|Publication number||US3705100 A|
|Publication date||Dec 5, 1972|
|Filing date||Aug 25, 1970|
|Priority date||Aug 25, 1970|
|Also published as||DE2100209A1|
|Publication number||US 3705100 A, US 3705100A, US-A-3705100, US3705100 A, US3705100A|
|Inventors||Edward A Agranat, William F Blatt, Peter N Rigopulos|
|Original Assignee||Amicon Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (82), Classifications (19), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, 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
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3878664 *||Nov 27, 1972||Apr 22, 1975||Cybersol||Process for producing a therapeutic composition|
|US3900398 *||Sep 24, 1973||Aug 19, 1975||Univ Iowa State Res Found Inc||System for exchanging blood ultrafiltrate|
|US3974068 *||Jul 18, 1974||Aug 10, 1976||Firma Heinrich Frings||Ultrafiltration process and apparatus using low hydrostatic pressure to prevent concentration polarization|
|US4191182 *||Sep 23, 1977||Mar 4, 1980||Hemotherapy Inc.||Method and apparatus for continuous plasmaphersis|
|US4212742 *||May 25, 1978||Jul 15, 1980||United States Of America||Filtration apparatus for separating blood cell-containing liquid suspensions|
|US4222871 *||Apr 28, 1978||Sep 16, 1980||Societe D'etudes Et De Realisations Industrielles - Seri||Improvements in the separation of liquid mixtures by ultrafiltration|
|US4228015 *||Jan 29, 1979||Oct 14, 1980||Baxter Travenol Laboratories, Inc.||Plasma treatment apparatus|
|US4343705 *||Oct 31, 1980||Aug 10, 1982||Instrumentation Laboratory||Biological liquid fractionation using alternate opposite flow directions across a membrane|
|US4374731 *||Mar 6, 1980||Feb 22, 1983||Baxter Travenol Laboratories, Inc.||Method and apparatus for obtaining a desired rate of plasma collection from a membrane plasmapheresis filter|
|US4381775 *||Aug 18, 1980||May 3, 1983||Takeda Chemical Industries, Ltd.||Method for low pressure filtration of plasma from blood|
|US4411792 *||Aug 10, 1981||Oct 25, 1983||Trimedyne, Inc.||Lymph filtration system|
|US4605503 *||May 26, 1983||Aug 12, 1986||Baxter Travenol Laboratories, Inc.||Single needle blood fractionation system having adjustable recirculation through filter|
|US4619639 *||Sep 11, 1985||Oct 28, 1986||Asahi Medical Co., Ltd.||Method and apparatus for low pressure filtration of plasma from blood|
|US4636312 *||Feb 16, 1982||Jan 13, 1987||E. I. Du Pont De Nemours And Company||Plasmapheresis filtration module having improved end plate|
|US4639243 *||Jan 17, 1984||Jan 27, 1987||Baerbel Schmidt||Process and apparatus for obtaining blood plasma|
|US4639316 *||Dec 14, 1984||Jan 27, 1987||Becton, Dickinson And Company||Automatic liquid component separator|
|US4639317 *||Feb 16, 1982||Jan 27, 1987||E. I. Du Pont De Nemours And Company||Plasmapheresis filtration module having improved sealing means|
|US4640776 *||Feb 16, 1982||Feb 3, 1987||E. I. Du Pont De Nemours And Company||Plasmapheresis filtration module having pressure balancing and sealing means|
|US4735726 *||Jan 28, 1987||Apr 5, 1988||E. I. Du Pont De Nemours And Company||Plasmapheresis by reciprocatory pulsatile filtration|
|US4746436 *||Dec 15, 1986||May 24, 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 *||Dec 23, 1985||Jul 5, 1988||Haemonetics Corporation||Couette membrane filtration apparatus for separating suspended components in a fluid medium using high shear|
|US4769150 *||Jul 18, 1986||Sep 6, 1988||E. I. Du Pont De Nemours And Company||Method and apparatus for plasmapheresis by reciprocatory pulsatile filtration|
|US4808307 *||Feb 16, 1988||Feb 28, 1989||Haemonetics Corporation||Couette membrane filtration apparatus for separating suspended components in a fluid medium using high shear|
|US4879098 *||Jan 25, 1985||Nov 7, 1989||Becton, Dickinson And Company||Device for the separation of the lighter fraction from the heavier fraction of a liquid sample|
|US4980054 *||Dec 30, 1987||Dec 25, 1990||Lavender Ardis R||System and method for mass transfer between fluids|
|US4980068 *||Aug 15, 1983||Dec 25, 1990||Lavender Ardis R||System, apparatus and method for continuously fractionating blood in situ|
|US5034135 *||May 8, 1987||Jul 23, 1991||William F. McLaughlin||Blood fractionation system and method|
|US5183569 *||Dec 16, 1991||Feb 2, 1993||Paradigm Biotechnologies Partnership||Filtration apparatus and process|
|US5194145 *||Jul 13, 1987||Mar 16, 1993||William F. McLaughlin||Method and apparatus for separation of matter from suspension|
|US5330420 *||Jan 13, 1992||Jul 19, 1994||Therakos, Inc.||Hemolysis detector|
|US5376263 *||Nov 2, 1993||Dec 27, 1994||William F. McLaughlin||Pump control apparatus for cellular filtration systems employing rotating microporous membranes|
|US5451321 *||May 24, 1991||Sep 19, 1995||Pall Corporation||Venting system|
|US5464534 *||Oct 12, 1993||Nov 7, 1995||William F. McLaughlin||Blood fractionation system and method|
|US5587070 *||Jun 4, 1993||Dec 24, 1996||Pall Corporation||System for processing biological fluid|
|US5601727 *||Nov 3, 1992||Feb 11, 1997||Pall Corporation||Device and method for separating plasma from a biological fluid|
|US5616254 *||May 26, 1995||Apr 1, 1997||Pall Corporation||System and method for processing biological fluid|
|US5695653 *||Dec 23, 1994||Dec 9, 1997||Pall Corporation||Device and method for separating components from a biological fluid|
|US5738792 *||Sep 6, 1994||Apr 14, 1998||Baxter International Inc.||Method for separation of matter from suspension|
|US5783085 *||May 15, 1996||Jul 21, 1998||Estate Of William F. Mclaughlin||Blood fractionation method|
|US5863436 *||Mar 31, 1997||Jan 26, 1999||Pall Corporation||Venting system|
|US5914042 *||Jun 10, 1994||Jun 22, 1999||Pall Corporation||Device and method for separating plasma from a blood product|
|US6001259 *||Sep 23, 1997||Dec 14, 1999||Johnson & Johnson Medical, Inc.||Preparation of autologous plasma and fibrin gel|
|US6086770 *||Oct 20, 1998||Jul 11, 2000||Pall Corporation||Venting system|
|US6099730 *||Nov 13, 1998||Aug 8, 2000||Massachusetts Institute Of Technology||Apparatus for treating whole blood comprising concentric cylinders defining an annulus therebetween|
|US6171493||Mar 19, 1999||Jan 9, 2001||Lexion Medical||Biological fluid filtration apparatus|
|US6197194||Sep 24, 1999||Mar 6, 2001||Elaine Whitmore||Single use system for preparing autologous plasma and fibrin gel|
|US6863821||Feb 2, 2002||Mar 8, 2005||Baxter International Inc.||Shear-enhanced systems and methods for removing waste materials and liquid from the blood|
|US6960178||Jul 15, 2002||Nov 1, 2005||Xepmed, Inc.||Apparatus for enhanced plasmapheresis and methods thereof|
|US6969367||Nov 24, 2003||Nov 29, 2005||Xepmed, Inc.||Extracorporeal pathogen reduction system|
|US7182867||Jan 26, 2005||Feb 27, 2007||Baxter International Inc.||Shear-enhanced systems and methods for removing waste materials and liquid from the blood|
|US7314460||Jul 6, 2005||Jan 1, 2008||Xep Med, Inc.||Extracorporeal pathogen reduction system|
|US7470245||Jun 22, 2005||Dec 30, 2008||Xepmed, Inc.||Extracorporeal pathogen reduction system|
|US7494591||Apr 12, 2007||Feb 24, 2009||Baxter International Inc.||Shear-enhanced systems and methods for removing waste materials and liquid from the blood|
|US7655124 *||Oct 5, 2007||Feb 2, 2010||Mady Attila||Apparatus to assist platelet manipulation to prevent and treat endovascular disease and its sequelae|
|US8268171 *||Apr 28, 2010||Sep 18, 2012||Qinghua Liao||Bottom control type specimen filtering container and filtering method thereof|
|US8961789||Dec 18, 2008||Feb 24, 2015||Baxter International Inc.||Systems and methods for performing hemodialysis|
