Breast pump unit and operating instructions

Abstract

A method of operating a breast pump unit (10) for producing human breast milk and the breast pump unit (10) are provided. The breast pump unit (10) includes a pump assembly (26) for generating a vacuum, a reservoir (24) for receiving breast milk, and a breastshield (11) for sealingly applying the breast to be pumped. The breastshield (11) includes a flexible inner chamber (15) for receiving the nipple of the breast and a second chamber (16), particularly an outer chamber, extending outwardly around the inner chamber (15) and at least partially enclosing the nipple inserted into the inner chamber (15). The method includes repeatedly evacuating the inner chamber (15) and reservoir (24) to a first vacuum pressure with the pump assembly (26), connecting the second chamber (16) to the pump assembly (26) and reservoir (24), evacuating the second chamber (16) to a second vacuum pressure that is higher or greater than the first vacuum pressure, and at least partially releasing the vacuum in the second chamber (16) to a lower vacuum pressure, particularly a pressure lower than the first vacuum pressure.

Description

Technical Field

[0001] This application claims priority to Australian Provisional Patent Application No. 2020900501, filed on February 21, 2020, the content of which is incorporated herein by reference.

[0002] The present invention relates to a breast pump and a breast pump unit for expressing human breast milk, and a method of operating the breast pump or breast pump unit. Hereinafter, throughout this specification, reference is made to the breast pump unit rather than the breast pump or breast pump unit.

Background Art

[0003] The following discussion of the background of the present invention is intended to facilitate understanding of the present invention. However, it should be understood that this discussion does not admit, nor does it purport to recognize, that any aspect of the discussion was part of common general knowledge at the priority date of this application, even if known.

[0004] Breast pump units are known in the prior art and consist of manually operated units and motor-driven units. The motor-driven unit can be connected to a main power supply or operated by a battery. The motor-driven unit includes a vacuum pump and one or two breast shields for placement on the mother's breast or both breasts. The breast pump unit is intended to reproduce the state in which a baby sucks on the mother's breast. Thus, the breast pump unit periodically pumps using a vacuum pressure to apply and release pressure on the breast and nipple through the breast shield and to create a vacuum state within each breast shield to draw milk from the mother's breast. The breast pump unit has a milk collection container for collecting breast milk drawn from the mother's breast and storing it later.

[0005] While breast shields themselves are available in numerous different forms intended to ensure a comfortable fit for breasts of different sizes and shapes, what they all have in common is a pulsating, flexible property that allows them to contact the nipple and sometimes the area around the nipple to extract breast milk. In other words, the breast shield is flexible, at least in the area where the nipple is inserted, so that the nipple periodically contracts and relaxes, facilitating milk expression. Pulsation is generated by creating and releasing vacuum pressure within the breast shield.

[0006] Traditionally, the level of vacuum generated within the breast shield was determined by the capacity of the vacuum pump. Furthermore, the capacity of the vacuum pump determined the speed at which the required vacuum pressure was reached. Therefore, larger vacuum pumps could achieve greater vacuum pressure faster than smaller ones. However, in breast pump units, space and weight, along with energy consumption (mainly in battery-powered units) and noise, are factors in selecting a vacuum pump for the breast unit. For these parameters, a smaller vacuum pump is usually preferable.

[0007] One example of a method for operating a breast pump unit disclosed in European Patent No. 3027240, in the name of Koninklijke Philips NV, is an apparatus and method for vacuuming a system, which can be applied to use in a breast pump unit. The system of European Patent No. 3027240 is intended to generate a vacuum greater than that which can be achieved by vacuum pump alone. The system generates a vacuum in a pressure chamber (e.g., a milk collection bottle) and another pressure tank by connecting the inlet of a vacuum pump to a pressure chamber and a pressure tank, and the outlet of the vacuum pump to atmospheric pressure. The vacuum pump evacuates both the pressure chamber and the pressure tank to the same degree of vacuum. Once the maximum vacuum is reached, the system of European Patent No. 3027240 switches the outlet of the vacuum pump to connect to the inlet of the pressure tank, so that the pressure at the outlet of the vacuum pump is the vacuum generated in the pressure tank, rather than atmospheric pressure. This allows the vacuum pump to increase the vacuum in the pressure tank, generating a larger vacuum than would be possible with the vacuum pump alone. When releasing the vacuum, activate the release valve to evacuate both the pressure chamber and the pressure tank to atmospheric pressure.

[0008] The system of European Patent No. 3027240 aims to enable the generation of higher or greater vacuum levels from vacuum pumps not rated to produce such vacuum levels, and consequently, to enable the use of smaller and less expensive vacuum pumps. However, a drawback of the system of European Patent No. 3027240 is that it requires both a pressure chamber and a pressure tank to achieve a vacuum pressure greater than that which can be generated by the vacuum pump alone. When used in a milking machine, the tank is undesirable because it is complex and bulky. [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention aims to provide an improved milking unit and a method for operating the milking unit. [Means for solving the problem]

[0010] According to the present invention, a method for operating a breast pump unit for expressing human breast milk is provided, the breast pump unit is, a. A pump assembly for generating vacuum pressure, b. A reservoir for receiving breast milk, c. A breast shield for sealing and applying to a breast to be pumped, comprising a flexible inner chamber for receiving the nipple of the breast, and a second chamber, in particular an outer chamber extending around the outside of the inner chamber and at least partially surrounding the nipple inserted into the inner chamber, Equipped with, This method is i. The pump assembly evacuates the inner chamber and reservoir to a first vacuum pressure, ii. Connecting the second chamber to the pump assembly and reservoir, and evacuating the second chamber to a second vacuum pressure higher than the first vacuum pressure, iii. A step of at least partially releasing the vacuum from the second chamber to a lower pressure, particularly a pressure lower than the first vacuum pressure. This is characterized by repeating the following steps in order.

