US 8,137,642 B2Granted

Method and apparatus for calibrating filters during specimen collection

AssigneeCytyc Corporation

InventorsTimothy Hutchins, Steven Scampini, Eric Baur

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Abstract

A bubble point of a combination of a filter and a liquid is calibrated by applying an initial back pressure through the filter toward the liquid; taking a first plurality of measurements of the level of the liquid in the container; calculating a first variance of the first plurality of measurements; and comparing the first calculated variance with a known threshold variance. Then a second plurality of measurements of the level of the liquid in the container is taken; a second variance of the second plurality of measurements is calculated; and the second calculated variance is compared with a known threshold variance. The above described steps are repeated at incrementally increased back pressures until the first and second calculated variances are each greater than or equal to the known threshold variance, which is about 0.01. The bubble point is determined to be the back pressure at that point. If the determined bubble point is less than or equal to the known threshold bubble point, which is about 0.8 pounds per square inch, the filter is identified as unsuitable for use in cell block formation.

Claims9

Dependent claims

A method of calibrating a bubble point of a filter and liquid combination, comprising:

(a) dispensing the liquid into a container, wherein the filter forms a surface of the container in contact with the liquid;
(b) applying an initial back pressure through the filter toward the liquid;
(c) taking a first plurality of measurements of a level of the liquid in the container;
(d) calculating a first variance of the first plurality of measurements;
(e) comparing the calculated first variance of the first plurality of measurements with a known threshold variance;
(f) taking a second plurality of measurements of a level of the liquid in the container;
(g) calculating a second variance of the second plurality of measurements;
(h) comparing the calculated second variance of the second plurality of measurements with the known threshold variance;
(i) incrementally increasing the applied back pressure;
(j) repeating steps (c) to (i) until the calculated first and second variances are each greater than or equal to the known threshold variance;
and
(k) identifying the bubble point as the back pressure when the calculated first and second variances are each greater than or equal to the known threshold variance.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/482,731Filed 11 Jun 2009 · us provisional application
Priority: 13 Jun 2008
Published: US 2009/0312955 A117 Dec 2009
Granted: 20 Mar 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification2 codes

G01N 1/36
Preparing specimens for investigation including physical details of chemical methods covered elsewhere, e.g. G01N33/50, C12Q: embedding or…
G01N
Investigating or analysing materials by determining their chemical or physical properties