WO1984003229A1 - A preprimed filter device and its method of manufacture - Google Patents
A preprimed filter device and its method of manufacture Download PDFInfo
- Publication number
- WO1984003229A1 WO1984003229A1 PCT/US1983/002004 US8302004W WO8403229A1 WO 1984003229 A1 WO1984003229 A1 WO 1984003229A1 US 8302004 W US8302004 W US 8302004W WO 8403229 A1 WO8403229 A1 WO 8403229A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- liquid
- porous material
- filter
- hydrophobic
- wetted
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 20
- 238000004519 manufacturing process Methods 0.000 title claims description 3
- 239000000463 material Substances 0.000 claims abstract description 71
- 239000011148 porous material Substances 0.000 claims abstract description 58
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 38
- 239000000126 substance Substances 0.000 claims abstract description 12
- 239000007788 liquid Substances 0.000 claims description 56
- 239000008280 blood Substances 0.000 claims description 21
- 210000004369 blood Anatomy 0.000 claims description 21
- 239000000306 component Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 239000012528 membrane Substances 0.000 claims description 9
- 230000001413 cellular effect Effects 0.000 claims description 8
- 238000009736 wetting Methods 0.000 claims description 8
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 5
- 239000012503 blood component Substances 0.000 claims description 5
- 239000007864 aqueous solution Substances 0.000 abstract 1
- 239000000243 solution Substances 0.000 abstract 1
- 239000004094 surface-active agent Substances 0.000 description 11
- 239000012530 fluid Substances 0.000 description 8
- 239000012510 hollow fiber Substances 0.000 description 7
- 230000002093 peripheral effect Effects 0.000 description 4
- -1 polypropylene Polymers 0.000 description 4
- 239000004743 Polypropylene Substances 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000012982 microporous membrane Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 102000004169 proteins and genes Human genes 0.000 description 2
- 108090000623 proteins and genes Proteins 0.000 description 2
- 230000008707 rearrangement Effects 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000001225 therapeutic effect Effects 0.000 description 2
- 102000009027 Albumins Human genes 0.000 description 1
- 108010088751 Albumins Proteins 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 208000007502 anemia Diseases 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 108010074605 gamma-Globulins Proteins 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000012229 microporous material Substances 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 238000004382 potting Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000002560 therapeutic procedure Methods 0.000 description 1
- 206010043554 thrombocytopenia Diseases 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0088—Physical treatment with compounds, e.g. swelling, coating or impregnation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
Definitions
- the invention generally relates to filter devices. More particularly, the invention relates to filter devices utilizing hydrophobic filter material. The invention also generally relates to the wetting of porous hydrophobic material.
- the clinically proven cellular components of whole blood include red cells, which can be used to treat chronic anemia; and platelets, which can be used to treat thrombocytopenia.
- the clinically proven noncellular components of whole blood include plasma and plasma-based fractions, such as albumin, protein fraction, gamma globulin, and various other specific coagulation protein concentrates.
- the present concensus is that patient care is improved by providing only the therapeutic components of whole blood which are required to treat the specific disease.
- the demand for therapeutic components of whole blood is thus ever increasing.
- the demand for safe and effective systems and methods for collecting, separating and storing the cellular and noncellular components of whole blood grows accordingly.
- Whole blood can be separated into its cellular and noncellular components by filtration.
- blood filtration devices utilize hydrophobic microporous material. Because the material is hydrophobic, the membrane needs first to be “wetted” to accommodate fluid flow through the membrane. A porous membrane has been "wetted” when the pore volume of the membrane has been completely filled with a liquid.
- a conventional method of wetting hydrophobic materials includes the application of surfactants, alcohol, or other fluids which spontaneously wet the hydrophobic material.
- surfactants for example, attention is directed to the copending U.S. Patent Application of Boggs et al, entitled “WETTABLE HYDROPHOBIC HOLLOW FIBERS", Serial No. 387,988, filed June 14, 1982.
- Another conventional wetting method involves the use of chemical means to alter the surface characteristics of the material.
- conventional wetting techniques involve the introduction of nonphysiological substances into the pore volume of the filter material. They also require the subsequent step of washing or flushing the nonphysiological substances from the pore volume of the filter material prior to use. Regardless of the thoroughness of the washing step, however, there is the possibility that traces of the nonphysiological substances used to wet the filter material will remain associated with the material.
- conventional substances which spontaneously wet hydrophobic materials may craze, or stress crack, plastic housings in which the hydrophobic materials are carried. Cracks and actual leaks in the housing can develop.
- the invention provides a device having a porous material which has been wetted without the use of a substance which, would spontaneously wet the material.
- a liquid which does not spontaneously wet the porous material can nevertheless be forced into the pore volume of the material.
- the porous material is wetted with, a liquid which would not spontaneously wet the material.
- the porous material is first subjected to reduced pressure or a vacuum prior to exposure to the pressurized liquid. It is believed that this additional step facilitates the overall effectiveness of the wetting process conducted in accordance with the invention.
- a physiological liquid such as water or an aqueous saline solution
- a physiological liquid such as water or an aqueous saline solution
- a physiological liquid can be used alone to wet a hydrophobic microporous membrane. Exposure of the membrane to surfactants or other nonphysiological liquids can thereby be completely avoided.
