| 摘要 |
A method of verifying sample volume quantifies the fluid volume aspirated and verifies sample uniformity by detecting the presence of foam or clots in the sample. After aspiration, a pressure sensor is used to measure the vacuum needed to hold up the column of fluid in the probe tip. By knowing the geometry of the probe tip, the vacuum can be converted to a sample weight and volume, based on sample densities. Non-ideal conditions, such as foam on the surface of the fluid or a clot in the fluid, result in a sample volume much lighter, in the case of foam, or much greater, in the case of a clot, than anticipated. The method also determines the elapsed time of the aspiration. Foamy samples result in aspiration times shorter than normal. Clotted samples result in aspiration times longer than normal. Additionally, a determination can be made as to whether an error condition occurred. The error condition could be the occurrence of the sample fluid container becoming substantially empty of sample fluid during aspiration or the sample probe no longer being in contact with the fluid due to the probe not following a declining fluid level as the fluid is aspirated.
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