US3765536A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blood filter cascade
Assignee: Pall Corp
•
Filing: 1972-06-16
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Granted: 1973-10-16
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Expires: 1992-06-16
Abstract
Abstract A disposable filter element is provided, capable of passing human blood at a high flow rate and useful in human blood transfusion systems, to remove undesired suspended particles, substantially without removal of normal and desirable blood components, comprising in combination three filter elements in a cascade, the first comprising plastic netting and having a pore size within the range from about 800 to about 4,000 microns, the second a woven square weave plastic mesh having a pore size within the range from about 20 to about 50 microns, and the third a fibrous unwoven mat having a pore size within the range from about 10 to about 30 microns.
Inventors
- 👤 D Rosenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:45
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/08; B01D39/083; A; A61; A61M; A61M5/00; A61M5/14; A61M5/165; B01D27/00; B01D27/005; B01D27/04; B01D27/06; B01D36/00; B01D36/001; B01D36/02; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/18; B01D39/20; B01D39/2003; B01D39/2017; B01D39/2068; B01D39/2082; B01D39/2089; B01D2239/00; B01D2239/06; B01D2239/0604; B01D2239/0627; B01D2239/065; B01D2239/0654; B01D2239/0681; B01D2239/12; B01D2239/1216; B01D2239/1233
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
239 words
A blood filter element cascade which can be used in blood transfusions without blockage, and which is capable of removing not only large particles, such as blood clots, but also small particles, such as platelets, while passing red blood cells and at least a substantial proportion of white blood celLs, comprising in combination, three filter sheets, arranged in downstream flow sequence in order of progressively increasing fineness; a the first filter sheet comprising coarse open netting of plastic filamentary material having a pore size within the range from about 800 to about 4,000 microns, small enough to remove blood clots, and coarse enough to do so without being subject to blocking by the blood clots that are strained out, b the second filter sheet comprising an open mesh fabric of plastic monofilaments, having a pore size within the range from about 20 to about 50 microns, capable of removing microemboli, lipids and debris, and gas emboli, that pass through the first filter element while passing platelets, white blood cells, and red blood cells, and c the third filter sheet comprising a nonwoven fibrous mat having a pore size within the range from about 10 to about 30 microns and capable of removing sticky particles of the dimensions of nonviable platelets, while permitting most white blood cells to pass through, and also permitting substantially all red blood cells, which have a particle size of approximately 7.5 microns, to pass through.
Claim 2
Dependent Claim
239 words
A blood filter element cascade which can be used in blood transfusions without blockage, and which is capable of removing not only large particles, such as blood clots, but also small particles, such as platelets, while passing red blood cells and at least a substantial proportion of white blood celLs, comprising in combination, three filter sheets, arranged in downstream flow sequence in order of progressively increasing fineness; a the first filter sheet comprising coarse open netting of plastic filamentary material having a pore size within the range from about 800 to about 4,000 microns, small enough to remove blood clots, and coarse enough to do so without being subject to blocking by the blood clots that are strained out, b the second filter sheet comprising an open mesh fabric of plastic monofilaments, having a pore size within the range from about 20 to about 50 microns, capable of removing microemboli, lipids and debris, and gas emboli, that pass through the first filter element while passing platelets, white blood cells, and red blood cells, and c the third filter sheet comprising a nonwoven fibrous mat having a pore size within the range from about 10 to about 30 microns and capable of removing sticky particles of the dimensions of nonviable platelets, while permitting most white blood cells to pass through, and also permitting substantially all red blood cells, which have a particle size of approximately 7.5 microns, to pass through.
Claim 3
Dependent Claim
32 words
A blood filter element cascade according to claim 1, in which the first filter sheet is an open-mesh netting prepared by extruding, casting, or molding plastic and having an integral filamentary structure.
Claim 4
Dependent Claim
23 words
A blood filter element cascade according to claim 2, in which the plastic material is selected from polypropylene, polyethylene, polyester, polyamide, and polycarbonate.
Claim 5
Dependent Claim
48 words
A blood filter element cascade according to claim 1, in which the second filter sheet is a woven square weave mesh of plastic monofilaments having a pore size within the range from about 20 to about 50 microns, the filaments being locked in place at their crossing points.
Claim 6
Dependent Claim
27 words
A blood filter element cascade in accordance with claim 4, in which the monofilaments have a diameter within the range from about 25 to about 50 microns.
Claim 7
Dependent Claim
19 words
A blood filter element cascade in accordance with claim 4, in which the plastic monofilaments are of polyester plastic.
Claim 8
Dependent Claim
22 words
A blood filter element cascade in accordance with claim 1, in which the filaments are heat set to lock them in place.
Claim 9
Dependent Claim
19 words
A blood filter element cascade according to claim 1, in which the third filter sheet is a paper sheet.
Claim 10
Dependent Claim
40 words
A blood filter element cascade according to claim 8, in which the paper sheet is of a fibrous material selected from the group consisting of cellulose fibers, glass fibers, polyester fibers, polyamide fibers, polyethylene fibers, polypropylene fibers, and polycarbonate fibers.
Claim 11
Dependent Claim
46 words
A blood filter element cascade according to claim 9, in which the paper sheet has a pore diameter larger than 30 microns, and carries a microporous layer laid down thereon to bring the pore size to within the range from about 10 to about 30 microns.
