Claims
- 1. A method of filtering a particulate matter-containing liquid specimen to collect a desired concentration of particulates on a filter collection site, comprising:
moving specimen liquid through a filter under substantially constant pressure; detecting when a first predetermined volume of liquid has passed through the filter; determining the time it takes (the reference time base) for the next incremental volume of liquid, equal to the first, to pass through the filter; determining the time it takes (the incremental time base) for each subsequent incremental volume of liquid, equal to the first, to pass through the filter; comparing each incremental time base after determination thereof to the reference time base, and terminating liquid flow through the filter when the ratio of the incremental time base to the reference time base reaches or exceeds a predetermined ratio value.
- 2. A method according to claim 1, further comprising monitoring the total volume of liquid that has passed through the filter, and terminating liquid flow through the filter when the total volume reaches a predetermined total value.
- 3. A method according to claim 2, further comprising generating an alert signal if liquid flow through the filter is terminated before the ratio of the incremental time base to the reference time base reaches or exceeds the predetermined ratio value.
- 4. A method according to claim 1, claim 2 or claim 3, wherein the predetermined ratio value is a function of the protocol for processing the specimen.
- 5. A method according to claim 1, claim 2 or claim 3 for collecting cells for cytology, wherein the particulate matter in the specimen comprises cellular material.
- 6. A method according to claim 5, wherein the predetermined ratio value is a function of the protocol for processing the specimen.
- 7. A method according to claim 5, wherein the first predetermined volume of liquid is in the range of about 0.1 ml to 5.0 ml.
- 8. A method according to claim 7, wherein the first predetermined volume of liquid is in the range of about 1.0 ml to 2.0 ml.
- 9. A method according to claim 8 for collecting a plurality of cell samples from the same specimen, wherein after the cell sample of desired concentration is collected on a first filter and liquid flow through the first filter is terminated, the recited collecting steps are repeated at least once to collect at least one more cell sample, each cell sample collected on a respective filter.
- 10. Apparatus for controlling filtration of a particulate matter-containing liquid specimen to obtain a desired concentration of particulates collected on a filter collection site, comprising:
a substantially constant pressure source effecting movement of liquid through the filter; a filtered liquid volume meter; and a controller operatively coupled to the pressure source and the meter, wherein the controller:
detects when a first predetermined volume of liquid has passed through the filter; determines the time it takes (the reference time base) for the next incremental volume of liquid, equal to the first, to pass through the filter; determines the time it takes (the incremental time base) for each subsequent incremental volume of liquid, equal to the first, to pass through the filter; and compares each incremental time base after determination thereof to the reference time base, and terminates liquid flow through the filter when the ratio of the incremental time base to the reference time base reaches or exceeds a predetermined ratio value.
- 11. Apparatus according to claim 10, wherein the controller monitors the total volume of liquid that has passed through the filter, and terminates liquid flow through the filter when the total volume reaches a predetermined total value.
- 12. Apparatus according to claim 11, wherein the controller generates an alert signal if liquid flow through the filter is terminated before the ratio of the incremental time base to the reference time base reaches or exceeds the predetermined ratio value.
- 13. Apparatus according to claim 10, claim 11 or claim 12, wherein the predetermined ratio value is a function of the protocol for processing the specimen.
- 14. Apparatus according to claim 10, wherein the filtered liquid volume meter comprises a tube through which filtered liquid passes to form a liquid column, and detector elements positioned along the tube and operatively coupled to the controller.
- 15. Apparatus according to claim 14, wherein the tube is transparent to a sensor, and the detector elements comprise evenly spaced optical detectors positioned to detect the meniscus edge of the liquid column.
- 16. Apparatus according to claim 15, wherein each detector element comprises an LED sensor.
- 17. Apparatus according to claim 15, wherein each detector element comprises an LED emitter and a photosensor.
- 18. Apparatus according to claim 14, wherein the detector elements comprise a pair of parallel capacitor electrodes positioned along the tube, one of the electrodes within the tube and the other electrode outside the tube.
- 19. A method of filtering a particulate matter-containing liquid specimen housed in a container to collect a desired concentration of particulates on a filter collection site, comprising:
aspirating specimen liquid from the container and drawing it through a filter; monitoring the rate of change of the weight of the container; comparing the monitored rate of change of container weight to a reference value; and terminating liquid flow through the filter when the rate of change of container weight diminishes to or below a predetermined rate-of-change value.
