Sequential aliqoting and determination of an indicator of sedimentation rate
A device is disclosed for centrifugally driving liquid flow to sequentially dispense aliquots from a reservoir while the device rotates. Also disclosed is a method and system for analyzing a liquid to derive an indicator of sedimentation rate of the liquid using sequential aliquoting, using the disclosed device in some embodiments. A particular application is the analysis of blood samples, including sedimentation rate and hematocrit.
1. A device for handling liquid, the device being rotatable about an axis of rotation to drive liquid flow within the device and comprising:
a reservoir chamber configured to accept a liquid and to dispense the liquid as the device rotates about the axis;
a plurality of receiving chambers connected to the reservoir chamber to receive liquid from the reservoir chamber as the devices rotates about the axis; and
a plurality of fluid conduits connecting the plurality of receiving chambers to the reservoir chamber to enable liquid to flow from the reservoir chamber to the plurality of receiving chambers and gas to be displaced by the liquid to vent from the plurality of receiving chambers, wherein the plurality of fluid conduits comprise a plurality of supply conduits each connected to a respective one of the plurality of receiving chambers to deliver liquid and a plurality of vent conduits each connected to a respective one of the plurality of receiving chambers to allow gas to escape, and
wherein the one or more fluid conduits are configured to begin filling each one of the plurality of receiving chambers at a different respective time while the device rotates at a substantially constant rate of rotation; and
wherein each vent conduit is connected to a respective vent port of a plurality of vent ports of the reservoir chamber to allow gas to escape into the reservoir chamber, the plurality of vent ports being mutually radially spaced along the reservoir chamber, thereby preventing liquid flow into each receiving chamber while the respective vent port is radially outward of a liquid level in the reservoir chamber and at least one other one of the plurality of vent ports is radially inward of the liquid level in the reservoir chamber.
2. A device as claimed in claim 1 , wherein the reservoir chamber is configured to provide a gas filled space radially inward of a maximum fill level of the reservoir chamber as the device is rotated and a first one of the vent ports is disposed radially inward of the maximum fill level.
3. A device as claimed in claim 1 , wherein a first one of the plurality of vent ports is disposed at a radially innermost aspect of the reservoir chamber.
4. A device as claimed in claim 1 , wherein each supply conduit is connected to a different supply port of a supply manifold conduit.
5. A device as claimed in claim 4 , wherein the vent conduit of a previous receiving chamber is connected to vent the previous chamber through a subsequent chamber subsequent to the previous chamber, the supply conduit of the subsequent chamber, or both.
6. A device as claimed in claim 5 , wherein the vent conduit of the previous chamber is connected to the supply circuit of the subsequent chamber.
7. A device as claimed in claim 4 , wherein the supply manifold conduit comprises a meandering portion, preferably extending from a first to a last one of the supply ports.
8. A device as claimed in claim 1 , configured as a microfluidic device.