Fluid holding and dispensing micro-feature

Abstract

Apparatus, system and method for dispensing a particle-laden fluid from a fluid holding and dispensing micro-feature. In some implementations, the apparatus includes: a chamber having one or more surfaces that define a volume to receive fluid containing particulate matter, and an outlet port to dispense at least a portion of the fluid from the chamber. The outlet port may have a normal vector that, when the apparatus is positioned to dispense the fluid, is substantially perpendicular to gravity. The apparatus may be used to measure a number of individual particles from the fluid that flow through the outlet port over a period of them, measure a total volume of the fluid dispensed through the outlet port over the period of time, and calculate a concentration of the particulate matter within the chamber. In some implementations, the particle-laden fluid may be whole blood.

What is claimed is: 
     
         1 . A method comprising:
 injecting a fluid containing particulate matter into a fluidic circuit comprising at least (i) a chamber having one or more surfaces that define a volume to receive the fluid containing particulate matter, wherein the fluid within the chamber includes, at least, a top region, a middle region, and a bottom region that, after at least a threshold time period has elapsed since the fluid is received into the chamber, contain different concentrations of the particulate matter, and (ii) an outlet port located at a position in the chamber that corresponds to the middle region;   dispensing a portion of the fluid containing particulate matter from the middle region of the chamber via the outlet port such that the fluid containing particulate matter flows from the chamber and into the outlet port in a direction that is substantially perpendicular to gravity; and   stopping, while the top and bottom regions of the chamber still include another portion of the fluid containing particulate matter, the dispensing of the fluid containing particulate matter based on one or more criteria being met.   
     
     
         2 . The method of  claim 1 , wherein:
 the one or more criteria being met comprise a particular period of time having elapsed since the fluid containing particulate matter was injected into the fluidic circuit having elapsed, and   the particular period of time corresponds to the fluidic circuit.   
     
     
         3 . The method of  claim 1 , further comprising:
 measuring, by an analyzer device, a number of individual particles from the fluid that flow through the outlet port over a period of time;   measuring, by the analyzer device, a total volume of the fluid dispensed through the outlet port over the period of time;   calculating, by the analyzer device, a remaining concentration of the particulate matter within the chamber based at least on (i) the number of individual particles measured as flowing through the outlet port, and (ii) the measured total volume of the fluid dispensed over the period of time; and   determining, by the analyzer device, whether the remaining concentration of the particulate matter in the fluid is greater than a threshold concentration for dispensing through the outlet port,   wherein the one or more criteria being met comprise the remaining concentration of the particulate matter being greater than the threshold concentration.   
     
     
         4 . The method of  claim 3 , wherein:
 the fluid containing particulate matter comprises whole blood, and determining the remaining concentration of the particulate matter within chamber comprises determining a red blood cell concentration within the whole blood in the chamber.   
     
     
         5 . The method of  claim 3 , wherein the number of individual particles is measured for fluid contained in the middle region of the fluid in the chamber having a threshold concentration of the particulate matter that is (i) greater than a first threshold concentration of the particulate matter within the top region of the chamber, and (ii) less than a second threshold concentration of the particulate matter within the bottom region. 
     
     
         6 . The method of  claim 3 , wherein the number of individual particles is measured using one or more optical detectors that are part of or in communication with the analyzer device. 
     
     
         7 . The method of  1 , wherein the dispensing comprises:
 injecting another fluid into the chamber after injecting the fluid containing particulate matter into the fluidic circuit, wherein the other fluid forces individual particles from among the particulate matter of the fluid to be dispensed through the outlet port.   
     
     
         8 . The method of  claim 7 , wherein injecting the another fluid into the chamber comprises injecting the other fluid into at least one of one or more inlet ports that is connected to the top region of the chamber, wherein the other fluid is less dense than the fluid containing particulate matter. 
     
     
         9 . The method of  claim 7 , wherein injecting the reagent fluid into the chamber comprises injecting the other fluid into at least one of one or more inlet ports that is connected to the bottom region of the chamber, wherein the other fluid is more dense than the fluid containing particulate matter. 
     
     
         10 . The method of  claim 1 , wherein:
 the fluid containing particulate matter comprises whole blood, and   after at least the threshold time period has elapsed since the whole blood is received into the chamber:   the top region contains a plasma supernatant of the whole blood,   the middle region contains pristine blood with blood cell concentrations that are within a threshold range of a blood cell concentration of the whole blood when it is initially received into the chamber, and   the bottom layer contains a packed cell layer that results from sedimentation over the threshold time period.   
     
     
         11 . The method of  claim 1 , further comprising:
 dispensing a portion of the fluid containing particulate matter from the middle region of the chamber via a second outlet port such that the fluid containing particulate matter flows from the chamber and into the second outlet port in a direction that is substantially perpendicular to gravity.