US4698155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for continuous metered removal or addition of small quantities of fluid
Assignee: Akzo NV
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Filing: 1985-06-27
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Granted: 1987-10-06
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Expires: 2005-06-27
Abstract
Abstract A very small uniform fluid stream is produced and kept constant over a prolonged period by using at least one fluid-permeable membrane which can be composed of hollow filaments, and the method and apparatus can be used, for example in cardiac catheterization and blood pressure measurement in the blood.
Inventors
- 👤 John Atkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:37
CPC Classifications
G; G01; G01F; G01F13/00; G01F13/006
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
143 words
An apparatus for continuous meter removal or addition of small quantities of fluid over a prolonged period, comprising a fluid permeable membrane arranged so that the fluid passes through said membrane and therefore at least one very small uniform fluid stream is produced and maintained; a housing which limits an internal space, said fluid permeable membrane being arranged so as to subdivide said internal space of said housing into a first chamber and a second chamber for passing the fluid from said first chamber through said fluid permeable membrane into said second chamber, said housing having a casing provided with a flexible and elastic portion; a sealing block which holds said membrane and arranged in said flexible and elastic portion in a fluid-tight manner but not rigidly connected thereto; and means for partially surrounding said flexible and elastic portion and deforming the same.
Claim 2
Independent Claim
143 words
An apparatus for continuous meter removal or addition of small quantities of fluid over a prolonged period, comprising a fluid permeable membrane arranged so that the fluid passes through said membrane and therefore at least one very small uniform fluid stream is produced and maintained; a housing which limits an internal space, said fluid permeable membrane being arranged so as to subdivide said internal space of said housing into a first chamber and a second chamber for passing the fluid from said first chamber through said fluid permeable membrane into said second chamber, said housing having a casing provided with a flexible and elastic portion; a sealing block which holds said membrane and arranged in said flexible and elastic portion in a fluid-tight manner but not rigidly connected thereto; and means for partially surrounding said flexible and elastic portion and deforming the same.
Claim 3
Dependent Claim
28 words
An apparatus as defined in claim 1, wherein said membrane has an ultrafiltration rate lying in the range from 2 to 500 ml/m 2 ·h·mm Hg for water.
Claim 4
Dependent Claim
28 words
An apparatus as defined in claim 1, wherein said membrane has an ultrafiltration rate lying in the range from 15 to 100 ml/m 2 ·h·mm Hg for water.
Claim 5
Dependent Claim
30 words
An apparatus as defined in claim 1, wherein said membrane is composed of a hollow filament having ends, said ends of said hollow filament being embedded in said sealing block.
Claim 6
Dependent Claim
32 words
An apparatus as defined in claim 1, wherein said membrane is composed of a plurality of hollow filaments having ends, said ends of said hollow filaments being embedded in said sealing block.
Claim 7
Dependent Claim
18 words
An apparatus as defined in claim 5, wherein said membrane is composed of at most twenty hollow filaments.
Claim 8
Dependent Claim
20 words
An apparatus as defined in claim 1, wherein said membrane is composed of cellulose regenerated from a cellulose cuprammonium solution.
Claim 9
Dependent Claim
15 words
An apparatus as defined in claim 1, wherein said membrane is composed of cellulose acetate.
Claim 10
Dependent Claim
20 words
An apparatus as defined in claim 1, wherein said membrane has pores with a maximum pore sizes of 0.2 μm.
Claim 11
Dependent Claim
40 words
An apparatus as defined in claim 1, wherein said surrounding and deforming means includes a U-shaped clip which partially surrounds said flexible and elastic portion and is rigidly connected at least in part to the remaining portion of said housing.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-05 | 1991-04-06 | 1991-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-05 | 1995-04-06 | 1995-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-05 | 1999-04-06 | 1999-10-06 | $7700.00 | Window Closed / Lapsed |