|Número de publicación||US3705100 A|
|Tipo de publicación||Concesión|
|Fecha de publicación||5 Dic 1972|
|Fecha de presentación||25 Ago 1970|
|Fecha de prioridad||25 Ago 1970|
|También publicado como||DE2100209A1|
|Número de publicación||US 3705100 A, US 3705100A, US-A-3705100, US3705100 A, US3705100A|
|Inventores||Edward A Agranat, William F Blatt, Peter N Rigopulos|
|Cesionario original||Amicon Corp|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citada por (75), Clasificaciones (19), Eventos legales (2)|
|Enlaces externos: USPTO, Cesión de USPTO, Espacenet|
Dec. 5,1912 w. F. BLATT ET AL 3,705,100
BLOOD FRACTIQNATING PROCESS AND APPARATUS FDR CARRYING OUT SAME Filed Aug. 25, 1970 .2 Sheets-Sheet 1 i l/ 1 I l I 1 l 49 16 I 32 3O IV\'\ 'ff.\"I'()HS WILLIAM F. BLATT EDWARD A. AGRANAT HY PETER N. R/GOPULOS Dec. 5, m: w. F. BLATT ET AL 3,705,100
BLOOD FRACTIONATING PROCESS AND APPARATUS FOR CARRYING OUT SAME Filed Aug. 25, 1970 .2 Sheets-Sheet I l.\'\'lf4\'l'()l WILLIAM F BLATT EDWARD A. AGRANAT H PETER N. R/GOPULOS United States Patent US. Cl. 210-43 8 Claims ABSTRACT OF THE DISCLOSURE A process for separating blood plasma from whole blood that dispenses with the known centrifugal-separation techniques and involves passing whole blood along a flow path which is shallow and substantially parallel to the upstream side of filtration membrane, recovering plasma from the downstream side of said membrane, and recovering the retained blood components (formed elements) from the upstream side of the membrane.
This application is a continuation-in-part of US. Ser. No. 828,935, filed May 29, 1969, now abandoned, and of Ser. No. 833,090, filed June 13, 1969, now abandoned.
When obtaining blood from a blood donor, it is very often desirable to be able to return the cellular components to the donor so that more frequent bleedings can be made. When only the plasma component of the blood is desired for emergency use, the formed elements of the blood (which include the red blood cells, white blood cells and platelets) can be discarded or used for other purposes or can profitably be returned to the donor. Such a return is particularly important because (1) it allows the donor to recuperate to a state where he can donate again within two weeks rather than in about 2 months as is the case when the non-plasma component of the blood is not returned to him, and (2) it avoids the temporary weakness suffered by some donors after they donate a pint of blood. The importance of a donors being able to contribute blood at relatively frequent intervals is obvious in circumstances such as those wherein injuries are incurred during military operations or wherein a donor bears a rare blood-type for which an emergency need exists.
However, blood fractionating of the type described is not used as frequently as desirable because no really convenient means for carrying out the process has been available. In general, this type of blood-fractionating has been done by (1) transferring the blood from a donor into a blood bag by means known to most blood donors, then (2) transferring the blood bag into a centrifugal separating apparatus, then (3) spinning the blood at a rate which optimizes the separation of plasma from other blood components, but substantially avoids damage to blood cells, then (4) separation of plasma by bag compression or withdrawal to a receiving vessel, and finally (5) returning the formed elements back into the patient by the usual transfusion techniques.
Not only does this process involve relatively expensive apparatus, but it also comprises a sufficiently large number of handling steps to significantly increase the chance of contamination and/ or cellular damage in the relatively crude environments of the type that may be encountered at accident scenes, in military ope-rations, etc.
Moreover, there are many situations in which it is desirable to separate blood components without returning any of them to the donor in order to use diagnostic tests without interference from either the formed cell or plasma components thereof.
The present invention provides a process and apparatus for simple fractionation of whole blood into a plasma component and a cellular component while subjecting the components to only very slight stress. The present invention is furthermore readily applicable to blood-donation procedures, making it possible to return the non-plasma component or fraction to the donor virtually simultaneously with the donation.