[0011] The inner chamber is flexible so that the nipple inserted therein for expressing breast milk can be compressed or compressed. Through the method of the present invention, the periodic compression and release of the nipple facilitates improved milk expression in terms of both the efficiency of milk expression and the comfort experienced by the mother.

[0012] The inner chamber can be formed by a flexible liner including an inlet for receiving the nipple, and in some embodiments of the present invention, the inner diameter of the inlet is smaller than the outer diameter of the mother's nipple on which the breast pump unit is used. This means that when the nipple is inserted into the inlet, the nipple is naturally compressed or compressed by the inner liner in the resting or relaxed state of the inner chamber. By the method of the present invention, the natural compression applied to the nipple can be reduced or completely released by a vacuum introduced into the second chamber in step ii above, thereby expanding the inner chamber, particularly the inlet of the inner liner. Thus, by applying and releasing or reducing the vacuum, periodic compression and relaxation can be applied to the nipple for milk extraction. In this embodiment of the present invention, the initial insertion of the nipple into the inlet of the inner liner can be facilitated by the initial introduction of a vacuum into the second chamber to expand the inlet, and thereafter the vacuum can be released or reduced against the inner liner to engage or grip the nipple before milk extraction is started by the method of the present invention. The inner liner may be annular or tubular.

[0013] In another embodiment of the present invention, the inner diameter of the inlet is approximately the same as, or larger than, the outer diameter of the mother's nipple in which the breast pump unit is used. This means that when the nipple is inserted into the inlet, the inner liner needs to be compressed or compressed.

[0014] The second chamber may be rigid or hard, but it may be less flexible than, or even less flexible than, the inner chamber.

[0015] The first vacuum pressure applied to the inner chamber is applied to draw or extract milk through the nipple for discharge into the reservoir. The first vacuum pressure can be a constant pressure, and in prototype tests to date, a pressure of approximately -200 mmHg has been used. The vacuum pressure in the second chamber can circulate or fluctuate around the first vacuum pressure. The first vacuum pressure tends to fold or contract the inner chamber until the vacuum pressure in the second chamber reaches the same pressure as the first vacuum pressure, after which the vacuum pressure in the second chamber tends to expand the inner chamber, particularly the inlet of the inner liner, as the vacuum pressure in the second chamber progresses to a second vacuum pressure, thereby releasing pressure on the nipple. This compression and release of the nipple has been shown to reduce the formation of ductal obstruction and hydrops, and to promote a good flow of milk through the nipple at a level comfortable for the mother. This is a very beneficial result.

[0016] The method according to the present invention advantageously allows for the rapid and efficient generation of a vacuum in the second chamber by connecting the second chamber to the pump assembly and reservoir, compared to evacuating the second chamber from the atmosphere. Because the connection allows the second chamber to be immediately or rapidly evacuated to a first vacuum pressure, which is the vacuum level in the reservoir, the pump assembly is not required to evacuate the second chamber to that level. Instead, the pump assembly is only required to evacuate the second chamber from the first vacuum pressure to the second vacuum pressure. This saves time and pumping effort. As an example, the first vacuum pressure in the inner chamber may be set to approximately -200 mmHg, and the second vacuum pressure in the second chamber to approximately -380 mmHg. To reach -380 mmHg, the second chamber may first be evacuated to -200 mmHg via the connection of the pump assembly and reservoir, eliminating the need for the pump assembly to evacuate the second chamber to that level. After that, the pump assembly only needs to increase the vacuum level in the second chamber from -200 mmHg to -380 mmHg.

[0017] When the second chamber is connected to the reservoir, a loss or decrease in vacuum pressure within the reservoir is expected, but this can be minimized by the reservoir's volume being much larger than the second chamber's volume. The typical size of a breast milk reservoir used with prior art breast pump units is expected to satisfy this requirement of having a volume much larger than the second chamber's volume.

[0018] The method according to the present invention also advantageously allows for a faster and more efficient reduction of the vacuum pressure in the second chamber by the reverse process of connecting the second chamber to the reservoir, thereby allowing the larger second vacuum pressure to decrease immediately or rapidly to the first vacuum pressure without the need for pumping. Simultaneously with connecting the second chamber to the reservoir, the pressure in the reservoir rises slightly, but this can also be minimized because the volume of the reservoir is much larger than the volume of the second chamber.

[0019] Once the vacuum in the second chamber reaches the first vacuum pressure in the reservoir, the pump assembly can operate to further reduce the vacuum pressure, such as to atmospheric pressure, as needed. Therefore, the pump assembly is only required to reduce the vacuum from -200 mmHg to atmospheric pressure, rather than from -380 mmHg to atmospheric pressure.

[0020] As shown above, the first vacuum pressure can be substantially constant, for example, -200 mmHg. Therefore, step i includes lowering the inner chamber from atmospheric pressure to -200 mmHg and then maintaining that vacuum during the operation of the milking unit. Thus, the method of the present invention can be operated to evacuate the second chamber or outer chamber of the milking unit from a first vacuum level lower than the first vacuum pressure, for example, from the atmosphere, to a second vacuum level higher than the first vacuum pressure. Thus, the method of the present invention can switch the connection of the second chamber between a connection to a reservoir and a connection to the atmosphere, and advantageously, the vacuum in the reservoir can be used for both vacuum generation and vacuum release, increasing the speed of vacuum generation and vacuum release and reducing the pump's effort.

[0021] In the example above, the first vacuum pressure is set to approximately -200 mmHg and the second vacuum pressure to approximately -380 mmHg. However, the vacuum pressure can be set arbitrarily, so for example, the second vacuum pressure can be set to at least 25% higher than the first vacuum pressure, or the second vacuum pressure can be set to approximately 75% higher than the first vacuum pressure. What is required is the difference between the vacuum pressures, and other ratios or values ​​can also be adopted. Other ratios or values ​​may be appropriate for stimulation of the breast or nipple before milk secretion, i.e., before the so-called lactation reflex. The appropriate range for the first vacuum pressure is -70 to -350 mmHg, more preferably -120 to -200 mmHg. The appropriate range for the second vacuum pressure is -150 to -480 mmHg, more preferably -250 to -380 mmHg.