|US9075042||Mar 15, 2013||Jul 7, 2015||Wellstat Diagnostics, Llc||Diagnostic systems and cartridges|
|US9081001||Mar 15, 2013||Jul 14, 2015||Wellstat Diagnostics, Llc||Diagnostic systems and instruments|
|US20020167875 *||Apr 10, 2002||Nov 14, 2002||Jia-Shing Sheu||Optical disk drive with adaptive compensator|
|US20020183677 *||Jul 15, 2002||Dec 5, 2002||Chang Yu-An||Apparatus for enhanced plasmapheresis and methods thereof|
|US20030146154 *||Feb 2, 2002||Aug 7, 2003||Julie Moriarty||Shear-enhanced system and methods for removing waste materials and liquid from the blood|
|US20050059921 *||Nov 24, 2003||Mar 17, 2005||Hosheng Tu||Extracorporeal pathogen reduction system|
|US20050242033 *||Jul 6, 2005||Nov 3, 2005||Hosheng Tu||Extracorporeal pathogen reduction system|
|US20050274672 *||Jun 22, 2005||Dec 15, 2005||Hosheng Tu||Extracorporeal pathogen reduction system|
|US20060278581 *||Aug 21, 2006||Dec 14, 2006||Julie Moriarty||Shear-Enhanced Systems And Methods For Removing Waste Materials And Liquid From The Blood|
|US20070181500 *||Apr 12, 2007||Aug 9, 2007||Julie Moriarty||Shear-Enhanced Systems and Methods for Removing Waste Materials and Liquid from the Blood|
|US20090090671 *||Oct 5, 2007||Apr 9, 2009||Mady Attila||Apparatus to assist platelet manipulation to prevent and treat endovascular disease and its sequelae|
|US20120118825 *||Jun 17, 2010||May 17, 2012||Leukocare Ag||Blood filter and method for filtering blood|
|USRE31688 *||Mar 2, 1982||Sep 25, 1984||Hemotherapy, Inc.||Method and apparatus for continuous plasmapheresis|
|DE3405706A1 *||Feb 17, 1984||Nov 8, 1984||Gelman Sciences Inc||Verfahren zur gewinnung von blutplasma und filtervorrichtung zur ausuebung dieses verfahrens|
|EP0041350A2 *||May 22, 1981||Dec 9, 1981||Japan Foundation For Artificial Organs||Method and apparatus for on-line filtration removal of macromolecules from a physiological fluid|
|EP0114698A1 *||Jan 23, 1984||Aug 1, 1984||Michael J. Lysaght||Process and apparatus for obtaining blood plasma|
|EP0189152A2 *||Jan 18, 1986||Jul 30, 1986||Becton, Dickinson and Company||A device for the separation of the lighter fraction from the heavier fraction of a liquid sample|
|EP0217624A2 *||Sep 24, 1986||Apr 8, 1987||Gelman Sciences, Inc.||Method and device for obtaining blood plasma samples|
|EP0733378A2 *||Mar 22, 1996||Sep 25, 1996||JOHNSON & JOHNSON MEDICAL, INC.||Preparation of autologous plasma and fibrin gel|
|EP2264453A1 *||Jun 17, 2009||Dec 22, 2010||Leukocare Ag||Blood filter and method for filtering blood|
|WO1979001120A1 *||May 24, 1979||Dec 27, 1979||Department Of Commerce||Filtration apparatus for separating blood cell-containing liquid suspensions|
|WO1979001121A1 *||May 24, 1979||Dec 27, 1979||Department Of Commerce||Process for separating blood cell-containing liquid suspensions by filtration|
|WO1982003567A1 *||Apr 13, 1982||Oct 28, 1982||Eng Inc Biomedical||Method and apparatus for treating blood and the like|
|WO1982003568A1 *||Apr 13, 1982||Oct 28, 1982||Eng Inc Biomedical||Method and apparatus for high-efficiency ultrafiltration of complex fluids|
|WO1996020020A2 *||Dec 19, 1995||Jul 4, 1996||Pall Corp||Device and method for separating components from a biological fluid|
|WO2010146123A1 *||Jun 17, 2010||Dec 23, 2010||Leukocare Ag||Blood filter and method for filtering blood|
|U.S. Classification||604/6.4, 604/6.9, 210/321.85, 210/456|
|International Classification||B01D61/14, B01D63/08, B01D61/18, A61M1/36, A61M1/34|
|Cooperative Classification||B01D63/087, B01D61/145, A61M1/3496, B01D61/18, A61M2001/3603, A61M2206/12|
|European Classification||B01D61/14D, B01D63/08F, B01D61/18, A61M1/34P|
|Mar 19, 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
|Dec 10, 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