The process of the present invention comprises conducting the whole blood in a flow path parallel to one face of a porous filter membrane having effective pore diam eters from 0.1 to 0.8 micron, the path having a maximum depth of 20 mils measured vertically from the face of the membrane, collecting from the opposite face of the membrane the plasma component, and collecting from the end of said flow path the cellular component while maintaining the pressure differential between opposite faces of the membrane from 1 to 15 p.s.i. For best results the rate of flow of the whole blood across the face of the membrane is maintained from 2 to 50 ft. per minute and the pore diameter is from 0.4 to 0.7 micron. The precise diameter of the pores within the stated ranges of size which gives best results depends upon the precise pressure differential employed, higher pressure differentials within the stated range requiring smaller pore diameters. The pressure differential is critical because it provides the driving force for controlling the velocity of the blood across, and plasma through the membrane, and also affects the degree of hemolysis which occurs during filtration.
'It is essential that the blood being filtered travel in a path substantially parallel to and within 20 mils of the membrane surface. Attempts to utilize the same membranes under conditions whereby the Whole blood is forced through the membrane by conventional filtration techniques (i.e., putting the blood in a reservoir over filtration membrane and applying a pressure difference across the membrane to push or pull the plasma fraction through the membrane) results in almost immediate plugging of the membrane.
The term filtration membrane is used in this application to means that class of filters normally supplied in thin sheet form and capable of effecting separation of very small particulate or molecular components from suspensions or solutions. Both anisotropic and depth-filter membranes are included within this description. The former type of membrane is preferred when conveniently available, but a particularly surprising feature of the invention is that homogeneous depth filters may be utilized in the blood separation process.
The filtration process of the invention is carried out at relatively low pressure differentials, e.g., from 1 to 15 p.s.i., as measured both from one side of the filter membrane to the other and as measured from the inlet of the whole blood passage to the outlet for the blood fraction which fails to pass through the filter membrane. As a matter of convenience, both the receptable for the filtrate (plasma) and for the rejected blood (non-plasma fraction) are preferably maintained at atmospheric pressure. Pressure differentials near the lower end of this range, i.e., from 1.5 to 5 p.s.i. are most advantageous, in part because they can be utilized in equipment which is less rigorously designed to avoid undue stress on the cells contained in the blood being fractionated. Likewise the velocity across the face of the membrane is relatively low, i.e., in the range of from 2 to 50 feet per minute. Under these conditions, the flow is substantially laminar. In the more preferable embodiments of the invention the blood, after passing over the surface of the membrane, is recycled back to the whole blood reservoir. The velocity of the stream being dissipated in the contents of the reservoir aids in keeping the blood mixed well.
In order to point out more fully the nature of the present invention, the following specific example is given as an illustrative embodiment of the present process and products produced thereby.
FIG. 1 shows a view in elevation, partly in section, of a thin channel ultrafiltration cell useful for carrying out the process of the invention.
FIG. 2 is a perspective view from the bottom of the reservoir and flow-directing means showing the apparatus of FIG. 1.
FIG. 3 is an exploded view in perspective showing a novel apparatus useful in the process of another embodiment of the invention which comprises a means to attach a hypodermic needle thereto.
FIG. 4 is a view in elevation showing the apparatus of FIG. 3 in operation.
Referring to FIGS. 1 and 2, it is seen that an ultrafiltration cell comprises a top cap 12, a bottom cap 14 and a cylinder assembly 16. The cylinder is compressed and sealed between caps 12 and 14 by means of toggle clamping assembly 18, top O-ring seal 20, and bottom O-ring seal 22.
Top cap 12 comprises a pressure relief valve 24 and a means to drive fluid across the membrane comprising a port 25 adapted for connection to a pressurized gas source for pressurizing liquid in reservoir 28.