[0022] The milking unit according to the present invention facilitates the generation of pulses by the generation of a second vacuum pressure in the second chamber, and the second vacuum pressure is a higher or greater vacuum pressure than the vacuum pressure in the inner chamber. Due to the rapid generation of the second vacuum pressure, the inner chamber expands and, thus, the pressure applied to the nipple inserted into the inner chamber can be partially or completely released. This cycle of compression and release of the nipple is thought to have a beneficial effect on breast milk secretion and is the result of a massage effect that cleans the milk ducts and prevents and eliminates swelling. This effect is considered to be closer to breastfeeding by an infant than existing milking units. The breast shield is also configured so that the generated pulses are also applied to the areola, and as a result, there is also a massage effect on that part of the breast. Also in this case, it has been measured that the massage effect on the areola improves breast milk secretion.

[0023] In one form of the present invention, when the second vacuum pressure is reached, it may immediately be released to a low pressure. However, in other forms of the present invention, in step ii prior to step iii, the second vacuum pressure is held substantially constant for a predetermined time. In either case, by releasing the second vacuum pressure to a lower pressure, the inner chamber, which contracts under the influence of the first vacuum pressure, can exert an increased compression on the nipple. In other words, by at least partially releasing the second vacuum pressure to a lower pressure, the inner chamber can at least partially recover towards a relaxed or stationary state.

[0024] In some embodiments of the present invention, the lower pressure in step iii is atmospheric pressure. However, in other embodiments of the present invention, the lower pressure in step iii is still less than the vacuum pressure of the inner chamber, or a negative pressure reduced to less than but greater than the vacuum pressure of the inner chamber. While reducing the second vacuum pressure in step iii to atmospheric pressure is convenient and relatively easy from an operational standpoint, the reduction of the second vacuum pressure in step iii to atmospheric pressure is not always performed, as the present invention has been developed to provide use over a wide range of physical parameters, such as those relating to breast and nipple dimensions, as well as parameters relating to maternal sensitivity and comfort.

[0025] The pressure levels described above can be varied to obtain the most efficient milk secretion, and the time intervals between each step can also be varied. In some embodiments of the present invention tested to date, beneficial results have been achieved when the duration of step i is approximately 540 ms, the duration of step ii is approximately 440 ms, and the duration of step iii is approximately 540 ms. In some embodiments of the present invention, the cumulative duration of steps ii and iii may be in the range of approximately 900 ms (at 54 cycles per minute) ± 200 ms. This cumulative duration may also apply when the cycle includes a period in step ii prior to step iii in which the second vacuum pressure is held substantially constant. The preferred ratio of the durations of steps ii and iii in current testing is between 3 / 7 and 4 / 6. Of course, these time intervals can be changed as needed, and if further testing reveals favorable vacuum levels and time intervals for the application.

[0026] In some forms of the present invention, the pump assembly includes a single vacuum pump, and a method of operating a milking unit according to the present invention includes, in step i, connecting the inner chamber and the reservoir in series to the inlet of the vacuum pump, connecting the second chamber to the atmosphere, and, in step ii, switching a valve to switch the second chamber to connection with the inlet of the vacuum pump and switching the inner chamber and the reservoir to connection with the outlet of the vacuum pump, and includes a valve assembly, particularly a solenoid valve, that facilitates this. In step iii, the switching valve is returned to the position of step i.

[0027] In other forms of the present invention, the pump assembly includes a single vacuum pump, and a method of operating a milking unit according to the present invention includes, in step i, connecting the inner chamber and the reservoir in series to the inlet of the vacuum pump via a first valve and connecting the second chamber to the atmosphere via a second valve, and, in step ii, closing the first and second valves and connecting the inner chamber and the reservoir in series to the outlet of the vacuum pump via a third valve and connecting the second chamber to the inlet of the vacuum pump via a fourth valve. In step iii, the first and second valves are returned to their respective positions of step i.

[0028] In some forms of the present invention, the pump assembly includes a pair of vacuum pumps arranged such that the inner chamber and the reservoir are connected in series to the inlet of a first vacuum pump and the second chamber is connected to the inlet of a second vacuum pump via a first valve, the pressure line extends between the inlet of the first vacuum pump and the outlet of the second vacuum pump and includes a second valve, and a method of operating a milking unit according to the present invention includes, in step i, opening the first valve to the atmosphere and closing the second valve to the fluid path and operating the first vacuum pump to evacuate the inner chamber and the reservoir to a first vacuum pressure, and, in step ii, closing the first valve to the atmosphere and opening the second valve to the fluid path and operating the second pump to evacuate the second chamber.

[0029] It will be apparent that the method of the present invention can be implemented with various configurations of vacuum pumps and valves. Specific examples are given in the accompanying drawings.

[0030] Furthermore, the present invention is implemented in a breast pump unit for expressing human breast milk, and the breast pump unit is a. A vacuum pump for generating pressure, b. A reservoir for receiving breast milk, c. A breast shield for sealing and applying to a breast to be pumped, comprising an inner chamber for receiving the nipple of the breast, and a second chamber, in particular an outer chamber extending around the outside of the inner chamber and at least partially surrounding the nipple inserted into the inner chamber. Equipped with, The aforementioned milking unit is i. The vacuum pump evacuates the inner chamber and reservoir to a first vacuum pressure. ii. The process of connecting the outer chamber to a vacuum pump and reservoir such that the outer chamber is evacuated to a second vacuum pressure where the second vacuum pressure is higher than the first vacuum pressure, iii. A process in which the vacuum in the outer chamber is released, at least partially, to a lower pressure, in particular to a pressure lower than the first vacuum pressure. This can be executed in a cycle.

[0031] In a breast pump unit according to the present invention, an inner chamber is defined by a flexible inner liner including an inlet for receiving a nipple, and a second chamber is defined by a rigid or stiff outer liner, and the inner and outer liners can define the second chamber between them. The inlet may have an inner diameter smaller than the outer diameter of the nipple on which the breast pump unit is to be used, and the inlet is expandable simultaneously with the introduction of vacuum into the inner chamber.

