Patent Description:
Breast pumps are used by breast feeding women to extract milk from their breast such that the extracted milk can be fed to their babies at a later time.

It is well known that best nutrition for babies is breast milk. The world health organization (WHO) recommends to breast feed babies for at least one year, preferably longer. However, mothers often go back to work after only several weeks or months. To provide the best nutrition to their babies, mothers may then express milk using a breast pump. The expressed milk can be stored and given to the baby at a later stage and/or by somebody else.

To use a breast pump, the breast is typically placed into a funnel-shaped cup and a vacuum is applied such that milk is extracted. A motorized breast pump typically has two operating modes, namely a stimulation mode and an extraction mode. During the stimulation mode, the milk ejection reflex is stimulated. When the breast pump is activated, a pressure source such as a vacuum pump inside the breast pump generates a vacuum and the stimulation mode can be started. The vacuum pump is typically driven by an electric motor. For portable breast pumps, these motors are driven by battery power.

Wearable breast pumps are characterized in that they can be fully worn on the user's body, allowing the user to move around freely. Some of these are small enough to fit into a user's bra. A motor, battery and milk container are for example integrated to form a single unit.

In order to avoid contamination of the pump with milk residue, many breast pumps employ a moveable membrane, known as a diaphragm, between the pump and the expression kit, the membrane forming a barrier against any milk being sucked into the pump. In some breast pumps, the membrane acts furthermore as a massaging element on the nipple, areola and/or breast of the user. The membrane touches parts of the user's breast during the use of the breast pump. There is movement away from the breast when vacuum is applied and towards the breast when vacuum is released. This stimulates the milk release of the user.

An opening in the chamber between the breast and the membrane guides the milk to a collection container. To prevent milk from flowing back into the chamber, it is known to position a valve between the chamber and the container. The valve furthermore separates the pressure changes in the chamber from the volume of the container.

Current breast pumps are often uncomfortable to use, and they do not faithfully replicate breast feeding. They are also made of many parts which have to be dismantled for cleaning.

<CIT> discloses a breast pump having a "hygiene module" which is connectable to the housing of the breast pump. <CIT> discloses a breast pump with a removable diaphragm mounted on the breast shield and front and rear parts which can be separated, wherein the front part includes the milk container.

There remains a need for a breast pump system that provides a natural feeling and comfortable action when in use and which has a simple design.

According to examples in accordance with the invention, there is provided a milk collection assembly, comprising:.

The milk collection assembly may be a passive unit or an active unit in which case the front assembly includes a breast pump actuator. This forms a breast pump, and the breast pump actuator for example comprises a power source, pump and controller.

In the case of a passive unit, breast stimulation may be implemented on the other breast, by a system having a passive and an active unit.

This breast pump or milk collection assembly design is easy to assemble and disassemble for the user, by forming a rear assembly from a breast shield (and optionally a diaphragm). These are the parts (other than the container) which may come into contact with milk and therefore require regular and thorough cleaning. By forming them as an assembly, and providing the remaining parts (pump, outer housing etc.) as a front assembly, the assembly and disassembly of the parts that need cleaning after each use, and parts that do not, is made simple.

The breast shield has a frame which acts as a support for the remaining parts of the breast pump or milk collection assembly. The rear assembly has a release element which extends to an external surface of the breast pump or milk collection assembly so that the breast pump or milk collection assembly can be disassembled generally from the front by actuating the release element. The passage of the release element along the channel provides automatic alignment of the two assemblies and provides a clear and easy to use mechanism to disassemble the breast pump or milk collection assembly for cleaning.

The rear assembly for example further comprises a diaphragm formed of a flexible membrane and comprising a cavity having an open end for receiving a nipple of a user and a closed end, wherein the diaphragm fits to the breast shield.

The open end of the diaphragm for example has top and bottom parts which connect to the breast shield, wherein the top part is set further back from the closed end in a direction parallel to a central outward axis of the diaphragm than the bottom part.

The diaphragm is in this way angled back towards the user at the top. By terminating the top of the diaphragm further back (i.e. closer to the user) than the bottom, the breast is stimulated by contact with the diaphragm further back than at the bottom. This enables the upper jaw movement of a baby during sucking to be simulated and it also enables more stimulation surface to be present.

A milk flow passage is for example defined at the bottom part of the open end, for example between the bottom part of the open end and the breast shield.

