Patent US4953975A successfully refreshed from Google Patents.
US4953975A
Expired / Lapsed
US
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Correction of material layer volume measurements
Assignee: Individual
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Filing: 1989-01-30
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Granted: 1990-09-04
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Expires: 2009-01-30
Abstract
Abstract Centrifuged material layer volume measurements are made in a transparent capillary tube containing an elongated float which expands the layers being measured. The extent of layer expansion will vary depending on the tube bore diameter and the float diameter. The tube bore diameter and float diameter for each tube/float pair are measured, and an indication of the difference between the two is marked on the tube. When the volume determinations are made, the measured difference between the tube bore diameter and the float diameter is taken into account before calculating actual layer volume malues.
Inventors
- 👤 Robert A. Levine
- 👤 Stephen C. Wardlaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:12
CPC Classifications
B; B01; B01L; B01L3/00; B01L3/50; B01L3/502; B01L3/5021; B01L3/50215
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A material sampling assembly comprising: a transparent tube for holding a material sampling to be separated by centrifugation; a cylindrical float for placement in the tube when the sample is centrifuged; and means printed on the tube or float which provides an indication of the ratio of the square of the tube bore radius to the difference between the squares of the tube bore radius and the float radius.
Claim 2
Dependent Claim
69 words
A material sampling assembly comprising: a transparent tube for holding a material sampling to be separated by centrifugation; a cylindrical float for placement in the tube when the sample is centrifuged; and means printed on the tube or float which provides an indication of the ratio of the square of the tube bore radius to the difference between the squares of the tube bore radius and the float radius.
Claim 3
Dependent Claim
18 words
The assembly of claim 1 wherein said means printed on the tube or float is an indicium mark.
Claim 4
Dependent Claim
17 words
The assembly of claim 2 wherein said indicium mark is a band whose width provides said indication.
Claim 5
Dependent Claim
15 words
The assembly of claim 2 wherein said indicium mark is a machine readable bar code.
Claim 6
Dependent Claim
68 words
A blood sample cell count assembly comprising: a transparent tube for holding the blood sample; a cylindrical float for placement in the tube when the sample is centrifuged; and an indicium mark printed on the tube or float which provides an indication of the ratio of the square of the tube bore radius to the difference between the squares of the tube bore radius and the float radius.
Claim 7
Dependent Claim
68 words
A blood sample cell count assembly comprising: a transparent tube for holding the blood sample; a cylindrical float for placement in the tube when the sample is centrifuged; and an indicium mark printed on the tube or float which provides an indication of the ratio of the square of the tube bore radius to the difference between the squares of the tube bore radius and the float radius.
Claim 8
Dependent Claim
25 words
The assembly of claim 5 wherein said indicium mark is a band disposed on said tube, the band having a width which provides said indicium.
Claim 9
Dependent Claim
15 words
The assembly of claim 5 wherein said indicium mark is a machine readable bar code.
Claim 10
Independent Claim
150 words
A method for providing true blood cell counts in a centrifuged sample of blood contained in a transparent tube which also contains a cylindrical float, said method comprising the steps of: (a) measuring lengths of bands of cells in the centrifuged sample which cells are positioned between the tube and the float; (b) determining a first ratio of the square of the tube bore radius to the difference between the squares of the tube bore radius and the float radius by scanning a correction indicium mark printed on the tube or float; (c) comparing said first ratio with a predetermined ratio of the square of a target tube bore radius to the difference between the squares of the target tube bore radius and a target float radius to determine a correction factor; and (d) using said correction factor to determine the true blood cell counts from measured cell band lengths.
Claim 11
Independent Claim
150 words
A method for providing true blood cell counts in a centrifuged sample of blood contained in a transparent tube which also contains a cylindrical float, said method comprising the steps of: (a) measuring lengths of bands of cells in the centrifuged sample which cells are positioned between the tube and the float; (b) determining a first ratio of the square of the tube bore radius to the difference between the squares of the tube bore radius and the float radius by scanning a correction indicium mark printed on the tube or float; (c) comparing said first ratio with a predetermined ratio of the square of a target tube bore radius to the difference between the squares of the target tube bore radius and a target float radius to determine a correction factor; and (d) using said correction factor to determine the true blood cell counts from measured cell band lengths.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |