Abstract:
An electric breast pump is disclosed as including a hood to be fitted over a breast of a user, a chamber in fluid communication with the hood member via a one-way valve, a pump motor operatively associated with a pump diaphragm movable to draw air from the hood into the chamber via the valve, in which the chamber has an opening and a lid which is operatively associated with the motor, in which the lid is movable between a first position to close the opening and a second position in which the opening is open, and in which the lid is at the first position when the motor is in operation and is at the second position when the motor is not in operation. The breast pump also includes sensors for detecting the passing of milk, and a microcontroller for calculating the rate of flow of milk on the basis of data received from the sensors.

Description:
[0001]     This invention relates to a breast pump and, in particular, an electrically operated breast pump for drawing milk from a user.  
       BACKGROUND OF THE INVENTION  
       [0002]     There are in existence a large number of electrically operated breast pumps, allowing a user, e.g. a mother, to pump milk from her breast. Various pumping mechanisms have been proposed for drawing milk from the mother&#39;s breast, including, for example, ones disclosed in U.S. Pat. Nos. 6,045,529 and 6,355,012 issued to Nüesch. Such mechanisms are generally speaking rather complicated, and thus costly to manufacture. In addition, most such mechanisms include gear trains which would generate much noise, especially when the motor is operating at a relatively high speed.  
         [0003]     In addition, although a user may, with some existing breast pumps, be able to adjust the pumping cycles, e.g. by varying the number of suction cycles per minute, or adjusting the vacuum level for pumping milk from the user&#39;s breast, it is up to the user to decide whether to make such variation or adjustment, and the user may simply have no information on which to decide whether the current pumping rate is suitable or not. In this connection, U.S. Pat. No. 6,547,756 issued to Greter et al. discloses a programmable breast pump which may be programmed to generate a number of different milk expression (extraction) sequences, or curves. In this arrangement, a motorized pump is provided with a microprocessor-based controller. Cards, with microprocessor “chips”, containing instructions for different suction curves are also included, which may be inserted into the breast pump, so that the instructions in the cards may be read and acted upon by the breast pump. However, as in the case of other adjustable breast pumps discussed above, it is still up to a user to decide whether to change the mode of pumping operation of the breast pump, and a user may not know whether an alternative, and if so which, suction curve should be applied. A further shortcoming associated with conventional electric breast pumps is that the user is provided with no information as to the time required to fill up the milk receptacle, e.g. bottle.  
         [0004]     Such and other shortcomings discussed above are also present in breast pumps disclosed in U.S. Pat. No. 6,673,036 issued to Britto and U.S. Pat. No. 6,090,065 issued to Giles.  
         [0005]     It is thus an object of the present invention to provide an electric breast pump in which the aforesaid shortcomings are mitigated or at least to provide a useful alternative to the public.  
       SUMMARY OF THE INVENTION  
       [0006]     According to a first aspect of the present invention, there is provided an electric breast pump including at least one hood member adapted to be fitted over a breast of a user; a chamber adapted to be in fluid communication with said hood member via a first valve; a first motor operatively associated with a pumping member which is movable to draw air from said hood member into said chamber via said first valve; said chamber having at least a first opening and a closure member operatively associated with said first motor, wherein said closure member is movable between a first position to close said first opening and a second position in which said first opening is open; and wherein said closure member is at said first position when said first motor is in operation and is at said second position when said first motor is not in operation.  