By having the milk flow passage defined at the back of the bottom of the diaphragm set further forward, the milk flow path to the outlet is shorter and the risk of leakage is reduced. The design also enables the diaphragm to be assembled with the breast shield in different ways than would otherwise be possible, and thus allows more design freedom. Typically, the diaphragm needs to be pushed along a horizontal axis towards the opening in the breast shield to create an airtight seal. The angled approach enables the diaphragm to be fixed to the breast shield also by a movement that is not horizontal, for example at or near a vertical angle, still creating mounting forces that allow for an airtight seal.

The milk flow passage allows milk to flow out at the bottom of the system. The milk flow passage may for example extend below the level of the opening in the breast shield over which the diaphragm and cover are mounted, so that the outward facing part of the breast shield can act as a wall to prevent back flow.

The front assembly for example comprises:.

The release actuator is for example at a front of the front assembly.

The milk container is for example for releasable coupling to the frame (e.g. beneath the rear assembly).

The release element for example projects fully through the channel in the front assembly, thereby to define a release actuator exposed at the front of the front cover.

The breast shield and frame may be formed as a single integral item. This reduces the number of components.

The rear assembly and the front assembly may each comprise a top hinge arrangement such that they may be coupled at the top in an open configuration and rotated relative to each other into a closed configuration. This provides a simple assembly as a click and twist function and a simple disassembly as an open and release function.

The rear assembly and the front assembly may be coupled by a snap fit and the release actuator is for releasing the snap fit coupling. The release element may be a part that is deformed to release the snap fit, or a button or knob.

The open end of the diaphragm for example fits over an opening in the breast shield. This may be a simple push fit. The coupling may be automatically made more secure when the front and rear assemblies are connected because the cover then engages over the diaphragm.

The frame for example defines a rim for engaging with an opening of the milk container, with a rim opening formed internally of the rim. The milk container can thus be docked reliably to the rim, and this may for example be located along the path of the release element. Thus, the breast shield acts as the support for the milk container as well as for the front assembly.

The rear assembly may further comprise a seal for sealing between the rim and the opening of the milk container.

The diaphragm may further comprise a valve closure element for forming part of a valve, the valve closure element for passing through the rim opening during fitting of the diaphragm to the breast shield.

The rim opening thus facilitates positioning of the valve closure element, in that it can be passed through the rim opening to position where it engages with a valve seat.

The valve closure element is for controlling a flow path to the milk container through a first part of the rim opening (leading to a first part of the container opening) and the diaphragm further comprises a lid for sealing a second part of the rim opening (leading to a second part of the container opening). Thus, once the valve closure element is in place, the rim opening is closed by the lid so that the only fluid path to the container is via the valve (and hence via the first part of the rim opening and the second part of the container opening).

The lid may comprise a gripping element for fixing the lid to the second part of the rim opening. This fixes the lid and hence the nearby valve closure element in position and thereby both closes the container opening as well as ensuring a correct bias of the valve closure element.

The frame for example comprises a valve seat for supporting the valve closure element of the diaphragm to form the valve, with the valve closure element at the container side of the valve seat (i.e. the valve seat is located above the valve closure element).

The invention also provides a rear assembly of a breast pump or milk collection assembly, comprising:.

The invention provides a milk collection assembly or a breast pump, which comprises a rear assembly for fitting over the breast of a user, a front assembly for fitting over the rear assembly and a milk container for fitting beneath the rear and front assemblies. The rear assembly comprises all parts (other than the container) which will contact milk in use, such as a breast shield and a diaphragm, and the front assembly comprises all parts which do not need cleaning, such as a cover for fitting over the diaphragm to define a sealed space between them, a power source, pump and controller, and a front cover. A release element which projects along a channel in the front assembly, thereby to define a release actuator at an external face of the front assembly for releasing the coupling together of the rear and front assemblies.

<FIG> shows a known breast pump system <NUM>, comprising an expression unit <NUM> and a drive arrangement for controlling the expression function of the breast pump.

In the example shown, the drive arrangement comprises a pump arrangement <NUM> which is connected via a tube <NUM> to the expression unit <NUM>. The pump arrangement includes various components in addition to a pump impeller and the pump motor, so may be considered to be a general operating unit.

The expression unit <NUM> is formed with a main body <NUM>, a funnel <NUM> (known as a breast shield) for receiving a breast of a user and a receptacle <NUM> for collecting the expressed milk. The funnel <NUM> and the receptacle <NUM> are connected to the main body <NUM>. The main body <NUM> comprises a vacuum chamber. A flexible membrane known as the diaphragm is located in the vacuum chamber. The diaphragm prevents expressed milk from flowing into the tube <NUM> leading to the pump arrangement unit <NUM>.

The operating unit, including the pump arrangement <NUM>, may instead be directly mounted and connected to the main body <NUM>. In this case, the membrane prevents expressed milk from flowing directly into the pump arrangement <NUM>.

