Submersible Breast Pump Protection Mechanism for a Breast Milk Collection Device with Self-Contained Reservoir

Abstract

A breast milk collection device includes a reservoir volume and an adaptor having one end to receive a woman's breast. The adaptor has a drip tube communicating with the reservoir. A source of cyclical application and relief of vacuum force is applied to the woman's breast located in the adaptor for the expression of breast milk. A one-way assembly permits breast milk to enter the reservoir and to submerge the valve element. The valve assembly includes a flexible barrier having an interior hollow chamber in fluid communication with said cyclical source of vacuum force and relief pressure, the flexible barrier fluidly isolating the source from the reservoir. The flexible barrier inflatably expands when relief pressure is applied to the interior of the flexible barrier, the flexible barrier becoming deflated when a vacuum force is applied to the hollow interior of the flexible barrier.

Claims

1. A breast milk collection device, comprising: an adaptor adapted at one end to receive a woman's breast therein, a second end of said adaptor communicating with a reservoir, said reservoir adapted to receive breast milk from said adaptor; a source of cyclical application and relief of vacuum force in communication with said adaptor, said application and relief of vacuum force adapted to be cyclically applied to the woman's breast located in said adaptor for the expression of breast milk into said adaptor; a valve assembly in communication with said adaptor, said valve assembly including a fluid passageway, a valve element at one end of said fluid passageway and said valve element extending into said reservoir, said valve element adapted to permit breast milk to enter said reservoir through said fluid passageway and to submerge said valve element in said milk, said valve element adapted to prevent breast milk from passing from said reservoir to said fluid passageway; said valve assembly further including a barrier housing at a second end of said fluid passageway, said barrier housing having an opening, an interior of said barrier housing in fluid communication with said fluid passageway; a barrier extending over said opening of said barrier housing; said source of cyclical application and relief of vacuum force in communication with said barrier, said application of vacuum force to said barrier producing a vacuum force in said barrier housing and in said fluid passageway, and said relief of vacuum force to said barrier relieving the vacuum force in said barrier housing and in said fluid passageway.

2. The breast milk collection device of claim 1, wherein: the application of vacuum force to said barrier produces a vacuum force in said adaptor, said vacuum force in said adaptor adapted to express milk from said breast and into said adaptor.

3. The breast milk collection device of claim 2, wherein: the application of said relief of vacuum force to said barrier produces a relief force in said barrier housing and in said fluid passageway, said relief of vacuum force adapted to convey milk through said valve element and into said reservoir.

4. A breast milk collection device, comprising: an adaptor adapted at one end to receive a woman's breast therein, a second end of said adaptor communicating with a reservoir, said reservoir adapted to receive breast milk from said adaptor; a source of cyclical application and relief of vacuum force in communication with said adaptor, said application and relief of vacuum force adapted to be cyclically applied to the woman's breast located in said adaptor for the expression of breast milk into said adaptor; a valve assembly in communication with said adaptor, said valve assembly including a fluid passageway and a valve element extending into said reservoir, said valve element adapted to permit breast milk to enter said reservoir through said fluid passageway and to submerge said valve element in said milk, said valve element adapted to prevent breast milk from passing from said reservoir to said fluid passageway; said valve assembly including a flexible barrier, said flexible barrier having an interior hollow chamber in fluid communication with said cyclical source of vacuum force and relief pressure, said flexible barrier fluidly isolating said source from said reservoir and isolating said source from the breast milk receiving portions of said valve assembly; said valve assembly further including a barrier housing, an interior of said barrier housing in fluid communication with said fluid passageway, said flexible barrier inflatably extending into said barrier housing when said relief pressure is applied to said interior hollow chamber of said flexible barrier, said flexible barrier becoming deflated when said source applies a vacuum force to said hollow interior chamber of said flexible barrier.

5. The breast milk collection device of claim 4, wherein: said adaptor includes a hollow drip tube extending outwardly at said second end of said adaptor and into said reservoir, said drip tube having an aperture in fluid communication with said reservoir.

6. The breast milk collection device of claim 4, wherein: said reservoir includes a reservoir housing removably attached to said adaptor.

7. The breast milk collection device of claim 4, wherein: said barrier housing has a hollow interior in fluid communication with said fluid passage of said valve assembly, said flexible barrier adapted to advance milk in said fluid passage through said valve element when said source applies relief pressure to said flexible barrier.