[0032] In some embodiments of the present invention, the vacuum pump has an inlet and an outlet, and the milking unit may include a valve assembly inserted into pressure lines extending from the inlet and outlet. The valve assembly is operable to switch the inner chamber and reservoir from a pressure connection to the vacuum pump's inlet to the vacuum pump's outlet, and the outer chamber from a pressure connection to the vacuum pump's outlet to the vacuum pump's inlet. The valve assembly may be a switching valve such as a 3 / 3 solenoid valve or a 4 / 3 solenoid valve. Alternatively, the valve assembly may consist of four valves, each located in a separate pressure line. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 schematically shows a breast pump unit used to express human breast milk. [Figure 2] Figure 2 schematically shows a breast pump unit used to express human breast milk. [Figure 3] Figure 3 schematically shows a breast pump unit used to express human breast milk. [Figure 4] Figure 4 is a graph of the vacuum pressure created in the inner and outer chambers of the milking unit shown in Figure 1. [Figure 5] Figure 5 schematically shows an example of an alternative breast pump unit used to express human breast milk. [Figure 6] Figure 6 schematically shows an example of an alternative to a breast pump unit used to express human breast milk. [Figure 7] Figure 7 schematically shows an example of an alternative to a breast pump unit used to express human breast milk. [Figure 8] Figure 8 schematically shows an example of an alternative breast pump unit used to express human breast milk. [Figure 9] Figure 9 schematically shows an example of an alternative to a breast pump unit used for expressing human breast milk. [Figure 10] Figure 10 schematically shows an alternative to a breast pump unit used for expressing human breast milk. [Modes for carrying out the invention]

[0034] Figures 1 to 3 schematically illustrate a breast pump unit 10 for expressing human breast milk. The breast pump unit 10 includes a breast shield 11 having a flexible annular inner liner 12 and a rigid or stiff annular outer liner 13. The inner liner 12 defines an inner chamber 15 for receiving the nipple of the breast, and the outer liner 13 defines an outer chamber 16 that extends around the inner liner 12 and extends around the outside of the inner chamber 15. The inner liner 12 and the outer liner 13 are sealed and connected at each end so that a vacuum can be created within the outer chamber 16. The inner liner 12 includes a funnel portion 18 for sealing against the surface of the mother's breast and a tubular inlet portion 20 for receiving the nipple. The inner diameter of portion 20 is intended to be smaller than the outer diameter of the nipple into which portion 20 is inserted, so that portion 20 compresses or compresses the nipple in the stationary or relaxed state of the inner liner 12. As will be described later in this specification, the compression or pressure applied to the nipple by portion 20 of the inner liner 12 can be reduced or released by the vacuum introduced into the outer chamber 16. By periodically changing the pressure or vacuum in the outer chamber 16, the nipple can be periodically compressed and relaxed for the purpose of breast milk extraction. Also, when the breast shield 11 is attached to the breast, the funnel portion 18 is stationary relative to the areola of the breast, and the vacuum introduced into the outer chamber 16 causes the funnel portion 18 to move or vibrate on the areola, which can massage the areola to help initiate breast milk secretion and improve breast milk secretion as a whole.

[0035] The inner liner 12 has a vacuum exhaust port 22 that the outer liner seals. The vacuum exhaust port 22 is connected to a reservoir 24, which is a collection reservoir for receiving breast milk in the illustrated embodiment. The reservoir 24 is connected to a vacuum pump 26 via a valve 28. The valve 28 is connected to the inlet 29 and outlet 30 of the vacuum pump 26, and in the orientation of the valve 28 in Figure 1 indicated by the arrow, the reservoir 24 is connected to the inlet 29 of the valve 28, and the outlet 30 of the valve 28 is connected to the atmosphere via a one-way check valve 34.

[0036] The pressure line 35 is also connected to the exhaust port 36 of the outer liner 13, but in the orientation of valve 28 in Figure 1, the inner chamber 15 and reservoir 24 are evacuated by the vacuum pump 26, and the liquid (air) discharged from the outlet 30 of the pump 26 is exhausted into the atmosphere through the check valve 34.

[0037] In this way, the vacuum pump 26 creates a vacuum in each of the inner chamber 15 and reservoir 24 to a predetermined level. In tests to date, one predetermined level has been -200 mmHg.

[0038] When a predetermined vacuum level is reached, valve 28 is switched to the position shown in Figure 2. In this position, pressure line 35 is connected to the inlet 29 of vacuum pump 26, and outlet 30 of vacuum pump 26 is connected to reservoir 24 and inner chamber 15. Thus, outlet 30 of vacuum pump 26 is almost instantaneously evacuated from atmospheric pressure to the predetermined vacuum level to which reservoir 24 and inner chamber 15 are pumped. This switching also almost instantaneously evacuates the outer chamber 16 to the predetermined vacuum level. This allows vacuum pump 26 to continue evacuating the outer chamber 16 to a vacuum level greater than or higher than the vacuum level of inner chamber 15 and reservoir 24. The suction or vacuum pressure applied to pressure line 35 tightly closes valve 34 so that pressure line 35 is closed to the atmosphere. In prototype tests to date, one of the greater or higher vacuum levels to which the outer chamber 16 is evacuated is 380 mmHg.

[0039] When valve 28 is switched from the position shown in Figure 1 to the position shown in Figure 2, a pressure loss or drop occurs in reservoir 24 and inner chamber 15, which is minimized by the fact that the volumes of reservoir 24 and inner chamber 15 are much larger than the volume of outer chamber 16. This ratio can be in the range of 1:10 or greater.

[0040] Furthermore, although there is a slight pressure loss due to the intrusion of breast milk into the reservoir 24, this is minimized because the volume of the reservoir 24 and the inner chamber 15 is much larger than the volume of the outer chamber 16.

