Method for regulating the operation of a milk pump

Abstract

The invention relates to a method of regulating the operation of a breast pump by applying a vacuum through a vacuum source operatively coupled with a controller for controlling the operation of the vacuum source, and aims to provide a method of pumping breast milk from a lactating mother's breast which is capable of providing sufficient milk yield by controlling the operation of the vacuum source without adversely affecting the breast tissue properties, such that the controller receives a signal indicative of the volumetric flow rate (V) of the milk and adjusts at least one of the following operating parameters of the vacuum source: vacuum intensity, cycle frequency or shape of the vacuum profile over time.

Description

[0001] The present invention relates to a method for regulating the operation of a milk pump by applying a vacuum through a vacuum source, the vacuum source being operatively connected to a controller for controlling the operation of the vacuum source.

[0002] The present invention relates in particular to a method for pumping breast milk in a breast pump, and more particularly to a motorized (e.g., electrically driven) breast pump.

[0003] Breast pumps are well-known for use by breastfeeding mothers. They allow breastfeeding women to express breast milk and further collect it for later use when necessary or convenient. For some mothers, a breast pump may be necessary, such as when the baby has difficulty sucking, or if the mother has problems with excessive or insufficient milk production, or if her nipples are painful, deformed, or injured.

[0004] Manual breast pumps are common, mainly because they are relatively inexpensive and easy to transport. However, because they are manually driven, the resulting stroke rate and suction pressure can be uneven, and operating such a pump can eventually be tiring. Electric breast pumps are also common. They can be quite large, either non-portable or semi-portable, and typically include a vacuum pump with an electric motor that plugs into a standard household outlet.

[0005] The advantages of this type of pump are its ease of control and vacuum regulation, and its ability to pump from both breasts simultaneously. That is, breastfeeding women can freely hold both pump shields in place with both hands to pump from both breasts at the same time. Battery-powered breast pumps have also been developed. These pumps offer the advantages of controllability, vacuum regulation, and portability. For example, such a battery-powered portable breast pump is described in U.S. Patent 4,964,851. This type of pump, sold by Medela under the name MINIELECTRIC, is lightweight and achieves good vacuum (i.e., negative pressure) regulation within preferred limits (e.g., between approximately 30 and approximately 300 mmHg).

[0006] The LACTINA breast pump, sold by Medela, is another type of breast pump that can be powered by batteries or household electricity. This type of breast pump is generally disclosed in U.S. Patent No. 5,007,899.

[0007] For a given pump, electrically driven motorized breast pumps are almost universally developed with a single type of "cycle." That is, in more complex pumps, the drive mechanism for generating the vacuum (negative pressure) to be applied to the breast is adapted to a specific sequence or curve of increasing negative pressure (i.e., increasing suction) and then releasing it. This is often, in a sense, to reproduce the sucking motion of an infant. However, breast pumping can encompass a range of different situations, such as when the mother's nipples are painful for some reason, are significantly engorged, may require additional nipple stimulation, may require milk expression and relaxation, or may require increased milk production. To address this need, WO 2003 / 082378 A1 discloses a breast pump programmed to generate multiple different milk expression sequences or curves.

[0008] WO 2010 / 096547 A1 discloses the control of an electrically driven motorized breast pump that mimics the sucking pattern of a newborn.

[0009] Typically, electrically driven motorized breast pumps are controlled to provide at least two different pumping modes. At the start of a cycle, a rapid vacuum cycle frequency, typically exceeding 100 cycles per minute, is applied to initiate milk expression, i.e., trigger the first milk flow. In addition to this milk expression program, the pump controller is also adapted to apply a slower vacuum cycle frequency, resulting in longer vacuum cycles for extracting milk from the breast once milk has been expressed (i.e., milk flow has occurred). For example, WO 2003 / 082378 A1 discloses a vacuum range of 100 to 250 mmHg and a frequency of 47 to 78 cycles per minute as operating parameters in the main pump program, while the milk expression or stimulation program applies a vacuum in the range of 50 to 150 mmHg at 120 to 150 cycles per minute. According to WO 2003 / 082378 A1, various programs for controlling the pump's operating parameters are selected by the user.

[0010] The present invention aims to provide a method for regulating the operation of a milk pump from the breasts of a lactating mother, which can provide a sufficient amount of milk without adversely affecting the characteristics of breast tissue.

[0011] As a solution to the above objectives, the present invention provides a method as defined in claim 1.

[0012] This method controls the operation of the vacuum source by adjusting the operating parameters of the vacuum source according to the actual milk volume flow rate, which is generated by the pumping performance of the milk pump.