8. The breast milk collection device of claim 5, wherein: said barrier housing has an interior chamber in fluid communication with said drip tube; said flexible barrier deflating in said interior chamber of said barrier housing upon the application of a first vacuum force to one surface of said flexible barrier, a second vacuum force being transferred to an opposite surface of said flexible barrier, said second vacuum force adapted to be applied through said adaptor to said woman's breast, expressing milk from said breast into said drip tube.

9. The breast milk collection device of claim 7, wherein: said fluid passage includes a channel disposed in the interior of said barrier housing, said channel having a first end communicating with a hollow chamber in said barrier housing and a second end communicating with the hollow interior of said drip tube.

10. The breast milk collection device of claim 4 wherein: said flexible barrier comprises at least one supporting rib on one of an internal and external surface of said flexible barrier.

11. The breast milk collection device of claim 4 wherein: said flexible barrier comprises a first internal surface in communication with said source of cyclical application and relief of vacuum force; said flexible barrier having a second external surface communicating with a rigid hollow interior of said barrier housing; said vacuum force transferred from said first internal surface of said flexible barrier to said second external surface of said flexible barrier when said vacuum force is applied to the internal surface of said flexible barrier.

12. A breast milk collection device, comprising: an adaptor adapted at one end to receive a woman's breast therein, a second end of said adaptor communicating with a reservoir, said reservoir adapted to receive breast milk from said adaptor; a source of cyclical application and relief of vacuum force in communication with said adaptor, said application and relief of vacuum force adapted to be cyclically applied to the woman's breast located in said adaptor for the expression of breast milk into said adaptor; a valve assembly in communication with said adaptor, said valve assembly including a fluid passageway and a valve element extending into said reservoir, said valve element adapted to permit breast milk to enter said reservoir through said fluid passageway and to submerge said valve element in said milk, said valve element adapted to prevent breast milk from passing from said reservoir volume to said fluid passageway; said valve assembly including a hydrophobic barrier, said hydrophobic barrier having a first surface in communication with said cyclical source of vacuum force and relief pressure, and a second surface adapted to be in contact with breast milk in said fluid passageway, said hydrophobic barrier isolating said source from said reservoir and isolating said source from the breast milk receiving portions of said valve assembly; said valve assembly further including a barrier housing, an interior of said barrier housing in fluid communication with said passageway, said hydrophobic barrier extending over an opening of said barrier housing; said hydrophobic barrier allowing said vacuum force and said relief pressure to pass through said hydrophobic barrier, said barrier adapted to prevent breast milk from flowing through said barrier from an interior volume of said barrier housing to said source of cyclical application of vacuum force and relief pressure.

13. The breast milk collection device of claim 12, wherein: said hydrophobic barrier has a rigid fixed shape.

14. The breast milk collection device of claim 12, wherein: said hydrophobic barrier is composed of polytetrafluoroethylene (PTFE).

15. The breast milk collection device of claim 12, wherein: the hydrophobic barrier is hermetically sealed to the adaptor and to the edges of the opening of said barrier housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:

[0013] FIG. 1 is a partial sectional perspective assembly view of the breast milk collection device with self-contained reservoir of the present disclosure, illustrating the funnel shaped breast adapter, and submersible barrier and one-way valve located in the reservoir;

[0014] FIG. 2 is a partial section elevation assembly view of the breast milk collection device of FIG. 1;

[0015] FIG. 3 is an exploded elevation cross-section view of the breast milk collection device of FIGS. 1 and 2;

[0016] FIG. 4 is a cross-section assembly view of the breast milk collection device shown in FIGS. 1, 2 and 3, showing the flexible barrier in its expanded position;

[0017] FIG. 5 is an exploded perspective view of the breast milk collection device shown in FIG. 4;

[0018] FIG. 6 is a cross-section assembly view of the breast milk collection device shown in FIG. 4, illustrating the flexible barrier in its contracted position;

[0019] FIG. 7 is a perspective detail view of the flexible barrier;

[0020] FIG. 8 is a perspective detailed view of the funnel and drip tube assembly, illustrating the rimmed flange for attachment of the barrier housing and flexible barrier to the funnel; and

[0021] FIG. 9 is a cross-section elevation view of an alternate embodiment where a rigid hydrophobic filter replaces the flexible barrier.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

[0022] The breast milk collection device with a self-contained reservoir, as described herein and in U.S. Pat. Nos. 7,559,915; 8,188,772 and 8,702,646 (incorporated by reference herein) significantly improves a lactating woman's ability to express and pump breast milk by providing a device that can be used by the lactating woman at a stationary place, such as while at work, in a vehicle with a power adaptor, or other public and private places with a minimum of interference or immodesty, and relative minor disruption to the lactating woman's normal activities. In addition, the present invention can function as a passive breast milk collection reservoir when a breast pump is not connected to the reservoir device.

