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US4193398A Expired / Lapsed US ⏱️ 0.0 years remaining

Fluid displacement

Assignee: Watson Marlow Ltd
•
Filing: 1978-05-25
•
Granted: 1980-03-18
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Expires: 1998-05-25
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Abstract

Abstract An extracorporeal osmotic pump has a first chamber containing an osmotic fluid e.g. aqueous polyethylene glycol solution and a second chamber containing a weaker solution or solvent e.g. water. Between the two there is a duct containing the semipermeable membrane and nearer the first chamber one or more layers of porous material (e.g. four contiguous face-to-face discs of porous polyethylene) as a flow-control means.

Inventors

  • 👤 Bernard H. Refson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-22 20:15
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/14; A61M5/142; A61M5/145; A61M5/148; A61M5/1483; A61M2005/14513

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 74 words
An extracorporeal osmotic pump comprising a first chamber for containing an osmotically stronger solution; a second chamber for containing an osmotically weaker solution or pure solvent; a duct located between the said chambers placing them in communication; a semi-permeable membrane across said duct located nearer the said second chamber; and at least one layer of liquid-permeable porous material across said duct located nearer the said first chamber, whereby it acts as a flow-control means.
Claim 2
Dependent Claim 74 words
An extracorporeal osmotic pump comprising a first chamber for containing an osmotically stronger solution; a second chamber for containing an osmotically weaker solution or pure solvent; a duct located between the said chambers placing them in communication; a semi-permeable membrane across said duct located nearer the said second chamber; and at least one layer of liquid-permeable porous material across said duct located nearer the said first chamber, whereby it acts as a flow-control means.
Claim 3
Dependent Claim 68 words
An extracorporeal osmotic pump as claimed in claim 1 further comprising: separate container means located within said first chamber for containing liquid material to be pumped, said container means having deformable walls and an outlet means placing in communication the exterior of the said first chamber, and the interior of the said container means, whereby build-up of pressure on osmosis pumps liquid from the said separate container means.
Claim 4
Dependent Claim 21 words
An entracorporeal osmotic pump as claimed in claim 2 wherein said separate container means is a flexible impervious synthetic polymeric sac.
Claim 5
Dependent Claim 20 words
An extracorporeal osmotic pump as claimed in claim 1 wherein said second chamber is a flexible impervious synthetic polymeric sac.
Claim 6
Dependent Claim 18 words
An osmotic pump as claimed in claim 1 in which the flow control means is a multi-layer structure.
Claim 7
Dependent Claim 25 words
An osmotic pump as claimed in claim 5 in which the flow control means consists of a plurality of layers of synthetic polymeric porous material.
Claim 8
Dependent Claim 25 words
An osmotic pump as claimed in claim 6 in which the flow control means consists of a plurality of face-to-face contiguous discs of porous polyethylene.
Claim 9
Dependent Claim 30 words
An osmotic pump as claimed in claim 7 wherein said discs of porous polyethylene are each 1 to 4 mm thick with pores on average 10 to 100 microns across.
Claim 10
Dependent Claim 48 words
An osmotic pump as claimed in claim 7 wherein the communicating duct is formed in the wall of the said first chamber to receive the said discs; further comprising a membrane assembly peripherally sealingly clamped over the said duct by clamping means adapted to mount said second chamber.
Claim 11
Dependent Claim 75 words
An extracorporeal osmotic pump comprising a first chamber charged with an osmotically stronger solution; a second chamber charged with an osmotically weaker solution or pure solvent; a duct located between the said chambers placing them in communication; a semi-permeable membrane across said duct located nearer the said second chamber; and at least one layer of liquid-permeable porous material across said duct located near the said first chamber, whereby it acts as a flow control means.
Claim 12
Dependent Claim 75 words
An extracorporeal osmotic pump comprising a first chamber charged with an osmotically stronger solution; a second chamber charged with an osmotically weaker solution or pure solvent; a duct located between the said chambers placing them in communication; a semi-permeable membrane across said duct located nearer the said second chamber; and at least one layer of liquid-permeable porous material across said duct located near the said first chamber, whereby it acts as a flow control means.
Claim 13
Dependent Claim 24 words
An extracorporeal osmotic pump as claimed in claim 10 charged in the first chamber with an aqueous solution of a water soluble polymeric material.
Claim 14
Dependent Claim 30 words
An extracorporeal osmotic pump as claimed in claim 11 charged in the first chamber with an aqueous solution of a polyethylene glycol and in the second chamber with deionized water.

References Cited (Backward Citations)

US2766907A Cited
US3153414A Cited
US3645111A Cited
US3760805A Cited
US3760804A Cited
US4041944A Cited
US4033345A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-03-18 1983-09-17 1984-03-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-03-18 1987-09-17 1988-03-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-03-18 1991-09-17 1992-03-18 $7700.00 Window Closed / Lapsed

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