Patent US4234428A successfully refreshed from Google Patents.
US4234428A
Expired / Lapsed
US
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Dual membrane mass transfer device
Assignee: Baxter International Inc
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Filing: 1978-10-12
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Granted: 1980-11-18
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Expires: 1998-10-12
Abstract
Abstract A hemodialysis apparatus is provided in which two blood compartments are formed by two different types of membranes. One membrane is a relatively high flux membrane, with relatively high hydraulic permeability, and the other membrane is a relatively low flux hemodialysis membrane. The blood compartment associated with the high flux membrane will be separated from the blood compartment associated with the low flux membrane. In use, dialyzing solution flows through only a dialysate compartment adjacent to the low flux membrane to accomplish diffusion at low transmembrane pressures. No dialyzing fluid perfuses the compartment adjacent the high flux membrane, but high transmembrane pressures draw ultra-diffusate into this compartment for collection and measurement of fluid loss in the patient.
Inventors
- 👤 William J. Schnell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:29
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/14; A61M1/16; A61M1/34; A61M1/3413; A61M1/3417; B; B01; B01D; B01D61/00; B01D61/14; B01D61/18; B01D61/24; B01D61/243; B01D61/28; B01D61/58; B01D63/00; B01D63/08; B01D63/082; B01D63/084; B01D2313/00; B01D2313/10; B01D2313/14; B01D2313/146; B01D61/145
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
311 words
In an apparatus for the treatment of blood by hemodialysis, having a stack of membrane support plates which support membranes on opposite sides therof and form open volumes between the membrane support plates and the membranes supported thereon, the improvement comprising, in combination: a first membrane support plate; a first relatively high flux membrane, with relatively high hydraulic permeability, supported on one side of said first membrane support plate and forming an open volume between said first relatively high flux membrane and said first membrane support plate; a first relatively low flux membrane supported on the opposite side of said first membrane support and forming an open volume between said first relatively low flux membrane and said first membrane support plate; a second membrane support plate spaced from said first membrane support plate, with a blood path formed in the spacing between said first and second membrane support plates; a second relatively high flux membrane, with relatively high hydraulic permeability, supported on one side of said second membrane support plate and forming an open volume between said second relatively high flux membrane and said first membrane support plate; a second relatively low flux membrane supported on the opposite side of said second membrane support plate and forming an open volume between said second relatively low flux membrane and said second membrane support plate; said open volume between said relatively high flux membranes and the respective membrane support plates comprising a low pressure path to provide significant ultrafiltration; said open volume between said relatively low flux membranes and the respective membrane support plates comprising a dialysate solution path to provide significant dialysis and relatively insignificant ultrafiltration; and said membrane support plates segregating said open volume between said relatively high flux membranes and the respective membrane support plates from said open volume between said relatively low flux membranes and the membrane support plates.
Claim 2
Dependent Claim
311 words
In an apparatus for the treatment of blood by hemodialysis, having a stack of membrane support plates which support membranes on opposite sides therof and form open volumes between the membrane support plates and the membranes supported thereon, the improvement comprising, in combination: a first membrane support plate; a first relatively high flux membrane, with relatively high hydraulic permeability, supported on one side of said first membrane support plate and forming an open volume between said first relatively high flux membrane and said first membrane support plate; a first relatively low flux membrane supported on the opposite side of said first membrane support and forming an open volume between said first relatively low flux membrane and said first membrane support plate; a second membrane support plate spaced from said first membrane support plate, with a blood path formed in the spacing between said first and second membrane support plates; a second relatively high flux membrane, with relatively high hydraulic permeability, supported on one side of said second membrane support plate and forming an open volume between said second relatively high flux membrane and said first membrane support plate; a second relatively low flux membrane supported on the opposite side of said second membrane support plate and forming an open volume between said second relatively low flux membrane and said second membrane support plate; said open volume between said relatively high flux membranes and the respective membrane support plates comprising a low pressure path to provide significant ultrafiltration; said open volume between said relatively low flux membranes and the respective membrane support plates comprising a dialysate solution path to provide significant dialysis and relatively insignificant ultrafiltration; and said membrane support plates segregating said open volume between said relatively high flux membranes and the respective membrane support plates from said open volume between said relatively low flux membranes and the membrane support plates.
