Abstract:
A breastpump unit for expressing human breastmilk has a breastshield for placing on a human mother&#39;s breast, a vacuum pump for generating an underpressure, and a suction line for connecting the breastshield to the vacuum pump and for transferring to the breastshield the underpressure generated by the vacuum pump. The breastpump unit also has a pressure sensor. In addition, a measuring line is present, wherein the measuring line extends from the breastshield to the pressure sensor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is the US national phase of International Patent Application No. PCT/EP2014/065024, filed Jul. 14, 2014, which application claims priority to Switzerland Application No. 1267/13, filed Jul. 16, 2013. The priority application, CH 1267/13, is hereby incorporated by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present invention relates to a breastpump unit for expressing human breastmilk and to a breastshield of such a breastpump unit. 
       PRIOR ART 
       [0003]    Manually operated breastpumps and also motor-driven breastpumps are known in the prior art. The breastpumps provided with an electric motor can be connected to a mains supply or can be battery-operated. These breastpumps comprise a vacuum pump, and one or two breastshields which are connected to the vacuum pump and are placed on one or both of the mother&#39;s breasts. The connection can be direct, i.e. the vacuum pump is arranged on the breastshield itself, or the vacuum pump and the breastshield are connected to each other via a suction hose, also called a vacuum hose. By means of the vacuum pump, an underpressure can be generated in the breastshield, as a result of which milk is sucked from the mother&#39;s breast. 
         [0004]    The breastshield is connected to a milk collection container, in which the expressed milk is collected. Milk collection containers can be bags or bottles, which are able to be connected in an airtight manner to a corresponding outlet of the breastshield. A known breastpump unit is described in WO 01/47577, for example. 
         [0005]    In order to limit the generated underpressure, some of the motor-driven and electronically controlled vacuum pumps have a pressure sensor. Examples of these are disclosed in U.S. Pat. No. 6,383,163, U.S. Pat. No. 8,137,305 and U.S. 2008/0009815. These pressure sensors each measure the pressure in the area of the suction line near the pump, or at the suction connector of the vacuum pump itself. U.S. 2007/0060873 discloses a breastshield with a vacuum pump fitted thereon, wherein the vacuum pump is equipped with a media separation membrane and with a pressure indicator. 
         [0006]    WO 2013/049944 proposes using the suction hose also as a milk line. A media separation membrane between the pump-side end of the suction hose and the vacuum pump protects the vacuum pump from contamination by milk. This media separation membrane is provided with a pressure sensor, in order to determine the pressure in this area. 
         [0007]    WO 2011/037841 proposes arranging a pressure sensor in the breastshield itself and connecting it via an electronic line to a control unit or controller of the vacuum pump. However, breastshields are products to be disposed of after one use or, if designed to be used more than once, are at least not designed for prolonged use. They therefore have to be inexpensive. If designed to be used more than once, they also need to be easy to clean, and therefore pressure sensors inside or on top of the breastshield get in the way. 
         [0008]    WO 2011/144984 discloses a device intended for directly breastfeeding a baby. This device also comprises a vacuum pump for generating an underpressure, and a breastshield for placing on a human mother&#39;s breast. The breastshield in this case ends in a milk receptacle, which is connected via a line to a teat for the baby. Milk is firstly expressed by means of the vacuum pump and collected in the milk receptacle. The vacuum pump is then stopped. If the baby now begins sucking, a vacuum sensor determines a drinking underpressure and, by way of a control unit, allows a valve to open in order to return the underpressure in the milk receptacle to atmospheric pressure. The baby is then able to suck. For as long as the drinking underpressure is detected, the vacuum pump remains inactive. 
       DISCLOSURE OF THE INVENTION 
       [0009]    It is an object of the invention to optimize the measurement of pressure during the expression of human breastmilk. 
         [0010]    The breastpump unit according to the invention for expressing human breastmilk has a breastshield for placing on a human mother&#39;s breast, a vacuum pump for generating an underpressure, and a suction line for connecting the breastshield to the vacuum pump and for transferring to the breastshield the underpressure generated by the vacuum pump. A pressure sensor is also present. According to the invention, a measuring line is additionally present, wherein the measuring line extends from the breastshield to the pressure sensor. It preferably ends at the pressure sensor. 
         [0011]    By virtue of the unit according to the invention, the pressure can be measured at the site of the desired action of the breastpump, namely in the area near the mother&#39;s breast. Nonetheless, the breastshields do not have to be equipped with expensive sensors. 
         [0012]    The arrangement according to the invention, with the separate and in particular air-filled measuring line, can be used in all known breastpump units. However, it is advantageous particularly in breastpump units in which the suction hose is also used as a milk line. Since a liquid column is therefore present in the suction hose and changes depending on the position of the suction hose, this can lead to an incorrect pressure measurement. The use of a separate, air-filled measuring line, preferably a measuring hose, guarantees an accurate measurement of the pressure, independently of the position of the vacuum pump, the length of the suction hose, and the position of the suction hose and of the measuring hose. 
         [0013]    In a preferred embodiment, the pressure sensor is arranged in the breastpump. The breastpump has a housing which accommodates the vacuum pump, an electronic control unit for controlling the vacuum pump, operating means for operating the electronic control unit, possibly display means, and also the pressure sensor. 
         [0014]    In a very simple embodiment, the pressure sensor serves only as a safety element, ensuring that an excessive underpressure is not applied. Alternatively or in addition, the safety element can serve to determine whether an underpressure is in fact present at all in the breastshield. If, for example, the breastshield is not placed tightly enough on the mother&#39;s breast, a warning signal can sound or an optical signal can displayed. 
         [0015]    In a preferred embodiment, the electronic control unit for controlling the vacuum pump is connected to the pressure sensor. In this way, the vacuum pump can be controlled according to the measured pressure values inside the breastshield, and the underpressure applied to the mother&#39;s breast is optimized. In a preferred embodiment, the pressure sensor also assumes one or both of the abovementioned safety functions. 
         [0016]    The measuring line and the suction line are preferably hoses, in particular flexible hoses. They can be made from silicone, for example. In a preferred embodiment, the measuring line and the suction line are designed together as a double-lumen hose. This facilitates the plugging in and the general handling of the breastpump unit. 
         [0017]    In a preferred embodiment, the suction line has a first breastshield-side end, and the measuring line has a second breastshield-side end, wherein these two ends extend separately from each other. This makes it easier to plug in the hoses and to equip the breastshield with a protective element or media separation device described below. 
         [0018]    The underpressure is usually generated in a suction chamber of the breastshield, wherein the underpressure in this suction chamber can be measured. In one embodiment, the measuring line opens into this suction chamber. In this way, measurement is actually carried out on the spot, i.e. at the place where the nipple of the mother&#39;s breast is also located. 
         [0019]    A protective element is preferably present, which separates the measuring line from an interior of the breastshield to which expressed breastmilk can be admitted. In this way, the measuring line and thus also the pressure sensor are protected from contamination with breastmilk. The protective element is impermeable to liquid. It can be an air-permeable filter, or an element that is impermeable to air and liquid. 
         [0020]    A media separation device is preferably present, which separates the measuring line from an interior of the breastshield, but which transfers pressure changes in the interior to the measuring line. The media separation device is preferably a flexible, fluid-impermeable membrane of the kind already also used in other areas of breastpump units, e.g. at the vacuum port of the breastpump and also at the breastshield-side connection of the suction hose. The interior is preferably the abovementioned suction chamber. The media separation device is preferably the abovementioned protective element. 
         [0021]    To ensure that the breastshield can be easily cleaned, or can be disposed of after use, the measuring line is preferably releasably connectable to the breastshield several times. In this way, the measuring line, but in particular the pressure sensor, can be used more than once. Alternatively, the measuring line is not connected to the breastshield free from destruction, but is easily releasable from the pressure sensor, without damaging the latter. 
         [0022]    The breastshield according to the invention has a first seat for receiving a suction line, and a second seat for receiving a measuring line. 
         [0023]    With a suitable design of a double-lumen suction and measuring hose, the latter can be plugged into a single opening of the breastshield. Preferably, the first seat is a suction opening for receiving a suction hose, and the second seat is a separate measurement opening for receiving a measuring line. The second seat is preferably provided with a media separation device. 
         [0024]    Further embodiments are set forth in the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    Preferred embodiments of the invention are described below with reference to the drawings, which are provided only for explanatory purposes and are not to be interpreted as limiting the invention. In the drawings: 
           [0026]      FIG. 1  shows a schematic view of a breastpump unit according to the invention in a first embodiment, 
           [0027]      FIG. 2  shows a schematic view of a breastpump unit according to the invention in a second embodiment, 
           [0028]      FIG. 3  shows a schematic view of a breastpump unit according to the invention in a third embodiment, 
           [0029]      FIG. 4  shows an enlarged detail as per  FIG. 3 ; 
           [0030]      FIG. 5  shows a schematic view of a breastpump unit according to the invention in a fourth embodiment, and 
           [0031]      FIG. 6  shows an enlarged detail as per  FIG. 5 . 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0032]      FIG. 1  shows a first example of a breastpump unit according to the invention. A vacuum pump  1  has a suction connector  10 . A suction line, here a suction hose  4 , is connected to this suction connector  10 . The suction hose  4  is preferably a conventional silicone hose of the kind used customarily in breastpump units. 
         [0033]    The breastpump unit further comprises one or two breastshields  7  for placing on a human mother&#39;s breast. The breastshield  7  can be of the types known in the prior art. The shape and configuration shown are provided only by way of illustration. 
         [0034]    The breastshield  7  shown here has a stub  71  and, formed integrally on the latter, an outwardly widening funnel  72 . The latter receives the mother&#39;s breast. Depending on the configuration of the breastshield, it is possible for the nipple of the mother&#39;s breast to protrude into the stub  71 . The breastshield  7  has an interior  70 , and a first opening  73  leading out from this interior  70 . The abovementioned suction hose  4  can be plugged with its first breastshield-side end  40  into this first opening  73  or can be connected otherwise to a seat formed via the first opening  73 . In these figures, an adapter  5  is provided for plugging in. 
         [0035]    A milk collection container is not shown. It can be mounted directly on the breastshield in a known way. However, the suction line can also serve at the same time as a milk line, such that the milk collection container is filled via a line (not shown) leading from the element  1 . This combination of suction line and milk line is disclosed in WO 2013/049944. 
         [0036]    The breastshield  7  has a second opening  74 , which likewise leads out from the interior  70 . From this seat or opening  74 , a measuring line  6  leads to a pressure sensor  3 . The measuring line  6  is preferably likewise a hose, for example a silicone hose. However, it preferably has a smaller diameter than the suction hose  4 . The measuring hose  6  is preferably filled with air. 
         [0037]    In this example, a second breastshield-side end  60  of the measuring hose  6  is plugged into the second opening  74 . It can also be connected to the breastshield  7  in another way. Preferably, the connection between measuring line  6  and breastshield  7  is designed such that it can be released and then brought together again. If measuring line  6  and breastshield  7  are not releasable from each other without destruction, then the connection between measuring line  6  and sensor  3  is preferably releasable, without damaging the sensor  3  or the sensor-side plug connection. 
         [0038]    In these examples, the suction hose  4  and the measuring hose  6  are shown as hoses extending separately from each other. However, a double-lumen hose can also be used. 
         [0039]    Known sensors, for example piezoelectric sensors, are suitable as pressure sensor  3 . The pressure sensor is connected to an electronic control unit  2  of the vacuum pump. The lines between control unit  2  and pressure sensor  3  and between control unit  2  and vacuum pump  1  are provided with arrows here. 
         [0040]    Vacuum pump  1 , control unit  2  and pressure sensor  3  are preferably arranged, together with manual operating means and a possible display or screen, in a common housing. The housing is not shown here. The breastshield  7  is separate from this housing, with the suction line  4  and the measuring line  6  leading from the housing to the breastshield  7 . 
         [0041]    Independently of the position of the milk line and the position of the suction line  4 , the pressure sensor  3  now measures the pressure in the interior  70  of the breastshield, i.e. at the place where an underpressure is generated via the vacuum pump and where the nipple is also located. The measured signal is fed to the control unit  2  which, depending on the configuration of the control unit, triggers one or more of the following actions:
       display of the pressure value on a screen (not shown here),   optical display or acoustic signal when a predefined minimum or maximum value is undershot or exceeded,   automatic adaptation of the underpressure generated by the vacuum pump at the suction connector  10 ,   switching-off of the vacuum pump in the event of a maximum value being exceeded, i.e. when the applied underpressure in absolute values becomes too high or, to put it another way, when the suction is too great.       
 
         [0046]    In the example according to  FIG. 1 , the first and second openings  73 ,  74  are arranged on the same side of the breastshield  7 , in this case on the end face of the stub  71  directed away from the breast. 
         [0047]    In the variant according to  FIG. 2 , the first opening  73  is again arranged in the end face of the stub  71  directed away from the breast. The second opening  74  is located at an angle of 90° thereto on the circumference of the stub  71 . 
         [0048]    In the examples according to  FIGS. 1 and 2 , the measuring line  6  leads directly, and without intermediate elements, into the interior  70 . However, the interior  70  can be provided with a liner, for example. 
         [0049]    The embodiments according to  FIGS. 3 to 6  correspond to those described above. However, they have a protective element in the form of a media separation membrane  8  in the area of the second opening  74 . The media separation membrane  8  is liquid-tight and preferably also airtight. It is preferably made from silicone or another flexible material. 
         [0050]    In these examples, the media separation membrane  8  is secured in the interior  70  on the inside face of the stub  71 . It can be arranged in a housing, for example, or can simply be affixed to the wall of the stub  71  or welded thereto. However, it can also be removable, for example in order to be cleaned. 
         [0051]    The media separation membrane  8  is preferably flat and round. It has circular elevations and depressions, in order to move when the underpressure changes. In this way, it transfers pressure changes in the interior  70  to the measuring line  6  and thus to the pressure sensor  3 . At the same time, it prevents expressed milk and bacteria or other contaminants from getting into the measuring line. 
         [0052]    The media separation membrane can also be arranged on the outside of the breastshield or on the second breastshield-side end  60  of the measuring line  6 . 
         [0053]    The breastpump unit according to the invention permits, in a cost-effective manner, a relatively precise measurement of the underpressure applied to the mother&#39;s breast.