Method for operating a milk pump

Abstract

The invention relates to a method for operating a milk pump (1) for pumping breast milk, which milk pump (1) is operated alternately in a negative pressure phase (PHU) and a subsequent ventilation phase (PHB), in which negative pressure phase (PHU) at least one motor (2) of the milk pump (1) drives a negative pressure unit (3) of the milk pump (1) to generate a negative pressure between a mother's breast and a breast shield (4) of the milk pump (1) resting against the mother's breast, and in which ventilation phase (PHB) the negative pressure is reduced, wherein the at least one motor (2) is operated with a starting power (PS) at the start of the negative pressure phase (PHU) and with an end power (PE) at the end of the negative pressure phase (PHU), wherein, in a low-noise operating mode, the motor power (P) is increased incrementally from the starting power (PS) to the end power (PE) between defined successive time intervals (TI) which together extend over the entire negative pressure phase (PHU).

Description

[0001] Method for operating a breast pump

[0002] The invention relates to a method for operating a breast pump for pumping breast milk, which breast pump is operated alternately in a negative pressure phase and a subsequent ventilation phase, in which negative pressure phase at least one motor of the breast pump drives a negative pressure unit of the breast pump to generate a negative pressure between a mother's breast and a breast shield of the breast pump resting on the mother's breast and in which ventilation phase the negative pressure is reduced, wherein the at least one motor is operated with a starting power at the beginning of the negative pressure phase and with a final power at the end of the negative pressure phase.

[0003] The invention further relates to a method for adjusting a breast pump with which the method for operating a breast pump is carried out.

[0004] Finally, the invention relates to a breast pump for pumping breast milk, with a breast shield for application to a mother's breast, a vacuum unit for generating a vacuum between the mother's breast and the breast shield applied to the mother's breast in a vacuum phase, at least one motor for operating the vacuum unit, a drive unit for the at least one motor and a ventilation device for reducing the vacuum in a ventilation phase following the vacuum phase, wherein a starting power of the at least one motor is provided at the beginning of the vacuum phase and a final power of the at least one motor is provided at the end of the vacuum phase.

[0005] It is known that breast pumps for expressing breast milk alternate between a vacuum phase and a subsequent ventilation phase. During the vacuum phase, a vacuum is created between the mother's breast and a breast shield attached to the mother's breast, e.g. a funnel of the breast pump. This vacuum is then released again during the ventilation phase. Breast pumps with a motor that drives a vacuum unit that creates the vacuum required for the pumping process are particularly convenient for a breastfeeding mother. The advantage of not having to carry out the pumping process manually using a hand pump is offset by the disadvantage that the motor makes a noise when in operation.The volume of the motor noise depends particularly on the motor speed, which in conventional breast pumps is particularly high at the beginning of the vacuum buildup, since at this point no significant vacuum has yet been built up between the mother's breast and the breast shield, and the motor only has to work against a very light load. The comparatively loud motor noise at the beginning of each vacuum phase, as well as during the vacuum phase, can be perceived as disturbing by the mother using the breast pump.

[0006] Breast pumps are known in the state of the art which start the vacuum phase with a reduced motor speed in order to avoid loud motor noise.

[0007] EP 2 897 664 B1 relates to a milk pump system with a vacuum pump driven by an electric motor and a controller which drives the electric motor at a first speed when the vacuum pump is switched on and at a second, higher speed after a load on the motor has reached a predetermined value. The first and second speeds can be achieved by means of a first voltage on the electric motor for the first speed and by means of a second, higher voltage on the electric motor for the second speed. The transition profile from the first to the second voltage can be abrupt, or the first voltage is gradually, in particular linearly, increased to the second voltage over a defined time interval, whereby the motor accelerates evenly.

[0008] The document EP 3 735 994 A1 relates to a breast pump which has a controller and a vacuum pump driven by an electric motor. The controller controls the electric motor in an extraction mode following a stimulation mode, in which each pumping cycle has a pumping period PP and an aeration period AP. The controller controls the supply voltage of the motor during the pumping period in five stages, wherein in two of the stages the supply voltage of the electric motor is increased at different gradients. In this way, the electric motor accelerates rapidly. Since the current in the electric motor is kept below a threshold value, the service life of the electric motor is increased.

[0009] However, the known breast pumps have the disadvantage that the noise they produce can still be perceived as disturbing.

[0010] The object of the invention is to provide a method for operating a breast pump, a method for adjusting a breast pump, and a breast pump of the type mentioned above, which avoid or at least mitigate the disadvantages known from the prior art. The methods and the breast pump are intended to ensure the quietest possible, i.e., quiet, yet still reliable operation of the breast pump.

[0011] To this end, the invention provides a method for operating a breast pump as defined in claim 1, a method for adjusting a breast pump as defined in claim 8, and a breast pump for expressing breast milk as defined in claim 10. Advantageous embodiments and further developments are specified in the dependent claims.

