Nipple device

Abstract

A nipple device that electronically measures the flow of milk drawn by a baby through its feeding orifice. The device measures milk flow from a differential pressure generated by the flow of milk through a fluid flow resistor. The resistor may be located in a peripheral area of ​​the base of the nipple device, and milk is transported to and from the resistor by a passage in the base unit. The differential pressure generated across the resistor is measured using a peripherally located pressure sensor. The pressure sensor and associated electronics may be incorporated into a flow measurement head that is attachable to the base unit of the device through a standard pair of fluid ports to which other heads can be attached for other measurements of milk properties. According to another implementation, the pressure difference across the feeding orifice is used to increase the accuracy of the nipple device for flow measurement purposes.

Description

[Technical field]

[0001] SUMMARY This disclosure describes technology related to the field of methods and systems for measuring and monitoring the amount of milk delivered to an infant, particularly from a mother to an infant during breastfeeding. [Background technology]

[0002] A desire often arises during breastfeeding to determine how much of the mother's milk the baby is actually taking during a feeding session, especially during the first few weeks of the baby's life. Babies tend to latch onto the breast as a soothing function, giving the mother the feeling that the baby is nursing, when in fact this is not the case. In addition, some mothers may not have a sufficient milk supply, especially before breastfeeding is established, so a hungry baby may latch onto the breast for a long time without receiving a sufficient milk supply. In addition, some babies may appear to fall asleep while feeding, and the mother may not realize that she is actually still nursing. A similar requirement may be placed on bottle-fed babies. Although it is possible to measure the exact amount of milk the baby is taking by weighing the bottle before and after feeding, or by looking at the graduations on the bottle, this measurement does not provide a real-time indication of the actual flow rate during feeding, other than an estimate of the rate at which the milk level in the bottle moves downward during feeding.

[0003] Furthermore, in addition to the total amount of milk consumed by an infant and the rate at which the infant drinks, there are other features of a feeding session that are not easily accessible with current simple devices, such as the feeding patterns encountered as a function of the time course of the feeding, which could provide useful and comparable information.

[0004] Various measurement systems have been proposed to provide a measure or at least an indication of the amount of milk delivered to the baby. Some are complex and require electronic measurement attachments, others are simple. One technique is disclosed in an article by SEJ Daly et al., Exp. Physiology, 77, 79-87 (1992). This technique tracks changes in breast volume by computer imaging the breast before and after feeding. US Pat. No. 5,399,433 to E. Kolberg et al., entitled "Apparatus and Method for Measuring Breast Milk Flow," discloses a technique in which a volumetric flow sensor is placed in a silicone nipple cap through which the baby feeds. Milk flow data from the sensor is converted to milk volume data and displayed to the mother. Such systems generally require the attachment of an electronic or electromechanical flow meter in the fluid passageway to measure the fluid flow. Several other systems have been proposed to measure milk flow using an external electronic flow measurement module attached to a milk collection device that is worn on the mother's breast. One such system is shown in US Pat. No. 5,399,433 to O. Melamed, entitled "Measurement of Breast Milk Fed." Therein is shown an external electronic measurement unit for measuring milk flow rate via a mechanical flow meter. Similarly, US Pat. No. 5,399,433 to LADrew for "Non-Invasive Breast Milk Monitoring" shows an external electronic flow measurement and display unit.

[0005] A simpler non-electronic device similar to a nipple shield is described in commonly owned US Patent No. 5,399,663 for "Apparatus and Method for Measuring Fluid Flow to a Baby During Feeding," in which a portion of the main milk flow is passed through a measurement channel that has a significantly higher resistance to fluid flow than the main milk flow channel, and fluid flow into the measurement channel can be measured, such as by observing the length of the measurement channel that fills with milk after a feeding session. Because the ratio of the fluid resistances of the two channels is known, the length of milk in the measurement channel can give a measure of the amount of milk that has been drawn through the main channel.

[0006] US Patent No. 5,399,993, also commonly owned by the applicant and co-pending with the present application, for "Breast Milk Flow Detection Device" describes a dedicated nipple shield device that allows a breastfeeding mother to easily display the flow rate of milk from a breastfeeding baby without the need for electronic attachments. In addition, the application also discloses a multitasking nipple shield device that can be used to perform many alternative functions related to different aspects of a breastfeeding mother's needs. The nipple shield device includes a universal base unit that is attached to the mother's breast and performs the transfer of the mother's milk from the nipple to the baby's mouth by a passageway that delivers the milk to and from the nipple to a remote location. Any of a number of different operating heads can be attached to the remote location, with each type of head adapted to perform a dedicated function or functions related to the milk. The remote location includes a standardized pair of fluid flow connection terminals, with the various operating heads having matching standardized fluid flow connectors that can be attached to the remote connector of the base nipple shield. That is, the nipple shield base unit is universal, and the method of use of the device depends on the head that is attached to the nipple shield remote terminal. The head, typically electronically operated, may be fitted for various measurement or indication functions, such as flow measurement, flow indication, drug addition, measurement of the baby's sucking pattern, milk quality analysis, detection of markers in the milk indicative of maternal illness, and many other functional applications.

