Milk squeezing device

Abstract

The utility model relates to a milk squeezing device. The device includes a teat enclosure wall for engaging with a teat-including region of a breast to define a chamber between the teat enclosure wall and the teat-including region of the breast in which a negative pressure may be provided. The apparatus includes an infrasound source for generating infrasound. The infrasound source includes a movable member, movement of which generates infrasound. The movable member has a first side facing and in fluid communication with the chamber and a second side opposite the first side. A fluid connection is disposed between the chamber and the second side. The fluid connection may provide pressure equalization between the chamber and the second side of the movable member such that both the first side and the second side of the movable member are subjected to negative pressure. The fluid connection is configured to control fluid communication between the chamber and the second side of the movable member during movement of the movable member, and thus the fluid connection assists in controlling a varying pressure experienced by the breast due to movement of the movable member.

Description

Technical Field

[0001] The utility model relates to a milk squeezing device. Background Art

[0002] The best source of nutrition for infants is human milk given by breastfeeding mothers. The World Health Organization recommends breastfeeding for at least one year, preferably longer. However, mothers often return to work after only a few weeks or months. In order to provide the best nutrition for their infants, mothers use breast pumps to express milk. The expressed milk can be stored and given to the infant at a later stage and / or by someone else.

[0003] Typically, a breast pump has two operating modes, a stimulation mode and an extraction mode. During the stimulation mode, the let-down reflex is stimulated by a relatively high frequency of suction (approximately 2 Hz). Once the milk comes out of the breast, it is recommended to switch to the extraction mode, in which a lower frequency (usually about 1 Hz) and a higher intensity of suction are used to extract the milk more effectively.

[0004] Recently, there has been a trend towards wearable breast pumps. These devices typically have a smaller form factor and are able to fit inside a user's bra.

[0005] Additionally, there are passive milk collectors that can be placed on the breast and often allow the user to apply static negative pressure to hold the device in place and help extract milk. These collectors are intended to be used when breastfeeding to collect milk from a breast that is not breastfed. The stimulation provided by the baby creates a milk ejection reflex on both breasts, and a simple passive vacuum is often sufficient to extract (some) milk.

[0006] WO 2022 / 132565 is about a breast pump that allows for an increased volume flow of milk and / or increased suction efficiency. Various devices and techniques are used to introduce a more diverse set of vibration patterns that enable the user to customize the performance of the vibration and / or enable the presence or absence of vibration in a way that is currently not possible in the state of the art. This would involve applying vibrations to the breast during a breast pump cycle (or "waveform") to increase the volume flow of expressed milk for a given cycle speed and suction level.

[0007] WO 2022 / 132565 relates to a funnel for a breast pump, the funnel comprising: a funnel body configured to receive a breast therein; and an elastic element arranged in the funnel body to contact a nipple of the breast and configured to impart movement to the nipple, in particular peristaltic movement by alternately deforming the elastic element and releasing the elastic element, wherein the elastic element is connected to the funnel body with its first end at or near the neck of the funnel body. Utility Model Content

[0008] The utility model is defined by the claims.

[0009] According to an example according to aspects of the present invention, a device for expressing milk from a mammalian breast is provided, the device comprising: a nipple enclosure wall for engaging with a nipple-including region of the breast to define a chamber between the nipple enclosure wall and the nipple-including region of the breast, in which negative pressure can be provided; an infrasound source for generating infrasound, the infrasound source comprising a movable member, movement of the movable member generating infrasound, the movable member having a first side facing the chamber and in fluid communication therewith and a second side opposite to the first side, the second side being outside the chamber; and a fluid connector between the chamber and the second side, the fluid connector being configured to control fluid communication between the chamber and the second side during movement of the movable member.

[0010] The fluid connection may provide pressure equalization between the chamber and the second side of the movable member such that both the first and second sides of the movable member are subject to negative pressure, eg, reduced pressure caused by operation of a negative pressure generator connectable to the chamber.

[0011] This may reduce negative pressure related disturbances to the movement of the movable member.

[0012] Nonetheless, the fluid connection is configured to control fluid communication between the chamber and the second side of the movable member during movement (eg, reciprocating movement) of the movable member to control, in conjunction with the infrasound source, the changing pressure experienced by the breast.

[0013] Thus, an infrasound source (eg, an electroacoustic transducer) changes the pressure in the chamber to provide mechanical stimulation to the breast.

[0014] In some embodiments, the fluid connection comprises or is in the form of a channel that fluidly connects the chamber to the second side of the moveable member.

[0015] In such embodiments, control of the fluid communication between the chamber and the second side of the movable member may be determined at least in part by the size of the channel.

[0016] In other words, the dimensions of the channel may be selected such that movement (eg, reciprocating movement) of the movable member causes varying pressures to be experienced by the breast.

[0017] For example, the channel may be sized so that the frequency of pressure variations (eg, 0.5 to 20 Hz) is blocked by the channel, such that the breast is subjected to the pressure variations and frequencies < 0.5 Hz are transmitted between the chamber and the second side of the moveable member.

