US4350593A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Assembly, compositions and method for separating blood
Assignee: Becton Dickinson and Co
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Filing: 1979-06-25
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Granted: 1982-09-21
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Expires: 1999-06-25
Abstract
Abstract The disclosure is of an improved assembly, compositions and method for the separation of blood into its light, liquid and heavy, substantially cellular phases with insertion of a non-Newtonian fluid between the phases as a barrier. The improvement comprises using as the non-Newtonian fluid, one which has substantially time independent rheological properties and a controlled yield stress value. The improved assemblies of the invention have enhanced shelf-lives and improved reliability of operation. The preferred assemblies may be sterilized by irradiation and the disclosure is also of a method for their manufacture.
Inventors
- 👤 Stephen B. Kessler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:24
CPC Classifications
B; B01; B01D; B01D43/00; G; G01; G01N; G01N33/00; G01N33/48; G01N33/483; G01N33/487; G01N33/49; G01N33/491
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
175 words
In a pre-assembled assembly for the collection and separation of blood into its light, liquid and heavy, substantially cellular phases under centrifugal force with the establishment of a non-Newtonian fluid barrier between the separated phases, wherein said assembly comprises, a tubular container having an open end and a closed end, a removable closure for said open end, and a non-Newtonian fluid disposed in said container, the improvement which comprises; as said non-Newtonian fluid a blend of from about 93 to 97 parts of a polyester prepared by the condensation of equal molar proportions of azelaic acid with a mixture of neopentyl glycol and butanediol in a molar ratio of 5:2 and having a viscosity of from 100 to 5,000 poises and a density of from 1.007 to 1.067 gms/cc with from 3 to 7 parts by weight of a fumed silica, saidblend having a specific gravity of from 1.03 to 1.09 and said fluid having substantially time independent rheological properties, said non-Newtonian fluid being inert in respect to chemical reactivity toward blood and blood components.
Claim 2
Dependent Claim
175 words
In a pre-assembled assembly for the collection and separation of blood into its light, liquid and heavy, substantially cellular phases under centrifugal force with the establishment of a non-Newtonian fluid barrier between the separated phases, wherein said assembly comprises, a tubular container having an open end and a closed end, a removable closure for said open end, and a non-Newtonian fluid disposed in said container, the improvement which comprises; as said non-Newtonian fluid a blend of from about 93 to 97 parts of a polyester prepared by the condensation of equal molar proportions of azelaic acid with a mixture of neopentyl glycol and butanediol in a molar ratio of 5:2 and having a viscosity of from 100 to 5,000 poises and a density of from 1.007 to 1.067 gms/cc with from 3 to 7 parts by weight of a fumed silica, saidblend having a specific gravity of from 1.03 to 1.09 and said fluid having substantially time independent rheological properties, said non-Newtonian fluid being inert in respect to chemical reactivity toward blood and blood components.
Claim 3
Dependent Claim
26 words
The assembly of claim 1 wherein said fluid has a yield stress value within the range of from about 200 to about 4000 dynes/cm 2 .
Claim 4
Dependent Claim
61 words
The assembly of claim 1 having a further improvement wherein said non-Newtonian fluid which has substantially time independent rheological properties is initially disposed adjacent said closed end so that said non-Newtonian fluid having substantially time independent rheological properties has a single unconfined surface and said surface is not a plane which is perpendicular to the longitudinal axis of said tubular container.
Claim 5
Dependent Claim
31 words
The assembly of claim 3 wherein said unconfined surface is on a plane which forms an angle of from about 5° to about 60° with the plane normal to said axis.
Claim 6
Dependent Claim
15 words
The assembly of claim 4 wherein said angle is from about 10° to about 20°.
Claim 7
Dependent Claim
25 words
The assembly of claim 1 wherein said blend has a bleed of less than 1.0 percent when ultracentrifuged at 250,000 X g for 4 hours.
Claim 8
Dependent Claim
90 words
The assembly of claim 1 wherein said fluid includes from 0.05 to 3 parts by weight of a stabilizing compound of the formula, R'O--C.sub.a H.sub.2a O).sub.x (C.sub.b H.sub.2b O).sub.y H where R' is a member selected from the class consisting of hydrogen and lower alkyl radicals having from 1 to 7 carbon atoms, a and b are integers equal to from 1 to 4, inclusive, x is an integer equal to from about 4 to 50 or more and y is a whole number equal to from 0 to 50.
Claim 9
Dependent Claim
21 words
The assembly of claim 7 wherein the stabilizing compound is present at a concentration of 0.1 to 2 parts by weight.
Claim 10
Dependent Claim
75 words
A composition, which comprises; from 93 to 97 parts by weight of a fluid polymeric polyester prepared by the condensation of substantially equimolar proportions of azelaic acid and a mixture of neopentyl glycol and butanediol in a molar ratio of 5:2, said polyester having a viscosity of from 100 to 5000 poises at 25° C. and a density of from 1.007 to 1.067; and from 3 to 7 parts by weight of a fumed silica.
Claim 11
Dependent Claim
75 words
A composition, which comprises; from 93 to 97 parts by weight of a fluid polymeric polyester prepared by the condensation of substantially equimolar proportions of azelaic acid and a mixture of neopentyl glycol and butanediol in a molar ratio of 5:2, said polyester having a viscosity of from 100 to 5000 poises at 25° C. and a density of from 1.007 to 1.067; and from 3 to 7 parts by weight of a fumed silica.
Claim 12
Independent Claim
150 words
A method of providing an assembly for the separation of blood into its light, liquid and heavy, substantially cellular phases under centrifugal force with establishment of a non-Newtonian fluid barrier between its separated phases, which comprises; providing a tubular container having an open end and a closed end; depositing adjacent the closed end a barrier material which comprises an inert non-Newtonian fluid which has substantially time independent rheological properties, a density of from about 1.03 to 1.09 and comprises from 93 to 97 parts of a polymeric polyester liquid having a viscosity of from 100 to 5000 poises at 25° C. and a density of 1.007 to 1.067, said polyester being the condensation product of substantially equal molar proportions of azelaic acid with a mixture of neopentyl glycol and 1,3-butanediol in a molar ratio of 5:2 compounded with from 3 to 7 parts by weight of a fumed silica filler.
Claim 13
Independent Claim
150 words
A method of providing an assembly for the separation of blood into its light, liquid and heavy, substantially cellular phases under centrifugal force with establishment of a non-Newtonian fluid barrier between its separated phases, which comprises; providing a tubular container having an open end and a closed end; depositing adjacent the closed end a barrier material which comprises an inert non-Newtonian fluid which has substantially time independent rheological properties, a density of from about 1.03 to 1.09 and comprises from 93 to 97 parts of a polymeric polyester liquid having a viscosity of from 100 to 5000 poises at 25° C. and a density of 1.007 to 1.067, said polyester being the condensation product of substantially equal molar proportions of azelaic acid with a mixture of neopentyl glycol and 1,3-butanediol in a molar ratio of 5:2 compounded with from 3 to 7 parts by weight of a fumed silica filler.
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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) | 1985-09-20 | 1986-03-22 | 1986-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-20 | 1990-03-22 | 1990-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-20 | 1994-03-22 | 1994-09-21 | $7700.00 | Window Closed / Lapsed |