Analyte detection system with interferent identification and correction
An apparatus for analyzing the composition of bodily fluid. The apparatus comprises a fluid handling network including a patient end configured to maintain fluid communication with a bodily fluid in a patient. The apparatus further comprises a pump unit in operative engagement with the fluid handling network. The pump unit has an infusion mode in which the pump unit is operable to deliver infusion fluid to the patient through the patient end, and a sample draw mode in which the pump unit is operable to draw a sample of the bodily fluid from the patient through the patient end. The apparatus further comprises a spectroscopic analyzer configured to obtain spectra from at least a portion of the sample, and a processor in communication with or incorporated into the spectroscopic analyzer. The apparatus further comprises stored program instructions executable by the processor to (a) identify one or more interferents to the measurement of one or more analytes in the bodily fluid as being possibly present in the portion, and (b) reduce errors in the measurement due to the presence of the determined possible interferents. The pump unit can comprise a single dual-mode or reversible pump operable in both the infusion and sample draw modes; or two pumps, one of which is operable in the infusion mode but not in the sample draw mode, and another of which is operable in the sample draw mode but not in the infusion mode.
1 . An apparatus for analyzing the composition of bodily fluid, said apparatus comprising:
a fluid handling network including a patient end configured to maintain fluid communication with a bodily fluid in a patient;
at least one pump in operative engagement with said fluid handling network, said at least one pump having an infusion mode in which said pump is operable to deliver infusion fluid to said patient through said patient end, and a sample draw mode in which said pump is operable to draw a sample of said bodily fluid from said patient through said patient end;
a spectroscopic analyzer positioned to obtain spectra from at least a portion of the sample;
a processor in communication with or incorporated into said spectroscopic analyzer; and
stored program instructions executable by said processor to identify one or more interferents to the measurement of one or more analytes in said bodily fluid as being possibly present in said portion, and reduce errors in the measurement due to the presence of the determined possible interferents.
2 . The apparatus of claim 1 , where said bodily fluid is blood.
3 . The apparatus of claim 2 , where said portion of the sample is whole blood.
4 . The apparatus of claim 2 , where said portion of the sample is blood plasma.
5 . The apparatus of claim 2 , where said portion of the sample is blood serum.
6 . The apparatus of claim 1 , where said spectroscopic analyzer includes an infrared analyzer.
7 . The apparatus of claim 1 , where one of said one or more analytes is glucose.
8 . The apparatus of claim 1 , where one of said one or more analytes is a sugar.
9 . The apparatus of claim 1 , where one of said one or more analytes is blood urea nitrogen (BUN), hemoglobin, or lactate.
10 . The apparatus of claim 1 , where said fluid handling network includes a first fluid passageway from an infusion fluid source to said patient end, and a second fluid passageway from patient end to said spectroscopic analyzer.
11 . The apparatus of claim 10 , where said sample draw mode first draws fluid through said first fluid passageway, then draws fluid through said second fluid passageway.
12 . The apparatus of claim 10 , where said bodily fluid is blood, where said sample draw mode draws fluid through said first fluid passageway, and then directs blood through said second fluid passageway to said spectroscopic analyzer.
13 . The apparatus of claim 12 , where said patient end includes a hematocrit analyzer configured to detect whole blood in the patient end, where said sample draw mode draws fluid through said first fluid passageway until the hematocrit analyzer detects whole blood in the patient end, and then directs blood through said second fluid passageway to said spectroscopic analyzer.
14 . The apparatus of claim 10 , where said patient end includes a gas injector, and where the gas injector injects gas bubbles into the fluid in the second fluid passageway.
15 . The apparatus of claim 2 , further comprising a separator to separate blood components, and where said portion is blood plasma.
16 . The apparatus of claim 1 , where said apparatus further includes a display to present measurements.
17 . The apparatus of claim 1 , where said pump alternates between said infusion mode and said sample draw mode.
18 . The apparatus of claim 1 , wherein said at least one pump comprises a first pump operable only in said infusion mode and a second pump operable only in said sample draw mode.