- the resulting filter device is preprimed with the physiological liquid and ready for immediate use, without any subsequent washing step and without the possibility of residual traces of surfactant or other nonphysiological substances.
- Figure 1 is a perspective view of a prewetted and preprimed filter device which embodies the features of the invention
- Figure 2 is a partially cut away perspective view of the prewetted and preprimed filter device shown in Figure 1;
- Figure 3 is a partially perspective view of a filter device and an apparatus which may be used to wet and preprime the filter device in accordance with the invention.
- Figure 4 is a perspective view of a filter device and an alternate apparatus which may be used to wet and preprime the filter device in accordance with the invention.
- a prewetted and preprimed filter 10 which embodies the features of the invention is shown in Figs. 1 and 2.
- the filter 10 can be variously constructed and used for different purposes. Because the invention is well suited for use with medical purpose filters, in the illustrated embodiment, the filter 10 is one suitable for separating the cellular and noncellular components of whole blood.
- the filter 10 includes a housing 12, which can be molded from a plastic material.
- the housing 12 includes end caps 14 and 16 which have suitable blood outlet and inlet ports, respectively 18 and 20.
- the housing 12 also includes a plasma port 22 and an optional fill port 24, the purpose of which will be explained later.
- a porous hydrophobic filter material 17, illustrated in Figure 2 is contained within the housing 12.
- the hydrophobic filter material 17 consists of a plurality of hollow microporous fibers 27 having a desired pore size. It should be appreciated that the filter material 17 can be alternately configured, such as in a flat sheet.
- the pore size and porosity of the hydrophobic material will depend on the particular filter application and is not a limitation on the general aspects of the invention.
- the pore size will generally be chosen on the basis of the components to be removed or the type of treatment that is desired.
- the desired pore size to separate cellular blood components from noncellular blood components is well known in the art.
- Suitable types of such microporous hydrophobic materials include those manufactured from polypropylene, for example.
- Other suitable types of such hydrophobic microporous membrane materials include those constructed of polyethylene.
- the filter 10 can be constructed by any suitable method.
- the bundle of the hydrophobic filter fibers 27 can be placed in housing 12 in a direction substantially parallel to the longitudinal axis of housing 12 and secured at both ends within housing 12 by use of a suitable potting compound.
- This concept is well known in the art and is not a limitation on the invention as any suitable construction can be used.
- a liquid 26 fills the interior of housing 12 and the pore volume of the hydrophobic hollow fibers 27.
- the liquid 26 is retained in the housing 12 by end caps 19, 21, 23, and 25 which seal the respective ports 18, 20, 22, and 24.
- the liquid fills the interior of housing 12 and the pore volume of the hydrophobic hollow fibers 27.
- the liquid 26 is retained in the housing 12 by end caps 19, 21, 23, and 25 which seal the respective ports 18, 20, 22, and 24.
- the liquid fills the interior of housing 12 and the pore volume of the hydrophobic hollow fibers 27.
- the liquid 26 is retained in the housing 12 by end caps 19, 21, 23, and 25 which seal the respective ports 18,
- FIG 3 an apparatus is shown which may be used to prewet and preprime the filter devices 54 and 56 in accordance with the invention.
- the apparatus includes a chamber 30 and peripheral equipment 32 for providing air and other fluids under pressure.
- Chamber 30 is designed to withstand positive and negative pressures.
- the peripheral equipment 32 includes lines for the delivery of fluid under pressure to chamber 30.
- the peripheral equipment 32 includes a solution line 34 and a liquid storage tank 36 having a valve 38.
- the liquid 26 in the tank 36 does not include any surfactant or the like which would spontaneously wet the porous material of the filter devices 54 and 56.
- the peripheral equipment 32 also includes a pressure and vacuum line 40 which communicates with the interior of the chamber 30.
- the line 40 includes suitable valves 42, 44, and 45; a vacuum source 47; a pressure regulator 46; and a source of compressed gas 48.
- a vent line 50 with a valve 52 is also provided for venting the chamber 30.
- valves 38, 42, 44, 45, and 52 are initially closed.
- the filter devices 54 and 56 similar to the filter 10, but not yet filled with the liquid 26, are placed in the chamber 30.
- One or more of the inlet and/or exit ports 18, 20, 22, and 24 of each of filters 54 and 56 are opened. It should be appreciated that, in accordance with the invention, only one of the inlet or outlet ports 18, 20, 22, and 24 associated with each filter 54 and 56 need be open.
- each filter 54 and 56 including the pore volume of each associated hollow fiber, are thereby evacuated through the open port or ports.
- valves 42 and 44 are again closed.
- the valve 38 is opened, and the chamber 30 is filled with the liquid 26 from the storage tank 36 via the solution line 34.
- the interior of each filter 54 and 56 is also thereby filled through the open port or ports.
- valve 38 is closed.
- the valve 45 is opened, and the interior of chamber 30 is pressurized by compressed gas from the compressed gas source 48.
- the pressure regulator 46 is utilized to provide the desired pressure.
- the liquid 26 used to achieve the surprising results of the invention can comprise virtually any liquid which does not spontaneously wet the porous filter material.
