Fluid handling cassette system for body fluid analyzer

Abstract

A fluid handling system for use in bodily fluid analysis. The system comprises a first fluid handling module configured to interface with a main instrument. The first fluid handling module has a first fluid handling network and the first fluid handling network includes an infusate passage and an infusion fluid pressure member suitable for moving fluid within the infusate passage. The fluid handling system also has a second fluid handling module separate from the first module which is configured to interface with the main instrument. The second fluid handling module has a second fluid handling network and at least one sample analysis cell which is accessible via the second fluid handling network. The first and second modules are configured to interconnect and provide fluid communication between the first and second fluid handling network and the sample cells.

1 .- 20 . (canceled) 
     
     
         21 . A method of handling a bodily fluid, said method comprising;
 injecting air into the fluid handling network;   drawing a volume of said bodily fluid from a patient into a fluid handling network;   retaining a sample of said drawn volume in said fluid handling network, said retained sample comprising less than half of said drawn volume;   returning the balance of said drawn volume to said patient in less than five minutes after said drawing was commenced;   advancing the air in the fluid handling network toward a sample cell so that the air pushes a least a portion of the sample into the sample cell; and   analyzing the at least a portion of said sample.   
     
     
         22 . The method of  claim 21 , comprising moving the retained sample to divide the injected air into a first body of air and a second body of air with the retained sample between the first body of air and the second body of air. 
     
     
         23 . The method of  claim 21 , comprising inserting an anticoagulant into the retained sample. 
     
     
         24 . The method of  claim 21 , wherein the analyzer is operable to complete the sample analysis at least three minutes after returning the balance of the drawn volume to the patient. 
     
     
         25 . The method of  claim 21 , wherein the analyzing takes at least two minutes. 
     
     
         26 . The method of  claim 21 , further comprising moving said sample to a waste container after the analyzing. 
     
     
         27 . The method of  claim 21 , further comprising:
 infusing a liquid into said patient via said fluid handling network; and   occasionally interrupting said infusing to facilitate said drawing.   
     
     
         28 . The method of  claim 21 , wherein returning the balance of said drawn volume to said patient comprises returning the balance in less than three minutes after said drawing was commenced. 
     
     
         29 . The method of  claim 21 , wherein returning the balance of said drawn volume to said patient comprises returning the balance in less than two minutes after said drawing was commenced. 
     
     
         30 . The method of  claim 21 , wherein said sample is less than 100 microliters in volume. 
     
     
         31 . The method of  claim 21 , wherein said sample is between 20 microliters and 100 microliters in volume. 
     
     
         32 . The method of  claim 21 , wherein said analyzing comprises spectroscopically analyzing. 
     
     
         33 . The method of  claim 21 , further comprising separating a component of said sample, and said analyzing comprises analyzing only said component. 
     
     
         34 . A bodily fluid analyzer comprising:
 a fluid handling network configured for fluid communication with a bodily fluid within a patient;   an air injector configured to inject air into the fluid handling network;   an analyte detection system configured to examine a sample of bodily fluid in said fluid handling network;   said analyzer further comprising a processor and stored program instructions executable by said processor so that said analyzer is operable to:
 inject air into the fluid handling network; 
 draw a volume of said bodily fluid into said fluid handling network; 
 retain a sample of said drawn volume in said fluid handling network, said retained sample comprising less than half of said drawn volume; 
 return the balance of said drawn volume to said patient in less than five minutes after said drawing was commenced; 
 advance the air in the fluid handling network towards the analyte detection system so that the air pushes at least a portion of the sample into the analyte detection system; and 
 analyze the at least a portion of said sample. 
   
     
     
         35 . The analyzer of  claim 34 , wherein the analyzer is operable to move the retained sample to divide the injected air into a first body of air and a second body of air with the retained sample between the first body of air and the second body of air. 
     
     
         36 . The analyzer of  claim 34 , comprising an anticoagulant source configured to insert an anticoagulant into the retained sample. 
     
     
         37 . The analyzer of  claim 34 , comprising a sample preparation unit configured to prepare the at least a portion of the sample before analysis. 
     
     
         38 . The analyzer of  claim 37 , wherein the analyzer is operable to perform the sample preparation and the sample analysis after returning the balance of the drawn volume to the patient. 
     
     
         39 . The analyzer of  claim 38 , wherein the analyzer is operable to complete the sample analysis at least three minutes after returning the balance of the drawn volume to the patient. 
     
     
         40 . The analyzer of  claim 34 , wherein the analyzing takes at least two minutes. 
     
     
         41 . The analyzer of  claim 34 , wherein said analyzer is further operable to move said sample to a waste container after analyzing said sample. 
     
     
         42 . The analyzer of  claim 34 , wherein said fluid handling network is in communication with an infusion liquid source and said analyzer is further operable to infuse said liquid via said fluid handling network, and wherein said analyzer is further operable to occasionally interrupt infusing said liquid to draw said volume. 
     
     
         43 . The analyzer of  claim 34 , wherein said analyzer is further operable to return the balance of said drawn volume to said patient in less than three minutes after said analyzer has commenced drawing said volume. 
     
     
         44 . The analyzer of  claim 34 , wherein said analyzer is further operable to return the balance of said drawn volume to said patient in less than two minutes after said analyzer has commenced drawing said volume. 
     
     
         45 . The analyzer of  claim 34 , wherein said sample is less than 100 microliters in volume. 
     
     
         46 . The analyzer of  claim 34 , wherein said sample is between 20 microliters and 100 microliters in volume. 
     
     
         47 . The analyzer of  claim 34 , wherein said analyte detection system comprises a spectroscopic analyte detection system. 
     
     
         48 . The analyzer of  claim 34 , further comprising a fluid component separator accessible via said fluid handling network.