Breast pump and pumping chamber module of such breast pump

Abstract

The present invention relates to a breast pump (2) comprising breast shield means (4) having a portion (10) for receiving a female breast for the expression of breast milk, a breast pump housing (12) comprising driving means (16), a flexible membrane (26), a membrane cover (28) covering the membrane (26), wherein the membrane (26) has a pumping side (34) defining between the membrane cover (28) and the membrane (26) a pumping chamber (36) and wherein the membrane (26) has a drive side (32) opposite to the pumping side (34), which drive side (32) is drivingly coupled to said driving means (16) for cyclically driving said membrane (26) between an expanded position, in which the membrane (26) projects towards the membrane cover (28), and a retracted position, in which the membrane is retracted from the membrane cover (28), the breast pump housing (12) furthermore comprises an interface (44) in communication with said pumping chamber for transferring pressure changes within the pumping chamber (36) to said breast shield means (4). To allow operation with a liquid or gaseous medium for driving the membrane (26), an expansion-assisting means (40) is provided, which expansion-assisting means (40) is adopted to assist the membrane (26) in assuming the expanded position.

Description

[0001] MAG 09 / 24 1

[0002] Breast pump and pumping chamber module of such breast pump

[0003] The present invention relates to a breast pump comprising breast shield means having a portion for receiving a female breast for the expression of breast milk. Such breast shield means may comprise a milk reservoir coupled to the portion such that expressed milk can be advanced from the portion towards the milk reservoir and will be temporarily stored within the breast shield means.

[0004] The breast pump furthermore has a breast pump housing, which breast pump housing comprises driving means, a flexible membrane and a membrane cover covering the membrane. The membrane has a pumping side defining between the membrane cover and the membrane a pumping chamber. The membrane furthermore has a drive side, which drive side is provided opposite to the pumping side of the membrane. The drive side is drivingly coupled to the above- mentioned driving means for cyclically driving the membrane between an expanded position and a retracted position. In the expanded position, the membrane projects towards the membrane cover. In the retracted position, the membrane is retracted from the membrane cover. The membrane is usually operated to be driven between two positions, which may be provided by the expanded position and / or the retracted position or which may be at different positions.

[0005] For fluid communication between the breast shield means and the pumping chamber and for transferring pressure changes within the pumping chamber to the breast shield means, the breast pump housing furthermore has an interface in fluid communication with the pumping chamber. On a general basis, a tube will be connected to the interface and the breast shield means to provide a cyclic pressure profile at the portion of the breast shield means receiving the female breast to thereby express breast milk.

[0006] A breast pump as described above is e.g. known from WO 01 / 47577 A2. This prior art pump has a rigid shell, which is placed over a membrane having a reinforced central portion, which reinforced central portion comprises a nut-like element for securing the membrane against a driving rod, which driving rod is moving in a reciprocating fashion to drive the membrane. The membrane is covered by a protective cover forming an outlet port, which defines the interface for connecting the tube leading to the breast shield means. Consequently, the membrane is driven like a piston with a mechanical coupling to the driving rod to thereby press the membrane towards an inner surface of the protective cover or retract the membrane away from this surface to expand the volume of the pumping chamber.

[0007] In general, such a rigid concept for driving the membrane is disadvantageous, as it will not allow the membrane to adapt to different pressure situations on the pumping side, which could e.g. result in a painful suction pressure at the breast shield means. Drive means within the breast shield housing may need to provide a more flexible way of adjusting the varying pressure at the MAG 09 / 24 2 breast shield means in term e.g. of cycle length and / or pressure difference, which may require another concept than the concept of a membrane functioning as a piston and being mechanically coupled to a reciprocating driving rod.

[0008] The present invention aims to provide an improved breast pump. Specifically, the present invention wishes to provide a breast pump, which can reliably provide a cyclic suction pressure at the breast shield means generated within the pump housing in particular by a working medium such as a liquid or gaseous working medium used to drive the membrane on the drive side thereof.

[0009] In absence of a mechanical coupling between the drive means and the membrane, the membrane may assume a fully retracted position but may not develop an expanded position in case the working medium provides a negative suction pressure on the drive side only, such working medium may not be able to fully expand the membrane. Release of the negative pressure on the drive side may not bring the membrane in the expanded position due to the restoring elastic forces thereof. Thus, the desired suction profile at the breast shield means, which is based on the assumption that the membrane flexes between a given expanded position and a given retracted position, may not satisfy the requirements.

[0010] To cope with this problem, the present invention proposes expansion-assisting means assigned to the membrane and adapted to assist the membrane to assume the expanded position.