[0012] With regard to the method for operating a breast pump, the invention provides that in a low-noise operating mode the motor power is increased gradually from the starting power to the final power between defined successive time intervals which together extend over the entire negative pressure phase. According to the method, the breast pump is thus operated alternately in a negative pressure phase and a subsequent ventilation phase until the process of pumping breast milk is ended by the mother or the breast pump itself. In the negative pressure phase, at least one motor of the breast pump drives a negative pressure unit of the breast pump in order to create a negative pressure between the mother's breast and the breast shield in a state of use of the breast pump in which a breast shield, for example a funnel of the breast pump, rests against the mother's breast, in particular receives part of the mother's breast.A negative pressure is understood here to be a pressure which is lower than the air pressure surrounding the breast pump. In the ventilation phase, the negative pressure built up in the negative pressure phase is at least partially reduced again, so that at the end of the ventilation phase the pressure between the breast shell and the mother's breast essentially corresponds or almost corresponds to the air pressure surrounding the breast pump, e.g. a value between the ambient air pressure and 30 mbar. For example, a ventilation valve which can be opened after the negative pressure phase can be provided to reduce the negative pressure. In order to build up the negative pressure, the motor (i.e. the at least one motor) is supplied with electrical energy and operated at a starting power at the beginning of the negative pressure phase and at a final power at the end of the negative pressure phase. Between the beginning and the end of the negative pressure phase, the motor power transitions from the starting power to the final power.

[0013] In order to operate the breast pump as quietly as possible, and in particular at the lowest possible speed, it has a low-noise operating mode. In the low-noise operating mode, the motor power is increased in stages from the starting power to the final power between defined, consecutive time intervals which together extend over the entire vacuum phase. This means that several consecutive time intervals are defined, namely a first time interval and several subsequent time intervals which, when strung together, extend over the entire vacuum phase. Between each two consecutive time intervals, the motor power is increased in stages. The stepped increase can essentially be a sudden increase. However, the description includes minor deviations from an exact sudden increase in the motor power, i.e.the motor power can increase steadily and rapidly in the borderline area between two successive time intervals, for example for a maximum of one third or one fifth, preferably for a maximum of one tenth of a time interval. An inaccurate sudden increase in motor power can, for example, be the result of inexpensive components or a generally inexpensive design of the breast pump. In any case, the motor power is gradually adapted to the current increasing load caused by the build-up of negative pressure by means of repeated gradual increases. This also keeps the motor speed within a suitable speed range and thus limits the noise generated by the motor. At the start of the negative pressure phase, i.e.If no vacuum has yet been generated, the engine is operated at a comparatively low starting power and low speed, which are sufficient to generate a slight vacuum by the end of the first time interval. The engine power is then increased to prevent the engine from stalling due to increasing vacuum, whereby a slightly greater vacuum is generated. However, the engine speed still remains low because of the increased load. This process is continued until the engine power has reached the final power in the last time interval of the vacuum phase and the vacuum has been fully built up. Even immediately before the end of the vacuum phase, the engine speed is still low because of the comparatively high final load.The engine power is therefore increased sufficiently before each time interval to avoid the engine coming to a standstill due to the increasing load on the engine during this time interval. However, the engine power is only increased enough before each time interval to enable the engine to operate at the lowest possible speed and thus as quietly as possible. As the engine power is increased in stages several times during the entire vacuum phase, the engine speed and therefore the noise level are kept low during the entire vacuum phase. The engine power can vary between the staged increases, i.e. during the individual time intervals. In this case, an average engine power value in one time interval is lower than an average engine power value in a subsequent time interval. I.e.The mean engine power values ​​are increased gradually from the starting power to the final power between defined consecutive time intervals, which together extend over the entire vacuum phase. The duration of a time interval can, for example, be between 10 ns and 500 ms, preferably between 1 ms and 100 ms.

[0014] Whenever this description refers to locations and directions such as "top", "bottom", "front", "back" or "side", these terms are to be understood in a position of use in which the breast pump is positioned on a mother's breast with the upper body held upright. The term "vertical" means in the direction of gravity, from "top" to "bottom", or vice versa. Of course, the breast pump can also be used in other positions, in which case the locations and directions must be translated accordingly. In addition, the motor is to be understood as at least one motor.

[0015] According to a preferred embodiment of the invention, it can be provided that at least four, preferably at least ten defined consecutive time intervals are provided which together extend over the entire negative pressure phase. The motor power is thus increased in stages at least three times, preferably at least nine times, once between each successive time interval. By frequently increasing the motor power in correspondingly small power steps, the motor power can be adapted particularly precisely to the current load on the motor due to the gradually building up negative pressure. Accordingly, the speed of the motor and the associated noise level of the breast pump can be kept as low as possible and have little fluctuation during the negative pressure phase. It is particularly advantageous here if the time intervals are the same.

[0016] The method can be carried out particularly simply and cost-effectively if the motor power is increased by a control for the at least one motor by specified values ​​between the time intervals. In this way, the speed of the motor can be kept in a suitable speed range that enables quiet operation of the breast pump. The breast pump is preferably configured with these specified values ​​before use. The specified values ​​by which the motor power is increased according to this control method between the time intervals during the negative pressure phase are particularly preferably the same. Alternatively, an individual increase in motor power, i.e. an individual power increase, can be assigned to each time interval if unequal power increases enable particularly quiet operation due to special properties of the breast pump.To achieve even lower noise levels during operation of the breast pump, it can be provided that a current speed of the at least one motor is detected, compared with a predetermined target speed, in particular one stored in the breast pump, and the motor power is increased by a control device for the at least one motor between the time intervals by a value which aligns the current motor speed with the target speed. Preferably, the current speed of the motor is detected in each time interval and compared with a target speed which can be the same or slightly different for the individual time intervals. The alignment of the current motor speed to the target speed can comprise a slight deviation from the target speed, for example in order to be able to manufacture the breast pump cost-effectively, as long as the deviation has no significant influence on the noise level.With such a control method, the engine power can be increased in steps of a suitable size between defined successive time intervals in order to maintain the speed as the load increases due to the building up of negative pressure, and in particular to keep it as constant as possible and at a low setpoint. The step size is determined by the control device. Speed ​​fluctuations and the associated noise fluctuations can thus be largely avoided. The current speed can be measured, for example, using a light barrier, by angle measurement at fixed time intervals, by electromagnetic induction or with a Hall sensor.