[0018] In some embodiments, the fluid connection is configured to operate as a fluid frequency-dependent impedance element configured to selectively restrict a fluid passage between the chamber and the second side of the movable member, which is driven by pressure changes at a frequency caused by movement of the movable member. Thus, the fluid frequency-dependent impedance element can enable the breast to experience pressure changes caused by movement of the movable member.

[0019] Such frequency dependent impedance elements may operate due to frequency dependent thermoviscous losses included in the fluid connection or in a channel defining the fluid connection.

[0020] In such embodiments, the frequency of pressure changes caused by movement of the movable member may be higher than the frequency of pressure changes caused by operation of the negative pressure generator.

[0021] In some embodiments, the device comprises an additional chamber, wherein the second side of the movable member faces the second chamber and is in fluid communication therewith.

[0022] In such embodiments, the channel and the further chamber may fluidly connect the chamber to the second side of the movable member, wherein the fluid connection is configured to operate with the volume of the further chamber as an acoustic filter that selectively blocks frequencies of pressure changes caused by movement of the movable member from passing from the chamber to the further chamber. Thus, the acoustic filter may enable the breast to experience pressure changes caused by movement of the movable member.

[0023] In such embodiments, the frequency of pressure changes caused by movement of the movable member may be higher than the frequency of pressure changes caused by operation of the negative pressure generator.

[0024] Thus, the acoustic filter can be a low pass filter that allows lower frequency pressure changes provided by the negative pressure generator to pass between the chamber and another chamber, but prevents higher frequencies of pressure changes caused by movement of the movable member from passing from the chamber to another chamber.

[0025] The length L and area A of the channel can be determined by using the well known Helmholtz resonance frequency f defined by f = c / 2(2*pi)*sqrt(A / (V*L)), where c is the speed of sound and V is the volume of the further chamber.

[0026] The Helmholtz resonator helps prevent pressure waves in opposite phase on each side of the movable member of the infrasound source from merging and canceling each other in the chamber, and further helps minimize the effect of reduced pressure (e.g., static vacuum) on the neutral position of the movable member (e.g., transducer diaphragm / membrane).

[0027] The air inside the channel may act as a mass, and the air inside the volume of the additional chamber may act as a spring, forming a mass-spring system. Above the resonant frequency of the mass-spring system, the air may not be able to pass through the channel due to its inertia, while at lower frequencies, the inertia may be relatively low, and the air may pass through the channel.

[0028] Thus, the fluid connection may act as a low pass filter.

[0029] The optimal choice of the Helmholtz frequency may coincide with the lowest frequency of pressure changes to which the breast is subjected that are caused by the movement of the movable member.

[0030] Strictly speaking, the above situation applies to an ideal system with no damping.

[0031] In practice, taking into account the volume V and the length L, the channel may be relatively narrow, for example having a diameter of approximately one tenth of a millimeter.

[0032] Such narrow channels can have high thermoviscous losses (proportional to the diameter ^4), resulting in significantly lower resonant frequencies (e.g., up to about 50 times), and can therefore act as more effective low-pass filters.

[0033] As a non-limiting illustrative example / ideal case, the volume V of the further chamber is 35 mL, the length L of the channel is 5 mm and the diameter d is 0.4 mm, giving a Helmholtz resonance frequency of about 20 Hz. When viscous losses are taken into account, the resonance frequency drops to about 0.5 Hz, which is a realistic resonance frequency in this context.

[0034] More typically, the diameter d of the channel may be from 0.05 to 0.9 mm, and / or the length of the channel may be from 1 to 10 mm.

[0035] Alternatively or additionally, the frequency of the pressure variation caused by the movement of the movable member may be equal to or greater than 0.5 Hz, such as 0.5 Hz to 20 Hz.

[0036] Alternatively or additionally, the frequency of the pressure changes caused by operation of the negative pressure generator may be less than 0.5 Hz.

[0037] In some embodiments, the device comprises a three-way coupling member for connecting the negative pressure generator to the chamber and the further chamber.

[0038] Such a three-way coupling member can assist in providing pressure equalization between the chamber and the second side of the movable member, such that both the first side and the second side of the movable member are subjected to the reduced pressure caused by operation of the negative pressure generator.

[0039] In at least some embodiments, the infrasound source includes a piston attached to a movable member, wherein movement of the piston causes movement (eg, reciprocating movement) of the movable member.

[0040] It should be noted that despite the inclusion of a fluid connection, changes in negative pressure in the chamber may still cause the starting position of the piston of the infrasound source to shift.

[0041] Therefore, the starting position of the piston can be adjusted based on the negative pressure in the chamber.

[0042] In this way, the piston can be adjusted to compensate for changes in vacuum levels during milk expression.For example, where the infrasound source is an electroacoustic transducer, a direct current may be applied to remove the starting position offset caused by changes in negative pressure.

[0043] In some embodiments, the device includes a breathable covering for limiting the passage of liquid from the breast to the movable member (eg, to the first side and / or the second side of the movable member).

[0044] The breathable cover can help protect the infrasound source from being damaged by expressed milk in the chamber.

[0045] Any suitable type of breathable covering is contemplated, such as Made of breathable cover.

[0046] In some embodiments, the changing pressure experienced by the breast caused by the movement (eg, reciprocating movement) of the movable member comprises a pressure waveform.Such a pressure waveform can assist in mechanically stimulating the breast and thus promote the extraction of milk from the breast.

