Patent ID: 7860543

Claim:
A method of sampling a body fluid of a patient and reducing sample dilution, said method comprising: providing a fluid handling system configured to provide access to the body fluid of the patient, the fluid handling system comprising a patient end, a junction in fluid communication with the patient end, a first fluid passageway connected to the junction, and a second fluid passageway connected to the junction; providing a body fluid detection sensor configured to detect the presence of substantially undiluted body fluid at a location in the fluid handling system and generate a signal; with said fluid handling system, infusing an infusion fluid into said patient through the patient end; positioning an air bubble at the entrance to the second fluid passageway adjacent the junction between the first and second fluid passageways; with said fluid handling system, drawing at least a portion of a sample of said body fluid from said patient, through the patient end, through the junction, and into the first fluid passageway, wherein the body fluid detection sensor identifies substantially undiluted body fluid at the location in the fluid handling network and generates a signal to facilitate the introduction of substantially undiluted body fluid into the first fluid passageway such that substantially undiluted body fluid is positioned at the junction between the first and second fluid passageways; with said fluid handling system, drawing at least a portion of the sample of said body fluid through the junction and into the second fluid passageway after the air bubble is positioned such that the leading portion of the sample that enters the second fluid passageway immediately following the air bubble is substantially undiluted blood, and wherein the air bubble is transported through the second fluid passageway forward of the sample such that the air bubble provides a barrier to reduce dilution of the leading portion of the sample that may result from contact with other fluids; with said fluid handling system, delivering at least an analysis portion of the sample to an analyte detection system operatively associated with the fluid handling system; with the analyte detection system, analyzing at least an analyzed portion of said sample to determine a concentration of at least one analyte.