Resting on bottom cap 14 is a macroporous support plate 30 formed of sintered polypropylene. Over plate 30 is a cellulosic ester filtration membrane 32 having a mean pore size of 0.45 :0.02 micron and available from Millipore Corporation under the trade designation HAW PO 9025. Lower O-ring seal 22 is compressed against the outer periphery of membrane 32, thereby providing an eflicient edge sealing means.
Cylinder assembly 16 comprises reservoir 28 and an aperture 34 leading from reservoir 28 into a spiral flow path 36 which is formed by spiral grooves 38 on the bottom surface 39 of assembly 16. This flow path 36 is 0.125 inch wide and 0.010 inch 10 mils) high. It follows a spiral path in a plane parallel to the membrane surface, terminating at a fluid outlet port 40 through which the retained liquid may, via conduit 41, be collected or recycled for another concentrating step. Filtrate, i.e., that fraction of material which comes through the filter is carried out of the cell through conduit 42 which is machined into bottom cap 14.
, A sample of whole blood (treated with ACD) was inserted into reservoir 28 and, under a 2 p.s.i.g. driving force, was divided into a plasma fraction and a cellular fraction. The Whole blood was forced through aperture 34 in cylinder assembly 16, and thereupon is caused to follow spiral flow path 36 over the surface of membrane 32. The blood plasma fraction passed through the filtration membrane, and was collected through conduit 41 at atmospheric pressure. About 60% of the plasma content of the blood was recovered and there was no evidence of hemolysis in the plasma so collected.
Although the optimum operation of the illustrated device was realized with an operating pressure of from 2 to 4 p.s.i.g., it is stressed that higher operating pressures may be used when particular care is taken to smooth bloodcontacting surfaces in such a way as to avoid excessive mechanical shear on the formed elements of the blood. For example, a stream-lined or smooth-surfaced wall 49 with gently rounded corners of aperture 34 is advantageous in this respect. In general, however, a low-pressure process is most desirable for use in emergency blood-donation procedures.
Another embodiment of the apparatus is disclosed in FIG. 3. In this apparatus, which is most useful in analytical work, a hypodermic syringe 50 has been utilized to withdraw a blood sample from a patient. The needle (not 4 shown) of the syringe is then removed and the syringe is attached, by means of a fastening means 52, such as Luer lock 54, to filtration cell 56. Filtration cell 56 comprises a top retaining plate 58, filtration membrane 60, a sintered porous polyethylene support disk 62, and a bottom retaining plate 64.
Retaining plate 58 comprises a spiral ridge forming a shallow flow path 66 having a depth of 6 mils, a width of 0.5 cm. and a length of 70 cm. between inlet port 68 and outlet port 70. Retaining plate 64 comprises a filtration outlet port 71.
In order to achieve the most reproducible filtration results, it has been found more desirable to provide the above-described apparatus with a positive pressure control means rather than to rely upon the manual pressure exerted by a number of different operators. Therefore, a spring means 72 is mounted, at one end 74 thereof, on projecting outlet port 7 0. The other end 76 of the spring is adapted to press on plunger 78 of the hypodermic syringe 50. When spring means 72 is so mounted as to rest on plunger 78, a controlled amount of pressure, about 2.5 p.s.i., is generated for filtering the blood. Another advantage is that one operator can utilize a number of these devices at a single time since they do not require close attention during the filtration operation. 0
FIG. 4 shows a schematic diagram showing the analytical device of FIG. 3 in operation. A plasma fraction of the blood is being collected in vessel 82 while the other blood components are being collected in vessel 80.
Using the cellulosic ester membrane described above, less than 0.1% hemolysis was observed, and the plasma obtained was not detectably difierent from that obtained by conventional centrifugation. From a 10 ml. sample of fresh blood of normal hematocrit, there was obtained, in a filtering time of 15 to 20 minutes, approximately 3.0 to 3.4 ml. of plasma. Similar results were obtained using under the same conditions a polycarbonate membrane 1-10 mils thick) having a pore size of 05:0.06 microns available under the trademark Nuclepore from the General Electric Company.