The pump arrangement <NUM> comprises a controller <NUM>, a power source <NUM>, a motor <NUM> and a vacuum pump <NUM> (i.e. the impeller driven by the motor <NUM>). The controller controls <NUM> the operation of the power source <NUM>, motor <NUM> and vacuum pump <NUM>. The pump arrangement <NUM> further comprises a solenoid valve <NUM>.

In use, the vacuum pump <NUM> applies a vacuum to the membrane located in the main body <NUM> so that it deforms. The membrane deforms to create a vacuum in the funnel <NUM> which in turns applies a vacuum to the breast which enables milk to be expressed.

The vacuum is applied to the breast at intervals. That is, a pressure differential is applied on a cyclic basis. After a vacuum has been established, the pressure from the vacuum is released by the use of the solenoid valve which is temporarily opened. The solenoid valve is an electromechanically operated valve configured to open and close an air passage that connects to the vacuum side of the vacuum pump to ambient air such that when the solenoid valve is closed, the vacuum pump generates a vacuum in the expression unit which enables milk to be expressed from the breast of a user. When the solenoid valve is opened, the vacuum generated by the vacuum pump is released as ambient air flows towards the vacuum or negative pressure created by the vacuum pump such that the pressure exerted on the breast of a user is partially or completely reduced.

This is a basic description of the known operation of a standard breast pump system.

There are also wearable breast pumps, which are for example for mounting within a feeding bra. All of the drivetrain components described above are then formed within an outer enclosure which fits over the breast. A top part contains the drivetrain (pump, motor, controller) and a bottom part forms the collection vessel. This enables breast pumping to be performed more discretely.

There are also other types of wearable breast pump whereby the expression unit is fixed to a breast and the pump unit and/or milk container are situated elsewhere on the body of a user.

<FIG> shows a wearable breast pump, comprising an expression kit <NUM> attached to a respective milk collection vessel <NUM>.

This invention in some aspects relates to the design of the flexible membrane, and particularly for a wearable breast pump design such as shown in <FIG>. In other aspects, the invention relates to the assembly and disassembly of different parts of a wearable system.

<FIG> shows the parts of one example of a design in accordance with the invention. The parts shown relate to the milk flow. <FIG> thus shows some internal parts of a breast pump, but does not show an outer housing or the vacuum source or associated control circuitry (i.e. controller, battery, valves etc.).

<FIG> shows a breast shield <NUM>, a diaphragm <NUM> formed as a flexible membrane and a vacuum cover <NUM> over the diaphragm <NUM> to define a sealed space between them. A milk collection container <NUM> is also shown. The cover <NUM> has a port <NUM> for coupling pressure from the vacuum source (not shown) to the sealed space between the diaphragm <NUM> and the cover <NUM>.

The diaphragm <NUM> defines a cavity having an open end <NUM> for receiving (at least) a nipple of a user and a closed end <NUM>. A connecting portion <NUM> in this example extends around the open end <NUM>. It is for fitting over an opening of the breast shield <NUM> defined by a connection collar <NUM>. A part of the connecting portion facing the user is for connecting the diaphragm to the collar <NUM> of the breast shield <NUM> and a part of the connecting portion <NUM> facing away from the user is for connecting the diaphragm to the cover <NUM>. There is thus a connection portion <NUM> for connecting the diaphragm to the breast shield and/or the vacuum cover <NUM>.

The breast shield includes an integral frame to which the other parts of the breast pump may be connected. The frame includes a release element <NUM> which projects forwards (i.e. away from the user) from the main body of the breast shield. As explained further below, the breast shield <NUM> and the diaphragm form a rear assembly for fitting over the breast of a user. A front assembly fits over the rear assembly and includes the cover <NUM>, the electrical parts of the breast pump, namely the power source (battery), pump and controller, as well as a front cover. The front assembly thus fits to, and forms a connection with, the frame, and the frame also supports the milk container. Thus, the front assembly can be removed leaving the milk container attached to the frame.

The release element <NUM> extends partly or fully through a channel in the front assembly, thereby to define a release actuator <NUM> at the front of the breast pump. In other designs, the release actuator may be at a side.

The breast shield <NUM> and release element <NUM> are formed as a single integral item.

Along the frame of the breast shield there is a rim <NUM> for engaging with an opening <NUM> of the milk container <NUM> formed by a top neck part <NUM>. A rim opening <NUM> is formed internally of the rim <NUM>. The milk container <NUM> can thus be docked reliably to the rim <NUM> as this a rigid part of the breast shield. Thus, the breast shield, and in particular the release element <NUM>, acts as the support for the milk container as well as providing the support for the front assembly. A seal may be provided for sealing between the underside of the rim <NUM> and the opening <NUM> of the milk container.