[0017] The operation of the breast pump can be particularly simple if the operating voltage of at least one motor is increased to increase motor power. Thus, in the low-noise operating mode, the operating voltage applied to the motor can be increased incrementally between defined consecutive time intervals, which together extend over the entire vacuum phase. For example, the operating voltage in each time interval can be a direct voltage that is increased from one time interval to the next.

[0018] It is particularly advantageous if the at least one motor is controlled via a pulse-width modulated voltage signal, in particular a rectified pulse-width modulated voltage signal, and if the pulse duration of the pulse-width modulated voltage signal is increased in order to increase the motor power. In this way, the voltage applied to the motor, i.e. the voltage signal applied to the motor, can be set simply and inexpensively with a suitable high resolution, which is predetermined by the number of time intervals. If the voltage signal is pulse-width modulated and not rectified, the voltage signal in each time interval is applied to the motor essentially as a set of square-wave signals with a defined amplitude level and adjustable pulse width, with voltage-free sections in between. The larger the pulse widths (and therefore the shorter the voltage-free sections), the more energy is made available to the motor.If, on the other hand, the voltage signal is pulse-width modulated and also rectified, for example by an electronic capacitor, the voltage signal is applied to the motor in each time interval essentially as a rectified alternating voltage signal without any dead sections but with a wavy amplitude curve. A rectified pulse-width modulated voltage signal has the advantage that the motor is treated somewhat better, since in the opposite case of a non-rectified pulse-width modulated voltage signal the motor is exposed to greater amplitude fluctuations. Before any rectification, the pulse-width modulated voltage signal can preferably have a frequency in the range between 50 Hz and 200 kHz, particularly preferably between 10 kHz and 30 kHz, in particular around 20 kHz.

[0019] According to a further embodiment of the method, it can be provided that the breast pump is operated in the low-noise operating mode or in a further operating mode, in the low-noise operating mode the vacuum phase is carried out during a first time period, the at least one motor is operated with a starting power in the amount of a first starting value and the at least one motor is operated with a final power in the amount of a first final value, and in the further operating mode the vacuum phase is carried out during a second time period, the at least one motor is operated with a starting power in the amount of a second starting value and the at least one motor is operated with a final power in the amount of a second final value, wherein the first final value is greater than the first starting value, the first time period is greater than the second time period,the first start value is smaller than the second start value and the first end value is smaller than or equal to the second end value. Thus, the negative pressure phase in the low-noise operating mode extends over a longer period of time than in the further operating mode. In addition, since the motor power is lower in the low-noise operating mode than in the further operating mode, the speed and thus the noise level of the motor can be kept lower than in the further operating mode, although at the end of the negative pressure phase essentially the same level of negative pressure is generated as in the further operating mode. The breast pump therefore needs more time to express the breast milk in the low-noise operating mode, but operates more quietly than in the further operating mode. The duration of the first period is preferably 1.3 to 2.5 times, in particular 2 times,the duration of the second time period. For example, the first time period lasts 2 seconds and the second time period 1 second. The first start value can preferably be between 10% and 30% of the second start value. The first end value can preferably be between 40% and 100% of the second end value. The speed of the motor in the low-noise operating mode can preferably be in a range between 500 rpm and 1500 rpm, in particular between 700 rpm and 1300 rpm, while the speed of the motor in the further operating mode can be in a range between 1000 rpm and 4000 rpm, in particular between 1400 rpm and 3600 rpm. The breast pump is preferably switched manually by the user between the low-noise operating mode and the further operating mode. Likewise, the breast pump could automatically select the low-noise operating mode when defined events occur, for example depending on the time of day.to pump out quietly in the evening.,