- the liquid 26 can comprise only water.
- the liquid 26 can also be a solution containing water, such as an aqueous saline solution.
- an aqueous saline solution In the context of the illustrated embodiment, the use of the aqueous saline solution is preferred.
- the valve 45 is closed, the valve 52 is opened, and the chamber 30 is vented via the vent line 50.
- the filters 54 and 56 can then be removed from chamber 30.
- the ports which were opened during the wetting process are closed, using the heretofore discussed caps, to retain the liquid 26 in the filter housing.
- the filter 10 as shown in Figs. 1 and 2 is thereby provided in which the previously unwetted hydrophobic fibers are now in a fully wetted condition.
- the liquid 26 remains in the housing 12 until time of use.
- the filter 10 is thus not only prewetted, but is also preprimed.
- the prewetted and preprimed filter 10 can be sterilized by autoclaving, radiation sterilization, or the like.
- the above-discussed step of first evacuating the chamber 30 prior to subjecting the filter material to the pressurized liquid 26 serves to facilitate wetting process.
- air which is normally present within the pore volume of the material is removed.
- the liquid 26, which is thereafter forced into the pore volume under pressure, will then remain in the pore volume after the pressure is removed. Otherwise, it is believed that air compressed within the pore volume by the entry of the pressurized liquid 26 could expand after the pressure is removed and force the liquid 26 from the pore volume.
- the initial evacuation step could be eliminated and other methods used to remove the air from the pore volume.
- the air present in the pore volume can be driven, or dissolved, into solution.
- This alternative technique could be enhanced by first purging the pore volume with carbon dioxide or another gas which will readily dissolve in the liquid 26. Any comparable technique which serves to increase the overall diffusion of gas into solution can also be utilized, such as the application of heat.
- the introduction of the pressurized liquid could be followed by a sudden decrease in pressure on one side of the porous material. This will rapidly draw the fluid through the pore volume toward the side of lesser pressure to effectively "flush" the air from the pore volume.
- the filter housing 12 could itself serve as the equivalent of pressure chamber 30.
- the housing 12 would be made of a material sufficient to withstand the pressures applied.
- the chamber 30 could be eliminated, and the lines 34 and 40 would be attached directly to the desired inlet and/or outlet ports or ports of the filter, as generally shown in Fig. 4.
- an air pressure chamber 58 is provided having a gas pressure line 62 which communicates with a source of compressed air.
- a filter 60 which is of similar design to filter 10 but not yet filled with the liquid 26, is placed within the chamber 58.
- a fluid line 64 communicates directly with at least one of the ports 66, 70, or 72. The fluid line 64 does not communicate with the chamber 58. In the illustrated embodiment, the line 64 communicates directly with the plasma port 66 and blood exit port 72.
- the liquid 26 is thus directed under pressure through the line 64 directly into the interior of filter 60.
- the interior of chamber 58 is at the same time pressurized to an external air pressure generally equal to the internal fluid pressure.
- This arrangement prevents the filter housing 12 from exploding as the pressurized liquid is driven into the pore volume of the filter material.
- all of the inlet and outlet ports 18, 20, and 22 of the filter 10 could have their final closure caps 19, 21, and 23 preattached.
- the pressurized liquid 26 could be introduced into the filter device via the separate fill port 24, as shown in Figs. 1 and 2.
- the fill port 24 could communicate with either the blood side or plasma side of the filter material, or both sides. After the filter material has been wetted, the fill port 24 could then be closed by its own cap 25.
- one of the inlet or outlet blood ports 18 or 20 could be closed, and a stream of pressurized liquid 26 directed through the other open port 18 or 20.
- the pressurized stream of the liquid 26 will be forced through the pore volume of the filter material and exit the filter housing 12 via the plasma port 22, which is left open.
- the pressurized stream of the liquid 26 alone wets the filter material.
- the liquid 26 could include a surfactant present in an amount substantially less than that required to spontaneously wet the filter material. The presence of small amounts of the surfactant will reduce the overall amount of pressure required to force the liquid 26 into the pore volume of the filter material.
- the porous material of the filter is wetted without the use of any surfactant or other nonphysiological material that spontaneously wets the hydrophobic material.
- EXAMPLE I A filter device similar to that shown in Figure 1 was wetted and preprimed in accordance with the invention.
- the microporous filter media which was utilized in the filter was a hydrophobic polypropylene hollow fiber material having the following physical specifications: inside diameter
- the filter was placed in the chamber 30. With all of the filter ports open, the chamber 30 was evacuated to about 0.3 inches of mercury absolute. The chamber 30 was then filled only with saline and thereafter pressurized to about 150 psi for less than one minute. The filter was removed from the chamber and tested by connecting the blood inlet of the filter to a low pressure water line. The blood outlet was closed, and water exited freely from the plasma exit port.
- EXAMPLE II Another filter device similar to that shown in Fig. 1 was wetted and preprimed in accordance with the invention.
- the microporous filter material used was the same polypropylene same hollow fiber material described in Example I. In this procedure, no external chamber was used.
- the blood outlet side of the device was closed.
- the plasma outlet side was opened.