The rim opening <NUM> has a front part (seen in <FIG>) and a rear part. The rear part of the rim opening has a top channel <NUM> which leads to a valve seat <NUM>. The top channel <NUM> is the milk flow passage from the cavity formed by the diaphragm to the milk container <NUM>.

The opening defined by the collar <NUM> of the breast shield is smaller than the opening of the open end <NUM> of the cavity of the diaphragm (at least at a lower area) such that milk is always caught against the outside of the opening to the breast shield and led to the container <NUM>.

When a vacuum is applied to the sealed space between the diaphragm <NUM> and the cover <NUM> (i.e. the opposite side of the diaphragm to the cavity), the diaphragm expands compared to a rest-state when vacuum is not applied. The membrane of the diaphragm <NUM> touches at least one part of the breast, typically the nipple but possibly the areola and/or the breast. In the rest state, the diaphragm is non-rotationally symmetric.

Milk is expressed into the cavity in use, and is ejected towards the closed end <NUM> (the back) of the cavity from where it then flows to the open end and into the collection container <NUM>.

The breast shield <NUM> is made of a different material to the flexible membrane of the diaphragm <NUM>, e.g. polypropylene for the breast shield and silicone for the flexible membrane of the diaphragm. This is for ease of cleaning, for ease of use and for manufacturing reasons.

The diaphragm has a valve closure element <NUM>, formed as in integral part of the flexible membrane, for forming part of a valve. The valve closure element may be a valve closure element of any type of valve. The valve closure element <NUM> is for example a flap of a flap valve. This flap valve is in the flow path from the cavity to the milk container <NUM> via the top channel <NUM>.

The flap <NUM> extends from a bottom edge of the open end <NUM> of the cavity. The valve seat <NUM> formed by the breast shield defines the seating location for the flap valve. By integrating the movable part of a valve, in this example the flap of a flap valve, into the flexible membrane of the diaphragm, there are few parts and those few parts can be made simple to manufacture, and easy to assemble and disassemble for cleaning.

The valve may instead be formed entirely by the diaphragm.

The diaphragm also defines a lid <NUM>. The lid <NUM> is for sealing the front (second) part of the rim opening <NUM>. The purpose of the rim opening is to make the diaphragm easy to position and couple to the breast shield, while reliably placing the valve closure element in its required position. In particular, the flap <NUM> is fed through the front part of the opening <NUM> into a position where it rests (upwardly) against the valve seat <NUM>. Thus, the flap passes through the rim opening <NUM> during fitting of the diaphragm to the breast shield and the lid <NUM> closes the rim opening <NUM> after fitting of the diaphragm to the breast shield. As shown more clearly below, the valve seat faces downwardly and the valve flap is biased upwardly against the valve seat.

Once in position, the lid <NUM> closes the front part of the opening <NUM> so that the only entrance to the container is via the top channel <NUM> and the valve. The milk collection container has a single opening <NUM> but it may be considered to define first and second parts; a first part beneath the valve seat <NUM> and a second part beneath the second part of the rim opening <NUM>. Thus, the valve closure element provides a flow path to a milk container through a first part of the milk container opening and the lid closes a second part of the milk container opening.

The lid <NUM> for example comprises a gripping element for fixing the lid to the second part of the rim opening. This is for example a tab or rib or rim which is pushed through the opening <NUM> and engages the underside of the rim <NUM>.

The container <NUM> clips to the underside of the rim <NUM>, for example with a snap fit or with a push and rotate (bayonet) coupling.

The diaphragm thus implements the normal diaphragm function (creating a sealed volume to which the vacuum pressure can be applied), a flap valve function and a function of closing the container opening (by closing the rim opening provided to simplify the connection of the diaphragm to the breast shield). In this way, the risk of spillage from the container into the rest of the system is reduced, for example as may happen when the user is mobile. The integration of these functions by the single flexible membrane means the assembly can be easily disassembled, cleaned and re-assembled while fitting inside a small, wearable form factor, at a low cost level.

The diaphragm with its integrated valve is asymmetrical (i.e. not rotationally symmetric about a horizontal axis), so that the breast pump can be assembled only in one specific way or in a set of specific ways (if there is some rotational symmetry, e.g. rotational symmetry of order <NUM> for a triangular design). This has the advantage that the flexible membrane shape can be formed to touch and stimulate the nipple of the user in a predetermined way.