[0020] As mentioned at the outset, the invention also relates to a method for adjusting a breast pump, with which a method is carried out which provides that the motor power is increased by a controller for the at least one motor by specified values ​​between time intervals. With regard to the method for adjusting the breast pump, the invention provides that in the low-noise operating mode, the duration of the time intervals and the values ​​by which the motor power is gradually increased are specified and stored in the breast pump in such a way that a speed of the at least one motor during the negative pressure phase fluctuates at most in a range of 0.3 times to 1.7 times the value of the speed at the start of the negative pressure phase. The speed of the motor in the low-noise operating mode can preferably be in a range between 500 rpm and 1500 rpm, in particular between 700 rpm and 1300 rpm.Accordingly, the length of the time intervals and the values ​​by which the motor power is gradually increased are determined before the breast pump is used to express breast milk, in particular at the factory, and the breast pump is configured accordingly. In order to be able to operate different types of breast pumps as quietly as possible, the length of the time intervals and the values ​​by which the motor power is gradually increased are preferably determined individually for each design of breast pump, for example through test series. The values ​​are set in such a way that the speed can be kept low and fluctuates only slightly despite increasing load on the motor due to the building up of negative pressure. The fluctuation of the motor speed in the negative pressure phase should be at most in a range of 0.3 times to 1.7 times the speed value at the start of the negative pressure phase.The values ​​thus determined before using the breast pump are stored in the breast pump. Please note that the breast pump can be operated in quiet mode with multiple adjustable power classes, with each power class being assigned a starting power or a final power in quiet mode. If multiple power classes are used, a separate series of tests can be conducted for each power class, and the length of the time intervals and the values ​​by which the motor power is gradually increased can be stored in the breast pump for each adjustable power class.

[0021] If the motor power is increased by a control system for at least one motor by specified values ​​between time intervals, it is also advantageous if, in the low-noise operating mode, the duration of the time intervals and the values ​​by which the motor power is gradually increased are specified and stored in the breast pump in such a way that the final power is at least 50% greater than the starting power. In this way, the starting power can be correspondingly low, and the motor can be operated quietly with low motor power and low speed right from the start of the vacuum phase.

[0022] As mentioned at the outset, the invention also relates to a breast pump for pumping breast milk. With regard to the breast pump, the invention provides for a low-noise operating mode in which a profile of the motor power extending from the starting power to the final power has step-by-step increases between defined successive time intervals which together extend over the entire negative pressure phase. The breast pump therefore has a breast shield, for example a funnel for application to a mother's breast, a negative pressure unit for generating a negative pressure between the mother's breast and the breast shield applied to the mother's breast in a negative pressure phase, at least one motor for operating the negative pressure unit, a drive unit for the at least one motor and a ventilation device for reducing the negative pressure in a ventilation phase following the negative pressure phase.To build up the negative pressure, the motor has a starting power at the beginning of the negative pressure phase and a final power at the end of the negative pressure phase. In order to operate the breast pump as quietly as possible, the breast pump has a low-noise operating mode in which the motor power curve extending from the starting power to the final power has step-by-step increases between defined, successive time intervals which together extend over the entire negative pressure phase. The motor power curve with step-by-step increases enables, as already described in connection with the method, the motor power to be gradually adapted to the increasing load on the motor. This is why the motor can be operated at low power, low speed and therefore low noise levels at the beginning of the negative pressure phase.The motor power is gradually increased in order to overcome the increasing load, while the speed fluctuates less due to the increasing load on the motor than if the motor were operated at higher power right from the start of the vacuum phase and initially idled at high speed. With regard to the features of the breast pump, reference is also made to the preceding description of the methods insofar as this is helpful for understanding the breast pump and insofar as features of the breast pump can be derived from this description of the methods. Likewise, with regard to the features of the methods, reference is also made to the description of the breast pump.

[0023] According to a preferred embodiment of the breast pump, at least four, preferably at least ten defined consecutive time intervals can be provided, which together extend over the entire vacuum phase. The motor power profile thus has at least three, preferably at least nine step-by-step increases. In particular, the high number of at least ten consecutive time intervals makes it possible to operate the motor at low speed right from the start of the vacuum phase. The power levels, i.e. the increases, can have a spontaneous or a rapid continuous rise. Furthermore, the power levels can have a substantially constant or fluctuating value during the individual time intervals.

[0024] For particularly cost-effective production of the breast pump, it can be provided that the drive unit for the at least one motor has a controller which is designed to increase the motor power by specified values ​​between the time intervals. The specified values ​​are preferably stored in a memory of the breast pump and were determined before use by a user, in particular by the manufacturer themselves. Preferably, the temporal extensions of the time intervals are also stored in a memory of the breast pump. The controller can have a processing unit, for example a microprocessor.

[0025] In order to achieve a particularly low and precise speed of the at least one motor with little fluctuation, it is preferred that the drive unit for the at least one motor has a control device which is designed to detect a current speed of the at least one motor, to compare it with a predetermined target speed stored in particular in the breast pump and to increase the motor power between the time intervals by a value which adjusts the current motor speed to the target speed. The control device is preferably designed to detect the current speed of the motor in each time interval, to compare it with a target speed assigned to each time interval and to increase the motor power between the time intervals accordingly. The control device can have a processing unit, for example a microprocessor.

[0026] The motor power can be changed particularly easily if the drive unit for the at least one motor has an operating voltage source for controlling the at least one motor, which is designed to increase the operating voltage of the at least one motor in steps to increase the motor power. The operating voltage source can also be designed to keep the operating voltage of the motor constant between the increases.

[0027] The motor power can be adjusted cost-effectively in particularly small steps if the drive unit for the at least one motor has a supply source for a pulse-width-modulated voltage signal, in particular a rectified pulse-width-modulated voltage signal, which supply source is designed to gradually increase the pulse duration of the pulse-width-modulated voltage signal in order to increase the motor power. The motor can thus be supplied with a pulse-width-modulated voltage signal. In order to rectify the pulse-width-modulated voltage signal, i.e. to substantially smooth it, the supply source can have an electronic capacitor.