- a pressurized stream of water was directed for approximately one minute through the blood inlet side at about 95 psi.
- the pressurized stream of water exited the device via the open plasma outlet side at a flow rate of about 22 liters per minute, indicating that the hydrophobic filter material had been wetted.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Filtering Materials (AREA)
- Cigarettes, Filters, And Manufacturing Of Filters (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
- External Artificial Organs (AREA)
Abstract
A filter device (10) has a porous material (17) which has been wetted without the use of any substance which would spontaneously wet the material. In one embodiment, the device includes a hydrophobic filter material (27) which has been wetted solely by subjecting the material to a pressurized stream of an aqueous solution (26). The solution (26) can remain associated with the filter material (27), resulting in a prewetted and preprimed device (10).
Description
A PREPRIMED FILTER DEVICE AND ITS METHOD OF MANUFACTURE
FIELD OF THE INVENTION
The invention generally relates to filter devices. More particularly, the invention relates to filter devices utilizing hydrophobic filter material. The invention also generally relates to the wetting of porous hydrophobic material.
BACKGROUND AND OBJECTS OF THE INVENTION
At the present time, over 12,000,000 units of whole blood are collected from volunteer donors in the United States each year. With the advent of blood component therapy, approximately 60% to 80% of the whole blood collected today is not itself stored and used for transfusion. Instead, the whole blood is separated into its clinically proven cellular and noncellular components, which are themselves stored and used to treat a multiplicity of specific conditions and diseased states.
The clinically proven cellular components of whole blood include red cells, which can be used to treat chronic anemia; and platelets, which can be used to treat thrombocytopenia. The clinically proven noncellular components of whole blood include plasma and plasma-based fractions, such as albumin, protein fraction, gamma globulin, and various other specific coagulation protein concentrates.
The present concensus is that patient care is improved by providing only the therapeutic components of whole blood which are required to treat the specific disease. The demand for therapeutic components of whole blood is thus ever increasing. Likewise, the demand for safe and effective systems and methods for collecting, separating and storing the cellular and noncellular components of whole blood grows accordingly.
Whole blood can be separated into its cellular and noncellular components by filtration. Often, blood filtration devices utilize hydrophobic microporous material. Because the material is hydrophobic, the membrane needs first to be "wetted" to accommodate fluid flow through the membrane. A porous membrane has been "wetted" when the pore volume of the membrane has been completely filled with a liquid. A conventional method of wetting hydrophobic materials includes the application of surfactants, alcohol, or other fluids which spontaneously wet the hydrophobic material. For example, attention is directed to the copending U.S. Patent Application of Boggs et al, entitled "WETTABLE HYDROPHOBIC HOLLOW FIBERS", Serial No. 387,988, filed June 14, 1982.
Another conventional wetting method involves the use of chemical means to alter the surface characteristics of the material. By their very nature, conventional wetting techniques involve the introduction of nonphysiological substances into the pore volume of the filter material. They also require the subsequent step of washing or flushing the nonphysiological substances from the pore volume of the filter material prior to use. Regardless of the thoroughness of the washing step, however, there is the possibility that traces of the nonphysiological substances used to wet the filter material will remain associated with the material.
In addition, conventional substances which spontaneously wet hydrophobic materials may craze, or stress crack, plastic housings in which the hydrophobic materials are carried. Cracks and actual leaks in the housing can develop.
It is one of the principal objects of this invention to provide a filter device having a hydrophobic porous material which has been wetted using only physiological substances, without the use of any surfactants, wetting agents, or other nonphysiological material which would spontaneously wet the hydrophobic material.
SUMMARY OF THE INVENTION
To achieve this and other objects, the invention provides a device having a porous material which has been wetted without the use of a substance which, would spontaneously wet the material. In accordance with the invention, it has been discovered that, surprisingly, by applying pressure, a liquid which does not spontaneously wet the porous material can nevertheless be forced into the pore volume of the material. Thus, in accordance with the invention, the porous material is wetted with, a liquid which would not spontaneously wet the material.
In one embodiment, the porous material is first subjected to reduced pressure or a vacuum prior to exposure to the pressurized liquid. It is believed that this additional step facilitates the overall effectiveness of the wetting process conducted in accordance with the invention.
By virtue of the invention, a physiological liquid, such as water or an aqueous saline solution, can be used alone to wet a hydrophobic microporous membrane. Exposure of the membrane to surfactants or other nonphysiological liquids can thereby be completely avoided. The resulting filter device is preprimed with the physiological liquid and ready for immediate use, without any subsequent washing step and without the possibility of residual traces of surfactant or other nonphysiological substances.
Other features and advantages of the invention will be pointed out in, or will be apparent from, the Specification and claims, as will obvious modifications of the embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a prewetted and preprimed filter device which embodies the features of the invention;
Figure 2 is a partially cut away perspective view of the prewetted and preprimed filter device shown in Figure 1;
Figure 3 is a partially perspective view of a filter device and an apparatus which may be used to wet and preprime the filter device in accordance with the invention; and
Figure 4 is a perspective view of a filter device and an alternate apparatus which may be used to wet and preprime the filter device in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
A prewetted and preprimed filter 10 which embodies the features of the invention is shown in Figs. 1 and 2. The filter 10 can be variously constructed and used for different purposes. Because the invention is well suited for use with medical purpose filters, in the illustrated embodiment, the filter 10 is one suitable for separating the cellular and noncellular components of whole blood.