- 20. A method according to claim 19, further comprising monitoring the total change of weight of the container, and terminating liquid flow through the filter when the total change of weight reaches a predetermined total value.
- 21. A method according to claim 20, further comprising generating an alert signal if liquid flow through the filter is terminated before the rate of change of container weight diminishes to or below the predetermined rate-of-change value.
- 22. Apparatus according to claim 19, claim 20 or claim 21, wherein the predetermined rate-of-change value is a function of the protocol for processing the specimen.
- 23. Apparatus for controlling filtration of a particulate matter-containing liquid specimen housed in a container to obtain a desired concentration of particulates collected on a filter collection site, comprising:
a substantially constant-pressure vacuum source for aspirating-specimen liquid from the container and drawing the liquid through the filter; a load sensor positioned to detect the weight of the container; and a controller operatively connected to the load sensor and the vacuum source, wherein the monitors the rate of change of the weight of the container and terminates liquid flow through the filter when the rate of change of container weight diminishes to or below a predetermined rate-of-change value.
- 24. Apparatus according to claim 23, wherein the controller monitors the total change of weight of the container, and terminates liquid flow through the filter when the total change of weight reaches a predetermined total value.
- 25. Apparatus according to claim 24, wherein the controller generates an alert signal if liquid flow through the filter is terminated before the rate of change of container weight diminishes to or below the predetermined rate-of-change value.
- 26. Apparatus according to claim 23, claim 24 or claim 25, wherein the predetermined rate-of-change value is a function of the protocol for processing the specimen.
- 27. A method of collecting a cell sample of desired concentration on a filter collection site from a biological liquid specimen in a container, comprising:
moving specimen liquid from the container through a filter under substantially constant pressure; monitoring the volume rate of liquid flow through the filter; comparing the monitored liquid flow rate to a reference value; and terminating liquid flow through the filter when the ratio of monitored liquid flow rate to the reference value reaches or exceeds a predetermined ratio value.
- 28. A method according to claim 27, further comprising monitoring the total volume of liquid that has passed through the filter, and terminating liquid flow through the filter when the total volume reaches a predetermined total value.
- 29. A method according to claim 28, further comprising generating an alert signal if liquid flow through the filter is terminated before the ratio of monitored liquid flow to the reference value reaches or exceeds the predetermined ratio value.
- 30. A method according to claim 27, claim 28 or claim 29, wherein the predetermined ratio value is a function of the protocol for processing the specimen.
- 31. A method according to claim 27 or claim 28 for collecting a plurality of cell samples from the same biological liquid specimen, wherein after the cell sample of desired concentration is collected on a first filter and liquid flow through the first filter is terminated, the recited collecting steps are repeated at least once to collect at least one more cell sample, each cell sample collected on a respective filter.
- 32. Apparatus for controlling filtration of a particulate matter-containing liquid specimen to obtain a desired concentration of particulates collected on a filter collection site, comprising:
a substantially constant pressure source effecting movement of liquid through the filter; a filtered liquid volume meter; and a controller operatively coupled to the pressure source and the meter, wherein the controller:
monitors the volume rate of liquid flow through the filter; compares the monitored liquid flow rate to a reference value; and terminates liquid flow through the filter when the ratio of monitored liquid flow rate to the reference value reaches or exceeds a predetermined ratio value.
- 33. Apparatus according to claim 32, wherein the controller monitors the total volume of liquid that has passed through the filter, and terminates liquid flow through the filter when the total volume reaches a predetermined total value.
- 34. Apparatus according to claim 33, wherein the controller generates an alert signal if liquid flow through the filter is terminated before the ratio of the monitored liquid flow rate to the reference value reaches or exceeds the predetermined ratio value.
- 35. Apparatus according to claim 32, claim 33 or claim 34, wherein the predetermined ratio value is a function of the protocol for processing the specimen.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of commonly owned U.S. provisional application Nos. 60/330,092, filed Oct. 19, 2001, 60/372,080, filed Apr. 15, 2002, and 60/373,658, filed Apr. 19, 2002, all of which are incorporated herein by reference. This application also is related to commonly owned U.S. non-provisional application Ser. No. 10/122,151, filed Apr. 15, 2002, which is also incorporated herein by reference.
Provisional Applications (3)
|
Number |
Date |
Country |
|
60330092 |
Oct 2001 |
US |
|
60372080 |
Apr 2002 |
US |
|
60373658 |
Apr 2002 |
US |