         [0007]     According to a second aspect of the present invention, there is provided an electric breast pump including at least one hood member adapted to be fitted over a breast of a user; and at least a first sensing unit adapted to detect the passing of milk. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:  
         [0009]      FIG. 1  is a perspective view of an electric breast pump according to the present invention;  
         [0010]      FIG. 2  is an exploded view of the breast pump shown in  FIG. 1 ;  
         [0011]      FIG. 3  is a sectional view of the breast pump shown in  FIG. 1 ;  
         [0012]      FIG. 4  is a sectional view taken along the line A-A in  FIG. 3 ;  
         [0013]      FIG. 5  is a circuit diagram of the breast pump shown in  FIG. 1 ;  
         [0014]      FIG. 6  shows part of the circuitry in the breast pump shown in  FIG. 1 ;  
         [0015]      FIG. 7  shows a liquid crystal display (LCD) setting in the breast pump shown in  FIG. 1 ;  
         [0016]      FIG. 8  is a block diagram of an exemplary microcontroller which may be used in the circuit shown in  FIG. 5 ;  
         [0017]      FIG. 9  is an enlarged view showing the engagement between the pump motor and the diaphragm in the breast pump shown in  FIG. 1 ;  
         [0018]      FIG. 10  is an enlarged sectional view of part of the breast pump shown in  FIG. 3 ;  
         [0019]      FIG. 11  is an enlarged perspective view showing the mechanism for manual adjustment of the level of vacuum in the breast pump shown in  FIG. 1 ;  
         [0020]      FIG. 12  shows a first configuration of the manual vacuum adjustment mechanism shown in  FIG. 11 ;  
         [0021]      FIG. 13  shows a second configuration of the manual vacuum adjustment mechanism shown in  FIG. 11 ;  
         [0022]      FIG. 14  shows an enlarged sectional view of the milk flow sensing mechanism in the breast pump shown in  FIG. 1 ; and  
         [0023]      FIG. 15  is a flow chart showing the steps of operation of the breast pump shown in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]      FIGS. 1 and 2  show an electrically operated breast pump according to a preferred embodiment of the present invention, generally designated as  10 . The breast pump  10  has a hood  12  adapted to be fitted over a breast of a user in an essentially gas-tight manner, for pumping milk from the breast. An insert  12   a  for contacting the user&#39;s breast is received within the hood  12 . The insert  12   a  is made of a soft plastic material, e.g. silicone, to provide comfort to the user during use. The hood  12  is in funnel shape and has a tunnel  14  leading to a connector  16 , which fluidly communicates with the hood  12 , and with a milk-receiving bottle  18  via a valve seat  20 , the structure and function of which will be further discussed below.  
         [0025]     The connector  16  is engaged with a head portion  22  which houses most of the operating components of the breast pump  10 , as will be clear from the ensuing discussion. On a top surface  24  of the head portion  22  is provided with an ON/OFF button  26  for selectively activating/deactivating the breast pump  10 . Also provided on the top surface  24  of the head portion  22  is a liquid crystal display (LCD)  28  for displaying various operation information and data relating to the operation of the breast pump  10 . The head portion  22  is connected with a handle  30 , which also acts as a battery compartment for housing a number of batteries  32  for powering the breast pump  10 . The handle  30  is swivellable relative to the head portion  22  for easy handling. On each side of the handle  30  is provided a PAUSE button  34 , allowing a user to temporarily suspend the operation of the breast pump  10  by pressing the button  34  once, and to resume its operation by pressing the button  34  once again. On a side of the head portion  22  is a power jack  36  which allows the breast pump  10  to be powered by an A/C source, possibly via a transformer (not shown).  
         [0026]      FIG. 3  shows a sectional view of the breast pump  10 . As shown in  FIG. 3 , provided in a chamber  37  of the connector  16  are two infrared (IR) units  38   a,    38   b,  each including an IR transmitter and an IR receiver. Housed in the head portion  22  is a pump motor  42  for operating a pump diaphragm  44  for generating a low pressure (vacuum) in the breast pump  10 . Within the handle  30  is a valve motor  46  for operating a needle valve  48 . The valve  48  is pneumatically connected, e.g. via a hose (not shown), with a nozzle  50  which is in turn pneumatically connected with the milk-receiving bottle  18 .  
         [0027]     Housed in the head portion  22  is a microcontroller  40  for controlling the operation of various electronic and electrical components of the breast pump  10 . As shown in  FIG. 5 , the microcontrolller  40  is electrically connected with and controls the operation of the pump motor  42 , the valve motor  46 , and the LCD display  28 . The microcontroller  40  is also connected with and receives instructions and/or signals from the PAUSE buttons  34  and the IR units  38   a,    38   b.    FIG. 6  shows in more detail a circuitry which controls the operation of the valve motor  46 , the pump motor  42 , and the IR units  38   a,    38   b,  of which only one set  38 a is shown here.  
         [0028]      FIG. 7  shows the setting of the LCD display  28 , and it can be seen that the LCD display  28  may display such information as the setting being used, the flow-rate (slow, medium, high), battery low, and the remaining time (in minutes) required for filling the bottle  18 .  
         [0029]     A microcontroller  40  suitable for use in the breast pump  10  may be one traded by Sino Wealth Microelectronics Corporation Limited, of Hong Kong, under serial number SH6622A, although other similar microcontrollers may also be used. SH6622A is a 4-bit microcontroller, which integrates a 4-bit CPU core with SRAM, 4K program ROM, timer and I/O Port.  FIG. 8  shows a block diagram of SH6622A. The CPU of SH6622A contains the following function blocks: Program Counter, Arithmetic Logic Unit (ALU), Carry Flag, Accumulator, Table Branch Register, Data Pointer (INX, DPH, DPM, and DPL), and Stack.  