Furthermore, in the design shown, there are only three elements of the breast pump that come into contact with the breast milk, and need to be cleaned in a regular and thorough way, namely the breast shield <NUM>, the membrane <NUM> with integrated valve <NUM> and lid <NUM> and the milk container <NUM>.

These form the same rear assembly and the container, and may thus be removed from the remainder of the breast pump as a unit. The front assembly may be removed leaving the rear assembly and the connected container, because the container is supported by the breast shield.

<FIG> shows one example of a design of the diaphragm <NUM>. The left image shows a perspective view and the right image shows a view looking into the open end <NUM> of the cavity.

The diaphragm comprises a radially inwardly projecting ridge <NUM>. It extends from a base <NUM> of the cavity towards the center of the cavity. The ridge is preferably convex shaped so that no milk pooling can take place on the ridge. In general, the shape of the diaphragm is such that milk, in normal use, always flows towards the container.

The cavity formed by the flexible membrane thus has an internal ridge <NUM> extending up from a base of the cavity. The cavity is no longer rotationally symmetric such as a typical conical cavity. The ridge is a tongue-simulation ridge for simulating the tongue of a baby, and in use it presses against a lower side of the nipple, simulating the sucking action of a baby. This improves user comfort of the breast pump in that it more accurately replicates breast feeding. The ridge projects to a position which represents the position of the surface of the tongue of a baby. It may also be designed to move during application of a controlled pressure to simulate the movement of the tongue during feeding.

A first side flow path <NUM> is formed to a first side of the ridge <NUM> and a second side flow path <NUM> is formed to an opposite second side of the ridge <NUM>. These flow paths facilitate the flow of milk from the closed (back) end of the diaphragm (to which the milk flow is directed) to the open (front) end <NUM> and then to the container. The fixed rotational orientation of the diaphragm, with the ridge projecting upwardly from the bottom, means the flow paths <NUM>, <NUM> can be designed to be more effective, based on their known orientation.

The flow paths slope downwardly from the closed end of the cavity to the open end of the cavity.

The diaphragm has a default orientation in which a central axis (pointing outwardly from the user) is horizontal. In this default orientation, the top of the ridge <NUM> is horizontal and hence parallel with a central outward axis of the cavity. The flow paths for example slope downwardly in the range <NUM> to <NUM> degrees relative to the horizontal, i.e. relative to the ridge direction. This means that there is a range of body feeding angles of the mother which still enable the expressed milk to flow freely to the milk collection container <NUM>.

The flow paths at the left and right of the ridge also allow for the user to angle to the left or right without leakage. Their depth at the open end of the cavity, relative to the position of the opening of the breast shield, allows the user to lean backward again without leakage. The slope of the incline mentioned above between the closed end of the cavity and the open end allows the user to lean forward without pooling of milk.

The cavity has a compact design around the nipple. The milk flow channels formed by the flow paths may for example be positioned further away from the central axis without significantly increasing the volume of the cavity, by keeping the width of the chamber around the nipple to smaller dimensions.

The ridge <NUM> extends most of the depth of the cavity, for example at least <NUM>%, preferably at least <NUM>% of the depth of the cavity (i.e. the distance between the open end and the closed end). It for example extends from the near the open end to the closed end. It may start immediately at the open end, but with a curved transition towards the top of the ridge.

The ridge <NUM> for example occupies an angle β around the cavity opening <NUM> in the range <NUM> to <NUM> degrees. The ridge for example extends from the outer edge of the open end towards the center of the open end by at least <NUM>%, for example at least <NUM>%, for example by at least <NUM>% of the (vertical) radius of the open end.

<FIG> shows second ridge <NUM> which extends from the first side of cavity towards the center of the cavity above the first flow path <NUM>. There is also third ridge <NUM> which extends from a second side of the cavity towards the center of the cavity above the second flow path <NUM>. The second and third ridges also extend from near the open end to the closed end. They may result in a rotationally symmetric design (with rotational symmetry of order <NUM>) so that there are three equivalent fixed orientations with which the diaphragm may be fixed.

The second and third ridges may be designed to move when the flexible membrane deforms so that they may simulate movement the lips of the baby by providing additional contact points to the nipple in addition to the contact of the first ridge which simulates the tongue.

However, the second and third ridges may instead not move significantly when the membrane deforms, and they may instead be provided for copying the shape of a baby's lips and / or jaws rather than simulating their movements.

The use of three ridges further reduces the volume of the cavity formed between the diaphragm and the breast.

By additionally limiting the volume of the sealed space between the diaphragm and the cover, a minimum of air is needed in the system on the pump side, thus reducing dead space and increasing the efficiency of the pump system.