[0047] Any suitable shape of pressure waveform is contemplated.In some embodiments, the pressure waveform is a sawtooth waveform, a sine waveform, or a square waveform.

[0048] In some embodiments, the pressure waveform is user selectable. Thus, the user can select whichever pressure waveform is deemed most effective for them in promoting the extraction of milk from the breast.

[0049] In such embodiments, the user interface may be configured to permit a user to select a pressure waveform, such as a sawtooth waveform, a sine waveform, or a square waveform, wherein the infrasound source is controllable to provide the user-selected pressure waveform.

[0050] In some embodiments, the device comprises a valve for selectively releasing expressed milk from the chamber into the milk collection volume.

[0051] Since it may be desirable to keep the volume of the chamber as small as possible in order to facilitate mechanical stimulation of the breast via movement of the movable member of the infrasound source, the expressed milk may fill the chamber relatively quickly. The valve may accordingly beneficially permit the release of expressed milk from the chamber to a milk collection volume (e.g., a milk collection volume that is larger than the volume of the chamber).

[0052] In some embodiments, the infrasound source is arranged to pause the movement (eg reciprocating movement) of the moveable member when expressed milk is released into the milk collection volume via the valve.

[0053] For example, the infrasound source may be arranged to pause movement (e.g. reciprocating movement) of the movable member in response to the valve opening to release expressed milk to the milk collection volume, and to resume movement of the movable member in response to the valve closing to stop releasing expressed milk to the milk collection volume.

[0054] For example, a control system (eg, included in the device or provided separately from the device but in communication with the subsonic source) may control the subsonic source to pause movement of the movable member based on the control system receiving input indicating that the valve is open.

[0055] During milk expression, the volume of the chamber becomes gradually filled with milk and thus the empty volume of the chamber decreases. This may result in a higher sound pressure inside the chamber.

[0056] In some embodiments, the apparatus comprises an acoustic sensor arranged to sense acoustic pressure in the chamber.

[0057] The acoustic sensor may include or be a microphone.

[0058] By sensing (eg, monitoring) the sound pressure via the acoustic sensor, the amount of milk expressed in the chamber may be estimated.

[0059] In embodiments where the device comprises a valve and an acoustic sensor, the valve may be configured to release expressed milk to the milk collection volume based on the sensed acoustic pressure (eg based on the sensed acoustic pressure indicating that the volume of the chamber is filled to a given extent).

[0060] A controller (eg included in the device or provided separately from the device but in communication with the valve) may control the valve to release expressed milk to the milk collection volume based on the sensed sound pressure.

[0061] There is further provided a computer program comprising computer program code configured to cause one or more processors to implement a method of operating an apparatus according to the embodiments described herein when the computer program is run on the one or more processors, the one or more processors being configured to control an infrasound source of an apparatus according to any of the embodiments described herein.

[0062] In some embodiments, the one or more processors may be further configured to control a negative pressure generator arranged to provide negative pressure in the chamber.

[0063] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to better understand the present invention, and to more clearly show how the present invention may be put into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0065] Figure 1 A device for expressing milk from a mammalian breast is schematically depicted;

[0066] Figure 2 Schematically depicts another apparatus for expressing milk from a mammalian breast;

[0067] Figure 3 Still another apparatus for expressing milk from a mammalian breast is schematically depicted;

[0068] Figure 4 A perspective view is provided showing a prototype of a device for expressing milk from a mammalian breast;

[0069] Figure 5 provides graphs of simulated acoustic pressure, displacement, and power versus infrasound frequency for a device having a chamber volume of 28 mL; and

[0070] Figure 6 Graphs of simulated acoustic pressure, displacement, and power versus infrasound frequency are provided for a device with a chamber volume of 14 mL. DETAILED DESCRIPTION

[0071] The present invention will be described with reference to the accompanying drawings.

[0072] It should be understood that the detailed description and specific examples indicate exemplary embodiments of the device, system and method, but they are intended for illustration purposes only and are not intended to limit the scope of the utility model. These and other features, aspects and advantages of the device, system and method of the utility model will become better understood from the following description, the attached claims and the drawings. It should be understood that the drawings are only schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the drawings to indicate the same or similar parts.

[0073] A device for expressing milk from a mammalian breast is provided. The device includes a nipple enclosure wall for engaging with a nipple-including region of the breast to define a chamber between the nipple enclosure wall and the nipple-including region of the breast, in which a negative pressure can be provided. For example, the chamber can be connected to a negative pressure generator for reducing the pressure in the chamber. The negative pressure can help to express milk from the breast, and / or can help to maintain the engagement between the nipple enclosure wall and the nipple-including region. The device includes an infrasound source for generating infrasound. The infrasound source includes a movable member, and the movement of the movable member generates the infrasound. The movable member has a first side facing the chamber and in fluid communication with it, and a second side opposite to the first side. The second side is outside the chamber. A fluid connector is disposed between the chamber and the second side. The fluid connector can provide pressure equalization between the chamber and the second side of the movable member, so that both the first side and the second side of the movable member are subjected to negative pressure. Nonetheless, the fluid connection is configured to control fluid communication between the chamber and the second side of the movable member during movement of the movable member, and thus the fluid connection helps to control (e.g., enhance) the changing pressure experienced by the breast caused by movement of the movable member.