         [0030]      FIG. 9  shows an enlarged perspective view of the pump motor  42 , having an output spindle  51  engaged with an eccentric cam  52  which in turn carries a yoke  54  fixed with the pump diaphragm  44 . By way of such an arrangement, rotational movement of the output pin  51  is converted into linear reciprocal movement of the diaphragm  44  in the direction of the bi-directional arrow L-L.  
         [0031]     As can be clearly seen in  FIG. 10 , fixed to the output spindle  51  of the pump motor  42  is a linkage mechanism  58  comprising six links  60  linked with one another in a hexagonal ring-shaped structure. Each link  60  is swivellable relative to two adjacent links  60  to which it is pivotally hinged. Over the output spindle  51  is also provided with a spring  62  which biases an end pin  64  outwardly, which in turn acts on and biases a lid  66  away from a vent hole  68 . The diaphragm  44  is positioned in a chamber  71  which is closeable by the lid  66 , a first one-way valve  70 , and a second one-way valve  74 . The first one-way valve  70  only allows air to enter the chamber  71  from a conduit  72 , which is in turn in fluid communication with the hood  12 . The second one-way valve  74  only allows air to exit the chamber  71 .  
         [0032]     When the motor  42  is not in operation, the linkage mechanism  58  will be biased by the spring  62  to assume the shape and configuration as shown in  FIGS. 3 and 10 . During operation of the pump motor  42 , rotation of the output spindle  51  will bring about simultaneous and corresponding rotation of the linkage mechanism  58 , whereby the hexagonal ring-shaped structure  58  will “flatten” because of the centrifugal force generated by the rotation, thus retracting the end pin  64  against the outward biasing force of the spring  62 . The lid  66  will thus close the vent hole  68 . With the vent hole  68  closed by the lid  66 , linear reciprocal movement of the diaphragm  44  in the direction of the bi-directional arrow L-L will draw air from the hood  12 , through the conduit  72  and the first one-way valve  70 , into the chamber  71 , and push the air out through the second one-way valve  74 , thus generating a lower pressure (“vacuum”) in the hood  12  relative to the outside atmospheric pressure, and mimicking a sucking action of a baby on a mother&#39;s breast. The sucking/releasing cycle is completed by a releasing action when the motor  42  stops rotation. Upon stopping of the motor  42 , the linkage mechanism  58  will, under the biasing force of the spring  62 , resume the stable shape and configuration as shown in  FIGS. 3 and 10 , whereupon the lid  66  will be pushed by the end pin  64  away from the vent hole  68 , to thereby open the vent hole  68 . When the vent hole  68  is opened, air will enter the vent hole  68 , and then back into the hood  12 , thus releasing the “vacuum” in the hood  12 .  
         [0033]     To allow further versatility of the breast pump  10 , a manual pressure adjustment mechanism is provided, allowing the user to manually adjust the level of “vacuum” applied during operation of the breast pump  10 , to suit individual need in different times. As shown in  FIG. 11 , the manual pressure adjustment mechanism includes a wheel  80  with a gear  82  in mesh with a pinion  84  on an end of a pin  86  and a valve seat  88 . As can be seen in  FIGS. 10, 12  and  13 , the wheel  80  is fixed to the handle  30  for rotational movement. The wheel  80  may be moved by a thumb of a user to rotate relative to the handle  30 , about the longitudinal axis of the wheel  80 . The valve seat  88  is also fixedly secured to the handle  30 . By way of such an arrangement, and because of the engagement between the gear  82  and the pinion  84 , rotation of the wheel  80  will cause the pin  86  to move in or out of a recess  90  in the valve seat  88 . In particular, rotation of the wheel  80  in the direction indicated by the arrow F in  FIG. 12  will retrieve the pin  86  from the recess  90 , whereas rotation of the wheel  80  in the direction indicated by the arrow R in  FIG. 13  will insert the pin  86  further into the recess  90 .  
         [0034]     The valve seat  88  is made of a thermoplastic elastomer (TPE) or silicone, and when the pin  86  is fully received within the recess  90 , the valve seat  88  is fully sealed, whereas air may enter the valve seat  88  if the pin  86  is retrieved from the valve seat  88 , and the amount of air allowed to enter the valve seat  88  will depend on the extent to which the pin  86  is retrieved from the valve seat  88 . The recess  90  is in fluid communication with a nozzle  92 , which is in turn in fluid communication with the hood  12 , e.g. via a hose (not shown) connected to the conduit  72 , so that the pressure within the hood  12  when such is applied over a breast of a user may be fine-tuned by the user by manually operating the wheel  80 .  