Claim 3
Dependent Claim
56 words
In an apparatus as described in claim 1, said one sides of said membrane support plates being oriented in a common direction whereby said first relatively low flux membrane will face said second relatively high flux membrane on opposite sides of the blood path formed in the spacing between said first and second membrane support plates.
Claim 4
Dependent Claim
20 words
In an apparatus as described in claim 1, said low pressure path being adapted for coupling to a vacuum pump.
Claim 5
Dependent Claim
22 words
In an apparatus as described in claim 1, said dialysate solution path being adapted for coupling to a supply of dialysate solution.
Claim 6
Dependent Claim
23 words
In an apparatus as described in claim 1, said relatively high flux membrane comprising one of the group consisting of polyacrylonitrile and polycarbonate.
Claim 7
Dependent Claim
15 words
In an apparatus as described in claim 1, said relatively low flux membrane comprising Cuprophan®.
Claim 8
Dependent Claim
92 words
In an apparatus as described in claim 1, and further including a blood manifolding path extending through said stack; and closing means sealing the membranes on opposite sides of each membrane support plate to each other adjacent said blood manifolding path, said closing means being spaced from each other to define a blood path therebetween and being independent of each other whereby the closing forces generated by one of the closing means on its respective membrane are independent of the closing forces generated by the other closing means on its respective membranes.
Claim 9
Dependent Claim
266 words
In an apparatus for the treatment of blood by hemodialysis having a stack of membrane support plates which support membranes on opposite sides thereof and form open volumes between the membrane support plates and the membranes supported thereon, the improvement comprising, in combination: a plurality of membrane support plates spaced from each other to form blood paths in the spacing between said membrane support plates; a relatively high flux membrane, with relatively high hydraulic permeability, supported on one side of each of said membrane support plates and forming an open volume between said relatively high flux membrane and said membrane support plate; a relatively low flux membrane supported on the opposite side of each of said membrane support plates and forming an open volume between said relatively low flux membrane and said membrane support plate; said one sides of said membrane support plates being oriented in a common direction whereby said relatively low flux membranes will face said relatively high flux membranes on opposite sides of the blood path formed in the spacings between said membrane support plates; said open volume between said relatively high flux membranes and the respective membrane support plates comprising a low pressure path to provide significant ultrafiltration; said open volumes between said relatively low flux membranes and the respective membrane support plates comprising a dialysate solution path to provide significant dialysis and relatively insignificant ultrafiltration; and said membrane support plates segregating said open volume between said relatively high flux membranes and the respective membrane support plates from said open volume between said relatively low flux membranes and the membrane support plates.
Claim 10
Dependent Claim
266 words
In an apparatus for the treatment of blood by hemodialysis having a stack of membrane support plates which support membranes on opposite sides thereof and form open volumes between the membrane support plates and the membranes supported thereon, the improvement comprising, in combination: a plurality of membrane support plates spaced from each other to form blood paths in the spacing between said membrane support plates; a relatively high flux membrane, with relatively high hydraulic permeability, supported on one side of each of said membrane support plates and forming an open volume between said relatively high flux membrane and said membrane support plate; a relatively low flux membrane supported on the opposite side of each of said membrane support plates and forming an open volume between said relatively low flux membrane and said membrane support plate; said one sides of said membrane support plates being oriented in a common direction whereby said relatively low flux membranes will face said relatively high flux membranes on opposite sides of the blood path formed in the spacings between said membrane support plates; said open volume between said relatively high flux membranes and the respective membrane support plates comprising a low pressure path to provide significant ultrafiltration; said open volumes between said relatively low flux membranes and the respective membrane support plates comprising a dialysate solution path to provide significant dialysis and relatively insignificant ultrafiltration; and said membrane support plates segregating said open volume between said relatively high flux membranes and the respective membrane support plates from said open volume between said relatively low flux membranes and the membrane support plates.
Claim 11
Dependent Claim
88 words
In an apparatus as described in claim 8, a blood manifolding path extending through said stack; closing means sealing the membranes on opposite sides of each membrane support plate to each other adjacent said blood manifolding path, said closing means being spaced from each other to define a blood path therebetween and being independent of each other whereby the closing forces generated by one of the closing means on its respective membranes are independent of the closing forces generated by the other closing means on their respective membranes.
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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) | 1983-11-18 | 1984-05-19 | 1984-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-18 | 1988-05-19 | 1988-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-18 | 1992-05-19 | 1992-11-18 | $7700.00 | Window Closed / Lapsed |