[0074] In other words, movement of the moveable member in combination with the fluid connection enables the breast to be subjected to varying pressures.

[0075] Figure 1 A device 100 is shown for expressing milk from a mammalian breast 102. The device 100 includes a nipple enclosure wall 104 for engagement with a nipple-inclusive region 106 of the breast 102. Thus, when the nipple enclosure wall 104 engages with the nipple-inclusive region 106 of the breast 102, a chamber 108 is defined between the nipple enclosure wall 104 and the nipple-inclusive region 106 of the breast 102.

[0076] During use of the device 100 for milk extraction, the chamber 108 receives milk from the nipple 110 .

[0077] In at least some embodiments, the nipple enclosure wall 104 includes a bra or is in the form of a bra. Such a bra can be, for example, funnel-shaped. Such a funnel-shaped bra can assist the nipple enclosure wall 104 in engaging with the nipple area 106 of the breast 102.

[0078] Negative pressure may be provided in chamber 108 .

[0079] For example, chamber 108 may be connected to a negative pressure generator (not visible) for reducing the pressure in chamber 108 .

[0080] Alternatively, such negative pressure may be provided by squeezing at least a portion of the nipple enclosure wall 104 before joining the nipple enclosure wall 104 to include the nipple area 106 , and releasing the squeezed nipple enclosure wall 104 after joining so that a static negative pressure is provided in the cavity 108 .

[0081] More generally, the negative pressure provided in the chamber 108 may assist in expressing milk from the breast 102 and / or may assist in maintaining engagement between the nipple enclosure wall 104 and the nipple region 106 .

[0082] The nipple enclosure wall 104 may be formed of any suitable material, provided that the nipple enclosure wall 104 is capable of engaging with the nipple area 106 and enabling negative pressure to be provided in the chamber 108, such as by reducing the pressure in the chamber 108 by a negative pressure generator.

[0083] In some embodiments, the nipple enclosure wall 104 is formed of an elastomeric material such as silicone rubber. Such a material can assist the nipple enclosure wall 104 in engaging the nipple area 106 in a manner that minimizes the amount of air that enters the chamber 108 when the pressure in the chamber is reduced.

[0084] In at least some embodiments, the negative pressure generator is arranged to apply a static negative pressure to chamber 108 .

[0085] In other words, the negative pressure generator may be configured to create a constant vacuum in the chamber 108 .

[0086] Such static negative pressure may assist in expressing milk from the breast 102 and / or may assist in maintaining engagement between the nipple enclosure wall 104 and the nipple area 106 .

[0087] In such embodiments, device 100 can be considered a passive milk collector.

[0088] For example, the device 100 in the form of such a passive milk collector may be employed to collect milk from one breast 102 while the other breast (not visible) is being used to breastfeed a baby or is being expressed using a breast pump (in other words, actively expressed).

[0089] Because the stimulation provided by active suction can generate a milk ejection reflex on all (eg, both) breasts, static negative pressure (eg, generated by a negative pressure generator) may be sufficient to extract at least some milk from the breast 102 engaged with the nipple enclosure wall 104 .

[0090] In some embodiments, the negative pressure generator is configured to provide a pressure (eg, a static pressure) in the chamber 108 that is at least 80 mBar below atmospheric pressure.

[0091] Such negative pressure (in other words, pressure below atmospheric pressure) may assist in extracting milk from breast 102 .

[0092] The design of the negative pressure generator is not particularly limited. In some embodiments, the negative pressure generator is a manual pump that includes a user-operable actuator that can be moved by the user to reduce the pressure in the chamber 108 when the chamber 108 is connected to the manual pump. Alternatively, the negative pressure generator is a power pump (e.g., a power pump that can be powered by one or more batteries and / or mains power) that is configured to reduce the pressure in the chamber 108 when the chamber 108 is connected to the power pump.

[0093] In some embodiments, device 100 includes a negative pressure generator.

[0094] Therefore, the negative pressure generator can be conveniently provided (eg, supplied) to the user together with the device 100 .

[0095] Alternatively, the device 100 may not be provided (eg, supplied) to the user together with the negative pressure generator. In such embodiments, for example, the device 100 may be connectable to a negative pressure generator that the user already has.

[0096] Figure 1 The device 100 shown in further comprises an infrasound source 112 for generating infrasound. The infrasound source 112 comprises a movable member 114 (eg in the form of a diaphragm) configured to move to generate infrasound.

[0097] For example, the movable member 114 may move in a reciprocating manner to generate infrasound.

[0098] The application of infrasound generated by infrasound source 112 may assist in stimulating breast 102 and, therefore, facilitate expression of milk from breast 102 .

[0099] Thus, the infrasound source 112 (eg, the electroacoustic transducer 112 ) changes the pressure in the chamber 108 in order to provide mechanical stimulation to the breast 102 .

[0100] like Figure 1 As shown in FIG. 1 , the movable member 114 includes a first side 114A facing the chamber 108 and in fluid communication therewith and a second side 114B opposite to the first side, wherein the second side 114B is outside the chamber 108 .