[0013] Breast pumps are typically electrically driven and may have a construction as described, for example, in WO 2003 / 082378 A1.

[0014] The breast pump further includes a sensor adapted to sense the volumetric flow rate of milk between a breast shield and a collection container, which is typically in fluid communication with the breast shield and adapted to receive the breast of a lactating mother. Typically, a milk channel is provided between the breast shield and the collection container, connected to a vacuum source to apply negative pressure at the nipple to force milk flow.

[0015] To obtain a signal indicating the milk volumetric flow rate, any suitable measurement technique can be used, such as counting milk droplets as they travel from the breast shield to the collection container. For this purpose, the milk flow rate can be continuously measured, for example, as described in US 2015 / 0283311 A1. It is also feasible to calculate the milk flow rate based on measurements of the fluid volume contained in the collection container over time, as taught in WO 2018 / 045349 A1, for example. Alternatively, a volume can be measured in a measuring chamber arranged between the breast shield and the collection container, the measuring chamber having an opening valve and adapted to store milk for a certain time, to measure the volume collected in the measuring chamber during said time.

[0016] In all the measurements described above, a signal indicating the volumetric flow rate of milk from the breast shield to the collection container can be obtained. The sensor can measure only the presence of the volumetric flow rate. Therefore, the sensor can provide only a signal, for example, indicating the presence or absence of the volumetric flow rate.

[0017] In other words, the signal indicating milk volumetric flow rate can be a signal that continuously provides information about the presence or amount of actual milk volumetric flow rate from the nipple through the breast shield to the collection container. Alternatively, discrete information about the presence or actual volume within the cavity and how that volume changes over time can be used as a signal indicating milk volumetric flow rate.

[0018] Based on this signal, at least one operating parameter of the vacuum source is adjusted. The operating parameter adjusted in response to the signal indicating the milk volume flow rate can be any operating parameter of the vacuum source (i.e., the pump). However, at least one of the following operating parameters is adjusted based on information retrieved from the signal indicating the milk volume flow rate: vacuum intensity, circulation frequency, or the shape of the vacuum curve over time.

[0019] Here, vacuum intensity is actually the absolute value of the applied vacuum level. Cyclic frequency assumes that the vacuum is applied in a cyclic manner between the maximum vacuum intensity (i.e., the highest absolute value of the applied suction force) and the minimum suction force (which can be a suction force of 0 mmHg).

[0020] Suction pressure is typically negative. For ease of understanding of the technical instructions, the applied suction pressure is referred to as absolute suction pressure, where high suction pressure provides the highest suction effect at the nipple, while low suction pressure provides the lowest suction effect or no suction effect at the nipple and / or any area of ​​the breast pump. The minimum suction pressure is typically 0 mmHg. Suction cycles may also apply some positive pressure to the breast or nipple.

[0021] Furthermore, at least one operating parameter adjusted in response to a signal indicating volumetric flow rate can be the shape of the vacuum curve. WO 2003 / 082378 A1 discloses various vacuum curves within a specific cycle. The vacuum curve can exhibit a parabolic or sinusoidal curve between the highest and lowest suction values. As shown in Figure 14 of WO2003 / 082378A1, the suction curve can also exhibit a specific distribution with a peak of maximum suction and a plateau near the peak, which has a fairly steep slope from the lowest suction (i.e., suction at 0 mmHg) to the plateau or peak. The vacuum curve can be generated by the single-stroke or multi-stroke operation of the pump, which serves as the vacuum source. In response to a signal indicating volumetric flow rate, the speed of the motor (i.e., the pump-suction unit) and the airflow velocity moving within the milk pump can be changed.

[0022] Operating parameters and their actual distributions and values—namely, vacuum intensity, cycle frequency, or the shape of the vacuum profile over time—can exist in specific locations on a breast pump, such as the vacuum source, milk channel, collection container, or breast shield, particularly near the nipple. Due to the compressibility of air, the actual vacuum intensity, cycle frequency, and / or the shape of the vacuum profile over time, measured, for example, at the nipple, may deviate from the operating parameters set for the pump in this respect.

[0023] For the purpose of implementing this invention, measuring each parameter at a specific location within the breast pump and the configuration of each parameter are not crucial. However, adjusting the operating parameters of the vacuum sources within the breast pump in response to the actual milk flow is crucial during pumping operations of one or more vacuum sources in the apparatus for applying the method.

[0024] This method is particularly suitable after the expression phase begins, i.e., during or after "milk discharge". In other words, the control and adjustment of operating parameters in response to signals indicating milk volume flow rate is preferably carried out after the stimulation phase ends and during the so-called expression phase of collecting milk from the udder.