[0028] Furthermore, it can be provided that the breast pump is switchable between the low-noise operating mode and a further operating mode, in the low-noise operating mode the negative pressure phase extends over a first time period, the starting power of the at least one motor has a first start value and the final power of the at least one motor has a first end value, and in the further operating mode the negative pressure phase extends over a second time period, the starting power of the at least one motor has a second start value and the final power of the at least one motor has a second end value, wherein the first end value is greater than the first start value, the first time period is greater than the second time period, the first start value is less than the second start value and the first end value is less than or equal to the second end value.The breast pump therefore needs more time to build up the negative pressure in the low-noise operating mode, for example twice as long, and presumably more time to pump out the breast milk, but operates at a lower speed and therefore less noise because of the lower power compared to the other operating mode. Preferred numerical values ​​and ratios of the first and second time periods, the first and second start values ​​and the first and second end values ​​were already given above in the description of the method. The breast pump can have an input device, for example a button, a switch or a touch-sensitive screen, to enable a user to switch between the low-noise operating mode and the other operating mode.In another example, a software application, for example on a smartphone, may be provided for controlling the breast pump, in particular for switching between the low-noise operating mode and the wider operating mode.

[0029] If a maximum speed of the at least one motor in the low-noise operating mode is between 20% and 70%, preferably between 25% and 50% of a maximum speed of the motor in the further operating mode, the at least one motor of the breast pump can be operated particularly quietly.

[0030] The invention will be further explained below using preferred, non-limiting embodiments with reference to the drawings. In the drawings:

[0031] Fig. 1A is a simplified illustration of a step-by-step increase in the motor power of a breast pump in a low-noise operating mode according to the method of the invention;

[0032] Fig. 1B is a simplified illustration of a gradual increase in the operating voltage of the breast pump in low-noise operating mode;

[0033] Fig. 1C is a simplified representation of the speed of the breast pump in low-noise mode;

[0034] Fig. ID is a simplified illustration of the motor performance of the breast pump in another operating mode;

[0035] Fig. IE is a simplified representation of the operating voltage of the breast pump in the further operating mode;

[0036] Fig. 1 F is a simplified representation of a speed of the breast pump in the further operating mode;

[0037] Fig. 2A shows a pulse width modulated voltage signal and a rectified pulse width modulated voltage signal with which the motor can be controlled, with a shorter pulse duration;

[0038] Fig. 2B shows a pulse width modulated voltage signal and a rectified pulse width modulated voltage signal with which the motor can be controlled, with a longer pulse duration;

[0039] Fig. 3 shows an example of a flatter stepwise increase in engine power; and

[0040] Fig. 4 is a simplified block diagram of the breast pump according to the invention.

[0041] It should be noted that the individual figures are not necessarily drawn to scale. Furthermore, parts of the method or breast pump that are visible in other figures may be omitted from individual figures, provided that the omitted parts are not essential to the description of the individual figures.

[0042] Fig. 1A shows an exemplary curve of a motor power P, represented as a function of time t, of a breast pump 1 in a low-noise operating mode, in which the breast pump 1 is operated in a method for operating the breast pump 1 for pumping breast milk. It can be clearly seen from the curve that the breast pump 1 is operated alternately in a negative pressure phase PHU and a subsequent ventilation phase PHB. In the negative pressure phase PHU, at least one motor 2 of the breast pump 1 drives a negative pressure unit 3 of the breast pump 1 to generate a negative pressure between a mother's breast (not shown) and a breast shield 4, which can be a funnel and is adjacent to the mother's breast, of the breast pump 1, see also Fig. 4. In contrast, in the ventilation phase PHB the negative pressure is at least largely reduced again, for example completely.The breast milk is pumped out by the alternating operation of the breast pump 1 in the negative pressure phase PHU and the ventilation phase PHB. In order to build up the negative pressure between the mother's breast and the breast shield 4, the motor 2 is operated with a starting power PS at the beginning of the negative pressure phase PHU and with a final power PE at the end of the negative pressure phase PHU. If, in contrast to the method according to the invention, the motor 2 were operated with a high starting power PS which is approximately the same as the final power PE, the motor 2 would be operated at a correspondingly high initial speed because no negative pressure has yet been built up which could place a load on the motor 2. The noise generated by the motor 2 would accordingly also be high. Only gradually would the motor speed N and therefore the volume emanating from the motor 2 decrease as the negative pressure increases. It should be noted that the description of the figures applies to the case of a single motor 2.If the breast pump 1 has several motors 2 , these can be considered as a single motor 2 .

[0043] In order to be able to operate the breast pump 1, in particular the motor 2, with as little noise as possible, the breast pump 1 is operated in a low-noise operating mode. As Fig. 1A clearly shows, in the low-noise operating mode the motor power P is increased step by step several times from the starting power PS to the final power PE between defined successive time intervals TI, which together extend over the entire negative pressure phase PHU. Such a power level is designated PL in Fig. 1A. The motor 2 therefore starts with low power P, and therefore low speed N and low noise level. During the transition from the starting power PS to the final power PE, the motor power P does increase, but the built-up negative pressure also increases, which is why the speed N and the noise level of the motor 2 remain low.