[0101] The first side 114A being in fluid communication with the chamber 108 can be considered to mean that the first side 114A is acoustically coupled to the chamber 108 .

[0102] In at least some embodiments, the infrasound source 112 is configured to cause the movement (eg, reciprocating movement) of the movable member 114 to be at a frequency within a range of 3 to 20 Hz.

[0103] Infrasound within this frequency range has been found to be effective in stimulating the breast 102 to facilitate expression of milk from the breast 102 .

[0104] The movable member 114 may be caused to move in any suitable manner. In some embodiments, the movable member 114 may be coupled to a piston (not visible) included in the infrasound source 112, wherein reciprocating motion of the piston causes the movable member 114 to correspondingly move in a reciprocating manner.

[0105] In some embodiments, the infrasound source 112 comprises a linear motor arranged to drive a piston.

[0106] In some embodiments, the infrasound source 112 is an electroacoustic transducer that includes a piston in the form of a coil that is axially displaceable in a magnetic field generated by a magnet (e.g., a permanent magnet). In such embodiments, the reciprocating motion of the movable member 114 (e.g., a diaphragm) is provided by the inductively driven reciprocating motion of the coil to which the movable member 114 is attached.

[0107] In some embodiments, the infrasound source 112 includes or is in the form of a speaker.

[0108] When negative pressure is provided in the chamber (e.g., provided by a negative pressure generator) and used in conjunction with the infrasound source 112, the negative pressure provided in the chamber 108 may present challenges in implementing the infrasound source 112 to facilitate expression of milk from the breast 102. This may be due to the negative pressure (e.g., static vacuum) exerting a force on the piston of the infrasound source causing it to deflect from its starting position. In particular, when the pressure in the chamber 108 is 80 mBar or more below atmospheric pressure, the force exerted on the piston may be too great to permit proper actuation of the movable member 114 (e.g., diaphragm).

[0109] For this reason, Figure 2 In the embodiment shown in , the fluid connection 116 is disposed between the chamber 108 and the second side 114B of the movable member 114 .

[0110] The fluid connection 116 can provide pressure equalization between the chamber 108 and the second side 114B of the movable member 114, so that both the first side 114A and the second side 114B of the movable member 114 are subjected to negative pressure, for example, a reduced pressure caused by the operation of the negative pressure generator. This can reduce negative pressure-related interference with the movement of the movable member 114.

[0111] In such embodiments, nonetheless, the fluid connection 116 is configured to control fluid communication between the chamber 108 and the second side 114B of the movable member 114 during movement (eg, reciprocating movement) of the movable member 114 .

[0112] Thus, the fluid connection 116 assists in controlling (eg, enhancing) the changing pressure experienced by the breast 102 resulting from the movement of the movable member 114 .

[0113] In other words, even though the fluid connection 116 causes both the first side 114A and the second side 114B of the movable member 114 to experience negative pressure, the infrasound source 112 may still change the pressure in the chamber 108 to provide mechanical stimulation to the breast 102 .

[0114] In some embodiments (such as, Figure 2 In the embodiment shown in FIG. 1 , the fluid connection 116 includes or is in the form of a channel that fluidly connects the chamber 108 to the second side 114B of the movable member 114 .

[0115] In such embodiments, control of the fluid communication between the chamber 108 and the second side 114B of the movable member 114 may be determined at least in part by the size of the passageway.

[0116] In other words, the dimensions of the passageway may be selected such that movement of the movable member 114 causes a varying pressure to be experienced by the breast 102 .

[0117] For example, the channel can be sized so that the frequency of pressure changes (e.g., 0.5 to 20 Hz) is blocked by the channel, so that the breast 102 experiences pressure changes and transmits frequencies of <0.5 Hz between the chamber 108 and the second side 114B of the movable member 114.

[0118] In some embodiments, the fluid connection 116 is configured to operate as a fluid frequency-dependent impedance element configured to selectively restrict a fluid passage between the chamber 108 and the second side 114B of the movable member 114, which is driven by pressure changes at a frequency caused by movement of the movable member 114. Thus, the fluid frequency-dependent impedance element can enable the breast 102 to experience pressure changes caused by movement of the movable member 114.

[0119] Such frequency dependent impedance elements may operate due to frequency dependent thermoviscous losses included in the fluid connection 116 or in the channels defining the fluid connection.

[0120] In such embodiments, the frequency of pressure changes caused by movement of the movable member 114 may be higher than the frequency of pressure changes caused by operation of the negative pressure generator.

[0121] In some embodiments (such as, Figure 2 In the embodiment shown in ), the device 100 includes an additional chamber 118, wherein the second side 114B of the movable member 114 faces the second chamber 118 and is in fluid communication therewith.

[0122] In such embodiments, the channel and the additional chamber 118 may fluidly connect the chamber 108 to the second side 114B of the movable member 114 .

[0123] The additional chamber 118 may be defined in any suitable manner. Figure 2 In the embodiment shown in ), the device 100 includes a subsound source housing 120 that abuts the nipple enclosure wall 104 and extends around the subsound source 112. In such embodiments, the additional chamber 118 may be defined by the subsound source housing 120 and the outer portion of the nipple enclosure wall 104.