[0041] Figure 3 shows a further position of valve 28, in which the inner chamber 15, outer chamber 16, and reservoir 24 are each separated from the vacuum pump 26, and the generated vacuum pressure is held or maintained for a predetermined time. After the predetermined time has elapsed, valve 28 can be switched back to the position shown in Figure 1. In that position, the inner chamber 15 and reservoir 24 are returned to direct connection with the suction port 29 of the vacuum pump 26, thus returning to the predetermined vacuum level mentioned earlier, and the outer chamber 16 returns to atmospheric pressure. The pressure loss in reservoir 24 is compensated for by the exhaust of fluid from reservoir 24 through check valve 34.

[0042] By circulating the series of operations of the breast pump unit 10 shown in Figures 1 to 3, pulsating motion is generated within the breast shield 11, allowing for the extraction of breast milk. A schematic graph of the pressure generated in the inner chamber 15 and outer chamber 16 is shown in Figure 4. This graph shows vacuum pressure (Y axis) versus time (X axis). The line labeled "Inner Chamber 15" starts at atmospheric pressure and decreases to a roughly constant negative pressure or vacuum pressure. The line labeled "Outer Chamber 16" changes periodically as shown in the figure.

[0043] Section 1 of the cycle, shown as S1 in Figure 4, is the section where valve 28 is in the position shown in Figure 1, causing the inner liner to be evacuated from atmospheric pressure to a predetermined pressure level, e.g., -200 mmHg. In Section 1, the outer chamber 16 within the outer liner 13 is maintained at atmospheric pressure. In Section 2 (S2), valve 28 is switched to the position shown in Figure 2, so the pressure in the outer chamber 16 rises to, for example, -380 mmHg. Importantly, the graph shows that the vacuum in the outer chamber 16 increases immediately from 0 mmHg to near the vacuum pressure of -200 mmHg in the inner chamber 15, and then gradually or slowly increases from -200 mmHg to -380 mmHg. This indicates that as soon as valve 28 is switched from the position shown in Figure 1 to the position shown in Figure 2, the outer chamber 16 is connected to the reservoir 24 via the suction port 29 of the vacuum pump 26, and this is reflected in the outer chamber 16 almost instantaneously going from atmospheric pressure to a vacuum pressure of -200 mmHg in the reservoir 24. The graph also shows that the vacuum pump 26 then works to further vacuum the outer chamber 16 to -380 mmHg, but this takes more time.

[0044] As shown above, when valve 28 is switched to the position shown in Figure 2, a slight pressure drop occurs in the inner chamber 15, but this can be made relatively small, as it is not easily discernible in the graph of Figure 2. In section 3 (S3), valve 28 is switched to the position shown in Figure 3, so the pressure in the outer chamber 16 is maintained without rising or falling. Finally, in section 4 (S4), valve 28 is switched to the position shown in Figure 1, thereby evacuating the outer chamber 16 to the atmosphere, while the inner chamber 15 is kept under vacuum. In section S4, the graph again shows an almost instantaneous decrease in vacuum pressure from -380 mmHg to -200 mmHg, which indicates that connecting the outer chamber 16 to the reservoir 24 via the vacuum pump 26 creates a condition that allows the pressure in the outer chamber 16 to be immediately or rapidly reduced to the vacuum pressure in the reservoir 24 without requiring pumping work. Subsequently, pumping work is required to evacuate the outer chamber 16 to atmospheric pressure, which takes more time, as shown in section S4.

[0045] Importantly, this cycle does not return the inner chamber 15 to atmospheric pressure; rather, the vacuum within the inner chamber 15 is maintained at a nearly constant level after the inner chamber 15 has been initially evacuated. That is, the cycle does not return to section 1 in Figure 4, but circulates through sections 2 to 4. This constant vacuum pressure draws the breast milk through the nipple into the reservoir 24.

[0046] In relation to the action of the breast shield 11 over the breast and nipple, as described above, the diameter of the inner liner 12 at the inlet end or tubular section 20 into which the nipple is inserted can be smaller than, and potentially much smaller than, the outer diameter of the nipple, so that in the relaxed state of the inner liner 12, the inserted nipple will be compressed or compressed. This compressed state is maintained throughout section S1. However, when a vacuum is generated in the outer chamber 16 in section S2, the tubular section 20 reduces or releases the pressure on the nipple. This is because when a larger level of vacuum is generated in the outer chamber 16 than in the inner liner 12, the inner liner 12 expands, and consequently, the vacuum in the outer chamber 16 applies a gradually decreasing pressure on the nipple until the inner liner 12 actually loses contact with the nipple surface (at least partially), so that no compressive or compressive pressure acts on the nipple. This configuration is achieved by the outer liner 13 being rigid or rigid and the inner liner 12 being flexible. Thus, the vacuum cycle periodically compresses and releases the nipple.

[0047] The compression or pressure applied to the nipple is reduced or released in part of section S2 and all of section S3 when the vacuum created in the outer chamber 16 exceeds the vacuum created in the inner chamber 15. The vacuum pressure in the outer chamber 16 is reduced to below the vacuum pressure in the inner chamber 15 in section 4, so that the portion 20 of the inner liner 12 can return to its compressed or compressed position on the nipple.

[0048] As can be seen from Figure 4, the vacuum pressure applied to the inner chamber 15 is approximately constant once the pressure reaches a predetermined level. This vacuum extracts milk from the nipple and transfers it to the reservoir 24. The periodic vacuum pressure applied to the outer chamber 16 is understood to cause the tubular section 20 to expand and contract, releasing and then compressing the nipple inserted into the tubular section 20. This effect of releasing and compressing the nipple periodically induces the secretion of breast milk from the breast.

[0049] Furthermore, the outer liner 13 also applies and releases pressure to the inner liner 12 at the funnel portion 18 of the inner liner 12, and the application and release of pressure at the funnel portion 18 also tends to massage the areola portion of the breast, which is understood to help both initiate milking (often called "milk release") and continue milking.