[0011] The expansion-assisting means are usually passive means, which do not require an actuator or an electric or electronic control. In fact, the expansion-assisting means are usually provided by an elastic member adapted to cooperate with the membrane, specifically to come in contact with the membrane as the membrane is retracted, thereby pre-tensioning the elastic member. Thus, restoring elastic forces of the elastic member will eventually assist the membrane to assume the expanded position. This means that the expansion assisting means may, upon relief of a suction pressure on the drive side, push the membrane back towards the expanded position and thus towards the membrane cover.

[0012] The membrane itself may provide some elastic restoring forces, which restoring forces are suitable to expand the membrane and may even be suitable to fully expand the membrane to reach the expanded position. However, those restoring forces may not be suitable to reliably expand the membrane. Thus, the expansion-assisting means will force the membrane towards the membrane cover, thereby assisting at best securing the expanded position of the membrane.

[0013] Usually, the membrane is contacted by the elastic member mentioned above as an example for the expansion-assisting means. Such an elastic member preferably is arranged on the drive side of the membrane. MAG 09 / 24 3

[0014] According to a preferred embodiment of the present invention, the membrane cover is re- leasably connectable to the breast pump housing. The membrane cover may directly be connectable with and thus against the breast pump housing. Alternatively, the membrane cover may be connected with the breast pump housing via another component of the breast pump.

[0015] Such component may e.g. be provided by a module base element. Such module base element according to a preferred embodiment of the present invention is part of a pumping chamber module, which pumping chamber module is releasably connectable to the breast pump housing and has a drive interface for drivingly coupling the drive side of the pumping chamber module with the driving means within the breast pump housing. The pumping chamber module furthermore has a cap element forming the membrane cover. The membrane is inter-disposed between the module base element and the cap element. The cap element is usually formed of a thin plastic material and has the predominant functionality to cover the pumping chamber and thus the membrane. The cap element and the module base element may be releasably coupled e.g. by means of a cuff as described in WO 01 / 47577 A2, which cuff may be part of the membrane. However, contrary to the membrane known from this prior art, the membrane of the present invention is usually thinner and thus more flexible.

[0016] The pumping chamber module has the advantage, that it can be replaced in case a component of the pumping chamber module is worn or needs repair. For releasably connecting the pumping chamber module with the breast pump housing, the module can be snap-connected or connected via a bayonet joint or a biasing element forcing the module against the breast pump housing. The module base element may be received within a module base element seat provided by the breast pump housing. In such a case, the module base element rests on and is connected to the breast pump housing.

[0017] In an alternate constitution, the pumping chamber module may be connected e.g. via a snap connection to the breast pump housing via a rigid tube projecting from the module base element and positively received in a recess of the breast pump housing. This tube is also provided for drivingly coupling the drive side of the pumping chamber module with the driving means within the breast pump housing. On a general basis, the pumping chamber module comprises inter alia the expansion-assisting means. Those expansion-assisting means are preferably formed by a plastic spring element connected to the module base element. Preferably, the plastic spring element comprises a ring-shaped segment, which is usually in contact with the module base element and from which circumferentially spaced spring arms project towards the membrane cover. In circumferential direction of the ring-shaped segment, the spring arms are usually spaced apart from each other. Each spring arm may extend in circumferential direction with an angle of between 30° and 80° relative to the center of the ring-shaped segment. In a cross-sectional view, the spring arms have usually a thinner free end in comparison with a base of the spring element, which base MAG 09 / 24 4 is connected to the ring-shaped segment. Moreover, an end section of each spring arm may assume a more pronounced inclination towards the middle of the ring-shaped segment. Usually, the spring arm is inclined towards the membrane cover over its entire length. Preferably, all spring arms are inclined towards each other.

[0018] According to a preferred embodiment of the present invention, the plastic spring element is connected to the module base element via co-injection molding.

[0019] The pumping chamber module or components thereof are in particular designed as disposable or cleaning parts. In particular, the breast pump will be dis-assembled for replacing at least one component.

[0020] The present invention also provides a pumping chamber module discussed above, which may be a spare part of the claimed breast pump and may releasable coupled with the breast pump housing.

[0021] Further aspects and details of the present invention will become apparent from the following description of an embodiment in connection with the figures. In the figures figure 1 is a perspective view of an embodiment of a breast pump; figure 2 is a perspective cross-sectional view of a first embodiment of a pumping chamber module; figure 3 is cross-sectional perspective view of a second embodiment of a pumping chamber module; figure 4 is a cross-sectional view of a module base element with a spring element of a third embodiment of a pumping chamber module and figure 5 is a cross-sectional view of the third embodiment of the pumping chamber module connected to a breast pump housing.

