EP0112152A2
Expired / Lapsed
EP
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Blood fractionation system and method
Assignee: McLaughlin William Francis
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Filing: 1983-12-13
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Granted: —
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Expires: 2003-12-13
Abstract
Abstract Blood is passed from inlet 22 to outlet 34 axially along a shear gap between a stationary outer wall 24 and a cylindrical membrane 62 carried by a rotating spinner 50 and plasma is filtered off through the membrane and withdrawn through axial passge 76. The width of the gap and the rate of rotation of the spinner (greater than 1000 r.p.m.) are chosen such as to establish shear of from 1000 to 15,000 sec -1 across the gap and centrifugal force at the membrane of 50 gravity. The spinner 50 is driven by magnetic coupling 68, 74 from outside the housing 40, 12, 44 which thus forms a disposable unit. In a construction for separation of anti-freeze solution with white cells from frozen concentrated red cells, saline solution is introduced through a porous outer wall 12 and passes radially through the mixture to carry the anti-freeze and white cells through the membrane.
Inventors
- 👤 Halbert Fischel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 16:52
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/16; A; A61; A61M; A61M1/00; A61M1/14; A61M1/16; A61M1/26; A61M1/262; A61M1/30; A61M1/301; A61M1/302; A61M1/303; A61M1/305; A61M1/308; A61M1/36; A61M1/3692; A61M1/3693; A61M1/3696; B01D61/00; B01D61/14; B01D61/18; A61M2202/00; A61M2202/04; A61M2202/0413; A61M2202/0429; A61M2202/0439; A61M2205/00; A61M2205/33; A61M2205/3306; A61M2205/331; A61M2205/3331; A61M2205/3344; A61M2205/3351; A61M2205/3379; A61M2205/3382; A61M2205/3386; A61M2205/3389; B01D2315/00; B01D2315/02
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
128 words
A separating system for constituents of blood comprising a rotary spinner having a surface membrane concentric with the central rotational axis of the spinner, stationary wall means surrounding and spaced from the surface membrane to provide a shear gap therebetween, means for feeding a.blood composition to the shear gap near one axial end of the spinner, means for withdrawing a separated blood constituent from the shear gap near the other end, means for rotating the spinner at a speed such that the surface velocity of the membrane divided by the shear gap width exceeds 1000 sec and that the centrifugal force at the surface of the membrane exceeds 50 gravities (490m/s 2 ), and means for withdrawing a lighter component of the blood composition from within the spinner.
Claim 2
Dependent Claim
128 words
A separating system for constituents of blood comprising a rotary spinner having a surface membrane concentric with the central rotational axis of the spinner, stationary wall means surrounding and spaced from the surface membrane to provide a shear gap therebetween, means for feeding a.blood composition to the shear gap near one axial end of the spinner, means for withdrawing a separated blood constituent from the shear gap near the other end, means for rotating the spinner at a speed such that the surface velocity of the membrane divided by the shear gap width exceeds 1000 sec and that the centrifugal force at the surface of the membrane exceeds 50 gravities (490m/s 2 ), and means for withdrawing a lighter component of the blood composition from within the spinner.
Claim 3
Dependent Claim
39 words
A system as claimed in claim 1 in which said feeding means includes a flow inlet disposed tangentially to the flow about the spinner and said withdrawal means includes a flow outlet tangential to the flow about the spinner.
Claim 4
Dependent Claim
47 words
A system as claimed in claim 1 or 2 including seal means disposed between the rotating spinner and the stationary wall means and providing an internal seal between the path of the blood composition and the path by which the lighter component is withdrawn from the spinner.
Claim 5
Independent Claim
36 words
A system as claimed in any of claims 1 to 3 in which the spinner includes conduit means providing internal flow paths relative to the membrane such that pressure differential is substantially alike throughout the membrane.area.
Claim 6
Independent Claim
25 words
A system as claimed in any of claims 1 to 4 in which the rotational speed of the spinner is in excess of 1000 r.p.m.