[0050] The time intervals between the different sections of the cycle shown in Figure 4 can be selected as needed or as optimal through testing. In some tests conducted to date, the time intervals for sections S1 through S4 have been 540ms, 440ms, 300ms, and 540ms, respectively.

[0051] The present invention differs from the configuration of European Patent No. 3027240 at least by the operation of a system that maintains the pressure in the inner chamber 15 and reservoir 24 while varying the pressure in the outer chamber 16 between atmospheric pressure and maximum vacuum pressure. The configurations in Figures 1 to 4 facilitate pulsating the vacuum pressure in the outer liner 13 to generate the application and release of pressure to the nipple and areola of the breast. The configuration of the present invention advantageously benefits from the pressure initially created in the reservoir 24 by both exhausting the outer chamber 16 to a pressure greater than the pressure in the inner chamber 15 and returning the pressure in the outer chamber 16 to atmospheric pressure. In this regard, the system of the present invention requires that when the exhaust port 36 of the outer chamber 16 is connected to the intake port 29 of the vacuum pump 26, the pressure in the outer chamber 16 is rapidly equal to the pressure in the reservoir 24, and only at that stage does the pump 26 operate to further increase the vacuum pressure in the outer chamber 16. Furthermore, when the vacuum in the outer chamber 16 is released by returning it to atmospheric pressure, reconnecting the outer chamber 16 to the outlet 30 of the pump 26 requires that the pressure in the outer chamber 16 rapidly decrease to the same pressure as the reservoir 24, and only at that stage is it required that the pump 26 operate to further reduce the vacuum pressure in the outer chamber 16 (to atmospheric pressure level). Advantageously, the increase in the vacuum pressure in the outer chamber 16 from atmospheric pressure to equal the pressure in the reservoir 24, and the subsequent decrease from a state greater than the pressure in the reservoir 24 to equal the pressure in the reservoir 24, occur rapidly in either direction.

[0052] Furthermore, the repressurization or re-vacuuming of the reservoir 24 in section S4 of Figure 4 is rapid because it is performed against the vacuum pressure maintained in the inner chamber 15, rather than starting from atmospheric pressure.

[0053] Furthermore, any air that leaks into the system is removed via the check valve 34 when the reservoir 24 is repressurized, thereby stabilizing the cycle during long-term operation.

[0054] Figure 5 shows the configuration of Figures 1 to 3, with valve 28 shown as a 4 / 3 solenoid valve, i.e., a 4-way 3-way switching valve. Figure 5 shows how valve 28 is switched by the linear movement between stages described in relation to Figures 1 to 3.

[0055] Figure 6 is a further schematic diagram of an alternative configuration employing four separate valves. Figure 6 shows the breast shield 11 of the previous embodiment as employed in a breast pump unit 50 including a reservoir 51 (milk bottle), a vacuum pump 52, valves V1 to V4, and a one-way check valve 55.

[0056] Valves V1 to V4 are controlled by a suitable control mechanism that allows for selective opening and closing of the valves. Although the control mechanism is not shown in Figure 6, it should be readily available and understandable to those skilled in the art.

[0057] The vacuum pump 52 has an inlet 56 and an outlet 57. Valves V1 to V4 operate to switch the inlet 56 and outlet 57 between the reservoir 51 and the outer chamber 16 of the breast shield 11. The breast pump unit 50 can be operated to generate the pressure graph shown in Figure 4 by first opening valves V1 and V4 and then closing valves V2 and V3. In this state, the inner chamber 15 of the breast shield 11 and the reservoir 51 are in communication with the inlet 56 of the pump 52, and the outlet 57 can be evacuated via the check valve 55. Thus, the operation of the pump 52 evacuates the inner chamber 15 and the reservoir 51.

[0058] When the pressure levels in the inner chamber 15 and reservoir 51 reach a predetermined level, valves V1 and V4 can be closed, and valves V2 and V3 can be opened simultaneously. Alternatively, to ensure the correct pressure transition between the respective pressure lines controlled by valves V1 to V4, all valves V1 to V4 can be kept closed for a very short time, for example, 5 to 10 ms, before opening valves V2 and V3.

[0059] This switches the pressure lines so that the outer chamber 16 of the breast shield 11 is connected to the inlet 56 of the pump 52, and the reservoir 51 and inner chamber 15 are connected to the outlet 57. As a result, a vacuum of the same level as in the reservoir 51 is immediately and rapidly created in the outer chamber 16, with only a slight decrease in vacuum pressure occurring in the reservoir 51.

[0060] Compared to the single-type solenoid valve shown in the previous figure, using four valves in Figure 6 results in different control of the four valves and the adoption of different circuits and hardware, but the same results as described in relation to the milking unit 10 can be obtained.

[0061] Figure 7 shows a further alternative configuration to achieve the same pressure graph as in Figure 4, but the milking unit 70 in Figure 7 employs first and second vacuum pumps 71 and 72 instead of the single vacuum pump in the previous figure. In Figure 7, the suction port 74 of the vacuum pump 71 is connected to the reservoir 76 and the inner chamber 15 of the breast shield 11. The discharge port 77 of the pump 71 is in communication with the atmosphere.

[0062] The suction port 79 of the vacuum pump 72 is connected to the outer chamber 16 of the breast shield 11, and the discharge port 80 is connected to the atmosphere via a one-way check valve 81.

[0063] The pressure line 82 extends between the inlet 74 of pump 71 and the outlet 80 of pump 72. A 2 / 2 solenoid valve 84 controls the pressure flow rate through line 82.

[0064] Furthermore, the 2 / 2 solenoid valve 85 is located within the pressure line 86 on the intake side of the pump 72 and controls the flow to the atmosphere through the pressure line 86.