The filter 10 includes a housing 12, which can be molded from a plastic material. The housing 12 includes end caps 14 and 16 which have suitable blood outlet and inlet ports, respectively 18 and 20. The housing 12 also includes a plasma port 22
and an optional fill port 24, the purpose of which will be explained later. A porous hydrophobic filter material 17, illustrated in Figure 2, is contained within the housing 12. As shown in Figure 2 , the hydrophobic filter material 17 consists of a plurality of hollow microporous fibers 27 having a desired pore size. It should be appreciated that the filter material 17 can be alternately configured, such as in a flat sheet. The pore size and porosity of the hydrophobic material will depend on the particular filter application and is not a limitation on the general aspects of the invention. Thus, the pore size will generally be chosen on the basis of the components to be removed or the type of treatment that is desired. The desired pore size to separate cellular blood components from noncellular blood components is well known in the art. Suitable types of such microporous hydrophobic materials include those manufactured from polypropylene, for example. Other suitable types of such hydrophobic microporous membrane materials include those constructed of polyethylene.
The filter 10 can be constructed by any suitable method. For example, the bundle of the hydrophobic filter fibers 27 can be placed in housing 12 in a direction substantially parallel to the longitudinal axis of housing 12 and secured at both
ends within housing 12 by use of a suitable potting compound. This concept is well known in the art and is not a limitation on the invention as any suitable construction can be used. A liquid 26 fills the interior of housing 12 and the pore volume of the hydrophobic hollow fibers 27. The liquid 26 is retained in the housing 12 by end caps 19, 21, 23, and 25 which seal the respective ports 18, 20, 22, and 24. In accordance with the invention, the liquid
26 which fills the housing 12 does not include any substances which would spontaneously wet the hydrophobic filter material 17, such as a surfactant or surfactants. Nevertheless, in accordance with the invention, the liquid 26 alone has been used to wet hydrophobic filter material 17.
More particularly, in Figure 3, an apparatus is shown which may be used to prewet and preprime the filter devices 54 and 56 in accordance with the invention.
The apparatus includes a chamber 30 and peripheral equipment 32 for providing air and other fluids under pressure. Chamber 30 is designed to withstand positive and negative pressures. The peripheral equipment 32 includes lines for the delivery of fluid under pressure to chamber 30. As illustrated in Figure 3, the peripheral equipment 32 includes a solution line 34 and a liquid
storage tank 36 having a valve 38. The liquid 26 in the tank 36 does not include any surfactant or the like which would spontaneously wet the porous material of the filter devices 54 and 56. In the embodiment illustrated in Fig. 3, the peripheral equipment 32 also includes a pressure and vacuum line 40 which communicates with the interior of the chamber 30. The line 40 includes suitable valves 42, 44, and 45; a vacuum source 47; a pressure regulator 46; and a source of compressed gas 48. A vent line 50 with a valve 52 is also provided for venting the chamber 30.
All of the valves 38, 42, 44, 45, and 52 are initially closed. The filter devices 54 and 56, similar to the filter 10, but not yet filled with the liquid 26, are placed in the chamber 30. One or more of the inlet and/or exit ports 18, 20, 22, and 24 of each of filters 54 and 56 are opened. It should be appreciated that, in accordance with the invention, only one of the inlet or outlet ports 18, 20, 22, and 24 associated with each filter 54 and 56 need be open.
With the valves 42 and 44 open, the chamber 30 is first evacuated by means of pressure and vacuum line 40. The interior of each filter 54 and 56, including the pore volume of each associated hollow fiber, are thereby evacuated through the open port or ports.
After evacuation of the chamber 30, the valves 42 and 44 are again closed. The valve 38 is opened, and the chamber 30 is filled with the liquid
26 from the storage tank 36 via the solution line 34. The interior of each filter 54 and 56 is also thereby filled through the open port or ports.
After the chamber 30 and filters 54 and 56 have been filled with the solution 26, the valve 38 is closed. In accordance with the invention, the valve 45 is opened, and the interior of chamber 30 is pressurized by compressed gas from the compressed gas source 48. The pressure regulator 46 is utilized to provide the desired pressure.
Surprisingly, even though the liquid 26 will not itself spontaneously wet the porous material 17 of the filter devices 54 and 56, it is nevertheless forced under the applied pressure into the pore volume of the material 17. The end result is that the material 17 is wetted with the liquid 26 which would not spontaneously wet the material 17.
The amount of pressure applied to achieve these surprising results will vary, depending on the particular type of hydrophobic filter material utilized.
The amount of pressure for a particular material can be determined empirically. While it is believed that there is a finite time required for the solution to wet the material, it is believed that pressure is the primary consideration. Generally, the actual time required to wet the material will be less than one minute, although it is to be understood that this is not a limitation of the invention.
