| 主权项 |
1. A fluid-bearing circuit for conveying a fluid from a reservoir to a sample container in an in vitro analyzer comprising:
a fluid-bearing conduit; two pressure sensors disposed a predetermined distance apart along the conduit, each for measuring pressure within the conduit proximate the respective pressure sensor and for generating a pressure signal indicative thereof; a probe having a probe tip; a first valve disposed within the conduit for selectively controlling fluid flow through the conduit; a pump disposed in association with the conduit for selectively pumping fluid in at least one direction within the conduit; and a controller in communication with the two pressure sensors, the first valve, and the pump, wherein the conduit is of substantially uniform cross-section and is unobstructed between the two pressure sensors, the conduit defines a fluid path and includes a proximal portion and a distal portion, the proximal portion of the fluid path extends from the probe to the first valve, the distal portion of the fluid path extends from the first valve to a reservoir and includes a first segment and a second segment, the first valve is disposed between the proximal portion and the distal portion for selectively controlling fluid flow therebetween, the pump is disposed between the first segment and the second segment of the distal portion, the controller receives the respective pressure signal from each of the two pressure sensors, the controller selectively controls the first valve to thereby control the fluid flow through the conduit, the controller selectively controls the pump to thereby selectively pump the fluid in at least one direction within the conduit, and the controller is configured to calculate the difference in the measured pressures and, from the difference, to calculate the volumetric flow rate of the fluid through the fluid-bearing conduit between the two pressure sensors. |