[0022] Figure 1 shows an embodiment of a breast pump 2 with breast shield means 4 comprising a milk container 6 and a breast shield 8 which breast shield 8 is the portion 10 of the breast shield means 4 adapted to receive the female breast for the expression of breast milk.

[0023] Reference numeral 12 identifies a breast pump housing, which is in fluid communication with the breast shield means 4 via a tube 14 and in use will contain air. The breast pump housing houses a driving means 16 in form of a vacuum pump 18, which vacuum pump 18 is only schematically sketched in figure 1.

[0024] Via a flow channel, which is identified in figure 5 with reference number 20, the vacuum pump 18 can be brought in fluid communication with a pumping chamber module 22 with the breast pump housing 12. The pumping chamber module 20 - also shown in figures 2 and 3 - has a module base element 24 and a flexible membrane 26 projected and protected by a membrane cover 28 in form of a thin walled cap element 30. The membrane 26 is sealingly sandwiched between an upper rim of the module base element 24 and a lower end of the cap element 30. MAG 09 / 24 5

[0025] The membrane 26 has a drive side directed towards the pumping chamber base element 24 and identified with reference numeral 32 and a pumping side 34, which is opposite to the drive side 32 and shown in figures 2, 3 and 5 to abut against an inner surface of the cap element 30.

[0026] Between the pumping side 34 of the membrane 26 and the cap element 30 there is provided a pumping chamber 36. In figures 2, 3 and 5, this pumping chamber 36 does not have an actual volume as the membrane 26 abuts the inner surface of the cap element 30 and thereby can be assumed to be in the fully expanded position.

[0027] Between the drive side of the membrane 32 and the module base element 24 there is provided a driving chamber 38.

[0028] As evident from figures 2, 3 and 5, this driving chamber 38 also contains an expansion assisting means 40 in form of an elastic member 42. In each of the embodiments according to figures 2, 3 and 5, the respective elastic member 42 is shown to project from the module base element 24 towards the membrane cover 28. In fact, the expansion-assisting means are shown in figures 2 and 5 to contact the drive side 32 of the membrane 26 to thereby hold the membrane 26 in the fully expanded position.

[0029] In figures 1 , 2 and 3, reference number 44 identifies an interface in form of a tube connector like a Luer-lock or another suitable connection, in particular a plug connection, which interface 44 connects with the pumping chamber 36 to transfer pressure changes in the pumping chamber 36 to the breast shield means 3.

[0030] In figure 2, the elastic member 42 is cup-shaped and has plural openings 46 recessed in the circumferential surface of the elastic member 42. The cup-shaped elastic member 42 is arranged concentrically to a central bore 48 recessed in a bottom 50 of the module base element 24, which bore 48 is adapted to drivingly connect the driving chamber 38 to the driving means 6.

[0031] Figure 3 shows an alternate embodiment, in which the elastic member 42 is formed as a bellows. Contrary to figure 2, this elastic member 42 of figure 3 being uncompressed is not in contact with the membrane 26 in the maximum expanded position of the membrane 26 shown in both of figures 2 and 3, respectively.

[0032] Figure 4 shows an alternate embodiment in which the elastic member 42 is formed of a plastic spring element 50, which is connected to the module base element 24 by co-injection molding. The plastic spring element 50 is made of a soft elastomeric material having a hardness Shore-A of between 45 and 55, in particular 60.

[0033] The plastic spring element 50 has spring arms 52 projecting towards the cap element 30 and thus away from the module base element 24. Each of the spring arms 52 is spaced from a neighboring spring arm 52 in circumferential direction of the ring-shaped segment 54. The spring arms 52 are each inclined slightly inwardly. The free end of each spring arm 52 is roof-shaped. As evident from figure 5, the form of the spring arms 52 is selected such that the elastic spring MAG 09 / 24 6 arms 52 when being uncompressed are aligned to and in or almost in contact with the inner surface of the cap element 30.

[0034] The spring arms 52 have the ability to elastically flex toward the module base element 24 and towards each other. Due to their restoring forces, the spring arms tend to assume the position shown in in figure 5 thereby assisting the membrane 26 to assume the position shown in this figure. The retracted position of the membrane 26, in which the membrane 26 is advanced towards the module base element 24 is obtained via the driving force of the driving means 16 within the breast pump housing 12. As evident from figure 5 and figures 2, 3, the module base element 24 provides a drive interface 56, which drive interface 56 in part is formed by the bore 48 in figures 2 and 3, respectively. Via this drive interface 56, the driving chamber 38 is drivingly connected to the driving means 16.