[0023] The inventive combination barrier and one-way valve assembly structure of the present invention is submersible in the collected breast milk in the reservoir, and functions to allow breast milk to enter the reservoir from a drip tube and valve assembly connected to the cyclic application and relief of vacuum force to the drip tube during a cessation or relief of the vacuum force application cycle, while at the same time preventing the milk from entering the drip tube or vacuum source from the reservoir during the vacuum force application or relief segments of the cycle. In this manner, the pump providing the vacuum force to the interior of the reservoir is totally isolated from the milk in the reservoir, protecting the vacuum pump from the effects of liquid corrosion or interference with the pump's operation.

[0024] Referring to FIGS. 1 and 2, the breast milk collection device 10 of the present invention includes an adaptor 12 having a funnel-shaped central portion 14 within which a lactating woman's breast is to be inserted, and a wall or plate 16 circumscribing the wide end 18 of the adaptor 12. Plate 16 includes an outer rim 20 extending inwardly from the outer edge of plate 16. Outer rim 20 includes an opening 22 and a tab 24 for purposes to be explained. Outer rim 20 also includes a second opening comprising a pour spout 23 that communicates with the interior 40 (FIG. 2) of reservoir 33, allowing milk to be poured from the reservoir into a suitable container. The funnel-shape of portion 14 of adaptor 12 is selected and can be adapted to accommodate a wide variety of female breast shapes and sizes.

[0025] Referring to FIG. 4, the funnel shaped portion 14 of adaptor 12 progressively narrows and terminates at a hollow drip tube 26 having an aperture 28 adjacent the distal end 30 of drip tube 26. In the illustrated embodiment, drip tube 26 is made of a material that prevents the drip tube from collapsing when vacuum pressure is applied to the drip tube.

[0026] Drip tube 26 receives milk expressed from the lactating woman's breast during the pumping operation, to be explained. A reservoir housing 32 forms a reservoir 33, and the housing 32 has a rim 34 including a radially outward extending bead 36 that removably engages circular groove 38 in outer rim 20 of adaptor 12, providing a snap-fit removable connection between reservoir housing 32 and adaptor 12, as shown in FIG. 4, to form reservoir 33. Breast milk flowing through funnel shaped adaptor 12 also flows to drip tube 26, and through aperture 28 and eventually into the reservoir 33, where the breast milk fills the reservoir. The drip tube 26 and funnel shaped adaptor 12 protrude a distance into the confines of the reservoir's internal volume 40, which can be an inch or more, giving the nipple of the breast room to elongate in a forward motion during pumping, providing an optimal nipple orientation for milk expression. The compact shape of the reservoir housing 32 allows the entire device 10 to fit discreetly within a woman's standard or nursing brassiere. The adaptor 12 and reservoir 33 comprise a single self-contained unit that does not depend on external milk collection containers.

[0027] As seen in FIGS. 1-6, a valve assembly 42 is adapted to frictionally fit tightly over the distal end 30 of drip tube 26 and control the flow of breast milk from adaptor 12 to reservoir 33. Valve assembly 42 in the illustrated embodiment includes a sleeve 44 having a hollow portion 46 formed within the sleeve 44. A wall 50 closes one end of hollow portion 46.

[0028] The opening or aperture 22 of rim 20 of adapter 12 includes a flared upper open end. The opening 22 is adapted to receive and frictionally hold a hollow vacuum tube 56 that leads to a source of cyclic vacuum force and relief pressure 57 (FIG. 1), as explained more fully in U.S. Pat. Nos. 7,559,915 and 8,118,772. The lower end of aperture 22 communicates with the interior chamber 81 of flexible barrier 78, as will be explained.

[0029] As shown in FIG. 4 extending downward from aperture 28 in drip tube 26 is a tubular valve mounting assembly 60 comprising a hollow interior chamber 62, communicating with the interior of hollow drip tube 26 and an opening 64. Opening 64 is circumscribed by a rim structure 65 having an outer circular surface 66.

