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US4233032A Expired / Lapsed US ⏱️ 0.0 years remaining

Fetal lung maturity test

Assignee: Beckman Coulter Inc
•
Filing: 1979-02-12
•
Granted: 1980-11-11
•
Expires: 1999-02-12
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Abstract

Abstract A simple rapid STAT test and test kit are provided for the reliable determination of prenatal lung maturity as well as other surfactant lipid dependent determinations. The method involves a shake test employing a plurality of vials having graduated volumes of ethanol, including a dye, normally in combination with a positive control. A predetermined amount of the sample is introduced into each of the vials, the vials shaken in a reproducible manner, and the highest ethanol volume fraction which provides for a stable foam determined. Based on statistical evaluations, an ethanol volume fraction above 0.45 will generally be regarded as positive, meaning healthy lung maturity, while a value below about 0.45 will generally indicate that further investigation is warranted.

Inventors

  • 👤 Bernard E. Statland
  • 👤 Geoffrey Sher

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 22:32
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N13/00; G01N13/02; G01N2013/0241; G01N2013/025

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 90 words
A method for measuring fetal or neonatal lung maturity employing amniotic fluid comprising: combining a predetermined volume of amniotic fluid with graduated amounts of 95% aqueous ethanol to 100% ethanol to provide at least six mixtures of graduated ethanol volume fractions from 0.45 to 0.50 to 0.01 graduations; agitating each of the mixtures in substantially the same manner; and determining the highest ethanol volume fraction which results in a persistent foam at the interface; wherein an ethanol volume fraction of greater than 0.45 with persistent foam indicates fetal lung maturity.
Claim 2
Independent Claim 90 words
A method for measuring fetal or neonatal lung maturity employing amniotic fluid comprising: combining a predetermined volume of amniotic fluid with graduated amounts of 95% aqueous ethanol to 100% ethanol to provide at least six mixtures of graduated ethanol volume fractions from 0.45 to 0.50 to 0.01 graduations; agitating each of the mixtures in substantially the same manner; and determining the highest ethanol volume fraction which results in a persistent foam at the interface; wherein an ethanol volume fraction of greater than 0.45 with persistent foam indicates fetal lung maturity.
Claim 3
Dependent Claim 17 words
A method according to claim 1, wherein a small amount of dye is introduced into said ethanol.
Claim 4
Dependent Claim 21 words
A method according to claim 1, wherein negative and positive controls are employed for comparison of said mixtures with said controls.
Claim 5
Dependent Claim 53 words
A kit for use in the method according to claim 1, containing six vials, each of the vials containing different amounts of 95% aqueous ethanol to 100% ethanol, so that upon admixture with a fixed amount of amniotic fluid, the vials provide ethanol volume fractions ranging from 0.45 to 0.50 at 0.01 graduations.
Claim 6
Dependent Claim 18 words
A kit according to claim 4, where included in said ethanol is a small amount of a dye.
Claim 7
Dependent Claim 53 words
A kit according to any of claims 4 or 5, including two additional vials, one vial containing 40 microg. dipalmitoyl lecithin, 377 microl. of ethanol and 500 microl. of saline as a positive control, and 20 microg. of dipalmitolyl lechthin, 500 microl. of ethanol and 500 microl. of saline as a negative control.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-11-11 1984-05-12 1984-11-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-11-11 1988-05-12 1988-11-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-11-11 1992-05-12 1992-11-11 $7700.00 Window Closed / Lapsed

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