Alternatively, the pressure requirements to wet the microporous hollow fiber material can be estimated by the equation:
where γ = liquid surface tension (dynes/cm) Θ = contact angle (degrees) d = hollow fiber pore size (cm). The liquid 26 used to achieve the surprising results of the invention can comprise virtually any liquid which does not spontaneously wet the porous filter material. For example, when the porous material is hydrophobic, the liquid 26 can comprise only water. The liquid 26 can also be a solution containing water, such as an aqueous saline solution. In the context of the illustrated embodiment, the use of the aqueous saline solution is preferred.
After the liquid 26 has been forced under pressure into the pore volume of the material 17, the valve 45 is closed, the valve 52 is opened, and the chamber 30 is vented via the vent line 50. The filters 54 and 56 can then be removed from chamber 30. The ports which were opened during the wetting process are closed, using the heretofore discussed caps, to retain the liquid 26 in the filter housing. The filter 10 as shown in Figs. 1 and 2 is thereby provided in which the previously unwetted hydrophobic fibers are now in a fully wetted
condition. The liquid 26 remains in the housing 12 until time of use. The filter 10 is thus not only prewetted, but is also preprimed.
The prewetted and preprimed filter 10 can be sterilized by autoclaving, radiation sterilization, or the like.
It is belived that the above-discussed step of first evacuating the chamber 30 prior to subjecting the filter material to the pressurized liquid 26 serves to facilitate wetting process. By first subjecting the filter material to a vacuum, or simply to a reduced pressure, air which is normally present within the pore volume of the material is removed. The liquid 26, which is thereafter forced into the pore volume under pressure, will then remain in the pore volume after the pressure is removed. Otherwise, it is believed that air compressed within the pore volume by the entry of the pressurized liquid 26 could expand after the pressure is removed and force the liquid 26 from the pore volume.
However, the initial evacuation step could be eliminated and other methods used to remove the air from the pore volume.
For example, by introducing the liquid 26 at a sufficient pressure, the air present in the pore volume can be driven, or dissolved, into solution.
This alternative technique could be enhanced by first purging the pore volume with carbon dioxide or another gas which will readily dissolve in the
liquid 26. Any comparable technique which serves to increase the overall diffusion of gas into solution can also be utilized, such as the application of heat. In yet another alternate embodiment which does not employ the evacuation step, the introduction of the pressurized liquid could be followed by a sudden decrease in pressure on one side of the porous material. This will rapidly draw the fluid through the pore volume toward the side of lesser pressure to effectively "flush" the air from the pore volume.
The foregoing descriptions with respect to Figure 3 represent several methods for fabricating the prewetted and preprimed filter 10 in accordance with the invention. However, other techniques could also be used.
For example, the filter housing 12 could itself serve as the equivalent of pressure chamber 30. In this embodiment, the housing 12 would be made of a material sufficient to withstand the pressures applied. In this arrangement, the chamber 30 could be eliminated, and the lines 34 and 40 would be attached directly to the desired inlet and/or outlet ports or ports of the filter, as generally shown in Fig. 4. Yet another alternate arrangement is more specifically shown in Figure 4. In this embodiment, an air pressure chamber 58 is provided having a gas pressure line 62 which communicates with a source of compressed air. A filter 60, which is of similar design to filter 10 but not yet filled with the
liquid 26, is placed within the chamber 58. A fluid line 64 communicates directly with at least one of the ports 66, 70, or 72. The fluid line 64 does not communicate with the chamber 58. In the illustrated embodiment, the line 64 communicates directly with the plasma port 66 and blood exit port 72.
The liquid 26 is thus directed under pressure through the line 64 directly into the interior of filter 60. The interior of chamber 58 is at the same time pressurized to an external air pressure generally equal to the internal fluid pressure. This arrangement prevents the filter housing 12 from exploding as the pressurized liquid is driven into the pore volume of the filter material. In yet another arrangement, all of the inlet and outlet ports 18, 20, and 22 of the filter 10 (see Fig. 1) could have their final closure caps 19, 21, and 23 preattached. In this arrangement, the pressurized liquid 26 could be introduced into the filter device via the separate fill port 24, as shown in Figs. 1 and 2. The fill port 24 could communicate with either the blood side or plasma side of the filter material, or both sides. After the filter material has been wetted, the fill port 24 could then be closed by its own cap 25.
In still yet another embodiment, one of the inlet or outlet blood ports 18 or 20 could be closed, and a stream of pressurized liquid 26 directed through the other open port 18 or 20. The pressurized stream of the liquid 26 will be forced
through the pore volume of the filter material and exit the filter housing 12 via the plasma port 22, which is left open. The pressurized stream of the liquid 26 alone wets the filter material. In yet another alternate arrangement, the liquid 26 could include a surfactant present in an amount substantially less than that required to spontaneously wet the filter material. The presence of small amounts of the surfactant will reduce the overall amount of pressure required to force the liquid 26 into the pore volume of the filter material. Regardless of which particular embodiment of the invention used, the porous material of the filter is wetted without the use of any surfactant or other nonphysiological material that spontaneously wets the hydrophobic material.
EXAMPLE I A filter device similar to that shown in Figure 1 was wetted and preprimed in accordance with the invention. The microporous filter media which was utilized in the filter was a hydrophobic polypropylene hollow fiber material having the following physical specifications: inside diameter
320μ , wall thickness 150 μ ; effective length 214 mm ; effective surface .17 m2; and maximum pore size
.55μ.
