sensor.
Specification