Claim 7
Independent Claim
36 words
A system as claimed in any of the preceding claims in which the surface velocity of the membrane divided by the shear gap is less than 12,000 sec-1 and the Reynolds number is less than 2000.
Claim 8
Independent Claim
52 words
A system as claimed in any of the preceding claims in which the spinner and the surrounding wall means are right circular cylinders and a confinement vessel includes the surrounding wall means and end walls close to the ends of the spinner and provided with bearings for the support of the spinner.
Claim 9
Dependent Claim
53 words
A system as claimed in claim 7 in which the spinner is arranged with its axis vertical and supported by upper and lower bearings of which the lower bearing has a central aperture in communication along the central axis with the interior of the spinner for the withdrawl of the said lighter component.
Claim 10
Dependent Claim
33 words
A system as claimed in claim 8 having a tangential inlet opening to the upper end of the shear gap and a tangential outlet opening from the lower end of the shear gap.
Claim 11
Dependent Claim
69 words
A system as claimed in claim 7, 8 or 9 including a magnetic end structure within the upper end of the confinement vessel and coupled to the spinner, magnetic drive means disposed outside the upper end of the confinement vessel concentric with the central axis and magnetically coupled to rotate the spinner, and non-magnetic wall means on the confinement vessel between the magnetic end structure and the magnetic drive.
Claim 12
Dependent Claim
58 words
A system as claimed in claim 10 in which the magnetic drive means is positioned along the central axis relative to the magnetic end structure to tend to position the spinner in a selected position and the bearing means permit limited axial movement of the spinner and include radial seal means between the blood and plasma flow paths.
Claim 13
Dependent Claim
46 words
. A system as claimed in claim 10 in which the magnetic end structure is vertically offset along the central axis above the magnetic center of the magnetic drive means such that a downward mechanical force is exerted on the magnetic end structure and the spinner.
Claim 14
Dependent Claim
67 words
A system as claimed in claim 12 in which the lower bearing has a converging exterior taper in the downward direction and the lower end wall of the confinement vessel includes a bearing seat region concentric with the central axis for receiving the lower bearing, the downward force exerted by the magnetic drive and the converging surfaces acting to maintain the bearing seal despite wear during use.
Claim 15
Independent Claim
37 words
A system as claimed in any of claims 7 to 13 in which the gaps between the ends of the cylindrical spinner and the opposed end walls of the confinement vessel are less than 0.050" (1.27 mm).
Claim 16
Dependent Claim
46 words
A system as claimed in claim 14 in which the upper end of the spinner comprises a cylinder of smaller diameter than the portion carrying the membrane, and the lower end of the spinner is concave relative to the lower end wall of the confinement vessel.
Claim 17
Independent Claim
34 words
A system as claimed in any of claims 7 to 15 in which the spinner has a diameter of the order of 1" (25 mm) and is rotated at between 3000 and 5500 r.p.m.
Claim 18
Independent Claim
41 words
A system as claimed in any of the preceding claims in which the spinner has a plurality of spaced circumferential grooves and intercommunicating grooves on its surface, a central conduit, and radial apertures coupling the surface grooves to the central conduit.
Claim 19
Independent Claim
23 words
A system as claimed in any of the preceding claims in which the shear gap width is less than 0.10 inch (2.5 mm).
Claim 20
Independent Claim
42 words
A system as claimed in any of the preceding claims in which the stationary wall means surrounding the spinner membrane comprises a porous wall and a plenum chamber for supplying liquid for flow through the porous wall and across the shear gap.
Claim 21
Dependent Claim
40 words
A system as claimed in claim 19 in which the blood composition comprises red cells in a carrier solution and the liquid flowing through the porous wall is a saline solution which passes through the membrane with the carrier solution.
Claim 22
Dependent Claim
32 words
A system as claimed in claim 20 in which the carrier solution also includes white cells and white cell aggregates and the membrane has openings in the range 60 to 100 µm.