[0065] With valves 84 and 85 in the positions shown in Figure 7, both vacuum pumps 71 and 72 can be operated simultaneously, with pump 71 evacuating the inner chamber 15 and reservoir 76, and pump 72 drawing in air through valve 85 and returning that air to the atmosphere through valve 81 for evacuating. It will be understood that pump 72 does not need to operate during the initial operation of pump 71 to vacuum the inner chamber 15 and reservoir 76, and instead, pump 72 may be operated continuously. This is advantageous for a given short cycle time in which the milking unit 70 operates under conditions that may be compromised if pump 72 is periodically turned on / off. The state reached in Figure 7 is section S1 in Figure 4.

[0066] When the vacuum pressure in the inner chamber 15 and reservoir 76 reaches a predetermined vacuum level (e.g., -200 mmHg), valves 84 and 85 are switched so that valve 84 facilitates or allows flow from the outlet 80 of pump 72 to the inlet 74 of pump 71, and valve 85 closes to prevent air from passing into the atmosphere. In these switched positions, the milking unit 70 enters section S2 of Figure 4, where the outlet 80 of pump 72 is connected to the inlet 74 of pump 71, so the pressure at the outlet 80 of pump 72 immediately reaches the vacuum pressure at the inlet 74. This means that the outer chamber 16 also immediately reaches that pressure. Pump 72 can then further increase the vacuum pressure in the outer chamber 16, starting from the vacuum pressure in reservoir 76.

[0067] When the vacuum pressure in the outer chamber 16 reaches a level greater than required (end of section S2 in Figure 4), valve 84 is returned to the closed position shown in Figure 7, noting that valve 85 has already been switched to its closed position in section S2. The milking unit 70 is now in section S3.

[0068] Finally, in order to return the vacuum pressure in the outer chamber 16 to atmospheric pressure, valves 84 and 85 return to the positions shown in Figure 7, thereby evacuating the outer chamber 16 to atmospheric pressure, while the inner chamber 15 remains under vacuum pressure. By returning to the valve positions shown in Figure 7, the outer chamber 16 immediately drops to a predetermined vacuum level present in the reservoir 76, and once that level is reached, pump 72 operates to reduce the vacuum pressure in the outer chamber 16 to atmospheric pressure.

[0069] Figure 8 shows a further alternative configuration of the breast pump unit 90 employing the breast shield 11 from the previous figure. The configuration in Figure 8 is very similar to the breast pump unit 70 in Figure 7, except that a 3 / 3 solenoid valve is used instead of the 2 / 2 solenoid valve 84 in Figure 7. Therefore, the same reference numerals used in Figure 7 are used in Figure 8 to indicate the same or common parts between the respective breast pump units 70 and 90.

[0070] In Figure 8, the 3 / 3 solenoid valve 92 is shown operating in section S1 of Figure 4, as the vacuum pump 71 draws vacuum from the inner chamber 15 and reservoir 76 of the breast shield 11. Since the valve 92 closes the path through the pressure line 82, if the vacuum pump 72 is also operating, it draws air from the pressure line 86 and discharges it through the valve 92 into the atmosphere from the pressure line 82.

[0071] When the vacuum pressure in the inner chamber 15 and reservoir 76 reaches a predetermined vacuum level, valves 85 and 92 are moved so that valve 85 closes the pressure line 86 to the atmosphere and valve 92 opens the pressure line 82 between the outlet 80 of pump 72 and the inlet 74 of pump 71. Similar to the previous embodiment, this valve movement shifts the intake pressure of the outer chamber 16 to the pressure at the inlet 74 of pump 71, so that the vacuum pressure in the outer chamber immediately and rapidly decreases to the pressure in reservoir 76. The vacuum level in the outer chamber 16 continues to increase by continuing to evacuate the outer chamber 16 through pump 72. This is represented in section S2 of Figure 4.

[0072] When the vacuum in the outer chamber reaches a vacuum pressure greater than required, the valve 94 is switched back to the closed position, which closes the pressure line 82. This brings the milking unit 90 to section S3 in Figure 4.

[0073] Finally, by returning valves 85 and 92 to the positions shown in Figure 8, the vacuum in the outer chamber 16 is evacuated, thereby immediately lowering the outer chamber 16 to the vacuum level present in the reservoir 76. At that level, the pump 72 can operate to continue lowering the vacuum pressure in the outer chamber 16 to atmospheric pressure.

[0074] Figure 9 shows a second pumping system that employs a vacuum pump 71 and reservoir 76 common to the previous embodiment, but the second pumping system represents a further alternative configuration of the milking unit 100, which is a single-stroke piston pump 102 communicating with 2 / 2 solenoid valves 104 and 106.

[0075] Figure 9 shows section S1 of the pressure graph in Figure 4, in which the pump 102 has its piston 103 at the inlet end 108.

[0076] When the vacuum in the inner chamber 15 and reservoir 76 reaches a predetermined level, valves 104 and 106 can be switched to the closed position, and valve 84 can be switched to open the pressure line 110. In this state, as shown in Figure 10, the piston 103 of the piston pump 102 moves to the outlet end 112, drawing vacuum into the outer chamber 16. The movement of the piston 103 in the pump 102 can create the necessary vacuum in the outer chamber 16.

[0077] Once the required vacuum is created within the outer chamber 16, the valve 84 is returned to the closed position shown in Figure 9, and each vacuum is maintained constant through section S3 in Figure 4.

[0078] When exhausting the outer chamber 16 back into the atmosphere, the valves 106 and 104 can be returned to the open position shown in Figure 9, and the piston pump 102 can be driven back by moving the piston 103 to the suction port end 108 of the pump 102.

[0079] The drawings illustrate various embodiments for achieving the pressure distribution within the breast shield as shown in Figure 4. Other configurations may also be employed. However, each illustrated embodiment facilitates the expansion and contraction of the inner liner 12, particularly the tubular portion 20 of the inner liner 12, and releases and reapplies pressure to the nipple inserted into the tubular portion 20. Each embodiment also promotes a massage effect on the areola of the breast, which has been shown in tests to assist in the initiation of milk production and improve overall milk production. Physical tests performed on breastfeeding mothers have also shown that the way the breast shield moves provides comfort to the mother and is more likely to cause the mother to continue producing breast milk for a longer period for the newborn rather than reverting to formula.