Apparatus similar to that shown in Fig. 3 was utilized. The filter was placed in the chamber 30. With all of the filter ports open, the chamber
30 was evacuated to about 0.3 inches of mercury absolute. The chamber 30 was then filled only with saline and thereafter pressurized to about 150 psi for less than one minute. The filter was removed from the chamber and tested by connecting the blood inlet of the filter to a low pressure water line. The blood outlet was closed, and water exited freely from the plasma exit port.
Further testing with whole blood demonstrated that the filtration characteristics of the filter material wetted in accordance with the invention were the same as those of a filter material wetted with a conventional surfactant.
EXAMPLE II Another filter device similar to that shown in Fig. 1 was wetted and preprimed in accordance with the invention. The microporous filter material used was the same polypropylene same hollow fiber material described in Example I. In this procedure, no external chamber was used. The blood outlet side of the device was closed. The plasma outlet side was opened. A pressurized stream of water was directed for approximately one minute through the blood inlet side at about 95 psi. The pressurized stream of water exited the device via the open plasma outlet side at a flow rate of about 22 liters per minute, indicating that the hydrophobic filter material had been wetted.
While the invention has been described with respect to numerous specific embodiments, it is to be understood that the invention is capable of numerous other rearrangements, changes and modifications and it is intended to cover all such rearrangements, modifications and changes as fall within the scope of the appended claims.
Claims
1. A device comprising a porous material that has been wetted under pressure using only a liquid which does not spontaneously wet the porous material.
2. A device according to claim 1 wherein said porous material is suited for separating cellular blood components from noncellular blood components.
3. A device according to claim 1 wherein said liquid used to wet said material is maintained in contact with said wetted material until time of use of said device.
4. A device according to claim 1 wherein said porous material is hydrophobic, and wherein said liquid includes water.
5. A device according to claim 1 wherein said porous material is exposed to said liquid under pressure sufficient to force said liquid into the pore volume of said porous material.
6. A device according to claim 5 wherein said porous material is subjected to a reduced pressure prior to contact with said liquid to remove air from the pore volume of said porous material.
7. A device according to claim 6 wherein said reduced pressure is substantially a vacuum or a vacuum.
8. A preprimed filter device comprising a housing, a hydrophobic membrane positioned in said housing, and a liquid including water which has been introduced into said housing under pressure to wet said hydrophobic membrane without the use of any substance which would spontaneously wet said hydrophobic membrane.
9. A filter device according to claim 8 where said hydrophobic membrane is operative for separating the cellular components of whole blood from the noncellular components thereof.
10. A filter device according to claim 9 wherein said liquid is an aqueous saline solution.
11. A method of wetting porous material without the use of a substance which spontaneously wets the material, said method comprising the steps of contacting the material with a liquid which does not spontaneously wet the material, and applying a pressure upon the liquid sufficient to force the liquid into the pore volume of the material.
12. A method according to claim 11 and further including the step of maintaining contact between the liquid and the pore volume of the material after the said application of pressure is terminated.
13. A method according to claim 11; and further including the step of applying a reduced pressure upon the porous material prior to said contacting step.
14. A method according to claim 13 wherein said reduced pressure application includes applying a vacuum or substantially a vacuum.
15. Hydrophobic porous material wetted in accordance with the method of claim 11.
16. A wetted material according to claim 15 wherein said liquid used to wet said material includes water.
17. Hydrophobic porous material wetted in accordance with the method of claim 14.
18. A method of manufacturing a prewetted filter device utilizing hydrophobic porous material comprising the step of contacting under pressure the initially unwetted hydrophobic filter material with a liquid comprising water, without utilizing any material which spontaneously wets the hydrophobic filter material.
19. A method according to claim 18 and further including the step of removing air from the pore volume of the porous material prior to said contacting step.