         [0035]     When the breast pump  10  is fitted over a breast of a user and the pump motor  42  is activated, the pump diaphragm  44  will reciprocate to generate a lower pressure (“vacuum”) in the hood  12 , thus stimulating milk ejection reflex and subsequent expression of milk. Milk from the breast of the user will flow into the hood  12  and subsequently into the chamber  37  in the direction of the arrow M. The milk will accumulate in the chamber  37 , first blocking the transmission of infrared signals between the transmitter and receiver of the lower IR unit  38   a,  and subsequently that between the transmitter and receiver of the upper IR unit  38   b.    
         [0036]     In the valve seat  20  is a one-way valve  96  which allows milk to enter the bottle  18 , but not vice versa. Because the hood  12  is at a lower pressure than the bottle  18  during operation of the pumping action of the diaphragm  44 , the higher pressure in the bottle  18  will prevent the milk in the chamber  37  from entering the bottle  18 , thus allowing the milk level to rise in the chamber  37 . It may take several sucking/releasing cycles before the milk level rises to, and blocks the transmission of infrared signals between the transmitter and receiver of, the upper IR unit  38   b.  When the milk level rises to the upper IR unit  38   b,  the motor  42  will stop, thus releasing the “vacuum” in the hood  12 , in the manner discussed above. In addition, the needle valve  48  will be opened by the valve motor  46 , whereby air will exit the bottle  18  via the nozzle  50 , and subsequently out of the needle valve  48 . The milk in the chamber  37  will thus fall, on its own weight, through the one-way valve  96  into the bottle  18 , during the course of which the level of milk in the chamber  37  will fall. The transmission of IR signals between the transmitter and receiver of the upper IR unit  38   b  will thus resume, and then that between the transmitter and receiver of the lower IR unit  38   a  will resume.  
         [0037]     As shown clearly in  FIGS. 4 and 14 , above the upper IR unit  38   b  is a partition  98  which prevents milk from entering the interior of the head portion  22 , e.g. when the breast pump  10  is accidentally knocked over. Milk entering the interior of the head portion  22  may damage the movement parts of the breast pump  10 , thus shortening its useful life, or necessitating servicing.  
         [0038]     Researches indicate that a baby&#39;s feeding is not a single continuous process, but rather a two-phased process in which the baby will initially suckle rapidly, called “stimulation”. Once the breast has been sufficiently stimulated, milk begins flowing and the baby will settle into a slower, more relaxed sucking speed for the actual feeding phase, called “expression”. The breast pump  10  can mimic the natural feeding pattern of a baby by first exhibiting rapid sucking/releasing actions to stimulate the milk ejection reflex (MER) or “let down”. Once milk begins to flow, the breast pump  10  will then exhibit slower and longer sucking/releasing actions which help to maximize milk flow in less time.  
         [0039]     The manner of operation of the breast pump  10  will be further discussed by reference to  FIG. 15 , which shows a flow,v chart of the steps of operation of the breast pump  10 . Once the breast pump  10  is started (Step  100 ), the valve motor  46  will be triggered once to close the needle valve  48 , which is called “retainer valve” in  FIG. 15  (Step  102 ). A “let down” sequence will be operated in which sucking/releasing actions will be carried out at a speed of  90  cycles per minute at a pressure of 5-7 inch mercury (in Hg) for 30 seconds (Step  104 ). If no milk flows (Step  106 ), an “expression” mode will be operated in which sucking/releasing actions will be carried out at a speed of 45 cycles per minute at a pressure of 7-9 in Hg for 30 seconds (Step  108 ). If there is still no milk flow (Step  110 ), the microcontroller  40  of the breast pump  10  (hereinafter simply referred to as the “breast pump  10 ” for simplicity) will determine if this is the first time such occurs since the breast pump  10  is started (Step  112 ). If not, the breast pump  10  will repeat the above process (Step  114 ) by carrying out the “let down” sequence again (Step  104 ). If, however, such a situation has already occurred once in this operation, a sign or symbol alerting the user to seek medical assistance, e.g. to undergo certain milk flow stimulation operation, will be displayed on the LCD display  28  (Step  115 ), and the breast pump  10  will also cease operation immediately (Step  116 ). For carrying out sucking/releasing actions at a frequency of 45 cycles per minute, the pump motor  42  may be activated for 0.8 second, then deactivated for 0.53 second, and then activated for 0.8 second, and so on.  
         [0040]     If milk flows after the “let down” sequence (Step  104 ) or the “expression” sequence (Step  110 ), the breast pump  10  will then check whether transmission of IR signals in the lower IR unit  38   a  is interrupted (Step  118 ). If so, a timer in the microcontroller  40  will start timing (Step  120 ). The breast pump  10  will then check whether transmission of IR signals in the upper IR unit  38   b  is interrupted (Step  122 ). If so, the timer will stop (Step  124 ). Because the volume in the chamber  37  between the lower IR unit  38   a  and the upper IR unit  38   b  is known, it is possible to thus calculate the rate of flow of milk (in grams per second, g/s) and such is calculated. The valve motor  46  will be triggered once to open the needle valve  48 , thus allowing milk in the chamber  37  to fall into the bottle  18 . The breast pump  10  will also count the number of times of such triggers of the valve motor  46  as “X” (Step  126 ).  
         [0041]     The breast pump  10  will then check whether transmission of IR signals in the lower IR unit  38   a  resumes (“released”) within 2.5 seconds (Step  128 ). If so, the valve motor  46  will be triggered once to close the needle valve  48  (Step  130 ). If transmission of IR signals in the lowver IR unit  38   a  does not resume (“released”) within 2.5 seconds (Step  128 ), or after the closing of the needle valve  48  (Step  130 ), the breast pump  10  will then check if transmission of IR signals in the upper IR unit  38   b  is still blocked in 2.5 seconds (Step  132 ). If so, the pump motor  42  will stop operation, and the needle valve  48  will be opened once again (Step  134 ). If transmission of IR signals in the upper IR unit  38   b  is still blocked (Step  136 ), the pump motor  42  will stop operation again, and the needle valve  48  will be opened once again (Step  138 ). If transmission of IR signals in the upper IR unit  38   b  is still blocked (Step  140 ), the pump motor  42  will stop, a warning signal will be given on the LCD display  28 , and the LCD display  28  will be turned off automatically in 5 minutes, (Step  142 ), and the operation of the breast pump  10  will also stop automatically (Step  116 ). Such will prevent the motor  42  from continuing operation when, e.g. the breast pump  10  accidentally topples over.  
         [0042]     If transmission of IR signals in the upper IR unit  38   b  is not blocked after Step  132 , Step  136  or Step  140 , the breast pump  10  will operate according to the milk flow rate obtained in Step  126 . If the flow rate is between 0.01 to 0.09 g/s (Step  144 ), the breast pump  10  will switch to “let down” sequence (Step  146 ) in which sucking/releasing action is carried out at a frequency of 90 cycles per minute at a pressure of 5-7 in Hg, and a sign or symbol indicating low flow rate will be displayed on the LCD display  28  (Step  148 ). If the flow rate is between 0.1 to 0.24 g/s (Step  150 ), the breast pump  10  will carry out sucking/releasing action at a frequency of 45 cycles per minute at a pressure of 7-9 in Hg (Step  152 ), and a sign or symbol indicating medium flow rate will be displayed on the LCD display  28  (Step  154 ). If the flow rate is 0.25 g/s or above (Step  156 ), the breast pump  10  will carry out sucking/releasing action at a frequency of 38 cycles per minute at a pressure of 6-8 in Hg (Step  158 ), and a sign or symbol indicating high flow rate will be displayed on the LCD display  28  (Step  160 ). According to the present example, the bottle  18  is designed to hold 151.51 g of milk, and in each cycle, the milk that enters, and is thus collected by, the bottle  18  is 1.5 g. Based on such information, and the frequency at which sucking/releasing action is carried out, the breast pump  10  is able to calculate and display the remaining time required to fill the bottle  18 . In this example, it normally requires  101  triggers of the valve motor  46 , “X”, to fill the bottle  18 . Depending on the number of times, “X”, the valve motor  46  has already been triggered to open the needle valve  48 , the breast pump  10  can calculate the remaining time required for filling up the bottle  18  (Step  162 ). The remaining time required will be displayed on the TCD display  28  (Step  164 ).  
         [0043]     If 1.5X&gt;151.51 (Step  166 ), it means that the bottle  18  is filled up, the breast pump  10  will stop (Step  116 ). If not, the breast pump  10  will check again if transmission of IR signals in the lower IR unit  38   a  is interrupted (Step  118 ), and the pumping action will go on again.  
         [0044]     It should be understood that the above only illustrates an example whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention. For example, although the present invention is here described in the context of a “one-pump” model, it is equally applicable to a “two-pump” model, in which a second breast pump is pneumatically connected with the first pump to share in the suction vacuum generated by the pump motor.  
         [0045]     It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.