[0080] Wherever the terms “consist of,” “includes,” “have,” or “equip” are used herein (including in the claims), they shall be construed as identifying the presence of a described feature, integer, process or component, but not as excluding the presence of one or more other features, integers, processes or components.

[0081] Those skilled in the art will understand that the invention described herein may be subject to variations and modifications other than those specifically described. The present invention is understood to include all such variations and modifications that fall within the spirit and aspects of the invention.

[0082] Future patent applications may be filed in Australia or abroad based on or claiming priority from this application. The following provisional claims are provided for illustrative purposes only and should not be understood as limiting the scope of what may be claimed in such future applications. Features may be added to or omitted from the provisional claims at a later date to further define or redefine the present invention or invention. [Prior art documents] [Patent Documents]

[0083] Patent Document 1: European Patent No. 3027240

Claims

1. A method for operating a breast pump unit for secreting human breast milk, wherein the breast pump unit, a. A vacuum pump for generating vacuum pressure, b. A reservoir for receiving breast milk, c. A breast shield for sealing application to a breast to be pumped, comprising a flexible inner chamber for receiving the nipple of the breast, and an outer chamber extending around the outside of the inner chamber and at least partially surrounding the nipple inserted into the inner chamber, d. A first valve capable of switching the flow path, e. A second valve, one end of which is connected to the atmosphere, f. Control means for controlling the operation of the vacuum pump, the first valve, and the second valve. Equipped with, The aforementioned method, i. The control means switches the first valve to a first position, thereby connecting the inner chamber to the vacuum pump via the reservoir and the first valve, and the outer chamber to the vacuum pump via the second valve and the first valve, and the control means controls the vacuum pump to evacuate the inner chamber and the reservoir to a first vacuum pressure; ii. A step in which the control means switches the first valve to a second position, thereby connecting the outer chamber to the vacuum pump and the reservoir via the first valve, and the control means controls the vacuum pump to evacuate the outer chamber to a second vacuum pressure, wherein the second vacuum pressure is higher than or greater than the first vacuum pressure. iii. The control means switches the first valve to the first position, thereby connecting the inner chamber to the vacuum pump via the reservoir and the first valve, and the outer chamber to the vacuum pump via the second valve and the first valve, and the control means stops the vacuum pump and operates the second valve, thereby partially releasing the vacuum from the outer chamber to a vacuum pressure lower than the first vacuum pressure; vi. The control means repeats the cycle including steps ii and iii, and during the cycle, the inner chamber maintains the first vacuum pressure. A method for providing this.

2. The method according to claim 1, characterized in that the second vacuum pressure is at least 25% higher than the first vacuum pressure.

3. The method according to claim 1, characterized in that the second vacuum pressure is about -200 to -480 mmHg, more preferably -280 to -420 mmHg, and even more preferably -380 mmHg, and the first vacuum pressure is about -70 to -350 mmHg, more preferably -120 to -250 mmHg, and even more preferably 200 mmHg.

4. The method according to claim 1, wherein the inner chamber includes an inlet into which a nipple is inserted, the inlet having a stationary or relaxed state for applying compressive pressure to the nipple, and the inlet expanding during the time of step ii to reduce or completely release the compressive pressure.

5. The method according to 4, characterized in that the inlet portion returns to a stationary or relaxed state during the time of process iii.

6. The method according to claim 1, characterized in that the lower pressure in step iii is atmospheric pressure.

7. The method according to claim 1, characterized in that the first vacuum pressure and the second vacuum pressure are kept constant during a predetermined time interval in step ii prior to step iii.

8. The method according to claim 1, characterized in that the duration of step i is approximately 540 ms, the duration of step ii is approximately 440 ms, and the duration of step iii is approximately 540 ms.

9. A breast pump unit for secreting human breast milk, a. A vacuum pump for generating vacuum pressure, b. A reservoir for receiving breast milk, c. A breast shield for sealing application to a breast to be pumped, comprising a flexible inner chamber for receiving the nipple of the breast, and an outer chamber extending around the outside of the inner chamber and at least partially surrounding the nipple inserted into the inner chamber, d. A first valve capable of switching the flow path, e. A second valve, one end of which is connected to the atmosphere, f. Control means for controlling the operation of the vacuum pump, the first valve, and the second valve. Equipped with, The aforementioned milking unit is i. When the control means switches the first valve to the first position, the inner chamber is connected to the vacuum pump via the reservoir and the first valve, and the outer chamber is connected to the vacuum pump via the second valve and the first valve, and the vacuum pump controlled by the control means evacuates the inner chamber and the reservoir to a first vacuum pressure. ii. When the first valve is switched to the second position by the control means, the outer chamber is connected to the vacuum pump and the reservoir via the first valve, and the vacuum pump, controlled by the control means, evacuates the outer chamber to a second vacuum pressure higher than the first vacuum pressure. iii. When the control means switches the first valve to the first position, the inner chamber is connected to the vacuum pump via the reservoir and the first valve, and the outer chamber is connected to the vacuum pump via the second valve and the first valve, and the control means stops the vacuum pump and activates the second valve, thereby releasing at least partially the vacuum from the outer chamber to a pressure lower than the first vacuum pressure. vi. The control means repeats the cycle including ii and iii above, and during that cycle, the inner chamber maintains the first vacuum pressure. A breast pump unit characterized by operating in a certain manner.

10. The breast pump unit according to claim 9, wherein the inner chamber is defined by a flexible inner liner including an inlet for receiving a nipple, the outer chamber is defined by a rigid or stiff outer liner, and the flexible inner liner and the rigid or stiff outer liner define the outer chamber between them.

11. The breast pump unit according to claim 10, characterized in that the inlet portion has an inner diameter smaller than the outer diameter of the nipple on which the breast pump unit is to be used, and the inlet portion is expandable at the same time as the introduction of a vacuum into the inner chamber.

Images