Claim 23
Independent Claim
121 words
A method for separating a blood composition into constituent parts comprising spinning a hollow cylind-, rical flow sheet of the composition by the action of viscous drag on the inner surface to establish a centrifugal force at the inner surface in excess of 50 gravities (490 m/s 2 ), concurrently limiting spinning movement at the outer surface of the flow sheet such that a shear of between 1000 and 15,000 sec -1 is imposed across the thickness of the flow sheet, continuously supplying the composition at one axial end of the flow sheet, filtering lighter constituent parts from the inner surface of the sheet through a membrane, and withdrawing heavier constituent parts from the other axial end of the flow sheet.
Claim 24
Independent Claim
121 words
A method for separating a blood composition into constituent parts comprising spinning a hollow cylind-, rical flow sheet of the composition by the action of viscous drag on the inner surface to establish a centrifugal force at the inner surface in excess of 50 gravities (490 m/s 2 ), concurrently limiting spinning movement at the outer surface of the flow sheet such that a shear of between 1000 and 15,000 sec -1 is imposed across the thickness of the flow sheet, continuously supplying the composition at one axial end of the flow sheet, filtering lighter constituent parts from the inner surface of the sheet through a membrane, and withdrawing heavier constituent parts from the other axial end of the flow sheet.
Claim 25
Dependent Claim
34 words
A method as claimed in claim 22 in which the rate of rotation of the inner surface is in excess of 1000 r.p.m. and the Reynolds number of the flow is maintained below 2000.
Claim 26
Dependent Claim
28 words
A method as claimed in claim 22 or 23 in which the spinning movement at the outer surface of the flow sheet is limited by a stationary wall.
Claim 27
Dependent Claim
35 words
A method as claimed in claim 22, 23 or 24 in which the blood composition is whole blood and the membrane has pores of no greater than 0.8 µm to filter plasma from the blood.
Claim 28
Dependent Claim
41 words
A method as claimed in claim 22, 23, or 24 including providing a cross flow of washing fluid radially inwardly over a substantial area of the flow sheet and filtering the washing fluid from the flow , sheet through the membrane.
Claim 29
Dependent Claim
89 words
A membrane filtration device in which the membrane comprises a relatively low area element for filtering constituents of blood, comprising: a cylindrical spinner body concentric with a central axis and having surface channels thereon; means in the spinner body providing conduits from the surface channels and an internal collection orifice coupled thereto; and membrane means disposed on the surface of the spinner body and bridging the surface channels such that blood constituents passing through the membrane are collected via the surface channels and the conduits in the collection orifice.
Claim 30
Dependent Claim
89 words
A membrane filtration device in which the membrane comprises a relatively low area element for filtering constituents of blood, comprising: a cylindrical spinner body concentric with a central axis and having surface channels thereon; means in the spinner body providing conduits from the surface channels and an internal collection orifice coupled thereto; and membrane means disposed on the surface of the spinner body and bridging the surface channels such that blood constituents passing through the membrane are collected via the surface channels and the conduits in the collection orifice.
Claim 31
Dependent Claim
29 words
A device as claimed in claim 27 wherein the surface channels are circumferentially disposed about the spinner body and the collection orifice is disposed concentric with the central axis.
Claim 32
Dependent Claim
71 words
A device as claimed in claim 28 wherein the spinner body is of synthetic resin material and the means providing conduits includes longitudinal surface grooves and radial conduits between the longitudinal grooves and the collection orifice, and wherein the cross-sectional areas of the surface channels and longitudinal grooves are sufficient to provide unimpeded flow of blood constituents passing through the membrane and substantially equal transmembrane pressure across the membrane surface area.
Claim 33
Independent Claim
187 words
A system utilising disposables for acceptance of blood from a donor, separation of plasma and return of blood cells to the donor comprising: disposable means including implantable needle means and flexible input tubing for providing blood flow from a donor; a console assembly including first blood pumping means, separator drive means and second blood pumping means disposed serially along a blood flow path, the'blood pumping means being of the type externally engageable to flexible tubing to transport blood therein without contact, the flexible input tubing being disposed in operative relation with the first blood pumping means; disposable separator means coupled to the separator drive means and having an input coupled to the input flexible tubing, the separator means including rotatable membrane means and shear wall means disposed to pass plasma filtrate.through the membrane means to a plasma outlet and to direct blood cells to a blood cell outlet; disposable plasma collection means coupled to receive plasma filtrate from the plasma outlet; and disposable flexible output tubing means coupling the blood cell outlet to the needle means while passing in operative relation to the second blood pumping means.