[0044] In the example according to Fig. 1A, only two vacuum phases PHU and one ventilation phase PHB are shown. Of course, the method for operating a breast pump 1 for expressing breast milk can have considerably more than two vacuum phases PHU. In the example shown, the vacuum phase PHU has been divided into ten, in particular equally long time intervals TU to TI 10 . The motor power P is thus increased in steps nine times from the starting power PS to the final power PE. The vacuum phase PHU extends, for example, over 2 seconds and the ventilation phase PHB, for example, over 0.2 seconds. According to this example, the motor power P is increased every 0.2 seconds during the vacuum phase PHU. In other examples, the vacuum phase PHU can extend between 0.7 seconds and 3 seconds and the ventilation phase PHB between 0.1 seconds and 0.5 seconds.Furthermore, according to examples not shown, the negative pressure phase PHU can be divided into fewer than ten, for example, four or five, time intervals TI, or more than ten, for example, 20, 50, or 100, time intervals TI. The time intervals TI can also have different sizes. For the sake of clarity, only individual time intervals TI are provided with a reference symbol in Figures 1B to 1F.

[0045] In Fig. 1A the power curve is shown in a simplified manner, in which the step-by-step increase in engine power P takes place abruptly and the engine power P is constant during the individual time intervals TI. Within the scope of the invention, however, the step-by-step increase in engine power P between the defined successive time intervals TI can also take place continuously, so that the rising edge of the power levels PL does not run perpendicular to the time axis but at an angle of less than 90° to the time axis. Likewise, the engine power P can vary during the individual time intervals TI. Fig. 3 shows an example of a step-by-step increase in engine power P in an enlarged view. Starting from the starting power PS at the beginning of the first time interval TU, the engine power P decreases slightly by a difference value DP due to the negative pressure that builds up.At the boundary between the first time interval TU and the second time interval TI2, the engine power P is increased in steps, whereby the increase does not occur abruptly, but continuously over a time range TB, for example to the extent of 1 to 10% of a time interval TI. The engine power P then decreases slightly again, and so on. The difference value DP is less than the power level PL (i.e., less than the step-like increase in power) between successive time intervals TI.

[0046] Fig . 1B shows that in the vacuum phase PHU of the low-noise operating mode for the stepwise increase of the motor power P an operating voltage U of the motor 2 applied to the motor 2 is increased stepwise.

[0047] Fig. 1C shows a simplified representation of a speed N of the breast pump 1 in the low-noise operating mode. The speed N is shown as constant in the vacuum phase PHU. This can be achieved by detecting a current speed N of the motor 2, comparing it with a predetermined target speed Nsoll, which is stored in particular in the breast pump 1, and increasing the motor power P by a control device 5 for the motor 2 between the time intervals TI by a value which adjusts the current motor speed N to the target speed Nsoll. If, on the other hand, the motor power P is increased by a control device 6 for the motor 2 by predetermined values ​​(the power levels PL) between the time intervals TI, the motor speed N can fluctuate slightly.

[0048] Figures 2A and 2B show, by way of example, a pulse-width modulated voltage signal UPW and, in a simplified representation, a rectified pulse-width modulated voltage signal UPWG, with which the motor 2 can be controlled. The voltage signal shown in Fig. 2A, for example for the time interval TI2, has a smaller pulse width PW than the voltage signal shown in Fig. 2B, for example for the time interval TI8. Accordingly, the motor power P is also smaller in the time interval TI2 than in the time interval TI8. It can therefore be seen that in order to increase the motor power P, the pulse duration PW of the pulse-width modulated voltage signal is increased. According to the example shown in Figures 2A and 2B, the pulse-width modulated voltage signal has a frequency of 20 kHz.

[0049] Fig. 1D shows an exemplary profile of a motor power P, shown as a function of time t, of a breast pump 1 in a further operating mode, in which the breast pump 1 can be operated in a method for operating the breast pump 1 for pumping breast milk. While in the low-noise operating mode shown in Figs. 1A to 1C the vacuum phase PHU is carried out during a first time period TUG, the motor 2 is operated with a starting power PS to the extent of a first starting value SW1 and the motor 2 is operated with a final power PE to the extent of a first final value EW1, in the further operating mode shown in Figs. 1D to 1F the vacuum phase PHU is carried out during a second time period TUW, the motor 2 is operated with a starting power PS to the extent of a second starting value SW2 and the motor 2 is operated with a final power PE to the extent of a second final value EW2.The first end value EW1 is greater than the first start value SW1, the first time period TUG is greater than the second time period TUW, the first start value SW1 is smaller than the second start value SW2 and the first end value EW1 is slightly smaller than the second end value EW2 in the example shown. For example, the first time period TUG is 2 seconds, the second time period TUW is 1 second, the first start value SW1 is 0.56 W, the first end value EW1 is 1.14 W, the second start value SW2 is 1.5 W, the second end value EW2 is 1.8 W, the engine speed N in the low-noise operating mode is 780 rpm to 1200 rpm, the engine speed N in the further operating mode is 1400 rpm to 3600 rpm and / or the generated negative pressure in both the low-noise operating mode and the further operating mode is 150 mbar.

[0050] In the exemplary further operating mode, the motor 2 is supplied with a constant voltage U in the vacuum phase PHU, see Fig. 1E, which is why the speed N at the beginning of the vacuum phase PHU is higher than in the low-noise operating mode and increasingly decreases due to the increasing load caused by the building up vacuum, see Fig. 1F.