[0124] In embodiments where the device 100 includes an additional chamber 118, the fluid connection 116 can be configured to operate together with the volume of the additional chamber 118 as an acoustic filter that selectively blocks frequencies of pressure changes caused by movement of the movable member 114 from passing from the chamber 108 to the additional chamber 118. Thus, the acoustic filter can enable the breast 102 to experience pressure changes caused by movement of the movable member 114.

[0125] In such embodiments, the frequency of pressure changes caused by movement of the movable member 114 may be higher than the frequency of pressure changes caused by operation of the negative pressure generator.

[0126] Thus, the acoustic filter can be a low-pass filter that allows lower frequency pressure changes provided by the negative pressure generator to pass between chamber 108 and the further chamber 118, but blocks higher frequencies of pressure changes caused by movement of the movable member 114 from passing from chamber 108 to the further chamber 118.

[0127] The length L and area A of the channel can be determined by using the well-known equation f = c / (2*pi)* sqrt The Helmholtz resonance frequency f is determined by (A / (V*L)), where c is the speed of sound and V is the volume of the further chamber 118.

[0128] The Helmholtz resonator helps prevent pressure waves in opposite phase on each side of the movable member 114 of the infrasound source 112 from merging and canceling each other in the chamber 108, and further helps minimize the effect of reduced pressure (e.g., static vacuum) on the neutral position of the movable member 114 (e.g., transducer diaphragm / membrane).

[0129] The air inside the channel may act as a mass, and the air inside the volume of the additional chamber 118 may act as a spring, forming a mass-spring system. Above the resonant frequency of the mass-spring system, the air may be unable to pass through the channel due to its inertia, while at lower frequencies, the inertia may be relatively low, and the air may be able to pass through the channel.

[0130] Thus, the fluid connection 116 may act as a low pass filter.

[0131] The optimal choice of the Helmholtz frequency may coincide with the lowest frequency of pressure changes to which the breast 102 is subjected that are caused by the movement of the movable member 114 .

[0132] Strictly speaking, the above situation applies to an ideal system with no damping.

[0133] In practice, taking into account the volume V and the length L, the channel may be relatively narrow, for example having a diameter of approximately one tenth of a millimeter.

[0134] Such narrow channels can have high thermoviscous losses (proportional to the diameter ^4), resulting in a significant reduction in the resonant frequency (e.g., up to about 50 times), and can therefore act as a more effective low-pass filter.

[0135] As a non-limiting illustrative example / ideal case, the volume V of the further chamber 118 is 35 mL, the length L of the channel is 5 mm and the diameter d is 0.4 mm, giving a Helmholtz resonance frequency of about 20 Hz. When viscous losses are taken into account, the resonance frequency drops to about 0.5 Hz, which is a realistic resonance frequency in this context.

[0136] More typically, the diameter d of the channel may be from 0.05 to 0.9 mm, and / or the length of the channel may be from 1 to 10 mm.

[0137] In some embodiments, the frequency of the pressure changes caused by the movement of the movable member 114 is equal to or greater than 0.5 Hz, such as 0.5 Hz to 20 Hz.

[0138] Alternatively or additionally, the frequency of the pressure changes caused by operation of the negative pressure generator may be less than 0.5 Hz.

[0139] It should be noted that despite the inclusion of the fluid connection 116 , changes in negative pressure in the chamber 108 may still cause the starting position of the piston of the infrasound source 112 to shift.

[0140] In some embodiments, the infrasound source 112 is configured to adjust the starting position of the piston based on the negative pressure in the chamber 108 .

[0141] In this way, the piston may be adjusted to compensate for changes in vacuum levels during milk expression.For example, where the infrasound source 112 is an electroacoustic transducer 112, a direct current may be applied to remove offsets in the starting position caused by changes in negative pressure.

[0142] For example, one or more sensors may be arranged to sense negative pressure (eg, static negative pressure) in chamber 108 caused by operation of the negative pressure generator, and infrasound source 112 may be configured to adjust the starting position of the piston based on the sensed negative pressure.

[0143] In some embodiments, the varying pressure experienced by the breast 102 caused by the movement of the movable member 114 comprises a pressure waveform. Such a pressure waveform can assist in mechanically stimulating the breast 102 and thus facilitate expression of milk from the breast 102.

[0144] Any suitable shape of pressure waveform is contemplated.In some embodiments, the pressure waveform is a sawtooth waveform, a sine waveform, or a square waveform.

[0145] In some embodiments, the pressure waveform is user selectable. Thus, the user can select whichever pressure waveform is deemed most effective for them in promoting milk extraction from the breast 102.

[0146] In such embodiments, a user interface (not visible) may be configured to permit a user to select a pressure waveform, such as a sawtooth waveform, a sine waveform, or a square waveform, wherein the infrasound source 112 is controllable to provide the user-selected pressure waveform.

[0147] In some embodiments, the device 100 includes a breathable cover (not visible) for limiting the passage of fluid from the breast 102 to the movable member 114 (eg, to the first side 114A and / or the second side 114B of the movable member 114).

[0148] The breathable covering may help protect the infrasound source 112 from being damaged by expressed milk in the chamber 108 .

[0149] Any suitable type of breathable covering is contemplated, such as Made of breathable cover.