Claim 12
Dependent Claim
42 words
A blood filter element cascade according to claim 1, in which the three filter sheets are in close juxtaposition, with the second and third filter sheets separated by spacers, and all corrugated or convoluted to provide a high surface area to flow.
Claim 13
Dependent Claim
37 words
A blood filter element cascade according to claim 11, in which the spacer has a pore size at least as large as the first filter sheet, and within the range from about 800 to about 10,000 microns.
Claim 14
Dependent Claim
35 words
A blood filter element cascade according to claim 12, in which the spacer has an uneven surface so as to provide drainage and prevent blocking of the medium and fine filter sheets by the spacer.
Claim 15
Dependent Claim
65 words
A disposable blood filter unit comprising a blood filter element cascade according to claim 1, and a housing having an inlet and an outlet and line connections thereat for fluid flow into and out from the housing, the blood filter element cascade being disposed in the housing across the line of flow therebetween so that fluid flow therebetween must pass through the filteR element cascade.
Claim 16
Dependent Claim
41 words
A disposable blood filter unit in accordance with claim 14, in which the blood filter element cascade is in the form of a cylinder, and one line connection has a direct fluid flow connection to the interior of the filter cylinder.
Claim 17
Dependent Claim
18 words
A disposable filter unit in accordance with claim 14, having a housing made in two portions bonded together.
Claim 18
Dependent Claim
20 words
A disposable filter unit in accordance with claim 16, made of plastic, with the portions fused together into one piece.
Claim 19
Dependent Claim
16 words
A disposable filter unit in accordance with claim 17, including line connections integral with the housing.
Claim 20
Dependent Claim
18 words
A disposable filter unit in accordance with claim 17, having the filter unit bonded to one housing portion.
Claim 21
Dependent Claim
39 words
A disposable filter unit in accordance with claim 18, having the filter unit bonded to one housing portion at the outlet with a direct fluid flow line connection from the filtrate-flow side of the filter element to the outlet.
Claim 22
Dependent Claim
192 words
A disposable blood filter unit according to claim 14, in which the housing is composed at least of first and second generally channel-shaped housing portions, defining therebetween a fluid chamber open at two sides, the first and second housing portions having opposed sides, with mating sections abutting and bonded in a fluid-tight seal to each other, and the blood filter element cascade in sheet form extending across the fluid chamber, across the line of fluid flow between the fluid ports and held at opposed side portions to at least one of the first and second housing portions, and side caps bonded to the first and second housing portions in a fluid-tight seal across the open sides of the fluid chamber and to the sides of the blood filter element cascade extending along such open sides, the side caps and the housing portions holding the sides of the blood filter element cascade, positioning the blood filter element cascade across the fluid chamber, and sealing all the sides of the blood filter element cascade to the housing, so that the fluid flow between the fluid ports must pass through the blood filter element cascade.
Claim 23
Dependent Claim
47 words
A disposable blood filter unit in accordance with claim 21, having four sides, two of the sides being defined by the side caps and two of the sides by the first and second housing portions, and the blood filter element cascade is in four sided sheet form.
Claim 24
Dependent Claim
23 words
A disposable blood filter unit in accordance with claim 22, in which the blood filter element cascade is in four-sided corrugated sheet form.
Claim 25
Dependent Claim
33 words
A disposable blood filter unit in accordance with claim 21, in which the first and the second housing portions and the fluid ports therein are arranged so that the fluid ports are coaxial.
Claim 26
Dependent Claim
21 words
A disposable blood filter unit in accordance with claim 21, in which all of the housing portions are of plastic material.
Claim 27
Dependent Claim
19 words
A disposable blood filter unit in accordance with claim 25, in which the plastic material is a thermoplastic resin.
Claim 28
Dependent Claim
17 words
A disposable blood filter unit in accordance with claim 26, in which the thermoplastic resin is polypropylene.
Claim 29
Dependent Claim
23 words
A disposable blood filter unit in accordance with claim 25, in which the housing portions are integrated together to form a one-piece housing.
Claim 30
Dependent Claim
34 words
A disposable blood filter unit in accordance with claim 21, in which the blood filter element cascade is held at opposed side portions between the mating sections of the first and second housing portions.
Claim 31
Dependent Claim
35 words
A disposable blood filter unit in accordance with claim 29, in which the blood filter element cascade is integrated to the mating sections by fusion thereof through the pores of the blood filter element cascade.
Claim 32
Dependent Claim
28 words
A disposable blood filter unit in accordance with claim 21, in which the side caps are integrated to the housing portions to form an integral one-piece filter unit.
Claim 33
Dependent Claim
46 words
A disposable blood filter unit in accordance with claim 21, in which each of the housing portions includes at least one projecting portion engaging and supporting opposite sides of the blood filter Element cascade, and extending with the blood filter element cascade across the fluid chamber.
Claim 34
Dependent Claim
35 words
A disposable blood filter unit in accordance with claim 21, in which one housing portion comprises a projecting member holding the opposite end portions of the blood filter element cascade against the other housing portion.
Claim 35
Dependent Claim
59 words
A disposable blood filter unit in accordance with claim 33, in which the mating sections of each housing portion have first projecting members extending towards each other, and abutting endwise, with the first housing portion having second projecting members extending internally of the two abutting portions, and engaging the blood filter element cascade at a portion near its edge.
Claim 36
Dependent Claim
33 words
A disposable blood filter unit in accordance with claim 34, in which the second projecting members also hold the blood filter element cascade tightly against an internal wall of the second housing portion.
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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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |