WO2025201624A1

WO2025201624A1 - Method for operating a breastpump

Info

Publication number: WO2025201624A1
Application number: PCT/EP2024/057972
Authority: WO
Inventors: Danielle Prime; Nienke VAN DEN ENDE
Original assignee: Medela AG
Current assignee: Medela AG
Priority date: 2024-03-25
Filing date: 2024-03-25
Publication date: 2025-10-02
Anticipated expiration: 2026-09-25

Abstract

The present invention relates to a method for operating a breastpump within a breastpumping session in a pattern of sequences, which pattern comprises at least one stimulation sequence (SI) for stimulating the breast having a rapid cycle rate and providing a moderate vacuum level and at least one expression sequence (E) having a lower cycle rate and providing a higher vacuum level, wherein the lower cycle rate is lower than the rapid cycle rate and wherein the higher vacuum level is higher than the moderate vacuum level. In order to provide a method that can be carried out at increased comfort for the user, the pattern has an transition sequence (T) preceding the expression sequence (E), in which transition sequence (T) the vacuum level is increased from the moderate vacuum level to the higher vacuum level over a number of cycles.

Description

Method for Operating a breastpump

FIELD OF THE INVENTION

The present invention relates generally to a method for operating a breastpump and a breastpump.

BACKGROUND

Breastpumps for use by nursing mothers are well known. They allow the nursing woman to express the breastmilk as necessary or convenient, and further provide collection of the breastmilk for later use.

Electrically-driven breastpumps are commonplace, typically including a vacuum pump which has an electric motor that plugs into standard house current, and/or operates off of battery power. Advantages of this type of pump are convenience, ready controllability and regulation of the vacuum, and in many instances the ability to pump both breasts at once.

Electrically-driven, motorized breastpumps generally have a driving mechanism for generating the vacuum (negative pressure) to be applied at the breast geared to a particular sequence, or curve, of negative pressure increase (i.e. , increasing suction), and then release. This is often aimed at reproducing in some sense the suckling action of a healthy infant during mature lactation, after the milk supply has been established, see for example WO 00/57934.

EP 2 878 317 B1 discloses a breastpump providing a sequence of pattern to initiate milk flow from a mother's breast. The sequence comprises a first pattern operating the breastpump at about 120 cycles per minute (cpm) with a vacuum level in the range of about 70-200 millimeters of mercury (mmHg). The second pattern comprises operating the breastpump at 90 cpm with a vacuum level in the range of about 70-200 mmHg. The third pattern comprises operating the breastpump between about 34 and 54 cpm, with a vacuum level in the range of about 100- 250 mmHg. The first two patterns provide stimulation phases whereas the third pattern provides an expression phase.

UNDERLYING PROBLEM

It was found that such patterns with many passages from different sucking patterns may be uncomfortable for the nursing mothers, this may negatively affect milk expression in the short term but also (and this is worst) in the long term. The discomfort from one side make nursing mothers to not use the pump, so that the breast is not stimulated and milk expression in the short and in particular in the long term is not activated. From the other side nursing mothers u- sing pumps to stimulate the breast and express milk can be able to express larger amounts of milk, not only in the short term but in particular in the long term. SUMMARY OF THE INVENTION

The present invention, as defined by the appended claims, provides an improved method for operating a breastpump for initiating the expression of milk, which method can be carried out at increased comfort for the user. In its preferred form, it is a method adapted for use with a mo- tor-driven breastpump, which has an aggregate and a controller controlling said aggregate as well as an energy supply connected to the aggregate via power cord or battery. The aggregate of the breastpump can be any unit, which transforms the electric energy into suction or motion eventually generating suction. More particularly, the present invention has a principal objective of providing a method especially useful to express milk in the early days after birth of an infant, and most particularly to express milk at a better comfort while maintaining efficiency and possible yield expressed milk previously achievable by applying e.g. the method known from EP 2 878 317 B1.

Specifically, the present invention provides a method for operating a breastpump within a breastpumping session in a pattern of sequences, which pattern comprises at least one stimulation sequence for stimulating the breast using a rapid cycle rate and providing a moderate vacuum level and at least one expression sequence for extracting milk at a lower cycle rate and providing a higher vacuum level, wherein the lower cycle rate is lower than the rapid cycle rate and wherein the higher vacuum level is higher than the moderate vacuum level. This part of the method may be realized in general and in details as described in EP 2 878 317 B1.

In the inventive method, a transition sequence preceding the expression sequence is carried out, which transition sequence is to equalize the discontinuity with respect to the vacuum level between the stimulation sequence and the expression sequence. Accordingly and within the transition sequence, the vacuum level is increased from the moderate vacuum level to the higher vacuum level over a number of cycles.

It was surprisingly found that discomfort is mainly due to the transition between the stimulation and expression sequence. In fact, even if transition between the stimulation sequence and the stimulation sequence can have the same or even bigger vacuum differential than the transition between stimulation sequence and expression sequence as described in prior art, it is the transition between stimulation sequence and expression sequence that was found to cause pain and thus generate discomfort.

On a regular basis, no pause exists between the stimulation sequence and the expression sequence. The same is true for the transition between the stimulation sequence and the transition sequence. In fact, the transition sequence usually has the same slower cycle rate as the ex- pression sequence. On a regular basis, no phase difference is implemented between the transition sequence and the expression sequence with a consequence that the cycle rate of each of the two sequences have the same fundamental frequency pulse.

Moreover and according to a preferred embodiment, the increase in vacuum level between two consecutive cycles in the transition sequence is approximately the same. Usually, a cycle provides a pressure difference between a pull suction defining the highest vacuum level of the cycle and/or the vacuum level and a release suction defining the lowest vacuum level of the cycle and/or the vacuum level. According to this preferred embodiment, the pressure difference is approximately the same for two consecutive cycles of the transition sequence.

The moderate vacuum level mentioned above preferably is between 70 and 200 mmHg wherein the higher vacuum level mentioned above preferably is between 90 and 250 mmHg.

In the transition sequence the pull suction is raised from 200 mmHg to 250 mmHg while the release suction is preferably not changed. In the above example, the pressure difference of each cycle of the stimulation phase is 200 mmHg -70 mmHg =130 mmHg, whereas the pressure difference of each cycle of the expression phase is 250 mmHg -70 mmHg =280 mmHg. This shows that in the transition sequence the pressure difference is preferably raised gradually with each subsequent cycle of the transition sequence.

In a first example, in the transition sequence the pressure difference is raised with a constant amount per cycle as the pull suction is raised by a constant amount per cycle and the release suction stays constant.

Thus, two consecutive cycles in the transition sequence preferably have approximately the same increase in vacuum level. Two consecutive cycles in the transition sequence preferably have approximately the same pull suction pressure increase. Preferably in this example each cycle of the transition sequence has features of the expression cycles, i.e. vacuum increases up to a maximum vacuum, to then decrease till a hold value than is maintained for a while; afterwards vacuum goes back to the release vacuum being ambient pressure.

In a second example, vacuum increases in the transition sequence similarly to what described for the first example, but instead of increasing at each cycle of the transition sequence, it increases every other cycle; i.e. the transition sequence is made of couples of equal cycles, where the maximum vacuum of cycles of successive couples increases.

In a third example, vacuum increases in the transition sequence similarly to what described for the second example, but the first couple of cycles following immediately after the stimulation sequence has a maximum vacuum lower than the maximum vacuum of the cycles of the stimulation sequence.

In a fourth example in the transition sequence is made of couples of cycles, where for each couple (i) a first cycle has the features of the stimulation cycles, i.e. increasing vacuum up to maximum vacuum and then vacuum going back to the release vacuum, being the ambient pressure, (ii) a second cycle has the features of the expression cycles as described above. In addition, the maximum vacuum of the first cycle is stronger than the maximum vacuum of the second cycle.

Preferably, the transition sequence consists 3 to 9 cycles, preferably 4 to 7 cycles.

The first cycle of the transition sequence has a higher or lower vacuum level than the last cycle of the stimulation sequence preceding the expression sequence. Further, a last cycle of the transition sequence has the vacuum level of the expression sequence, which vacuum level of the expression sequence is considered to be held constant throughout the entire expression sequence.

Preferably, the pattern of the inventive method comprises a first and a second stimulation sequence followed by the expression sequence with the transition sequence provided between the second stimulation sequence followed by the expression sequence. In such a subpattern, the first stimulation sequence preferably has an e.g. by about 30% higher cycle rate than the second stimulation sequence.

Preferably, the first stimulation sequence has a cycle rate of 120 +/- 10 cycles per minute. Preferably, the second stimulation sequence has a cycle rate of 90 +/- 10 cycles per minute. Preferably, the expression sequence and/or the transition sequence has a cycle rate of 66 +/- 14 cycles per minute, preferably 66 +/- 12 cycles per minute.

As already indicated above, the moderate vacuum level preferably is between 70 and 200 mmHg and that the higher vacuum level preferably is between 90 and 250 mmHg.

In addition, to the subpattern mentioned above, the pattern of the inventive method may comprise an alternate subpattern having only stimulation sequences as sequences of this subpattern. Specifically, the alternate subpattern may consist of two stimulation sequences with or without a pause in between, which stimulation sequences vary, in particular with respect to cycle rate but may have identical vacuum levels including pressure difference, pull suction and release suction. In such an alternate subpattern, a stimulation sequence may follow a preceding stimulation sequence having a by about 30% lower cycle rate than the following stimulation sequence. One or more of such alternate subpattern may form part of the pattern of the inventive method.

Preferably, the pattern of the inventive method comprises or consists of a first subpattern, a second subpattern, a third subpattern and a further stimulation sequence following the third subpattern. This second subpattern may be the alternate subpattern described above. First, second and third identifies the sequence of the subpattern. The further stimulation sequence following the third subpattern usually defines or forms part of the last subpattern of the pattern and defines the end of the pattern. In such a pattern, the first and the third subpattern comprises a first and a second stimulation sequence followed by the expression sequence. The second subpattern comprises a first and a second stimulation sequence usually without an expression sequence.

The last expression sequence of said third subpattern is followed by the last stimulation sequence. Preferably, the pattern includes pauses between certain sequences, in particular between the subpatterns. Preferably, no pauses exist within each pattern, i.e. between each sequence of each subpattern.

Preferably, the first subpattern has a longer duration than the second subpattern. Preferably, the first subpattern has a longer duration than the third subpattern. Preferably, the second subpattern has the shortest duration among the first, the second and third subpattern.

A first and long embodiment of a specific pattern is provided, which pattern comprises a first, second and third subpattern. For the first embodiment, the total duration of the first, second and third subpattern and a stimulation sequence following the third subpattern is not more than 15 minutes, preferably 13 minutes +/- 2 minutes, more preferably 14 minutes +/- 1 minutes and most preferably 15 minutes. A stimulation sequence follows the sequence of the first, second and third subpattern. According to this first embodiment of a specific pattern and within the first subpattern, the first stimulation sequence has a duration of 180 seconds +/- 20 seconds and/or the second stimulation sequence has a duration of 120 seconds +/- 10 seconds and/or the expression sequence has a duration of 60 seconds +/- 5 seconds. Further, within the second subpattern, the first stimulation sequence has a duration of 120 seconds +/- 20 seconds and/or the second stimulation sequence has a duration of 60 seconds +/- 10 seconds. In the third subpattern of this first pattern embodiment, the first stimulation sequence has a duration of 120 seconds +/- 20 seconds and/or the second stimulation sequence has a duration of 60 seconds +/- 10 seconds and/or the expression sequence has a duration of 60 seconds +/- 10 seconds. The following stimulation sequence has a duration of 90 seconds +/- 10 seconds.

In connection with the description of the invention, the following terms shall be understood as follows:

“Followed” means that no further sequence of cycles exists between following sequences or the following subpattern.

“Subpattern” consists of a specific sequence of generally different “sequences”.

“Sequence” is a sequence of multiple, on a regular basis identical cycles.

“Cycle” is a cylic element of a sequence. Each “cycle” provides a vacuum profile consisting of a pull suction, reducing the pull suction to a release suction and raising the suction pressure to reach pull suction again. “Pressure difference” is the absolute pressure difference between the pressure of pull suction and the pressure of release suction. Pressure values are (on a regular basis) pressure values generated by the breastpump for application to the breast.

“Vacuum level” can be understood as the mean vacuum provided by one cycle. The “vacuum level” is defined by two pressure values, one being the pressure of value pull suction, the other being the pressure value of release suction.

“Pull suction” is the suction pressure, i.e. negative pressure.

“Release suction” is the release pressure and may be positive, negative or ambient pressure.

As for as the present application refers to “high”, “higher”, “highest”, “low”, “lower” or “lowest” absolute pressure values are meant or compared.

“Consist” means that an entity exclusively has the items of which the entity consists. As far as an entity is described to consist of a listing of items, respective listing is to be understood to provide an exhaustive enumeration.

“Sucking pattern” is specified by a specific cycle rate and a vacuum level.

“Cycle rate” provides information on the cycles per time increment; “cpm” means cycles per minute.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the invention will be further understood upon consideration of the following detailed description of certain embodiments, taken in conjunction with the drawings, in which:

Figure 1 is an illustration of a breastpump assembly for use in accordance with one embodiment of the present invention; figure 2 is a diagram of a process to initiate milk flow from a mother's breast in accordance with a first embodiment of the invention and figures 3 through 8 are different examples of the transition phase, where the transition phase is shown with reference D in figure 2.

DETAILED DESCRIPTION

Figure 1 is an illustration of a breastpump assembly in accordance with one embodiment of the present invention. That breastpump is generally described in U.S. Patent No. 6,547,756 or EP 2 878 317 B1 , reference thereto can be made for salient details of this breastpump. While the invention has found particular application for use with this kind of programmable breast- pump and with respect to premature babies, it can be used or adapted for use with other motorized pumps capable of being operated with the varying sequences (hereinafter described), and aspects are considered adaptable to full-term babies including breast pumps wearable inside a bra, as disclosed in WO2022/268998.

As shown in Figure 1, the breastpump assembly 100 includes a breastpump 110, a plurality of the breastshield and container assemblies 120, and a user input interface, such as a program card 130. Power may be provided to the breastpump apparatus 110 either through standard current via a power cord, a battery, or some other appropriate power supply.

The breastpump 110 may be either a double or a single pump. The single pump extracts milk from one breast at a time, and the double pump can be used to extract milk from both breasts at the same time. The breastpump 110 is attached to each of the plurality of the breastshield and container assemblies 120 with a tube 140. Each of the plurality of the breastshield and container assemblies 120 comprises a breastshield 122 and a container 124. The container 124 is used to store the pumped milk.

One significant aspect of the present invention is the ability to operate, as by program, the breastpump 110 with different types of suction sequences in a selected order. The breastpump 110 utilizes a controller 126 for controlling an aggregate 128. The controller 126 or microprocessor-based system is provided with user input through such as a program card 130. The breastpump 110 has a program card insert slot through which a user inserts the program card 130. Once inserted, the program card 130 is read. The particular program on the program card 130 is then communicated to the controller 126. The controller 126 is provided within a housing of the breastpump 110 to control the aggregate 128 for providing the suction sequences of the suction pattern described hereinafter.

One embodiment contemplated, for instance, provides a sequence that can be engaged without the need of a separate program card for the same. In this embodiment, the sequence is pre-programmed in the controller 126, or may otherwise be wired into the circuitry of the controller 126 or transmitted to the controller 126 in any suitable way with or without wire in a manner to override the then-existing operating program.

To extract breastmilk from a mother, the breastshields 122 are placed and centered over a mother's nipples. The breastpump apparatus 110 may be turned on by a user pressing a first button 112, and in this embodiment, the program card 130 is used with the apparatus. The apparatus reads the program contained on the program card 130. The breastpump 110 may display instructions to the user via interface 150. The instructions may ask the user to start the program. If the mother wants to start the program, the mother may press a second button 114. Interface 150 may then show instructions and/or graphics that let the mother know that the program is starting. The program card 130 may operate a preset pattern comprised of non-repeating suction sequences. Alternatively, the program card 130 may operate a preset pattern comprised of repeating suction sequences that appear to be non-repeating to the user, due to the overall length of the pumping session such that the sequences seem to be occurring at unpredictable times in the pattern with extended pauses between some of the sequences. An extended pause is a pause that is approximately greater than about five seconds in duration. Some of the pauses may be of shorter duration, however, but still of a length that yields a noticeable hiatus to the mother.

The sequences comprise at least one stimulation sequence and one expression sequence, and may additionally comprise further stimulation sequences and/or expression sequences.

Figure 2 depicts examples of how the breast pump may be operated to initiate flow from a mother's breast. The steps in Figures 2 are designed so that a most-desired pattern of stimulation, expression, and pauses is provided. This particular set of sequences and pauses is considered to more closely resemble the sucking pattern of a newly-born infant during the early days post-birth before the onset of lactogenesis II.

The sequences described in Figure 2 are designed to stimulate the breast and eventually achieve the lactogenesis II stage.

In Figure 2, at 0 seconds on the time scale, a first stimulation sequence SI is set into motion for approximately three minutes. This first stimulation sequence SI has a moderate vacuum level at a higher cycle rate of about 120 cycles per minute (cpm). The moderate vacuum level has a range of about 70-200 millimeters of mercury (mmHg). The cycles per minute indicate the sucking rhythm, or the number of pulls and releases per minute. This means that the vacuum will alternate cyclically between a pull suction of 200 mmHg and a release suction of 70 mmHg. Thus, the pressure difference of each cycle is 200 mmHg -70 mmHg =130 mmHg.

At 3 minutes, the first stimulation sequence SI is followed by a second stimulation sequence Sil having a slower rate than the first stimulation sequence SI. The rate of the second stimulation sequence SI I is about 90 cpm, which is applied for approximately two minutes. As in the first stimulation sequence I, the pull suction is 200 mmHg and a release suction is 70 mmHg.

At 5 minutes, the controller of the pump starts an expression sequence E, which follows the second stimulation sequence SI I. This expression sequence E is applied for approximately one minute. The expression sequence E has a relatively higher vacuum level and provides a slower cycle rate. In the expression sequence E the breastpump is operated between about 34 and 54 cpm with a vacuum level in the range of about 90-250 mmHg. The sequence of the first stimulation sequence SI followed by the second stimulation sequence SI I followed by the expression sequence E defines a first subpattern SPI.

The breastpump is then paused for ten seconds. During the pause step, a zero or near zero negative pressure (ambient) within the breastpump remains relatively constant.

After this first pause PI, the breastpump is operated at the cycle rate and the vacuum level of the second stimulation sequence SI I mentioned above for approximately one minute. This second stimulation sequence SI I is followed by a first stimulation sequence SI mentioned above for approximately two minutes.

The sequence of the second stimulation sequence SI I followed by the first stimulation sequence SI defines a second subpattern SPI I.

Then, the breastpump is paused for ten seconds, indicated in figure 2 as a second pause PH.

After this second pause PH, the breastpump is operated to provide the first subpattern SPI. However, in this subpattern the first stimulation sequence SI is applied for approximately two minutes, the second stimulation sequence Sil is applied for approximately one minute and the expression sequence E is applied for approximately one minute. While this third subpattern SPHI has the same consecutive sequences as the first subpattern SPI, for a clear discrimination, it is identified in the drawings as a third subpattern SPHI.

Then, the breastpump is paused for ten seconds, indicated in figure 2 as third pause PHI.

A transition T between the second stimulation sequence SI I and the expression sequence E will be further described by referring to figures 3 through 6.

Figure 3 is an enlarged increment D of the transition between the second stimulation sequence SI I and the expression sequence E for each of the first subpattern SPI and the third subpattern SPHI. Evidently, no pause exists between the second stimulation sequence SI I, the transition sequence T and the expression sequence E.

In figure 3, the pressure alternates between the upper and lower lines indicating the release suction at ambient pressure and the pull suction with pressure values between 200 mmHg and 250 mmHg.

In this embodiment, those two values follow a release suction profile RS and a pull suction profile PS, which are provided by straight lines connecting the set pressure values for the pull suction and the release suction in the respective second stimulation sequence SI I and the expression sequence E, respectively.

In the example of figure 3, two consecutive cycles in the transition sequence have approximately the same pull suction pressure increase. In this example each cycle of the transition sequence has features of the expression cycles, i.e. vacuum increases up to a maximum vacuum (curve section 300), to then decrease (curve section 310) till a hold value (curve section 320) that is maintained for a while; afterwards vacuum goes back to the release vacuum being ambient pressure (curve section 330).

Figures 4 and 5 show examples of the transition phases similar to the one of figure 3, but figure 3 refers to an example with release pressure equal to ambient pressure, figure 4 refers to an example with release pressure lower than ambient pressure and figure 5 refers to an example with release pressure higher than ambient pressure.

In the second example (figure 6), vacuum increases in the transition sequence similarly to what described for the first example, but instead of increasing at each cycle of the transition sequence, it increases every other cycle; i.e. the transition sequence is made of couples 340 of equal cycles, where the maximum vacuum of cycles of successive couples increases.

In a third example (figure 7), vacuum increases in the transition sequence similarly to what described for the second example, but the first couple 345 of cycles following immediately after the stimulation sequence has a maximum vacuum lower than the maximum vacuum of the cycles 350 of the stimulation sequence.

In the fourth example (figure 8) the transition sequence is made of couples of cycles 360, where for each couple 360 a first cycle 362 has the features of the stimulation cycles 350, i.e. increasing vacuum up to maximum vacuum and then vacuum going back to the release vacuum, being the ambient pressure. In addition, a second cycle 364 of the couple 360 has the features of the expression cycles as described above, and thus has curve section 300, curve section 310, curve section 320, curve section 330. Here, the maximum vacuum of the first cycle 362 is stronger than the maximum vacuum of the second cycle 364.

Reference List

100 breastpump assambly

110 breastpump

112 first button

114 second button

120 container assembly

122 breastshield

124 container

126 controller

128 aggregate

130 program card

140 tube

150 interface

300, 310, 320, 330 cycle curve sections

340 couple of cycles

345 first couple of cycles after stimulation sequence

350 cycle of stimulation sequence

360 couple of cycle

362 first cycle of couple 360

364 second cycle of couple 360

E expression sequence

PI first pause

PH second pause

Pill third pause

PIV fourth pause

PD pressure difference

PS pull suction

RS release suction

SI first stimulation sequence

Sil second stimulation sequence SPI first subpattern

SPII second subpattern

SPI 11 third subpattern

T transition sequence RS release suction profile

PS pull suction profile

Claims

1. A method for operating a breastpump within a breastpumping session in a pattern of sequences, which pattern comprises at least one stimulation sequence (PSI; SPII) for stimulating the breast using a rapid cycle rate and providing a moderate vacuum level and at least one expression sequence (E) for extracting milk at a lower cycle rate and providing a higher vacuum level, wherein the lower cycle rate is lower than the rapid cycle rate and wherein the higher vacuum level is higher than the moderate vacuum level, characterized by a transition sequence (T) preceding the expression sequence (E), in which transition sequence (T) the vacuum level is increased from the moderate vacuum level to the higher vacuum level over a number of cycles.

2. The method as defined in claim 1, characterized in that each cycle of the transition sequence (T) has the rate corresponding to the lower cycle rate.

3. The method as defined in claim 1 or 2, characterized in that each cycle provides a pressure difference (PD) between a pull suction (PS) defining the highest vacuum level of the cycle and a release suction (RS) defining the lowest vacuum level of the cycle and that two consecutive cycles in the transition sequence (T) have approximately the same increase in vacuum level and/or have approximately the same increase in pressure difference (PD) and/or have approximately the same pressure increase in pull suction (PS).

4. The method as defined in claim 1 or 2, characterized in that the transition sequence (T) comprises cycles having the features of the expression cycles, wherein vacuum increases up to a maximum vacuum, to then decrease till a hold value and then vacuum goes back to the release vacuum

5. The method as defined in any of claims 1 through 4, characterized in that vacuum increases in the transition sequence every other cycle and the transition sequence is made of couples of equal cycles, where the maximum vacuum of cycles of successive couples increases.

6. The method as defined in claim 5, characterized in that a first couple of cycles following immediately after the stimulation sequence has a maximum vacuum lower than the maximum vacuum of the cycles of the stimulation sequence.

7. The method as defined in claim 1, characterized in that the transition sequence is made of couples of cycles, where for each couple

(i) a first cycle has the features of the stimulation cycles and has increasing vacuum up to maximum vacuum and then vacuum going back to the release vacuum,

(ii) a second cycle has the features of the expression cycles and has increasing vacuum up to a maximum vacuum, then decreasing vacuum till a hold vacuum and then vacuum goes to the release vacuum, wherein the maximum vacuum of the first cycle is stronger than the maximum vacuum of the second cycle.

8. The method as defined in any of the preceding claims, characterized in that a pattern of sequences comprises a first and a second stimulation sequence (SI; SI) followed by the expression sequence (E), wherein the first stimulation sequence (SI) and the second stimulation sequence (SI I) have a different vacuum level and/or a cycle rate.

9. The method as defined in claim 8, characterized in that the first stimulation sequence (SI) has a higher cycle rate than the second stimulation sequence (Sil).

10. The method as defined in claim 9, characterized in that the first stimulation sequence (SI) has a cycle rate of 120 +/- 10 cycles per minute and that the second stimulation sequence (SI I) has a cycle rate of 90 +/- 10 cycles per minute.

11. The method as defined in any of the preceding claims, characterized in that the expression sequence (E) and/or the transition sequence (T) has a cycle rate of 66 +/- 14 cycles per minute, preferably 66 +/- 12 cycles per minute.

12. The method as defined in any of the preceding claims, characterized in that the transition sequence (T) and the expression sequence (E) provide a uniform sequence of cycles.

13. The method as defined in any of the preceding claims, characterized in that the moderate vacuum level is between 70 and 200 mmHg and that the higher vacuum level is between 90 and 250 mmHg.

14. The method as defined in any of the preceding claims, characterized in that the pattern comprises a first subpattern (SPI) and a second subpattern (SPII) following the first subpattern (SPI), wherein the first subpattern (SPI) comprises a first and a second stimulation sequence (SI; Sil) followed by the expression sequence (E), wherein the second subpattern (SPII) comprises a first and a second stimulation sequence (SPI; SPII).

15. The method as defined in claim 14, characterized in that in the first subpattern (SPI) the second stimulation sequence (SI I) follows the first stimulation sequence (SI) and that in the second subpattern (SPII) the first stimulation sequence (SI) follows the second stimulation sequence (Sil).

16. The method as defined in claim 14 or 15, characterized by a third subpattern (SPIN) following the second subpattern (SPII), wherein said third subpattern (SPIN) is identical with the first subpattern (SPI).

17. The method as defined in any of the claims 14 to 16, characterized by pauses between the first and the second subpattern (SPI; SPII) and/or between the second and the third subpattern (SPII; SPIN).

18. The method as defined in claim 17, wherein at least some of the pauses (PI; PH; PHI) of said periods of pauses are greater than 5 seconds.

19. The method as defined in any of the claims 14 to 18, characterized in that the first subpattern (SPI) has a longer duration than the second subpattern (SPII) and/or that the first subpattern (SPII) has a longer duration than the third subpattern (SPIN).

20. The method as defined in any of the preceding claims, characterized in that

- for the first subpattern (SPI): the first stimulation sequence (SI) has a duration of 180 seconds +/- 20 seconds and/or that the second stimulation (SI I) sequence has a duration of 120 seconds +/- 10 seconds and/or that the expression sequence (E) has a duration of 60 seconds +/- 5 seconds and/or

- for the second subpattern (SPII): the first stimulation sequence (SI) has a duration of 120 seconds +/- 20 seconds and/or that the second stimulation sequence (SI I) has a duration of 60 seconds +/- 10 seconds and/or

- for the third subpattern (SPIN): the first stimulation sequence (SI) has a duration of 120 seconds +/- 20 seconds and/or that the second stimulation sequence (SI I) has a duration of 60 seconds +/- 10 seconds and/or that the expression sequence (E) has a duration of 60 seconds +/- 10 seconds and/or

- the stimulation sequence (Sil) following the third subpattern (SPI 11) has a duration of 80 seconds +/- 10 seconds.

21. The method as defined claim 15, characterized in that the first, the second, the third subpattern (Si; Sil; SIH) and the stimulation sequence (Sil) following the third subpattern (SPIN) have a total duration of not more than 15 minutes, preferably 13 minutes +/- 2 minutes, more preferably 14 minutes +/- 1 minutes, and most preferably 15 minutes.

22. A breastpump (110) comprising an aggregate (128) and a controller (126) for controlling said aggregate (128), which controller (126) is adapted to operate the breastpump (110) by controlling said aggregate (128) to provide a pattern as specified in any of the claims 1 to 21.