[0025] The operating parameters are continuously or cyclically adjusted. To avoid unstable operating conditions of the vacuum source due to sudden changes in vacuum source parameters, once the operating parameters are set in response to a signal indicating the milk volume flow rate, the vacuum source control can apply a holding time to maintain the operating parameters at a certain level for a predetermined period of time. This holding phase can be applied for several seconds to several minutes. Preferably, the holding time is set between 5 seconds and 300 seconds.

[0026] According to a preferred embodiment of the invention, the signal used to adjust at least one operating parameter is a signal indicating a quantitative milk volumetric flow rate. In other words, the actual volumetric flow rate, and not merely the presence or absence of milk flow, is used to adjust at least one operating parameter. The resolution of the volumetric flow rate over time can be quite coarse, especially if the volumetric flow rate is determined periodically by measuring the volume in the measuring chamber. The method of implementing the invention may not require continuous information about the actual amount of volumetric flow rate. Assigning the volumetric flow rate to different masses may be sufficient, such as a normal volumetric flow rate, a high volumetric flow rate, or a low volumetric flow rate, where a low volumetric flow rate may include zero milk volumetric flow rate.

[0027] Typically, when the milk volumetric flow rate is between a low and a high flow rate threshold, the operating parameters of the vacuum source can be selected within a conventional range, particularly the vacuum intensity, circulation frequency, or the shape of the vacuum profile over time. These conventional or default operating parameters may correspond to those typically applied during the extrusion stage in the prior art. Depending on the individual needs of the milk pump user, if the user is uncomfortable with one or more preset default operating parameters, they can change these default operating conditions to set parameters that optimize the volumetric flow rate for higher yields under comfortable conditions, while also being suitable for milder conditions.

[0028] Once set by the user, when the milk volume flow rate is between the low flow rate threshold and the high flow rate threshold, one or more corresponding operating parameters are used as new regular operating parameters and can be stored as new default values.

[0029] Preferably, if the signal indicating milk volumetric flow rate is higher than a high flow rate threshold, the default operating parameters are adjusted to enhance the operating parameters of the vacuum source. The inventors have observed that, in particular, a high milk volumetric flow rate allows enhanced operating parameters to be applied to the breasts of lactating women without adversely affecting user comfort and / or negatively impacting breast tissue properties. Therefore, in cases where the milk flow rate is higher than the high flow rate threshold, a preferred embodiment of the method of the present invention selects enhanced operating parameters for achieving higher yields.

[0030] With enhanced vacuum strength, the corresponding vacuum strength has a higher absolute value than the conventional vacuum strength, and it is applied when the milk volumetric flow rate is between the low flow rate threshold and the high flow rate threshold. For example, if the default vacuum strength is set to 200 mmHg, the enhanced vacuum strength can be a suction force corresponding to 250 mmHg or even 300 mmHg.

[0031] The enhanced cycle frequency may be lower than the default frequency. During the stimulation phase, the cycle frequency can be set to 100 to 150 cycles per minute, while during the extrusion phase and when there is milk volume flow, a cycle frequency of approximately 10 to 78 cycles per minute (preferably approximately 28 to 78 cycles per minute) can be applied. Within this range, the default cycle frequency can be set, for example, to 45 to 99 cycles per minute, preferably 45 to 78 cycles per minute, while the enhanced cycle frequency can be 28 to 44 cycles per minute.

[0032] Regarding the vacuum curve, when the volumetric flow rate of the milk is between a low flow rate threshold and a high flow rate threshold, conventional (i.e., normally applied) conditions can be applied. The enhancement shape of the time-varying vacuum curve can be any distribution that is observed to lead to a higher volumetric flow rate, i.e., milk being expelled from the udder. The enhancement shape of the time-varying vacuum curve can exhibit a fairly steep curve from a low vacuum intensity value or a zero vacuum intensity value to the maximum suction value, where the plateau is near the maximum suction value and drops sharply at the end of the cycle, returning to a low vacuum or no vacuum being applied at the end of the cycle.

[0033] In summary, enhancing one or more operating parameters will apply a higher vacuum intensity to improve the efficiency of milk extraction from the breast. Sensors can, for example, notify the volumetric flow rate and observe information indicating the amount of volumetric flow. Such sensor signals can be transmitted to algorithmically defined threshold levels to change the operating parameters, thereby switching to operation that increases milk output. Default operating conditions, either automatically or after individual adjustment by the user of the breast pump, conform to comfortable operation within low and high flow thresholds, and these one or more operating parameters will be enhanced to increase milk output.