[0051] If the breast pump 1 has a controller 6 for the motor 2, the breast pump 1 is configured before use by setting the duration of the time intervals TI and the values ​​by which the motor power P is gradually increased in the low-noise operating mode and storing them in the breast pump 1 such that a speed N of the motor 2 during the negative pressure phase PHU fluctuates at most in a range of 0.3 times to 1.7 times the value of the speed N at the start of the negative pressure phase PHU. In particular, the breast pump 1 can be configured before use such that in the low-noise operating mode a speed N of the motor 2 remains as constant as possible from one time interval TI to the next time interval TI, in particular that in the low-noise operating mode a speed N of the motor 2 changes from one time interval TI to the next time interval TI by at most 20%, preferably at most 10%, particularly preferably at most 5%.In addition, the breast pump 1 can be configured such that the duration of the time intervals TI and the values ​​by which the motor power P is gradually increased in the low-noise operating mode are determined and stored in the breast pump 1 such that the final power PE is at least 50% greater than the starting power PS.

[0052] Fig. 4 shows a simplified block diagram of the breast pump 1 according to the invention. The breast pump 1 has a breast shield 4 for contact with a mother's breast, a vacuum unit 3 connected to the breast shield 4 for generating a vacuum between the mother's breast and the breast shield 4 contacting the mother's breast in a vacuum phase PHU, a motor 2, in particular an electric motor, connected to the vacuum unit 3 for operating the vacuum unit 3, a drive unit 7 for the motor 2 connected to the motor 2 and a ventilation device 8 connected to the vacuum unit 3 for reducing the vacuum in a ventilation phase PHB following the vacuum phase PHU. The drive unit 7 has a controller 6 for the motor 2 and / or a regulating device 5 for the motor 2.In addition, the drive unit 7 has an operating voltage source 9 connected to the controller 6 or the regulating device 5 and / or a supply source 10 connected to the controller 6 or the regulating device 5 or contained therein for a pulse-width-modulated voltage signal UPW, in particular a rectified pulse-width-modulated voltage signal UPWG. To generate a rectified pulse-width-modulated voltage signal UPWG, the drive unit 7 can have an electronic capacitor 11 connected to the supply source 10.The controller 6 or the regulating device 5 can control the motor 2, in particular the operating voltage source 9 or the supply source 10, so that in the low-noise operating mode a curve of the motor power P extending from the starting power PS to the final power PE has step-wise increases between defined successive time intervals TI, which together extend over the entire vacuum phase PHU. The breast pump 1 can also have a memory 12 in which the number 13 of successive time intervals TI of the vacuum phase PHU, as defined during the setting of the breast pump 1, is stored. In addition, the memory 12 can store the step height 14, as defined during the setting of the breast pump 1, by which the motor power P is increased by the controller 6 between the time intervals TI.Furthermore, the target speed Nsoll for the control device 5 determined during the adjustment of the breast pump 1 can be stored in the memory 12. To record a current speed N of the motor 2, the drive unit 7 can have a tachometer 15. The current speed N can be compared with the predetermined target speed Nsoll and the motor power P can be increased by the control device 5 between the time intervals TI by a value which adjusts the current motor speed N to the target speed Nsoll. To switch between the low-noise operating mode and the other operating mode, the breast pump 1 can have an input device 16, for example a button, a switch, a touch-sensitive screen or a software application on a smartphone.

Claims

Patent claims:

1. Method for operating a breast pump (1) for pumping breast milk, which breast pump (1) is operated alternately in a negative pressure phase (PHU) and a subsequent ventilation phase (PHB), in which negative pressure phase (PHU) at least one motor (2) of the breast pump (1) a negative pressure unit (3) of the breast pump (1) for generating a negative pressure between a mother's breast and a breast shield lying on the mother's breast (4) of the milk pump (1) and in which ventilation phase (PHB) the negative pressure is reduced, wherein the at least one motor (2) is operated at the beginning of the negative pressure phase (PHU) with a starting power (PS) and at the end of the negative pressure phase (PHU) with a final power (PE), characterized in that in a low-noise operating mode the motor power (P) is increased in steps from the starting power (PS) to the final power (PE) between defined successive time intervals (TI) which together extend over the entire negative pressure phase (PHU).

2. Method according to claim 1, characterized in that at least four, preferably at least ten defined successive time intervals (TI) are provided, which together extend over the entire negative pressure phase (PHU).

3. Method according to claim 1 or 2, characterized in that the engine power (P) is increased by a controller (6) for the at least one engine (2) by predetermined values between the time intervals (TI).

4. Method according to claim 1 or 2, characterized in that a current speed (N) of the at least one motor (2) is detected, compared with a predetermined target speed (Nsoll) stored in particular in the milk pump (1), and the motor power (P) is increased by a control device (5) for the at least one motor (2) between the time intervals (TI) by a value which adjusts the current motor speed (N) to the target speed (Nsoll).

5. Method according to one of claims 1 to 4, characterized in that characterized in that in order to increase the motor power (P), an operating voltage (U) of the at least one motor (2) is increased.