Claim 34
Independent Claim
187 words
A system utilising disposables for acceptance of blood from a donor, separation of plasma and return of blood cells to the donor comprising: disposable means including implantable needle means and flexible input tubing for providing blood flow from a donor; a console assembly including first blood pumping means, separator drive means and second blood pumping means disposed serially along a blood flow path, the'blood pumping means being of the type externally engageable to flexible tubing to transport blood therein without contact, the flexible input tubing being disposed in operative relation with the first blood pumping means; disposable separator means coupled to the separator drive means and having an input coupled to the input flexible tubing, the separator means including rotatable membrane means and shear wall means disposed to pass plasma filtrate.through the membrane means to a plasma outlet and to direct blood cells to a blood cell outlet; disposable plasma collection means coupled to receive plasma filtrate from the plasma outlet; and disposable flexible output tubing means coupling the blood cell outlet to the needle means while passing in operative relation to the second blood pumping means.
Claim 35
Dependent Claim
33 words
A system as claimed in claim 30 including in addition means for adding saline solution coupled to the flexible output tubing means between the blood cell outlet and the second blood pumping means.
Claim 36
Dependent Claim
53 words
A system as claimed in claim 31 wherein the means for adding saline solution establishes a volumetric balance between the blood flow at the input of the separator means relative to the blood cell output flow to compensate for extraction of plasma, and wherein the first and second blood pumping means are synchronized.
Claim 37
Dependent Claim
27 words
A system as claimed in claim 32 wherein the first and second blood pumping means comprise a single roller pump having a pair of oppositely disposed rollers.
Claim 38
Dependent Claim
77 words
A system as claimed in claim 33 wherein the system further includes a disposable reservoir in the flexible output tubing means for receiving blood cells from the second blood pumping means, means disposed along the flexible output tubing between the reservoir and the needle means for expressing blood from the reservoir, and control means responsive to the blood cell level in the reservoir for operating the expressing means to provide a return flow to the needle means.
Claim 39
Dependent Claim
34 words
A system as claimed in claim 34 wherein the needle means is a single needle and wherein the control means shuts off the first blood pumping means concurrently with operation of the expressing means.
Claim 40
Dependent Claim
66 words
A system as claimed in claim 35 wherein the means for expressing blood comprises a flexible reservoir and platen means including means for compressing the reservoir, and wherein the control means includes means for sensing the volume of matter in the reservoir and means for blocking flow from the reservoir to the needle means when the volume in the reservoir is less than a selected amount.
Claim 41
Dependent Claim
41 words
A system as claimed in claim 36 further including means for momentarily separating the platen means after completion of delivery to a donor to remove return blood cells from the needle means prior to recommencement of blood flow from the donor.
Claim 42
Dependent Claim
39 words
A system as claimed in claim 37 wherein the separator drive means includes a rotatable magnetic coupling and wherein the separator means includes magnetic means in fixed relation to the membrane means and magnetically coupled to the magnetic coupling.
Claim 43
Dependent Claim
67 words
A system as claimed in claim 30 wherein the system further comprises disposable reservoir means coupled to receive the blood cells, detector means responsive to the level of blood in the reservoir means, and blood return means coupling the reservoir to the needle means and responsive to the detector means, and wherein the first and second blood pumping means are separate roller pumps operating at selectable rates.
Claim 44
Dependent Claim
65 words
A system as claimed in claim 30 wherein the needle means comprises a pair of needles for implantation in a donor, one coupled to the flexible input tubing, and wherein the system further includes flexible output tubing coupled from the separator means to the second needle, and the second pumping means engages the flexible output tubing for transferring blood cells directly back to the patient.
References Cited (Backward Citations)
No citation records indexed.
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