[0034] The acceptable range for enhanced operating parameters (such as vacuum intensity) can be varied by the user based on the volumetric flow rate (i.e., the flow rate of milk from the breast). The sensor can detect volumetric flow rates above a threshold level defined by the algorithm and enables the vacuum source system to automatically enhance at least one operating parameter.

[0035] According to a preferred embodiment of the invention, if the signal indicating milk volume flow rate is below a low flow rate threshold, at least one operating parameter of the vacuum source is reduced. The reduced vacuum intensity will be a lower vacuum intensity. This lower vacuum intensity can be as low as the vacuum intensity applied during the stimulation phase. The reduced vacuum intensity can be assumed to be even lower than the value of the vacuum intensity applied during the stimulation phase. Different vacuum intensity values ​​can be applied, each lower than the default vacuum intensity.

[0036] A reduced cycle frequency is a more moderate cycle frequency and can be achieved by applying a larger number of cycles per minute. The reduced cycle frequency can correspond to the frequency applied during the stimulation phase.

[0037] The decreasing shape of the vacuum curve over time can be represented by a smoothing of the vacuum curve, such as the extremely gentle suction described in WO2003 / 082378 A1 (compare Figure 12). Specifically, in the vacuum intensity curve, the smooth transition from zero suction intensity to maximum suction intensity and the return to zero suction intensity without sharp edges and abrupt increases can characterize the decreasing shape of the vacuum curve over time. Furthermore, each cycle may include a period of no suction, which can be assumed to correspond to 30% to 50% of the duration of each cycle. In other words, suction can be applied only for a portion of each vacuum cycle, while no suction is applied for the remainder.

[0038] With reduced operating parameters applied, the aforementioned sensor can detect milk volume flow rates above the low flow threshold defined by the algorithm, and can enable the vacuum source to automatically enhance at least one operating parameter to apply the default parameter, and increase milk output, for example, after a period in the extrusion stage when no milk volume flow rate is detected or the detected milk volume flow rate is very low.

[0039] When milk flow decreases to a low-flow or no-flow state, applying a relatively high vacuum intensity and a slow, long circulation can adversely affect breast tissue properties, leading to swelling and edema, as well as ductal contraction and reduced milk output. Based on this finding, the present invention preferably proposes reducing at least one operating parameter when milk flow is below a low-flow threshold.

[0040] Generally, the actual amount of milk flowing from the breast shield to the collection container can be used as a signal indicating volumetric flow rate. However, the first or second derivative of the signal over time can also be used, for example, to compare this value with a pre-selected threshold to determine whether one or more operating parameters should be adjusted to address different flow conditions or different expected flow conditions.

[0041] The first derivative, which approaches zero over time, can be used to detect changes in milk volumetric flow rate. If the change in volumetric flow rate over time is positive (i.e., the first derivative is positive), and the corresponding first derivative is close to zero, a local or absolute maximum value of the volumetric flow rate may have been reached. This could be a reason to adapt the operating parameters to either a stronger or weaker setting. Conversely, if the corresponding first derivative of the volumetric flow rate over time (i.e., the change in volumetric flow rate over time) is negative and close to zero, an absolute or local minimum value of the milk volumetric flow rate curve over time may be approaching, which could again necessitate adjusting at least one operating parameter.

[0042] When the volumetric flow rate changes over time (i.e., the first derivative of volume over time) is assumed to be high, the operating parameters can be strengthened to increase the efficiency of milk extraction. However, when the first derivative of volumetric flow rate over time is low (i.e., the volumetric flow rate increases slowly over time), that is, when the volumetric flow rate signal reaches a plateau over time, at least one operating parameter can be reduced.

[0043] High volume change over time (dV / dt) is typically between 15 ml / min (0.27 g / s) and 18 ml / min (0.33 g / s), while low dV / dt is between 5 ml / min (0.9 g / s) and 7 ml / min (1.3 g / s).

[0044] As described above, by comparing the value of the second derivative of the volumetric flow rate over time with a pre-selected threshold, the second derivative of the volumetric flow rate over time can also be used to adjust operating parameters in order to determine whether to adjust at least one operating parameter to an enhanced or reduced state.

[0045] According to an alternative embodiment, it can also be implemented in the control of the vacuum source to adapt at least one operating parameter, analyzing the volumetric flow rate during at least one vacuum cycle to adjust at least one operating parameter of the vacuum source for at least one subsequent vacuum cycle. In other words, the decisive basis for setting the operating parameters is not the absolute volumetric flow rate obtained during milk extraction from the udder, but the output of at least one particular previous vacuum cycle to set at least one operating parameter for a subsequent vacuum cycle, which may be a vacuum cycle directly preceding the previous vacuum cycle. As previously mentioned, a holding time can also be applied in this embodiment to avoid instantaneous adaptation of the operating parameters between each cycle. Therefore, at least one vacuum cycle may be a sequence of multiple vacuum cycles and / or at least one subsequent vacuum cycle may be a sequence of multiple vacuum cycles.