6. Method according to one of claims 1 to 5, characterized in that the at least one motor (2) is controlled via a pulse-width modulated voltage signal (UPW), in particular a rectified pulse-width modulated voltage signal (UPWG) and in order to increase the motor power (P), the pulse duration (PW) of the pulse-width modulated voltage signal (UPW) is increased.

7. Method according to one of claims 1 to 6, characterized in that the breast pump (1) is operated in the low-noise operating mode or in a further operating mode, in the low-noise operating mode the vacuum phase (PHU) is carried out during a first time period (TUG), the at least one motor (2) is operated with a starting power (PS) in the amount of a first starting value (SW1) and the at least one motor (2) is operated with a final power (PE) in the amount of a first final value (EW1), and in the further operating mode the vacuum phase (PHU) is carried out during a second time period (TUW), the at least one motor (2) is operated with a starting power (PS) in the amount of a second starting value (SW2) and the at least one motor (2) is operated with a final power (PE) in the amount of a second final value (EW2), wherein the first final value (EW1) is greater than the first starting value (SW1), the first time period (TUG) is greater than the second time period (TUW) is,the first start value (SW1) is less than the second start value (SW2) and the first end value (EW1) is less than or equal to the second end value (EW2).

8. Method for setting a breast pump (1) with which a method according to claim 3 is carried out, characterized in that in the low-noise operating mode, the duration of the time intervals (TI) and the values by which the motor power (P) is gradually increased are determined and stored in the breast pump (1) in such a way that a speed (N) of the at least one motor (2) during the negative pressure phase (PHU) is at most in a range of 0.3 times to 1.7 times the value of the speed (N) at the beginning of the negative pressure phase (PHU) fluctuates .

9. Method according to claim 8, characterized in that in the low-noise operating mode, the duration of the time intervals (TI) and the values by which the motor power (P) is gradually increased are determined and stored in the milk pump (1) in such a way that the final power (PE) is at least 50% greater than the starting power (PS).

10. Breast pump (1) for pumping breast milk, with a breast shield (4) for application to a mother's breast, a vacuum unit (3) for generating a vacuum between the mother's breast and the breast shield applied to the mother's breast (4) in a vacuum phase (PHU), at least one motor (2) for operating the vacuum unit (3), a drive unit (7) for the at least one motor (2) and a ventilation device (8) for reducing the vacuum in a ventilation phase (PHB) following the vacuum phase (PHU), wherein a starting power (PS) of the at least one motor (2) is provided at the beginning of the vacuum phase (PHU) and a final power (PE) of the at least one motor (2) is provided at the end of the vacuum phase (PHU), characterized in that a low-noise operating mode is provided in which a profile of the motor power (P) extending from the starting power (PS) to the final power (PE) has step-wise increases between defined successive time intervals (TI), which together extend over the entire vacuum phase (PHU).

11. Breast pump (1) according to claim 10, characterized in that at least four, preferably at least ten defined successive time intervals (TI) are provided, which together extend over the entire negative pressure phase (PHU).

12. Breast pump (1) according to claim 10 or 11, characterized in that the drive unit (7) for the at least one motor (2) has a controller (6) which is designed to increase the motor power (P) by predetermined values between the time intervals (TI).

13. Breast pump (1) according to claim 10 or 11, characterized in that the drive unit (7) for the at least one motor (2) has a control device (5) which is designed to detect a current speed (N) of the at least one motor (2), to compare it with a predetermined target speed (Nsoll) stored in particular in the breast pump (1) and to increase the motor power (P) between the time intervals (TI) by a value which adjusts the current motor speed (N) to the target speed (Nsoll).

14. Breast pump (1) according to one of claims 10 to 13, characterized in that the drive unit (7) for the at least one motor (2) has an operating voltage source (9) for controlling the at least one motor (2), which is designed to increase the operating voltage (U) of the at least one motor (2) in stages in order to increase the motor power (P).

15. Breast pump (1) according to one of claims 10 to 14, characterized in that the drive unit (7) for the at least one motor (2) has a supply source (10) for a pulse-width modulated voltage signal (UPW), in particular a rectified pulse-width modulated voltage signal (UPWG), which supply source (10) is designed to gradually increase the pulse duration (PW) of the pulse-width modulated voltage signal (UPW) in order to increase the motor power (P).

16. Breast pump (1) according to one of claims 10 to 15, characterized in that the breast pump (1) is switchable between the low-noise operating mode and a further operating mode, in the low-noise operating mode the vacuum phase (PHU) extends over a first time period (TUG), the starting power (PS) of the at least one motor (2) has a first starting value (SW1) and the final power (PE) of the at least one motor (2) has a first final value (EW1), and in the further operating mode the vacuum phase (PHU) extends over a second time period (TUW), the starting power (PS) of the at least one motor (2) has a second starting value (SW2) and the final power (PE) of the at least one motor (2) has a second final value (EW2), wherein the first final value (EW1) is greater than the first starting value (SW1), the first time period (TUG) is greater than the second time period (TUW), the first start value (SW1) is less than the second start value (SW2) and the first end value (EW1) is less than or equal to the second end value (EW2).

17. Breast pump (1) according to claim 16, characterized in that a maximum speed (N) of the at least one motor (2) in the low-noise operating mode is between 20% and 70%, preferably between 25% and 50% of a maximum speed (N) of the at least one motor (2) in the further operating mode.

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