Patent ID: 7860542

Claim:
A body fluid handling system configured to reduce sample dilution, the system comprising: a fluid handling network configured to provide access to a body fluid in a patient, the fluid handling network 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; a body fluid detection sensor configured to detect the presence of substantially undiluted body fluid at a location in the fluid handling network and generate a signal; a pump system coupled to said fluid handling network, said pump system having an infusion mode in which said pump system is operable to infuse an infusion fluid toward said patient via said fluid handling network; one or more air injectors configured to position an air bubble at the entrance to the second fluid passageway adjacent the junction between the first and second passageways; said pump system being configured to: draw 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 positioning of substantially undiluted body fluid at the junction between the first and second passageways, draw at least a portion of the sample 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 maintain the air bubble immediately forward of the undiluted leading portion of the sample as the sample is transported through the second fluid passageway such that the air bubble provides a barrier to reduce dilution of the leading portion of the sample that enters the second fluid passageway by insulating the leading portion of the sample from dilution that may result from contact with other fluids; and an analyte detection system accessible via said fluid handling network and configured to measure an analyte in an analyzed a portion of said drawn sample of body fluid.