The design with three ridges defines a triangular arrangement of ridges. However, there may be only a single bottom ridge, or an upper ridge and a lower ridge, or more than three ridges.

As can be seen in <FIG>, the shape of the open end of the cavity, i.e. the shape formed by the path around the connecting portion <NUM>, is also non-rotationally symmetric (as well as the internal volume of the cavity being non-rotationally symmetric). For example, it has a flatter base than top, to better match the typical shape of a baby's mouth. The shape of the open end, and indeed the diaphragm as a whole, may be left-right symmetric.

The flexibility of the flexible membrane of the diaphragm enables the contact areas to move so as to accommodate different nipple sizes.

<FIG> additionally shows an optional positioning tab <NUM> extending from a top edge of the open end, i.e. extending upwardly from the connection portion <NUM>. The positioning tab is used to simplify the connection of the diaphragm to the breast shield <NUM>, discussed further below.

<FIG> shows a slightly different design of the diaphragm, in which the ridge <NUM> has a flat top <NUM> to simulate the tongue shape.

<FIG> shows a cross section of the assembled breast pump applied to the breast. The nipple <NUM> is received by the cavity <NUM> formed by the flexible membrane <NUM> of the diaphragm <NUM>.

The ridge <NUM> is shown as having a horizontal top edge (which may be flat or rounded in front view as shown in <FIG>).

<FIG> also shows how the lid <NUM> engages under the rim <NUM> to hold the diaphragm in place and also to set the position of the flap <NUM>. The outer cover <NUM> of the front assembly is also shown.

<FIG> shows a design feature more clearly, as an enlarged image of part of <FIG>. The design feature relates to the orientation of the components and is to simplify assembly and disassembly and also to improve breast stimulation during milk expression. <FIG> shows that the breast shield <NUM> has an opening <NUM> over which the cover <NUM> and diaphragm <NUM> are coupled.

The open end <NUM> of the cavity <NUM> has a top part 121a which connects to the breast shield <NUM> and a bottom part 121b, with a milk flow passage <NUM> defined at the bottom part, in particular as a gap or channel opening between the bottom part 121b and the breast shield <NUM>. The top part 121a is set further back from the closed end in a direction parallel to a central outward axis of the diaphragm than the bottom part. In other words it is set back further along a horizontal direction, i.e. closer to the user. The top part 121a is for example set back horizontally (i.e. parallel to the ridge <NUM>) by at least <NUM> further than the bottom part 121b.

The diaphragm may be considered to be angled back at the top, for example by an angle α as shown in <FIG>. This angle is for example in the range <NUM> to <NUM> degrees. The connecting portion <NUM> formed at the open end of the cavity for example connects to the breast shield in a plane <NUM> which is thus (in a normal operating orientation of the expression assembly), is at an angle α of between <NUM> and <NUM> degrees to the vertical.

There is a gap <NUM> between the bottom of the opening <NUM> and the bottom of the open end <NUM> and this defines a milk flow passage. This gap leads to the top channel <NUM>.

The opening <NUM> of the breast shield is smaller than the open end <NUM>, in particular at the bottom so that the opening <NUM> overlaps the open end. A lip <NUM> which forms the bottom of the opening <NUM> thereby blocks milk and ensures all flow reaches the container via the top channel <NUM>. This lip <NUM> extends partly over the top channel <NUM> (leading to the valve), to act as a barrier to prevent splash back from the container to the breast pump.

The lip <NUM> also means that the first and second side flow paths (on opposite sides of the tongue-simulation ridge) are directed against the lip. Thus, the ends of the first and side flow paths at the open end of the cavity are positioned outside the area of the opening <NUM> in the breast shield (i.e. below the opening <NUM>) so that milk is directed to the outlet.

There is preferably a seal all around the interface between the breast shield <NUM> and diaphragm <NUM> except at the bottom where the milk flow passage <NUM> is formed. Instead of a top channel <NUM> defined within in the collar, the milk flow passage may be formed as a notch set back into the opening <NUM> of the breast shield.

By terminating the top of the diaphragm further back (i.e. closer to the user) than the bottom, the breast is stimulated by contact with the diaphragm further back at the top than at the bottom. This enables the upper jaw movement of a baby during sucking to be simulated and it also enables more stimulation surface to be present. By having the milk flow passage defined at the back of the bottom of the diaphragm, and set further forward, the milk flow path to the outlet is shorter and the risk of leakage is reduced.

The angled interface allows for the diaphragm to be assembled with the breast shield in different ways than would otherwise be possible, and thus allows more design freedom.