[0030] In the illustrated embodiment of FIGS. 1-8, a valve mount 68 has an interior circular surface 69 constructed to frictionally and tightly fit over outer circular surface 66 of rim structure 65. A one way valve element 70 is mounted over opening 72 of mount 68 to allow breast milk to pass in one direction from the lactating woman's breast eventually into reservoir 33. The valve 70 also prevents the reverse flow of milk from the reservoir 33 into vacuum hose 56 or into drip tube 26.

[0031] In the illustrated embodiment, valve 70 is a duckbill check valve, but other one-way check valves as are known in the art may be substituted for duckbill valve 70. Duckbill valves commonly have a duckbill-shaped inner elastomeric sleeve that responds to changes in fluid pressure, both on the internal and external surfaces of the valve. In the present invention, the valve 70 comprises two soft adjacent walls, with a slit at the bottom of the valve. The slit opens when there is positive pressure or no vacuum force if the valve's outer walls are not submersed in milk. When vacuum force is applied, the two walls are “sucked” together.

[0032] As the reservoir 33 fills with collected milk and submerses the valve 70, liquid pressure surrounding the valve 70, in the absence of a vacuum, also keeps the valve 70 closed. Vacuum force causes valve 70 to close and stop milk migration back into the drip tube and barrier/valve assembly that may result from backflow milk pressure in the reservoir 33 caused by the cyclic application of vacuum force and relief pressure during the milk pumping process, thus preventing milk from the reservoir 33 from being drawn into hollow vacuum tube 56, which prevents damage to the vacuum pumping system.

[0033] When the milk pumping cycle is relieved of the vacuum force, or the source of vacuum force cycles off, valve 70 opens to allow milk to advance from drip tube 26 to the interior volume 40 of reservoir 33. The buildup of milk in interior chamber 62 of valve assembly 42, combined with positive pressure returning during the pump's positive cycle, forces duckbill valve 70 open, as the pressure behind the milk passing through valve 70 is temporarily greater than the ambient pressure of the milk in the reservoir which is acting across the duckbill shaped outer surfaces of the valve 70, so the valve 70 opens and milk flows through the valve. However, during a vacuum portion of the pumping cycle, the vacuum force is applied to the inner walls of the valve 70, and the duckbill elastomer valve 70 flexes closed, preventing the backflow of milk out of reservoir 33. Other suitable one-way check valves may be used in place of the illustrated duckbill valve 70.

[0034] The presently disclosed breast milk collection device, in an embodiment, incorporates an improved flexible barrier structure that allows vacuum pressure to be cyclically applied to the breast for the expression of milk into the reservoir 33, while at the same time prevents any of the milk in the reservoir 33 from entering the vacuum tube 56 or the vacuum pump 57. The improved barrier also continues to function when submerged in the milk in the reservoir volume 40.

[0035] Referring to FIGS. 1, 2, 4 and 6, the upper portion of valve assembly 42 comprises a rigid barrier housing 76 that encloses a flexible barrier 78 in hollow chamber 80 of barrier housing 76, as seen in FIG. 4. In the illustrated embodiment, flexible barrier 78 is made of a soft rubbery or thin plastic material that is readily collapsible and inflatable, as will be explained. Hollow chamber 80 communicates with a hollow tubular channel 82 of barrier housing 76, and tubular channel 82 communicates through aperture 58 with drip tube 26, allowing milk to flow through tubular channel 82 and into chamber 80. Hollow chamber 80, tubular channel 82, aperture 58 and hollow portion 46 of sleeve 44 combine to form a fluid passageway in valve assembly 42. Ultimately, milk in chamber 80 is conveyed to reservoir 33 upon the opening of one-way valve 70.

