US4331862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for calibrating a particle counting machine and a calibration standard therefor
Assignee: Individual
•
Filing: 1979-02-23
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Granted: 1982-05-25
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Expires: 1999-02-23
Abstract
Abstract A calibration method and standard for calibrating particle counting instruments such as blood platelet counting instruments in which the particles have a distribution of sizes, wherein the method includes the following steps performable in any order. A first known concentration of particles having a mean size which is substantially near the lower extreme size distribution of particles normally counted by the instrument being calibrated are counted and the counts thus obtained are compared with the known count of the concentration. A second known concentration of particles are then counted with the instrument to be calibrated in which the mean size of the second particles is substantially near the upper extreme size distribution of the particles normally counted by the instrument. The count thus obtained is then compared to the known count of the concentration.
Inventors
- 👤 Wayne L. Ryan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:53
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/1031; G01N15/12; G01N15/131; G01N33/00; G01N33/48; G01N33/50; G01N33/96; G01N2496/00; G01N2496/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
148 words
A method for testing an instrument used to count a plurality of particles having a particle size distribution that extends between a lower extreme size distribution and an upper extreme size distribution to see if it is in calibration, the method comprising in any order: counting a first known concentration of particles having a known count with the instrument to be calibrated, the mean size of the particles in said first known concentration being substantially near the lower extreme size distribution; comparing the count of said first counted concentration with the known count of said first known concentration; counting a second known concentration of particles with the instrument to be calibrated, the mean size of the particles in said second known concentration being substantially near the upper extreme size distribution; and comparing the count of said second counted concentration with the known count of said second known concentration.
Claim 2
Independent Claim
148 words
A method for testing an instrument used to count a plurality of particles having a particle size distribution that extends between a lower extreme size distribution and an upper extreme size distribution to see if it is in calibration, the method comprising in any order: counting a first known concentration of particles having a known count with the instrument to be calibrated, the mean size of the particles in said first known concentration being substantially near the lower extreme size distribution; comparing the count of said first counted concentration with the known count of said first known concentration; counting a second known concentration of particles with the instrument to be calibrated, the mean size of the particles in said second known concentration being substantially near the upper extreme size distribution; and comparing the count of said second counted concentration with the known count of said second known concentration.
Claim 3
Dependent Claim
27 words
A method as claimed in claim 1 wherein said first and second known concentrations of particles are each in a carrier comprising water and a non-ionic surfactant.
Claim 4
Dependent Claim
22 words
A method as claimed in claim 2 wherein the concentration of said surfactant is in the range of about 0.059% to 0.3%.
Claim 5
Dependent Claim
15 words
A method as claimed in claim 2 wherein said surfactant is a polyoxyethylene-polyoxypropylene block polymer.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 4 wherein said surfactant has a molecular weight of polyoxypropylene hydrophobe of about 2250 and is about 80% by weight polyoxyethylene.
Claim 7
Dependent Claim
14 words
A method as claimed in claim 4 wherein said surfactant concentration is approximately 0.2%.
Claim 8
Dependent Claim
15 words
A method as claimed in claim 3 wherein said carrier has a substantially neutral pH.
Claim 9
Dependent Claim
16 words
A method as claimed in claim 2 wherein said carrier also includes a fungicide or bactericide.
Claim 10
Dependent Claim
20 words
A method as claimed in claim 8 wherein said fungicide is phenol in a concentration of about 0.17% to 0.25%.
Claim 11
Dependent Claim
24 words
A method as claimed in claim 1 wherein said particles in both said first and second known concentrations are of an elastomeric, stable material.
Claim 12
Dependent Claim
25 words
A method as claimed in claim 10 wherein said first particle is of polystyrene and said second particle is a copolymer of styrene and methylstyrene.
Claim 13
Independent Claim
146 words
A method for testing known blood platelet counting instruments wherein the platelets have a known volume distribution from a lower extreme size distribution of about 2.5 cubic micrometers to an upper extreme size distribution of about 40 cubic micrometers to see if the instruments are in calibration; said method comprising in any order: counting a first known concentration of particles having a known count with the instrument to be calibrated, the mean volume of said first particles being about 2 to 3 cubic micrometers; comparing the count of said first counted concentration with the known count of said first known concentration; counting a second known concentration of particles with the instrument to be calibrated, the mean volume of said second particles being about 25 to 26 cubic micrometers; and comparing the count of said second counted concentration with the known count of said second known concentration.
Claim 14
Independent Claim
146 words
A method for testing known blood platelet counting instruments wherein the platelets have a known volume distribution from a lower extreme size distribution of about 2.5 cubic micrometers to an upper extreme size distribution of about 40 cubic micrometers to see if the instruments are in calibration; said method comprising in any order: counting a first known concentration of particles having a known count with the instrument to be calibrated, the mean volume of said first particles being about 2 to 3 cubic micrometers; comparing the count of said first counted concentration with the known count of said first known concentration; counting a second known concentration of particles with the instrument to be calibrated, the mean volume of said second particles being about 25 to 26 cubic micrometers; and comparing the count of said second counted concentration with the known count of said second known concentration.
Claim 15
Dependent Claim
25 words
A method as claimed in claim 12 wherein said first particles have a volume distribution from about 2.5 cubic micrometers to about 4.6 cubic micrometers.
Claim 16
Dependent Claim
27 words
A method as claimed in claim 12 or 13 wherein said second particles have a volume distribution from about 22 cubic micrometers to about 42 cubic micrometers.
References Cited (Backward Citations)
US1118981A
Cited
US3412037A
Cited
US3634868A
Cited
US3791192A
Cited
US3874850A
Cited
US3975727A
Cited
US4160644A
Cited
US4193288A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-24 | 1985-11-23 | 1986-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-24 | 1989-11-23 | 1990-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-24 | 1993-11-23 | 1994-05-25 | $7700.00 | Window Closed / Lapsed |