[0035] Due to this and in case the driving means 16 / vacuum pump 18 is operated to provide a negative pressure, such negative pressure via the drive interface 56 is transmitted to the driving chamber 38. As a consequence, the pressure drops in the driving chamber 38 and the membrane 26 is collapsed and advanced towards a retracted position. Accordingly, the spring arms 52 are elastically flexed and bent toward the module base element 24. If the negative pressure within the driving chamber 38 is increased, the spring arms 52 will due to their restoring forces bend away from the module base element 24 thereby advancing the membrane 26 towards the cap element 30.

[0036] Evidently, the present invention proposes a breast pump 2 which can be operated with a vacuum instead of a mechanical connection between the driving means and the membrane as previously known from WO 01 / 475778A2. While the vacuum may be able to collapse and thereby advance the membrane 26 into the retracted position, the present invention proposes expansionassisting means 40 which at least assist the membrane 26 to advance into the fully expanded position. In addition to the resilient restoring forces of those expansion-assisting means 40, the membrane 26 itself can have restoring forces to redevelop the expanded position.

[0037] In the embodiment of figure 4, the elastic member 42 is made of a plastic material, which is injection molded around the module base element 24. Thus, both components 24, 42 are formed as a unitary body. As evident from figure 4, the soft elastomeric material forming the elastic member 42 likewise provides a sealing ring 58 exposed on a contact surface 60, which sealing ring 58 and contact surface 60 abut against the breast pump housing 12. The soft elastomeric material forming the elastic member 42 likewise provides a radial sealing ring 58 exposed on the outer circumference for sealing against a holding member, which is not shown here but may be provided by a clamping plate 66 shown figure 5.

[0038] In this embodiment, it is assumed that a plug section 62 projecting the contact surface 60 and being formed by the pumping chamber module 22 will not only project into the channel 20 to MAG 09 / 24 7 provide fluid communication, but also will mechanically couple and hold the pumping chamber module 22 in place on a housing surface of the breast pump housing 12, which housing surface is identified in figure 5 with reference number 64.

[0039] In this third embodiment of figure 5, the module base element 24 and the elastic member 42 are provided as separate elements, which are laid against each other in a sealed a fashion and are held by a clamping plate 66. The clamping plate 66 provides a stepped lower surface following the contour provided by a base section of the module base element 24 and the elastic member 42. Moreover, the stepped configuration is to provide adequate positioning relative to a base plate 68 of the pumping chamber module 22. The base plate 66 provides the contact surface 60, which cooperates with the housing surface 64 and is projected by plural fastening screws 70, which project through a bore 72 provided in the clamping plate 66 and the base plate 68 to join the different components of the pumping chamber module 22.

[0040] The clamping plate 66 furthermore provides a rim 74, having an annular bead 76 for sealing clamping a lower end of the membrane 26, which lower end is sandwiched between this rim 74 and a collar 78 of the cap element 30. Due to this design, the membrane 26 is sealed and fastened towards the inner circumferential surface. The lower end of the membrane 26 provides a well 80 with an outer bed 82 cooperating with the outer circumferential surface of the collar 78 to sealingly clamp and thereby releasable hold the cap element 30. Details of the embodiment in this respect are described in WO 01 / 47577 A2 of the present applicant. The disclosure thereof in this respect is incorporated herein by reference.