[0150] In some embodiments (such as, Figure 3 In the embodiment shown in FIG. 1 ), the device 100 includes a valve 122 for selectively releasing expressed milk from the chamber 108 into a milk collection volume (not visible).

[0151] Because it may be desirable to keep the volume of chamber 108 as small as possible in order to facilitate mechanical stimulation of breast 102 via movement of movable member 114 of infrasound source 112, expressed milk may relatively quickly fill chamber 108. Valve 122 may accordingly beneficially permit release of expressed milk from chamber 108 to a milk collection volume (e.g., a milk collection volume that is greater than the volume of chamber 108).

[0152] In some embodiments, the milk collection volume is included in the device 100. Alternatively, the milk collection volume may be provided (eg, supplied) separately from the device 100 to the user.

[0153] In some embodiments, the infrasound source 112 is arranged to pause the movement of the movable member 114 when expressed milk is released into the milk collection volume via the valve 122 .

[0154] For example, the infrasound source 112 may be arranged to pause movement of the movable member 114 in response to the valve 122 opening to release expressed milk to the milk collection volume, and to resume movement of the movable member 114 in response to the valve 122 closing to stop releasing expressed milk to the milk collection volume.

[0155] In other words, during the opening of the valve 122, the mechanical stimulation provided by the infrasound source 112 is temporarily stopped, but after the expressed milk is released, the valve 122 is closed and the mechanical stimulation resumes again.

[0156] During milk expression, the volume of the chamber 108 becomes gradually filled with milk and thus the empty volume of the chamber 108 decreases. This may result in the sound pressure inside the chamber 108 being higher.

[0157] In some embodiments, the device 100 includes an acoustic sensor (not visible) arranged to sense the acoustic pressure in the chamber 108 .

[0158] The acoustic sensor may include or be a microphone.

[0159] By sensing (eg, monitoring) the acoustic pressure with the acoustic sensor, the amount of expressed milk in the chamber 108 can be estimated.

[0160] In embodiments where the device 100 includes a valve 122 and an acoustic sensor, the valve 122 may be configured to release expressed milk to the milk collection volume based on the sensed acoustic pressure (e.g., based on the sensed acoustic pressure indicating that the volume of the chamber 108 is filled to a given extent).

[0161] When the sensed acoustic pressure indicates that the volume of chamber 108 is close to being full, for example, valve 122 may be opened to release expressed milk to the milk collection volume.

[0162] Figure 4A perspective view is provided showing a prototype of a device 100 for expressing milk from a mammalian breast. The device 100 may have Figure 2 Although the interior design is depicted in Figure 4 The breast 102 is not shown in FIG. Figure 4 Still shown in FIG. 1 is the location of the cavity 108 defined between the nipple enclosure wall 104 (eg, the funnel) and the location of the breast 102 including the nipple region 106 where it would be when the nipple enclosure wall 104 is joined thereto.

[0163] In some embodiments (such as, Figure 4 In the embodiment shown in ), the device 100 includes a connection point 124 at which the device 100 can be connected to a negative pressure generator (not visible), for example via a tube extending between the device 100 and the negative pressure generator.

[0164] In some embodiments, device 100 includes a three-way coupling member (not visible) for connecting the negative pressure generator to chamber 108 and further chamber 118 .

[0165] In existing breast pumps, the amplitude of the pressure change during extraction is typically around 5000 Pa. Simulations were performed using the electroacoustic simulation toolbox in in order to verify that such amplitudes can be achieved with the apparatus 100 according to the present disclosure using off-the-shelf components.

[0166] Figure 5 Graphs of simulated sound pressure, displacement, and power versus infrasound frequency are provided for an apparatus 100 having a chamber 108 with a volume of 28 mL and a 40 mm infrasound source 112 obtained from a Philips desktop speaker system.

[0167] The vertical line in each of these graphs indicates 1 Hz. It is apparent from these graphs that the speaker requires approximately 4.5 W and a relatively modest 0.7 mm displacement to achieve an amplitude of 4400 Pa.

[0168] Figure 5 It is also apparent in Figure 1 that the resonant frequency of the infrasound source 112 is at approximately 120 Hz.

[0169] Figure 6 Graphs of simulated acoustic pressure, displacement, and power versus infrasound frequency are provided for apparatus 100, which is similar to that used for the infrasound test except that chamber 108 has a volume of 14 mL instead of 28 mL. Figure 5 The simulations in Figure 5). Keeping the input power constant at 4.5W, the amplitude increased from 4300Pa to 4800Pa, while the required piston displacement decreased from 0.7 to less than 0.4. Also, due to the smaller volume of chamber 108, the resonant frequency shifted to 200Hz.

[0170] The present disclosure also provides a method of operating a device suitable for expressing milk from a mammalian breast, wherein the device includes: a nipple enclosure wall, which is used to engage with a nipple-including area of ​​the breast to define a chamber between the nipple enclosure wall and the nipple-including area of ​​the breast; an infrasound source for generating infrasound, the infrasound source having a movable member, the movable member including a first side facing the chamber and in fluid communication with the chamber and a second side outside the chamber and opposite to the first side; and a fluid connection between the chamber and the second side.

[0171] The method may be a method of operating the device 100 according to any of the embodiments described herein.