[0046] According to a preferred embodiment of the invention, the milk volumetric flow rate during at least one vacuum cycle is analyzed for the peak volumetric flow rate and / or total volumetric flow rate during at least one vacuum cycle. Based on the analysis of the cycle, if the peak volumetric flow rate and / or total volumetric flow rate increases between earlier and later cycles, at least one operating parameter of the vacuum source is strengthened in at least one subsequent vacuum cycle. On the other hand, if the peak flow rate and / or total volumetric flow rate of a subsequent vacuum cycle is lower than the flow rate in the vacuum cycle preceding the earlier vacuum cycle, at least one operating parameter of the vacuum source is reduced.

[0047] Adjustments to at least one operating parameter based on cycle-to-cycle analysis can lead to an instantaneous adaptation of the operating parameter to actual milk flow conditions, which is evaluated based on peak flow rate or total volumetric flow rate during at least one vacuum cycle.

[0048] A preferred embodiment of the method can be performed by utilizing information from a memory indicating the volumetric flow rate during at least one vacuum cycle. The memory may store data indicating the volumetric flow rate during a specific time period, during which operating parameters are adjusted. The setting of the operating parameters can also be performed based on information obtained by learning the control behavior of the operating parameters in response to signals indicating the milk volumetric flow rate. Therefore, similar control of operating parameters responding to specific behaviors of the milk volumetric flow rate can be retrieved from the memory to adjust at least one operating parameter. In other words, the memory may store a history of operating parameters and / or a history of milk volumetric flow rates. As previously mentioned, corresponding data can be obtained within the same time period. The memory may also store the correlation between at least one operating parameter and the time-varying milk volumetric flow rate of a previous time period or all previous time periods, and apply this data to the actual control of at least one operating parameter during the actual time period.

[0049] Generally, the appropriate setting of operating parameters according to this preferred embodiment will be performed based on history stored in memory, and this history belongs to the history of operating parameters and / or the history of milk volumetric flow rate. The history of operating parameters may store the setting of at least one operating parameter (preferably all operating parameters) of the vacuum source over time. Preferably, this data is stored together with the history of milk volumetric flow rate in order to correlate the final milk flow rate of each user and to correlate the milk discharge efficiency of each user with the setting of at least one operating parameter.

[0050] Therefore, the control of the vacuum source is based on the experience of the specific user, so as to provide the best milk extraction efficiency for the corresponding user by triggering a signal indicating the milk volume flow rate.

[0051] In summary, where the signal indicating milk volumetric flow rate confirms the hypothesis that at least one enhanced operating parameter will increase the extracted milk volumetric flow rate, the method of the present invention allows for improved milk extraction efficiency by applying at least one enhanced operating parameter. On the other hand, if the milk volumetric flow rate signal indicates a period of low or no flow during milk extraction, at least one operating parameter is reduced to avoid negatively impacting breast tissue properties due to high or conventional operating parameters used to generate a higher volumetric flow rate than during periods of no or low flow.

[0052] At least one operating parameter can be set based on the actual milk volume flow rate. This can be based, for example, on the first derivative with time (dV / dt) or the second derivative with time (d...). 2 V / dt 2 This method analyzes signals indicating milk volumetric flow rate to identify transitions from increasing to decreasing milk flow rate over time and / or the rate of change of milk flow rate at different flow velocities. For the purposes of the above description, the fact that the first derivative of the volumetric flow rate with time approaches zero does not necessarily mean that a zero actual value of the change in volumetric flow rate over time (dV / dt) must be observed. In fact, the plateau between the first and second periods of increasing milk flow rate can also be considered as the change in volumetric flow rate over time approaching zero. This plateau may still indicate a slight increase in volumetric flow rate. The same applies to the plateau between the first and second periods of decreasing milk flow rate, which may indicate no change in milk flow rate or a slight decrease over time.

[0053] Alternatively, different vacuum cycles can be compared with signals indicating milk flow rate to set at least one operating parameter for the actual vacuum cycle or previous vacuum cycles. This control allows for the analysis of a single vacuum cycle or multiple vacuum cycles and / or the setting of at least one operating parameter for a single vacuum cycle or multiple subsequent vacuum cycles.