Various other advantages and modifications will be apparent to those skilled in the art and fall within the scope of the appended claims.
1. Apparatus constructed and arranged to carry out a separation of whole blood into a plasma fraction and a cellular fraction, said apparatus comprising (1) a reservoir for holding whole blood which is to be fractionated,
(2) a filtration membrane having a pore size from about 0.1 to 0.8 micron diameter,
(3) a flow directing means adjacent one side of said membrane for conducting whole blood from said reservoir across the face of said membrane in a zone having a maximum depth of 20 mils measured vertically from the face of said membrane, and
(4) pressure-generating means constructed and arranged to drive said whole blood to be fractionated through said flow path only within the range of a pressure differential from 1 to 15 p.s.i. and at a flow velocity across the face of the membrane from 2 to 50 feet per minute.
2. Apparatus as defined in claim 1 wherein said reservoir is formed of the barrel of a hypodermic syringe, wherein said pressure-generating means comprises the piston of a hypodermic syringe, and wherein said syringe is detachably connected to said membrane and flow directing means.
3. Apparatus as defined in claim 1 wherein said filtration membrane has a pore size from about 0.4 to about 0.7 micron in diameter.
4. Apparatus as defined in claim 2 comprising additionally a spring for automatically operating the piston of said hypodermic syringe.
5. A process for separating blood plasma from the other components of blood comprising the steps of (1) conducting whole blood in a flow path which is substantially parallel to the upstream side of a filtration membrane and has a maximum depth of 20 mils measured vertically from the face of the membrane, said membrane having a pore size from about 0.1 to about 0.8 micron in diameter,
(2) applying sufiicient pressure to said whole blood to cause pressure differential from 1 to 15 p.s.i. between upstream and downstream sides of said membrane and to provide a fiow velocity across the face of the membrane from 2 to 50 feet per minute,
(3) recovering plasma ultrafiltrate from the downstream side of said membrane, and
(4) recovering the retained blood components from the upstream side of the membrane.
6. A process as defined in claim 5 wherein said filtration membrane has a pore size from about 0.4 to about 0.7 micron in diameter.
7. A process as defined in claim 6 wherein the pressure differential is from 2 to 5 p.s.i.
8. In a process for removing whole blood from a blood donor and returning the blood constituents to the donor while keeping the plasma for medical use, the improvement consisting of (1) transferring said whole blood from said donor into contact with the upstream side of filtration membrane having a pore size from about 0.1 to about 0.8 micron in diameter,
(2) conducting said whole blood across the surface of the membrane in a path which is substantially parallel to the upstream side of said membrane and has References Cited UNITED STATES PATENTS 3,488,768 1/1970 Rigopulos 210--23 2,156,023 4/1939 McKay 128--234 X 3,489,145 1/1970 Judson et a1. 1282l4 3,483,867 12/1969 Markovitz 210321 X 3,567,031 3/1971 Loefiler 210456 X OTHER REFERENCES Bixler et al.: The Development of a Diafiltration System for Blood Purification, from Trans. Amer. Soc. 'Krtif. Int. Organs, vol. XIV, June. 14, 1968, 99-108 relied on.
Dorson et al.: A Pulsating Ultrafiltration Artificial Kidney, from the Artificial Kidney, Chemical Engineering Progress Symposium Series, No. 84, vol. 64, received in Patent Office Dec. 4, 1968, pp. -89 relied on.