To assemble the parts, if the optional positioning tab <NUM> is provided, it is coupled to a receiving area of the breast shield <NUM>. This may be achieved with a significant amount of freedom of movement, and does not need to be a perfectly horizontal fitting. The diaphragm is then pivoted down into position using this positioning tab as a pivot.

The flap of the valve <NUM> is inserted through the rim opening defined by the rim <NUM> and brought into engagement with the underside of the valve seat <NUM>. The lid <NUM> is then fixed to the opening by pushing a retaining tab or tabs 59a through the opening. This then seals the rim opening, leaving the top channel <NUM> as the only fluid path between the cavity and the container.

The cover <NUM> is then positioned, in particular as a part of an overall front assembly. The cover <NUM> secures the diaphragm into its end position. The element <NUM> is another part of the front assembly and it holds the cover <NUM> in place. The front assembly which includes the cover <NUM> also has an external front housing of the breast pump.

It can be seen that the assembly involves coupling of positioning tab <NUM> as a simple coupling, followed by a pivot motion to attach the diaphragm to the breast shield, and finally connection of the cover <NUM>, diaphragm <NUM> and breast shield <NUM> using a front assembly. The tab <NUM> is optional, and the diaphragm may simply be slid over the connection collar <NUM> of the breast shield and then fixed in place using the lid <NUM>.

The examples above show a uniform wall thickness of the flexible membrane which forms the diaphragm.

As shown in <FIG>, the flexible membrane of the diaphragm may have a varying thickness.

For example, the part of the membrane which defines the cavity <NUM> may have a smaller thickness near the open end than near the closed end. This may be used to effect peristaltic actions when vacuum is applied. In particular, the cavity may move in an axial direction due the greater elasticity at the open end, compared to lower elasticity of the remainder of the cavity wall.

To control the deformation characteristics, the flexible membrane may be locally strengthened by ribs or protrusions. In addition, <FIG> shows locally thinner regions <NUM>,<NUM> to define hinge points. By having locally thinner regions, the resulting hinge points can also influence the distortion of the flexible membrane to create a desired peristaltic pumping action such as is created by a baby's mouth.

The flexible membrane for example has a hinge point <NUM> at the back of the ridge <NUM>, near the closed end. This hinge point helps to create an up and down motion of the tongue as well as the in and out movement formed by the thinner region <NUM> at the open end of the cavity.

The use of strengthening ribs also may be used to enable the movement of the flexible membrane to be restricted to avoid the creation of an undesirably large amount of under pressure on the breast side.

As mentioned above, by limiting the volume of the sealed space between the diaphragm and the cover, a minimum of air is needed in the system on the pump side, thus reducing dead space and increasing the efficiency of the pump system.

<FIG> shows that the cover <NUM> may have internal ribs <NUM>. Two different rib designs are shown. These may be used both to reduce the dead volume of the pump but also to influence the deformation characteristics of the flexible membrane of the diaphragm. For the same purpose, the diaphragm may have external ribs.

It is mentioned above that the breast pump comprises three modules.

<FIG> shows the three modules in exploded view.

A first module is a rear assembly <NUM> is for fitting over the breast of a user. It comprises the breast shield <NUM> (and integrated release element <NUM>) and the diaphragm <NUM>. A second module is a front assembly <NUM> for fitting over the rear assembly. It comprises the cover <NUM> for fitting over the diaphragm <NUM> to define a sealed space between them, a power source, pump and controller (and valves etc.) and a front cover <NUM>.

The release element <NUM> projects forwards through a channel <NUM> in the front assembly to define a release actuator at a front of the front assembly. It could be exposed at the front surface or it could lie just beneath the surface, for example as a push button beneath a flexible cover.

The third module is the milk container <NUM>, which fits beneath the rear and front assemblies.

This breast pump design is easy to assemble and disassemble for the user, by forming a rear assembly from a breast shield and a diaphragm. These are the parts (other than the container) which may come into contact with milk and therefore require regular and thorough cleaning. By forming them as an assembly, and providing the remaining parts (pump, outer housing etc.) as a front assembly, the assembly and disassembly is made simple.

The breast shield acts as support for the remaining parts of the breast pump. The breast pump can be disassembled from the front side by actuating the release actuator <NUM>.

<FIG> shows the three modular parts coupled together.

<FIG> shows the rim <NUM> by which the breast shield engages with the top opening of the milk container <NUM>. The rim opening <NUM> has a first part which is closed by the lid <NUM> and which leads to a first area of the opening to the milk container, and a second part which at which (or through which) the valve seat is provided and is closed by the flap <NUM>.

<FIG> shows two possible disassembly routines.