[0036] As seen in FIGS. 4 and 8, a somewhat oval rimmed flange 84 extends outwardly from inner face 86 of adaptor 12. The outer rim 88 of barrier housing 76 is the same somewhat oval shape as rimmed flange 84, and the outer rim 88 extends over flange 84 as seen in FIG. 4. The outer rim 90 of barrier 78 is similarly oval in shape, and is held securely between flange 84 and outer rim 88 of the barrier housing 76. Thus, a hermetic seal is formed between barrier 78, the barrier housing 76 and reservoir 33. As seen in FIG. 4, vacuum tube 56 extends into opening 22 such that vacuum force from vacuum source 57 (FIG. 1) is applied to the interior of barrier 78, but the vacuum force and subsequent relief pressure from vacuum tube 56 are completely isolated from interior chamber 80 of barrier housing 76. The vacuum force and relief pressure are also isolated from reservoir 33. This structure prevents milk from reservoir 33 or hollow chamber 80 from migrating to vacuum tube 56 or vacuum source 57. In the illustrated embodiment, the exterior surface of flexible barrier 78 is shaped so that the exterior surface lies adjacent the interior surface of barrier housing 76 when flexible barrier 78 is in its inflated or expanded position, as seen in FIG. 4. In one embodiment of flexible barrier 78, a plurality of strengthening ribs 92 extend around the inner surface of barrier 78, as seen in FIG. 4. Other variations in flexible barrier wall thicknesses and shapes may be utilized in other embodiments of the invention, to accommodate various performance attributes that may be desired for suction sources 57 produced by different manufacturers.

[0037] Vacuum tube 56 is manually removed from opening 22 of rim 20 of adaptor 12, where air is sucked from chamber 81 of flexible barrier 80 by applying a slight upward axial force to tube 56. Reservoir housing 32 is removed from adaptor 12 by applying manual pressure to tab 24 of the adaptor, and applying an opposite manual force to reservoir housing 32 to release bead 36 from groove 38. The valve assembly 42 is then removed from adaptor 12 by applying manual force that overcomes the friction fit that holds valve assembly 42 to drip tube 26. Mount 68 of one-way valve 70 is axially removed from rim structure 65, removing valve 70 for cleaning.

[0038] Upon removal of valve assembly 42 from the distal end 30 of drip tube 26, barrier housing 76 and flexible barrier 78 are also disengaged from rimmed flange 84, allowing barrier 78 to be manually axially removed from hollow chamber 80. This allows the chamber 80 of rigid barrier housing 76 and the flexible barrier 78 to be separately cleaned. After cleaning of all of the separated elements, including valve 70, the flexible barrier is reinserted in the chamber 80 of rigid barrier housing 76, following which valve assembly 42 with valve 70 attached to mount 68 is reinserted over drip tube 26. Reservoir housing 32 is then reattached to adaptor 12 by snapping bead 36 into groove 38 of adaptor rim 20. Vacuum hose 56 is reinserted into opening 22, and the assembled breast milk collection device is ready for additional use.

[0039] In operation, the breast milk collection device 10 is assembled as shown in FIGS. 2 and 4. Valve assembly 42 is attached over the distal end 30 of drip tube 26, and then hollow vacuum tube 56 is inserted into flared upper end 54 of opening 22 of rim 20 of adaptor 12, where tube 56 communicates with chamber 81 of the flexible barrier 78. Vacuum tube 56 is manually manipulated into the adaptor's funnel's opening 22 until the tube 56 wedges itself into the opening. Next, reservoir housing 32 is inserted into rim 20 of plate 16 until bead 36 is fully seated in groove 38. Tab 24 is used to grip adaptor 12 when attaching reservoir housing 32 to adaptor 12, and also to remove the reservoir housing from the adaptor.

[0040] The end of vacuum tube 56 shown in FIGS. 1 and 4 is now wedged into a frictional fit into the flared upper end 54 of opening 22, which holds tube 56 in tight engagement with rim 20 of adaptor 12. The tube 56 extends downward such that the hollow interior of tube 56 communicates with the interior chamber 81 of flexible barrier 78.

[0041] One or a pair of milk collection devices 10 are then inserted onto the breast and into one or each of the cups of the nursing or standard brassiere of the lactating woman to be held in place there. One or both breasts will firmly fit into a respective funnel-shaped central portion 14 of each adaptor 12. The contact between the breast and the adaptor 12 creates a seal, whereby the vacuum force applied to the outer end of the breast does not escape between the breast and the adaptor.

[0042] The outer end of hollow vacuum tube 56 is attached to cyclical operating vacuum pump 57 (FIG. 1) as is known in the art. The pump furnishes alternating vacuum force and relief to ambient pressure to the interior of tube 56.

[0043] The cyclical vacuum force is communicated from vacuum tube 56 directly to the interior chamber 81 of flexible barrier 78, which causes barrier 78 to collapse, as seen in FIG. 6, and a vacuum is created on the opposite side of barrier 78. As a result of the decrease of volume of barrier 78 due to deflation, a vacuum is drawn in hollow chamber 80 of barrier housing 76, which vacuum force is transmitted to the breast through aperture 58 and through drip tube 26. The nipple of the breast extends into the drip tube 26, and milk is expressed from the breast. The cycle of applying and relieving the vacuum force on the breast causes milk to be expressed from the breast and into the drip tube. Due to the hermetic seal between flexible barrier 78, barrier housing 76 and inner face 86 of adaptor 12, no milk can migrate to vacuum tube 56, or to source of vacuum pressure 57 (FIG. 1).