FRANK A. SPEAR, 111., Primary Examiner US. Cl. X.R. 210321, 433, 456
|Patente citante||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US3878664 *||27 Nov 1972||22 Abr 1975||Cybersol||Process for producing a therapeutic composition|
|US3900398 *||24 Sep 1973||19 Ago 1975||Univ Iowa State Res Found Inc||System for exchanging blood ultrafiltrate|
|US3974068 *||18 Jul 1974||10 Ago 1976||Firma Heinrich Frings||Ultrafiltration process and apparatus using low hydrostatic pressure to prevent concentration polarization|
|US4191182 *||23 Sep 1977||4 Mar 1980||Hemotherapy Inc.||Method and apparatus for continuous plasmaphersis|
|US4212742 *||25 May 1978||15 Jul 1980||United States Of America||Filtration apparatus for separating blood cell-containing liquid suspensions|
|US4222871 *||28 Abr 1978||16 Sep 1980||Societe D'etudes Et De Realisations Industrielles - Seri||Improvements in the separation of liquid mixtures by ultrafiltration|
|US4228015 *||29 Ene 1979||14 Oct 1980||Baxter Travenol Laboratories, Inc.||Plasma treatment apparatus|
|US4343705 *||31 Oct 1980||10 Ago 1982||Instrumentation Laboratory||Biological liquid fractionation using alternate opposite flow directions across a membrane|
|US4374731 *||6 Mar 1980||22 Feb 1983||Baxter Travenol Laboratories, Inc.||Method and apparatus for obtaining a desired rate of plasma collection from a membrane plasmapheresis filter|
|US4381775 *||18 Ago 1980||3 May 1983||Takeda Chemical Industries, Ltd.||Method for low pressure filtration of plasma from blood|
|US4411792 *||10 Ago 1981||25 Oct 1983||Trimedyne, Inc.||Lymph filtration system|
|US4605503 *||26 May 1983||12 Ago 1986||Baxter Travenol Laboratories, Inc.||Single needle blood fractionation system having adjustable recirculation through filter|
|US4619639 *||11 Sep 1985||28 Oct 1986||Asahi Medical Co., Ltd.||Method and apparatus for low pressure filtration of plasma from blood|
|US4636312 *||16 Feb 1982||13 Ene 1987||E. I. Du Pont De Nemours And Company||Plasmapheresis filtration module having improved end plate|
|US4639243 *||17 Ene 1984||27 Ene 1987||Baerbel Schmidt||Process and apparatus for obtaining blood plasma|
|US4639316 *||14 Dic 1984||27 Ene 1987||Becton, Dickinson And Company||Automatic liquid component separator|
|US4639317 *||16 Feb 1982||27 Ene 1987||E. I. Du Pont De Nemours And Company||Plasmapheresis filtration module having improved sealing means|
|US4640776 *||16 Feb 1982||3 Feb 1987||E. I. Du Pont De Nemours And Company||Plasmapheresis filtration module having pressure balancing and sealing means|
|US4735726 *||28 Ene 1987||5 Abr 1988||E. I. Du Pont De Nemours And Company||Plasmapheresis by reciprocatory pulsatile filtration|
|US4746436 *||15 Dic 1986||24 May 1988||Baxter Travenol Laboratories, Inc.||Membrane plasmapheresis apparatus and process which utilize a flexible wall to variably restrict the flow of plasma filtrate and thereby stabilize transmembrane pressure|
|US4755300 *||23 Dic 1985||5 Jul 1988||Haemonetics Corporation||Couette membrane filtration apparatus for separating suspended components in a fluid medium using high shear|
|US4769150 *||18 Jul 1986||6 Sep 1988||E. I. Du Pont De Nemours And Company||Method and apparatus for plasmapheresis by reciprocatory pulsatile filtration|
|US4808307 *||16 Feb 1988||28 Feb 1989||Haemonetics Corporation||Couette membrane filtration apparatus for separating suspended components in a fluid medium using high shear|