In step A, the breast pump is assembled. The release actuator <NUM> is operated to unlatch the front and rear assemblies.

In step B, the front assembly is pivoted up. The front and rear assemblies have a releasable hinge connection at the top for this purpose.

Once opened up, the hinge connection can be released as shown in step C so that the front assembly is removed. The milk container remains attached to the breast shield of the rear assembly.

In step D1, the diaphragm <NUM> is removed and then in step E1 the milk container is removed.

Alternatively, in step D2, the milk container is removed and then in step E2 the diaphragm is removed.

In step A the container <NUM> is fitted and the diaphragm <NUM> is fitted to the breast shield <NUM> (in either order) to create the complete rear assembly with container attached.

In step B the front assembly is engaged with the rear assembly at the top hinge.

In step C the front assembly is pivoted closed over the rear assembly.

In step D the front assembly clicks into engagement with the rear assembly.

The rear assembly and the front assembly may for example engage by a snap fit and the release actuator <NUM> releases the snap fit coupling.

The snap fit coupling may be provided on the release element <NUM> or on the rear assembly. Similarly, the milk collection container could be locked into place using snap fit elements or a twist and lock coupling to the rim <NUM>.

The breast facing side of the breast shield may have a soft a cushion to improve comfort.

The coupling of the front assembly may instead use hooks to first provide an anchor to the breast shield, followed by a rotary motion lock the assemblies into place. Alternatively, the coupling may use linear sliding motion to first position elements in a guiding track, and then lock them into place.

The release element <NUM> may be hidden within the outer contour of the assembled breast pump system, or it can be fully or partially exposed on the outside, opposite the breast of the user when in use. As the flexible release button is integrated as part of the breast shield, the front assembly can easily be manufactured in a well-sealed and self-contained manner, for example protecting the electrics and electronics from liquids. Two-shot molding or similar techniques may be used to add materials with different characteristics, for example for release element, for sealing to the milk container or for providing a soft interface to the user.

<FIG> shows the breast shield more clearly in cross section. A lip <NUM> extends down from the rim <NUM> to engage with the top of the container opening. This lip surrounds the rim opening <NUM>.

The diaphragm is designed to deform in a predictable way in response to the applied under-pressure. It may for example be designed to implement a breast stimulation function.

The diaphragm of the invention may have a single fixed rotational orientation as explained above, meaning the flow paths can be designed to be more effective, based on their known orientation. There may however be a set of possible rotational orientations, for example there may be three possible orientations for a triangular design.

Various design features have been described above, in particular:.

These features are all independent design options with separate advantages and they may therefore be used in any combination.

In the examples above, the breast shield (in particular the frame) forms the valve seat. In other examples, the valve seat could be formed by the cover.

In the examples above, the tongue-simulation ridge extends from the open end of the cavity towards the closed end. It may also project forwards out of the cavity, i.e. towards the breast of the user.

In the examples above, the release actuator is at a front external surface of the front assembly. It may instead be at a side.

In the examples above, the diaphragm is connected to the breast shield and then held in place by the cover. In other designs, it may instead be fitted to the cover and then the cover and diaphragm may fit to the breast shield as a unit.

In the examples above, the milk container is directly attached to the remainder of the breast pump to form a wearable unit. Some of the design features may be applied to designs where the milk container is mounted somewhere else on the body, connected by a milk tube.

The breast pump described above has pump (typically of a motor and an impeller) a controller and a power source. Together these define a breast pump actuator and these are part of a wearable unit. However, some of the design features may be applied to designs where the breast pump actuator is located elsewhere on the body, connected by a pressure tube. The breast pump actuator may operate based on stimulation rather than mechanical pumping.

Claim 1:
A milk collection assembly, comprising:
a rear assembly (<NUM>) for fitting over the breast of a user;
a front assembly (<NUM>) for fitting to the rear assembly; and
a milk container (<NUM>),
wherein the rear assembly (<NUM>) comprises:
a breast shield (<NUM>);
a diaphragm formed of a flexible membrane (<NUM>) and comprising a cavity (<NUM>) having an open end (<NUM>) for receiving a nipple of the user and a closed end (<NUM>), wherein the diaphragm fits over an opening in the breast shield (<NUM>); and
a frame;
wherein the front assembly (<NUM>) comprises a cover (<NUM>) for fitting over the diaphragm (<NUM>) to define a sealed space between them, and the front assembly is for releasable coupling to the frame,
wherein the frame comprises a release element (<NUM>) which projects along a channel (<NUM>) in the front assembly, thereby to define a release actuator at external surface of the front assembly for releasing the coupling together of the rear and front assemblies.