[0044] Upon the relief of maximum negative vacuum force in the interior chamber 81 of flexible barrier 78 during the cyclic operation of vacuum source 57, the inherent forces acting on flexible barrier 78 cause the barrier to expand to its natural shape, as seen in FIG. 4, simultaneously increasing the pressure in hollow chamber 80 of barrier housing 76.

[0045] At this time, milk expressed during the previous cycle and any remnants from previous cycles migrate through the fluid passageway formed by interior chamber 62 of valve assembly 42 and valve 70 to reservoir 33 where the milk is stored, and little or no milk remains in drip tube 26 or in interior chamber 62 of valve assembly 42.

[0046] As the above milk-expression cycles repeat, the fluid level in internal volume 40 of reservoir 33 rises eventually to a level above the location of one-way valve 70. The then submerged valve 70 continues to function normally as the level of milk in reservoir 33 rises and submerses the valve. As the milk in reservoir 33 continues to rise, the outer submerged walls of valve 70 are collapsed together by the vacuum force during the negative cycle and are also being compressed by the liquid pressure of the milk in the reservoir 33 when the vacuum pump is turned off, thus closing the valve and preventing the backflow of milk into drip tube 26 and adaptor 12, even during the absence of vacuum force in hollow vacuum hose 56. This allows the maximum internal volume 40 of reservoir 33 to be utilized, thus collecting the maximum amount of expressed milk.

[0047] As the milk in reservoir 33 rises beyond the level of drip tube 26, the milk is prevented from migrating into chamber 80 of rigid barrier housing 76, and the hermetic seal between rims 88, 90 and rimmed flange 84 (FIGS. 4, 6) prevents any milk from entering vacuum tube 56. As a result, there is no impediment to the cyclical expansion and contraction of flexible barrier 78 as negative vacuum force and alternate relief pressure is cyclically applied and relieved. The milk can rise to the upper level of the reservoir without interfering with the operation or efficiency of flexible barrier 78.

[0048] In the disclosed embodiment of FIGS. 1-8, milk is withdrawn from reservoir 33 by removing the breast milk collection device 10 from the mother's existing or nursing brassiere, and then inverted. The milk in the reservoir 33 pours out of spout 23 and is transferred into a suitable container (not shown). The hollow vacuum tube 56 can remain attached to adaptor 12 in aperture 22 while pouring the milk from spout 23, or the tube 56 can be removed. The reservoir housing 32 remains attached to adaptor 12 as milk is poured from spout 23.

[0049] During the pouring operation, ambient air enters reservoir 33 through valve 70. This ambient air replaces the volume of milk poured from the reservoir 33, such that the milk pours out of spout 23 in a smooth, even and uninterrupted flow stream.

[0050] An alternate embodiment of the present disclosure is illustrated in FIG. 9, which shows a rigid hydrophobic, fixed shape filter 94 replacing the flexible barrier assembly of FIGS. 1-8 in barrier housing 76. The filter 94 is made of polytetrafluorethylene (PTFE) material or any other suitable hydrophobic filter material as is known in the art, which is non-permeable to liquids, but allows air to pass through the filter without the liquid plugging up the filter. The filter 94 is hermetically sealed at its edges between rimmed flange 84 of adaptor 12 and outer rim 88 of barrier housing 76, as previously described in association with FIG. 4.

[0051] During cyclical operation of vacuum source 57 (FIG. 1) negative vacuum force or relieved air or positive pressure, can pass through filter 94, applying cyclic pumping pressure to hollow chamber 80 of barrier housing 76 and ultimately to the breast to express milk as previously described. As milk enters hollow chamber 80 of the barrier housing, the liquid milk cannot pass through filter 94, while the flow of air through the filter is not impeded. Thus, milk cannot flow into vacuum tube 56 or to pump 57 providing the source of vacuum force and relief pressure.

[0052] The foregoing description of illustrated embodiment of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The description was selected to best explain the principles of the invention and practical application of these principles to enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention not be limited by the specification, but be defined by the claims set forth below.