|US4879098 *||25 Ene 1985||7 Nov 1989||Becton, Dickinson And Company||Device for the separation of the lighter fraction from the heavier fraction of a liquid sample|
|US4980054 *||30 Dic 1987||25 Dic 1990||Lavender Ardis R||System and method for mass transfer between fluids|
|US4980068 *||15 Ago 1983||25 Dic 1990||Lavender Ardis R||System, apparatus and method for continuously fractionating blood in situ|
|US5034135 *||8 May 1987||23 Jul 1991||William F. McLaughlin||Blood fractionation system and method|
|US5183569 *||16 Dic 1991||2 Feb 1993||Paradigm Biotechnologies Partnership||Filtration apparatus and process|
|US5194145 *||13 Jul 1987||16 Mar 1993||William F. McLaughlin||Method and apparatus for separation of matter from suspension|
|US5330420 *||13 Ene 1992||19 Jul 1994||Therakos, Inc.||Hemolysis detector|
|US5376263 *||2 Nov 1993||27 Dic 1994||William F. McLaughlin||Pump control apparatus for cellular filtration systems employing rotating microporous membranes|
|US5451321 *||24 May 1991||19 Sep 1995||Pall Corporation||Venting system|
|US5464534 *||12 Oct 1993||7 Nov 1995||William F. McLaughlin||Blood fractionation system and method|
|US5587070 *||4 Jun 1993||24 Dic 1996||Pall Corporation||System for processing biological fluid|
|US5601727 *||3 Nov 1992||11 Feb 1997||Pall Corporation||Device and method for separating plasma from a biological fluid|
|US5616254 *||26 May 1995||1 Abr 1997||Pall Corporation||System and method for processing biological fluid|
|US5695653 *||23 Dic 1994||9 Dic 1997||Pall Corporation||Device and method for separating components from a biological fluid|
|US5738792 *||6 Sep 1994||14 Abr 1998||Baxter International Inc.||Method for separation of matter from suspension|
|US5783085 *||15 May 1996||21 Jul 1998||Estate Of William F. Mclaughlin||Blood fractionation method|
|US5863436 *||31 Mar 1997||26 Ene 1999||Pall Corporation||Venting system|
|US5914042 *||10 Jun 1994||22 Jun 1999||Pall Corporation||Device and method for separating plasma from a blood product|
|US6001259 *||23 Sep 1997||14 Dic 1999||Johnson & Johnson Medical, Inc.||Preparation of autologous plasma and fibrin gel|
|US6086770 *||20 Oct 1998||11 Jul 2000||Pall Corporation||Venting system|
|US6099730 *||13 Nov 1998||8 Ago 2000||Massachusetts Institute Of Technology||Apparatus for treating whole blood comprising concentric cylinders defining an annulus therebetween|
|US6171493||19 Mar 1999||9 Ene 2001||Lexion Medical||Biological fluid filtration apparatus|
|US6197194||24 Sep 1999||6 Mar 2001||Elaine Whitmore||Single use system for preparing autologous plasma and fibrin gel|
|US6863821||2 Feb 2002||8 Mar 2005||Baxter International Inc.||Shear-enhanced systems and methods for removing waste materials and liquid from the blood|
|US6960178||15 Jul 2002||1 Nov 2005||Xepmed, Inc.||Apparatus for enhanced plasmapheresis and methods thereof|
|US6969367||24 Nov 2003||29 Nov 2005||Xepmed, Inc.||Extracorporeal pathogen reduction system|
|US7182867||26 Ene 2005||27 Feb 2007||Baxter International Inc.||Shear-enhanced systems and methods for removing waste materials and liquid from the blood|
|US7314460||6 Jul 2005||1 Ene 2008||Xep Med, Inc.||Extracorporeal pathogen reduction system|
|US7470245||22 Jun 2005||30 Dic 2008||Xepmed, Inc.||Extracorporeal pathogen reduction system|
|US7494591||12 Abr 2007||24 Feb 2009||Baxter International Inc.||Shear-enhanced systems and methods for removing waste materials and liquid from the blood|