20. A method according to claim 18 and futher including the step of maintaining contact between the liquid and the porous material after said contacting step.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU24350/84A AU2435084A (en) | 1983-02-24 | 1983-12-19 | A preprimed filter device and its method of manufacture |
JP84500655A JPS60500560A (en) | 1983-02-24 | 1983-12-19 | Pre-primed filter device and method of manufacturing the same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US46936283A | 1983-02-24 | 1983-02-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1984003229A1 true WO1984003229A1 (en) | 1984-08-30 |
Family
ID=23863492
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1983/002004 WO1984003229A1 (en) | 1983-02-24 | 1983-12-19 | A preprimed filter device and its method of manufacture |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0135511A4 (en) |
JP (1) | JPS60500560A (en) |
AU (1) | AU2435084A (en) |
IT (1) | IT1173303B (en) |
WO (1) | WO1984003229A1 (en) |
ZA (1) | ZA84124B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0217874A1 (en) * | 1985-03-28 | 1987-04-15 | Memtec Ltd | Rapid vapour transport through unwetted porous barriers. |
DE3834126C1 (en) * | 1988-10-07 | 1989-12-28 | Fresenius Ag, 6380 Bad Homburg, De | |
WO1998028067A1 (en) * | 1996-12-20 | 1998-07-02 | Pall Corporation | Apparatus and methods for wetting or flushing filters |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110304315A (en) * | 2018-03-27 | 2019-10-08 | 杭州科百特过滤器材有限公司 | A kind of filter pre-wets packing method |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3526001A (en) * | 1968-11-26 | 1970-08-25 | Du Pont | Permeation separation device for separating fluids and process relating thereto |
US4184963A (en) * | 1977-10-28 | 1980-01-22 | Millipore Corporation | Immersible molecular filter unit and process of making it |
US4214020A (en) * | 1977-11-17 | 1980-07-22 | Monsanto Company | Processes for coating bundles of hollow fiber membranes |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3322266A (en) * | 1964-12-08 | 1967-05-30 | Kumlon Crafts Inc | Film pack for hemodialyzing membranes |
US3342328A (en) * | 1966-04-14 | 1967-09-19 | Harvey F Swenson | Dialyzer membrane storage assembly |
DE2125027A1 (en) * | 1970-05-20 | 1971-12-02 | Wilson Pharm & Chem Corp | Device for separating aqueous solutions from suspensions |
DE3043073C2 (en) * | 1980-11-14 | 1984-07-05 | Fresenius AG, 6380 Bad Homburg | Filtration membrane and method for hydrophilization |
-
1983
- 1983-12-19 JP JP84500655A patent/JPS60500560A/en active Pending
- 1983-12-19 WO PCT/US1983/002004 patent/WO1984003229A1/en not_active Application Discontinuation
- 1983-12-19 AU AU24350/84A patent/AU2435084A/en not_active Abandoned
- 1983-12-19 EP EP19840900569 patent/EP0135511A4/en not_active Withdrawn
-
1984
- 1984-01-06 ZA ZA84124A patent/ZA84124B/en unknown
- 1984-02-17 IT IT19696/84A patent/IT1173303B/en active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3526001A (en) * | 1968-11-26 | 1970-08-25 | Du Pont | Permeation separation device for separating fluids and process relating thereto |
US4184963A (en) * | 1977-10-28 | 1980-01-22 | Millipore Corporation | Immersible molecular filter unit and process of making it |
US4214020A (en) * | 1977-11-17 | 1980-07-22 | Monsanto Company | Processes for coating bundles of hollow fiber membranes |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0217874A1 (en) * | 1985-03-28 | 1987-04-15 | Memtec Ltd | Rapid vapour transport through unwetted porous barriers. |
EP0217874A4 (en) * | 1985-03-28 | 1987-07-09 | Memtec Ltd | Rapid vapour transport through unwetted porous barriers. |
DE3834126C1 (en) * | 1988-10-07 | 1989-12-28 | Fresenius Ag, 6380 Bad Homburg, De | |
WO1998028067A1 (en) * | 1996-12-20 | 1998-07-02 | Pall Corporation | Apparatus and methods for wetting or flushing filters |
Also Published As
Publication number | Publication date |
---|---|
AU2435084A (en) | 1984-09-10 |
JPS60500560A (en) | 1985-04-25 |
EP0135511A1 (en) | 1985-04-03 |
EP0135511A4 (en) | 1987-01-20 |
IT1173303B (en) | 1987-06-24 |
IT8419696A0 (en) | 1984-02-17 |
ZA84124B (en) | 1984-09-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3483867A (en) | Artificial glomerulus and a method for treating blood | |
US5162102A (en) | Medical instrument and production thereof | |
JP2928913B2 (en) | Plasma separation method | |
JP2000083649A (en) | Device for separating and recovering cell and separation and recovery of cell | |
JPH01194921A (en) | Filter and method for removing particulate substance from moving gas stream | |
US20210106745A1 (en) | Blood-degassing apparatus and blood-treatment system | |
WO1984003229A1 (en) | A preprimed filter device and its method of manufacture | |
JP2672051B2 (en) | Method for manufacturing blood purification device | |
JPS62243561A (en) | Leucocyte removing filter device | |
JPH1015059A (en) | Method for testing leakage of hollow fiber membrane module and testing device therefor | |
JPH1147269A (en) | Medical heat-exchanger | |
JP3875231B2 (en) | Liquid processing module manufacturing method and liquid processing module manufacturing apparatus | |
JPS6334746B2 (en) | ||
EP0112094A1 (en) | Apparatus for blood treatment | |
JPH01113064A (en) | Priming method of plasma exchanger | |
US20220297032A1 (en) | An apparatus for filtering amniotic fluid | |
JP2000042100A (en) | Hollow fiber membrane type liquid treatment apparatus | |
JPH07256061A (en) | Liquid treatment device | |
JPH02156957A (en) | Hollow fiber film type oxygen enriching device | |
JPS5827685A (en) | Sterilized water-making unit | |
JPH0357784B2 (en) | ||
JPS61143076A (en) | Medical filter apparatus | |
JP2967205B2 (en) | Air trap with particulate filter | |
JPH05317416A (en) | Priming method | |
JPH06148B2 (en) | Plasma separation method and device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Designated state(s): AU DK JP |
|
AL | Designated countries for regional patents |
Designated state(s): BE CH DE FR GB SE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1984900569 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1984900569 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1984900569 Country of ref document: EP |