[0172] The method includes: reducing the pressure in the chamber, such as by controlling a negative pressure generator to reduce the pressure in the chamber; and causing movement of the movable member.

[0173] The fluid connection controls fluid communication between the chamber and the second side of the movable member during movement of the movable member.

[0174] The present disclosure further provides a computer program comprising computer program code configured to cause one or more processors to implement a method of operating a device 100 when the computer program is run on the one or more processors, the one or more processors being configured to control an infrasound source 112 of the device 100 according to any of the embodiments described herein.

[0175] In some embodiments, the one or more processors may be further configured to control a negative pressure generator arranged to provide negative pressure in the chamber 108 .

[0176] By studying the drawings, the disclosure and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments when practicing the claimed utility model. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0177] The functions implemented by a processor may be implemented by a single processor or by multiple separate processing units, which may be collectively considered to constitute a “processor.” In some cases, such processing units may be remote from each other and communicate with each other in a wired or wireless manner.

[0178] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0179] The computer program may be stored / distributed on suitable media (such as optical storage media or solid-state media supplied with or as part of other hardware), but may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0180] If the term "suitable for" is used in the claims or description, it should be noted that the term "suitable for" is intended to be equivalent to the term "configured to". If the term "arranged" is used in the claims or description, it should be noted that the term "arranged" is intended to be equivalent to the term "system" and vice versa.

[0181] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A milk extraction device (100) for extracting milk from a mammalian breast (102), the device comprising: a nipple enclosure wall (104) for engaging with a nipple-inclusive region (106) of the breast to define a chamber (108) between the nipple enclosure wall and the nipple-inclusive region of the breast, wherein negative pressure can be provided in the chamber; a subsound source (112) for generating subsound, the subsound source comprising a movable member (114), movement of which generates the subsound, the movable member having a first side (114A) facing the chamber and in fluid communication with the chamber, and a second side (114B) opposite the first side, the second side being outside the chamber, Characterized in that the device (100) for expressing milk further comprises: A fluid connection (116) between the chamber and the second side is configured to control fluid communication between the chamber and the second side during movement of the movable member.

2. The milk extraction device (100) according to claim 1, characterized in that: The fluid connection (116) includes a channel that fluidly connects the chamber (108) to the second side (114B) of the movable member (114), and the control of the fluid communication between the chamber and the second side is at least partially determined by the size of the channel.

3. The milk extraction device (100) according to claim 2, characterized in that: It includes a second chamber (118), the second side (114B) of the movable member (114) faces the second chamber and is in fluid communication with the second chamber, wherein the channel and the second chamber fluidically connect the chamber (108) to the second side.

4. The milk extraction device (100) according to claim 3, characterized in that: It comprises a three-way connection member for connecting a negative pressure generator to the chamber (108) and the second chamber (118).

5. The milk extraction device (100) according to claim 3 or claim 4, characterized in that: The channel is configured to operate together with the volume of the second chamber (118) as an acoustic filter that selectively blocks frequencies of pressure changes caused by the movement of the movable member (114) from passing from the chamber (108) to the second chamber, thereby enabling the breast (102) to experience the pressure changes.

6. The milk extraction device (100) according to any one of claims 1 to 4, characterized in that: The fluid connection (116) is configured to operate as a fluid frequency-dependent impedance element configured to selectively restrict a fluid passage between the chamber (108) and the second side (114B) of the movable member (114), driven by pressure changes at a frequency caused by the movement of the movable member, thereby enabling the breast (102) to experience the pressure changes.

7. The milk extraction device (100) according to claim 5, characterized in that: The frequency of the pressure variation caused by the movement of the movable member (114) is equal to or greater than 0.5 Hz.

8. The milk extraction device (100) according to any one of claims 1 to 4, characterized in that: The subsound source (112) is configured to cause the movement of the movable member (114) to be at a frequency in the range of 3 to 20 Hz.

9. The milk extraction device (100) according to any one of claims 1 to 4, characterized in that: It comprises a breathable covering for limiting the passage of liquid from the breast (102) to the movable member (114), the breathable covering being arranged to cover the first side (114A) and / or the second side (114B) of the movable member.

10. The milk extraction device (100) according to any one of claims 1 to 4, characterized in that: The infrasound source (112) comprises a piston attached to the movable member (114), movement of the piston causing the movement of the movable member, and wherein a starting position of the piston is adjustable based on the negative pressure in the chamber (108).

11. The milk extraction device (100) according to any one of claims 1 to 4, characterized in that: The movement of the movable member (114) provides a pressure waveform that is user selectable.

12. The milk extraction device (100) according to any one of claims 1 to 4, characterized in that: It comprises a valve (122) for selectively releasing expressed milk from the chamber (108) to a milk collection volume.

13. The milk extraction device (100) according to claim 12, characterized in that: The infrasound source (112) is arranged to be controlled by a control system to pause the movement of the movable member (114) when expressed milk is released into the milk collection volume via the valve.

14. The milk extraction device (100) according to claim 12, characterized in that: It comprises an acoustic sensor arranged to sense acoustic pressure in the chamber (108), wherein the valve (122) is arranged to be controlled by a controller to release expressed milk to the milk collection volume based on the sensed acoustic pressure.

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