|US7655124 *||5 Oct 2007||2 Feb 2010||Mady Attila||Apparatus to assist platelet manipulation to prevent and treat endovascular disease and its sequelae|
|US8268171 *||28 Abr 2010||18 Sep 2012||Qinghua Liao||Bottom control type specimen filtering container and filtering method thereof|
|US8961789||18 Dic 2008||24 Feb 2015||Baxter International Inc.||Systems and methods for performing hemodialysis|
|US9075042||15 Mar 2013||7 Jul 2015||Wellstat Diagnostics, Llc||Diagnostic systems and cartridges|
|US9081001||15 Mar 2013||14 Jul 2015||Wellstat Diagnostics, Llc||Diagnostic systems and instruments|
|US20050059921 *||24 Nov 2003||17 Mar 2005||Hosheng Tu||Extracorporeal pathogen reduction system|
|US20050242033 *||6 Jul 2005||3 Nov 2005||Hosheng Tu||Extracorporeal pathogen reduction system|
|US20050274672 *||22 Jun 2005||15 Dic 2005||Hosheng Tu||Extracorporeal pathogen reduction system|
|USRE31688 *||2 Mar 1982||25 Sep 1984||Hemotherapy, Inc.||Method and apparatus for continuous plasmapheresis|
|DE3405706A1 *||17 Feb 1984||8 Nov 1984||Gelman Sciences Inc||Verfahren zur gewinnung von blutplasma und filtervorrichtung zur ausuebung dieses verfahrens|
|EP0041350A2 *||22 May 1981||9 Dic 1981||Japan Foundation For Artificial Organs||Method and apparatus for on-line filtration removal of macromolecules from a physiological fluid|
|EP0114698A1 *||23 Ene 1984||1 Ago 1984||Michael J. Lysaght||Process and apparatus for obtaining blood plasma|
|EP0189152A2 *||18 Ene 1986||30 Jul 1986||Becton, Dickinson and Company||A device for the separation of the lighter fraction from the heavier fraction of a liquid sample|
|EP0217624A2 *||24 Sep 1986||8 Abr 1987||Gelman Sciences, Inc.||Method and device for obtaining blood plasma samples|
|EP0733378A2 *||22 Mar 1996||25 Sep 1996||JOHNSON & JOHNSON MEDICAL, INC.||Preparation of autologous plasma and fibrin gel|
|EP2264453A1 *||17 Jun 2009||22 Dic 2010||Leukocare Ag||Blood filter and method for filtering blood|
|WO1979001120A1 *||24 May 1979||27 Dic 1979||Department Of Commerce||Filtration apparatus for separating blood cell-containing liquid suspensions|
|WO1979001121A1 *||24 May 1979||27 Dic 1979||Department Of Commerce||Process for separating blood cell-containing liquid suspensions by filtration|
|WO1982003567A1 *||13 Abr 1982||28 Oct 1982||Eng Inc Biomedical||Method and apparatus for treating blood and the like|
|WO1982003568A1 *||13 Abr 1982||28 Oct 1982||Eng Inc Biomedical||Method and apparatus for high-efficiency ultrafiltration of complex fluids|
|WO1996020020A2 *||19 Dic 1995||4 Jul 1996||Pall Corp||Device and method for separating components from a biological fluid|
|WO2010146123A1 *||17 Jun 2010||23 Dic 2010||Leukocare Ag||Blood filter and method for filtering blood|
|Clasificación de EE.UU.||604/6.4, 604/6.9, 210/321.85, 210/456|
|Clasificación internacional||B01D61/14, B01D63/08, B01D61/18, A61M1/36, A61M1/34|
|Clasificación cooperativa||B01D63/087, B01D61/145, A61M1/3496, B01D61/18, A61M2001/3603, A61M2206/12|
|Clasificación europea||B01D61/14D, B01D63/08F, B01D61/18, A61M1/34P|
|19 Mar 1987||AS||Assignment|
Owner name: W.R. GRACE & CO., A CORP. OF CT
Free format text: MERGER;ASSIGNOR:AMICON CORPORTION, A MASS. CORP.;REEL/FRAME:004704/0627
|10 Dic 1986||AS||Assignment|
Owner name: W.R. GRACE & CO., A CORP OF CT.
Free format text: MERGER;ASSIGNOR:AMICON CORPORATION;REEL/FRAME:004655/0480
Effective date: 19850911