[0054] Additionally or alternatively, particularly after the breast pump has been running for an extended period, the control of the vacuum source in response to signals indicating milk flow can be adjusted based on historical data, particularly based on the correlation between the setting or adjustment of at least one operating parameter and the individual user's response to the milk extraction rate (i.e., milk volumetric flow rate). This aspect is particularly well-suited to addressing the individual needs and behaviors of a particular user. The system preferably employs artificial intelligence to refine the setting of the operating parameter regarding milk volumetric flow rate, ultimately enabling the setting of at least one operating parameter best suited to each user, thereby optimizing milk flow while gently treating breast tissue during periods of no flow.

[0055] The present invention also relates to a breast pump having a controller for controlling a vacuum source, as described above.

[0056] The invention will now be further explained with reference to various embodiments thereof and to the accompanying drawings. In the drawings:

[0057] Figure 1 shows the milk volumetric flow rate as a function of time. Figure 1a A schematic diagram showing the relationship between vacuum intensity and different operating parameters. Specifically, these different parameters are vacuum intensity (…). Figure 1b ), cycle frequency ( Figure 1c ) and the vacuum curve as a function of time ( Figure 1d ) and the different phases during the stimulation and extrusion phases ( Figure 1e ),and

[0058] Figure 2 is an example of an analysis between cycles, with the graph showing the milk volumetric flow rate changing over time. Figure 2b ) and the vacuum intensity applied in each cycle ( Figure 2a (related to)

[0059] exist Figure 1a In the graph, the vertical axis represents the actual value of the volumetric flow rate, and the horizontal axis represents time. At time t = 0, the stimulation phase is applied. As a response, milk expulsion will eventually occur at t1. t1 represents the first significant milk volumetric flow rate. Shortly after t1, the volumetric flow rate curve will intersect with the low flow threshold line I, which corresponds to a milk volumetric flow rate of 5 ml / min (0.09 g / s). At t2, the volumetric flow rate curve will intersect with the high flow threshold line II, which is 11.9 ml / min (0.22 g / s). Between t2 and t4, the milk volumetric flow rate is higher than this high flow threshold II. Therefore, enhanced operating parameters are applied, which will be determined by referencing... Figures 1b to 1d Let me explain further.

[0060] During the stimulation phase and before t1, a stimulation vacuum intensity of approximately 50 mmHg will be applied. Figure 1b ) and a cycle frequency of 100 to 120 cycles per minute ( Figure 1c Curve shape () Figure 1d This means that the vacuum curve, which varies with time, has a parabolic shape, reaching its maximum value in the middle of each cycle, but transitions smoothly from 0 mmHg to the maximum vacuum intensity. Figure 1d In the process, all curves reach 100% vacuum intensity, where the vacuum intensity level of each curve can be different and can be obtained from... Figure 1b Detected in the medium.

[0061] The first milk volumetric flow rate at point t1 is sensed, and the operating parameters for the stimulation phase are controlled by shutting down the milk pump. The operating parameters for the expression phase control the performance of the vacuum source of the milk pump. With the start of milk flow, normal (i.e., default) operating parameters are used to control the vacuum source. The cycle frequency is set lower than in the stimulation phase. The normal cycle frequency is set to 50 CPM. The vacuum curve shows a sharp increase in vacuum in each cycle, reaching a plateau at maximum vacuum intensity, which then drops to another plateau approximately 80% of maximum vacuum intensity. At the end of the plateau, the vacuum drops to 0 mmHg before rising again to reach the next plateau of the next vacuum curve. A corresponding vacuum curve varying over time is applied to each cycle frequency. This is in... Figure 1c and 1d This is not adequately reflected in the figure because some details of the vacuum curve changing over time need to be clarified in the figure.

[0062] However, the cycle frequency and cycle profile generally do not necessarily originate directly from the stroke of the vacuum pump that forms the vacuum source. Each cycle frequency and / or each vacuum profile that varies over time can originate from multiple strokes of the pump, which may have additional chambers for storage and / or valves for controlling the actual vacuum, the vacuum profile that varies over time, and possible vacuum frequencies, for example, at a breast shield or in the milk duct.

[0063] from Figure 1a , 1c The comparison with 1d clearly shows that regardless of whether the actual milk volumetric flow rate is below or above the high flow threshold II, the default operating parameters of the circulation frequency and the vacuum curve over time remain the same. However, as clearly shown at t4, if the volumetric flow rate intersects with the high flow threshold, which has a negative dV / dt (i.e., the descending phase of the volumetric curve), the vacuum intensity will decrease. At t5, a value of dV / dt = 0 is observed, which triggers the setting of the normal vacuum intensity.

[0064] Between t2 and t4, enhanced operating parameters for the cycle frequency, time-varying vacuum curve, and vacuum intensity are applied. Clearly, the enhanced vacuum intensity is higher than the conventional vacuum intensity before t1. On the other hand, the enhanced cycle frequency and the enhanced time-varying vacuum curve are the same as the corresponding default operating parameters between t1 and t2.