[0041] MAG 09 / 24 8

[0042] List of references signs

[0043] 2 Breast pump

[0044] 4 breast shield means

[0045] 6 milk container

[0046] 8 breast shield

[0047] 10 portion

[0048] 12 breast pump housing

[0049] 14 tube

[0050] 16 driving means

[0051] 18 vacuum pump

[0052] 20 channel

[0053] 22 pumping chamber module

[0054] 24 module base element

[0055] 26 membrane

[0056] 28 membrane cover

[0057] 30 cap element

[0058] 32 drive side

[0059] 34 pumping side

[0060] 36 pumping chamber

[0061] 38 driving chamber

[0062] 40 expansion-assisting means

[0063] 42 elastic member

[0064] 44 interface

[0065] 46 opening

[0066] 48 bore

[0067] 50 plastic spring element

[0068] 52 spring arms

[0069] 54 ring-shaped segment

[0070] 56 drive interface

[0071] 58 sealing ring

[0072] 60 contact surface

[0073] 62 plug section

[0074] 64 housing surface

[0075] 66 clamping plate

[0076] 68 base plate

[0077] 70 fastening screws

[0078] 72 bore

[0079] 74 rim

[0080] 76 annular bead

[0081] 78 collar

[0082] 80 well

[0083] 82 outer bed

Claims

MAG 09 / 24 9Claims1. Breast pump (2) comprising breast shield means (4) having a portion (10) for receiving a female breast for the expression of breast milk, a breast pump housing (12) comprising driving means (16), a flexible membrane (26), a membrane cover (28) covering the membrane (26), wherein the membrane (26) has a pumping side (34) defining between the membrane cover (28) and the membrane (26) a pumping chamber (36) and wherein the membrane (26) has a drive side (32) opposite to the pumping side (34), which drive side (32) is drivingly coupled to said driving means (16) for cyclically driving said membrane (26) between an expanded position, in which the membrane (26) projects towards the membrane cover (28), and a retracted position, in which the membrane is retracted from the membrane cover, the breast pump housing (12) furthermore comprises an interface (44) in communication with said pumping chamber (36) for transferring pressure changes within the pumping chamber (36) to said breast shield means (4) characterized by expansion-assisting means (40) adopted to assist the membrane (26) to assume the expanded position.

2. Breast pump according to claim 1 , wherein the expansion-assisting means (40) is an elastic member (42) adapted to cooperate with the membrane (26).

3. Breast pump according to claim 2, wherein the elastic member (42) is arranged on the drive side (32) of the membrane (26).

4. Breast pump according to any of the preceding claims, wherein the membrane cover (28) is releasable connectable with the breast pump housing (12).

5. Breast pump according to any of the preceding claims, wherein said driving means (16) comprises working fluid compression means adapted to cyclically introduce a working medium into a driving chamber (38) covered by the drive side of the membrane (26).

6. Breast pump according to any of the preceding claims, comprising a pumping chamber module (22) comprising a module base element (24), a cap element (30) forming the mem-MAG 09 / 24 10 brane cover (28) and the membrane (26) inter-disposed between the module base element (24), the cap element (30) and the expansion-assisting means (40), wherein the pumping chamber module (22) is releasable connectable to the breast pump housing (12) and has a drive interface (56) for drivingly coupling the drive side (32) of said membrane (26) with the driving means (16).

7. Breast pump according to claim 6, wherein the pumping chamber module (22) comprises a plastic spring element (50) connected to the module base element (24).

8. Breast pump according to claim 7, wherein the plastic spring element (50) comprises a ring-shaped segment (54) and circumferentially spaced spring arms (52) projecting form the ring-shaped segment (54) towards the membrane cover (26).

9. Breast pump according to claim 7 or 8, wherein the plastic spring element 50 is connected to the module base element 24 via co-injection molding.

10. Breast pump according to any of the claim 7 to 9, wherein the spring arms (52) are inclined towards each other.

11. Pumping chamber module (22) for a breast pump (2) according to any of the preceding claims, wherein the pumping chamber module (22) comprises a module base element (24), a cap element (30) forming a membrane cover (28) and a membrane (26) inter-dis- posed between the module base element (24) and the cap element (30), wherein a pumping chamber (36) is provided between the cap element (30) and the membrane (26) and wherein the pumping chamber module (22) is releasable connectable to the breast pump housing (12) and has a drive interface (56) for drivingly coupling the drive side (32) of said pumping chamber module (22) with a driving means (16) of said breast pump (2).

12. Pumping chamber module to claim 11 , wherein the pumping chamber module (22) comprises a plastic spring element (50) connected to the module base element (24).

13. Pumping chamber module according to claim 12, wherein the plastic spring element (50) comprises a ring-shaped segment (54) and circumferentially spaced spring arms (52) projecting from the ring-shaped segment (54) towards the membrane cover (28).

14. Pumping chamber module according to claim 12 or 13, wherein the plastic spring element (50) is connected to the pumping chamber (36) via co-injection molding.MAG 09 / 24 1115. Pumping chamber module according to any of the claim 12 to 14, wherein the spring arms (52) are inclined towards each other.

16. A method for operating a breast pump (2), the breast pump comprising breast shield means (4) having a portion (10) for receiving a female breast for the expression of breast milk, a breast pump housing (12) comprising driving means (16), a flexible membrane (26), a membrane cover (28) covering the membrane (26), wherein the membrane (26) has a pumping side (34) defining between the membrane cover (28) and the membrane (26) a pumping chamber (36) and wherein the membrane (26) has a drive side (32) opposite to the pumping side (34), which drive side (32) is drivingly coupled to said driving means (16) for cyclically driving said membrane (26) between an expanded position, in which the membrane (26) projects towards the membrane cover (28), and a retracted position, in which the membrane is retracted from the membrane cover, the breast pump housing (12) furthermore comprises an interface (44) in communication with said pumping chamber (36) for transferring pressure changes within the pumping chamber (36) to said breast shield means (4) characterized by expansion-assisting the membrane (26) to assume the expanded position.

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