[0065] At t6, dV / dt is observed between dV / dt>0 and dV / dt<0. However, this observation falls between the high flow threshold II and the low flow threshold I, and therefore will not lead to adjustment of the operating parameters of the vacuum source in the exemplary embodiment.

[0066] At t7, the flow rate curve intersects with the low flow rate threshold I. Therefore, the vacuum intensity drops to 80 mmHg, which is the first decrease in vacuum intensity. The circulation frequency will increase to 78 CPM, which is the first decrease in circulation frequency value. Figure 1d The shape of the first decreasing curve shown in the example corresponds to the curve during the stimulation phase.

[0067] Between t9 and t10, the flow rate is very low and eventually reaches zero. Therefore, the vacuum intensity is further reduced to a second decreasing level of 50 mmHg, while a cycle frequency of 100 to 120 cycles per minute is applied, as in the stimulation phase; this represents the second decreasing cycle frequency. The curve shape between t9 and t10 is essentially the same as that between t7 and t9. This decreasing shape of the vacuum curve over time shows a smooth increase and decrease without a plateau. It corresponds to a sine curve, with its absolute minimum corresponding to a vacuum intensity of 0 mmHg.

[0068] While the volumetric flow rate curve between t10 and t11 (i.e., the curve from zero flow to a flow value above the low flow threshold at t11) can resemble the volumetric flow rate curve after t1, the pump control is made aware of the fact that this volumetric flow rate behavior is observed during the extrusion phase. Although the vacuum intensity and cycle frequency are set to "default" as previously stated, the time-varying vacuum curve between t11 and t13 (i.e., between the high flow threshold II and the low flow threshold I) presents a different curve than that between t1 and t7. The time-varying vacuum curve shows multiple steps from zero to the maximum intensity value and a sharp drop from there to the zero line before the start of the next cycle.

[0069] After t13, the milk volumetric flow rate further decreases and eventually dries up at t14. During this period, the decreasing shape of the vacuum curve is given a fairly sharp edge between the vacuum rise and the vacuum drop to zero. The cycle frequency between t13 and t14 is the same as between t10 and t13. The vacuum intensity is the same as between t7 and t9, i.e., 80 mmHg.

[0070] After t14, a reduced vacuum intensity of 50 mmHg was applied, the same as in the stimulation phase. The cycle frequency was the same as in the stimulation phase. The vacuum curve over time after the reduced vacuum curve appeared at t14 was the same as between t13 and t14.

[0071] As from Figure 1e It is evident that there are problems with milk extraction from the user's breast during the expression phase and after the stimulation phase, i.e., after t1. Between t8 and t10, controlling the vacuum source to gently treat breast tissue is the ultimate goal of vacuum source control. Attempts to optimize the milk expression protocol are underway. Figure 1e The letter E is used to represent the general treatment of the tissue, while G is used to represent the general treatment of the tissue.

[0072] When milk flow increases after t10, the mild treatment regimen G is switched to the extraction regimen E to improve the efficiency of milk extraction. Intersecting the low flow threshold I with negative dv / dt (i.e., when milk flow decreases) will make the mild treatment regimen G effective (comparison). Figure 1e ).

[0073] The above description in Figure 1 is merely an example. In this embodiment, the adjustment of the operating parameters is primarily triggered by thresholds I and II. However, over time, it may be triggered by the first derivative. For example, if the increase in volumetric flow rate between t1 and t2 is considered high, observing this change in volumetric flow rate over time, dV / dt, can also trigger the adjustment of the operating parameters. On the other hand, if the decrease between t4 and t5 is considered high, and because the volumetric curve has a negative dV / dt, a very high absolute value of dV / dt can also trigger a shift from enhanced operating parameters to default or reduced ones.

[0074] Figure 2 illustrates the adjustment of vacuum intensity as the sole operating parameter based on cycle-to-cycle operation. In the embodiment described, Figure 2b The observed volumetric flow rate analysis is the response to the applied cycles C1, C2, and C3. Figure 2a ).Notice, Figure 2a The vertical axis has a negative pressure value on the positive scale.

[0075] DV1, DV2, and DV3 are each subsequent peak flow differences. For example, DV2 is the difference between the peak flow PV1 caused by the first cycle C1 and the minimum flow observed in the second cycle C2. Each cycle C1, C2, and C3 has a high-phase vacuum intensity HV and a low-phase vacuum intensity LV. In each subsequent cycle, the DV value increases with time, thus cycling. Therefore, a positive evolution of the volumetric flow rate over time can be observed.

[0076] Therefore, the high-phase vacuum intensity HV of the second cycle C2 is set higher than that of C1, while the low-phase vacuum intensity LV of the second cycle C2 is set lower than that of C1. Consequently, the absolute pressure difference at the nipple will increase in subsequent cycles C1 and C2. Based on the corresponding findings from comparing DV3 with DV2, the absolute pressure difference and / or vacuum intensity HV between LV and HV may increase and thus be enhanced in the high-phase phase of cycle C, with the expectation of a further increase in volumetric flow rate in subsequent cycles C4, C5, or C6 (not shown).

[0077] The absolute volumetric flow rate PV2 in cycle C2 is also higher than the peak volumetric flow rate PV1 in the earlier cycle C1, which can serve as another criterion for strengthening the vacuum intensity in the next cycle C3.

Claims

1. A method for regulating the operation of a milk pump by applying a vacuum through a vacuum source, said vacuum source being operatively coupled to a controller for controlling the operation of said vacuum source, wherein said controller receives a signal indicating a volumetric flow rate (V) of milk and adjusts at least one of the following operating parameters of said vacuum source: vacuum intensity, circulation frequency, or the shape of a vacuum curve over time, and wherein: -If the signal indicating the volumetric flow rate (V) of the milk is between a low flow rate threshold and a high flow rate threshold, then at least one operating parameter of the vacuum source is set to a default value (D). - If the signal indicating the volumetric flow rate (V) of the milk is higher than the high flow rate threshold, at least one operating parameter of the vacuum source is enhanced (I). - If the signal indicating the volumetric flow rate (V) of the milk is below the low flow rate threshold, at least one operating parameter of the vacuum source is reduced (DE).

2. The method according to claim 1, wherein, The operating parameters are adjusted after the extrusion stages (E, G) begin.

3. The method according to claim 1, wherein, The signal indicates a quantitative volumetric flow rate (V).

4. The method according to claim 1, wherein, If the signal indicating the volumetric flow rate (V) of the milk is between the low flow rate threshold and the high flow rate threshold, all operating parameters are set to their default values ​​(D).

5. The method according to claim 1, wherein, If the signal indicating the volumetric flow rate (V) of the milk is below the low flow threshold, then at least one operating parameter of the vacuum source applied in the stimulation phase (S) is selected during the extrusion phase (E; G).

6. The method according to claim 1, wherein, If the value of the change in volumetric flow rate (V) over time (dV / dt) approaches zero, then at least one operating parameter of the vacuum source is adjusted.

7. The method according to claim 6, wherein, If the positive value of the change in volumetric flow rate (V) over time (dV / dt) is close to zero, then at least one operating parameter of the vacuum source is enhanced.

8. The method according to claim 6, wherein, If the negative value of the volumetric flow rate (V) change over time (dV / dt) approaches zero, then at least one operating parameter of the vacuum source is reduced.

9. The method according to claim 1, wherein, The value of the volumetric flow rate (V) changing over time (dV / dt) is analyzed, and when the value of the volumetric flow rate (V) changing over time (dV / dt) is high, at least one operating parameter of the vacuum source is enhanced, and when the value of the volumetric flow rate (V) changing over time (dV / dt) is low, at least one operating parameter of the vacuum source is reduced.

10. The method according to claim 1, wherein, Analyze the volumetric flow rate (V) during at least one vacuum cycle (C1, C2, C3) to adjust at least one operating parameter of the vacuum source for at least one subsequent vacuum cycle (C2, C3).

11. The method according to claim 1, wherein, Analyze the volumetric flow rate (V) during at least one vacuum cycle (C1, C2, C3), i.e., the peak volumetric flow rate (V) and / or total volumetric flow rate (V) during said at least one vacuum cycle (C1, C2, C3); Wherein, if the peak volumetric flow rate (PV1, PV2) and / or the total volumetric flow rate (V) increases between earlier and later vacuum cycles, then at least one operating parameter of the vacuum source is enhanced in at least one subsequent vacuum cycle (C2, C3), and If the peak volumetric flow rate (V) and / or the total volumetric flow rate (V) decreases between earlier and later vacuum cycles, then at least one operating parameter of the vacuum source is reduced in at least one subsequent vacuum cycle (C2, C3).

12. The method according to claim 1, wherein, The at least one operating parameter is adjusted based on data stored in a memory containing the history of operating parameters and / or the history of milk volumetric flow rate (V).

13. The method according to claim 10 or 11, wherein, Information indicating the volumetric flow rate (V) during the at least one vacuum cycle is obtained from a memory that stores the history of operating parameters and / or the history of milk volumetric flow rate (V).

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