[0007] In U.S. Patent No. 6, "Miniature Sensor-Based Feeding Volume Measurement Device" to Coroflo Limited, a differential pressure measurement module is shown placed in the orifice of the nipple through which the baby sucks, with a first pressure sensor placed at the inlet port of the orifice close to the mother's milk source and a second pressure sensor placed near the outlet port where the baby sucks. The differential pressure calculated from the measurements of the two sensors gives an indication of the milk flow in the channel of the feeding orifice.

[0008] A common drawback of all such systems that rely on the measurement of pressure drop as milk flows through a measurement path with significant flow resistance is that the infant must exert a significant effort to obtain a good flow of milk. One of the reasons for the additional effort required from the infant in such nipples with high resistance flow paths is that the infant's sucking pattern is not a continuous application of negative sucking pressure to the nipple, but rather a series of separate sucking actions that pulse in a sinusoidal pattern, typically at a rate of approximately two per second. This pulsating sucking pattern should not be confused with the breathing pause that the infant must take every few seconds, which are involved in such a sucking cycle. This repeating pattern of negative pressure pulses applied to the nipple results in an oscillatory flow of milk to and from the infant. This is because with each release of the suck by the infant, some of the milk in the infant's mouth flows back through the nipple orifice into the volume around the mother's breast, where it is reabsorbed by the infant in the next sucking action of the cycle. As a result, instead of being consumed by the baby, some of the milk flows back and forth in a cyclical fashion through the nipple orifice, so that the net flow consumed by the baby is only the portion of milk moved by the baby with each sucking action of that cycle. This additional flow represents an unnecessary energy expenditure by the baby, and uncertainty on the part of the mother as to whether the baby is receiving a sufficient amount of milk during the feeding session. A further relevant potential problem for devices that measure the flow of milk consumed by the baby is that if the flow of milk is not constant, or at least not unidirectional, the constantly changing flow rate can cause noise problems in a measurement system that would be accurate if a constant flow of milk was available for measurement.

[0009] As the benefits of breastfeeding become more widely known, more mothers are breastfeeding than ever before, highlighting the need for a simple, yet accurate device to measure a baby's milk intake.

[0010] The disclosures of each of the publications mentioned in this and other sections of the specification are each incorporated herein by reference in their entirety. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] International Publication No. 2006 / 054287 [Patent Document 2] International Publication No. 2014 / 174508 [Patent Document 3] US Patent Application Publication No. 2018 / 0147124 [Patent Document 4] U.S. Patent No. 7,896,835 [Patent Document 5] International Publication No. 2022 / 175833 [Patent Document 6] International Publication No. 2020 / 025337 [Non-patent literature]

[0012] [Non-Patent Document 1] SEJ Daly et al., “The Determination of Short-Term Breast Volume Changes and the Rate of Synthesis of Human Milk Using Computerized Breast Measurement” published in Exp. Physiology, 77, 79-87 (1992) Summary of the Invention

[0013] The present disclosure provides a novel device and method for measuring milk flow to a nursing infant that overcomes at least some of the shortcomings of prior art systems and methods. The nipple device described herein has a dome structure similar to commonly used nipple shields, with an internal milk collection volume between the dome structure and the mother's breast, from which the infant draws milk through one or more orifices in the tip region of the nipple dome structure. The nipple device uses the fact that the flow to the infant through the nipple orifice or orifices is proportional to the pressure difference between the milk secreted at the mother's breast and the milk the infant draws at the output end of the orifice or orifices, and the nipple device described herein uses a novel structure to determine this pressure difference.

[0014] The nipple structure incorporates an element that provides a pressure differential measurement that allows milk flow to be easily measured by a dedicated pressure sensor device. Such a pressure sensor device may be incorporated into a small electronic chip mounted on the nipple device. The nipple device may be configured to be used as a nipple shield to measure milk flow from the mother's breast to the baby, or as a nipple cover mounted on a baby bottle.

[0015] According to a first implementation of these devices, the nipple device uses the principle that the flow of milk from the internal volume of the nipple device is proportional to the pressure difference generated by the nursing baby across the orifice or orifices of the nipple device, whether mounted on the mother's breast or on a baby bottle. The orifice or orifices of the nipple connect the volume inside the dome of the nipple device to the volume outside the dome of the nipple device that the baby holds in his mouth. The pressure on the outer surface of the nipple dome, and therefore the pressure at the outer end of the orifice or orifice channel or channels of the nipple device, is therefore the negative pressure caused by the baby sucking on the nipple dome. The pressure at the inner end of the orifice or orifice channel or channels is equal to the pressure in the inner volume of the nipple dome, which in the case of a nursing mother is the volume between the mother's breast and the nipple device. In the case of a nipple device used in a baby bottle, the pressure inside is the pressure of the contents in the bottle. The pressure both inside and outside the flexible layer of the nipple device can vary between atmospheric pressure and subatmospheric pressure. When the baby pauses to breathe between a few pulsating sucking movements, the pressure in both volumes generally returns to the equilibrium atmospheric pressure. However, at other moments, the baby's sucking creates a pressure difference across the orifice channel, and as the system always seeks to reach pressure equilibrium, the pressure in the baby's mouth and the pressure in the space between the nipple dome and the mother's nipple tend to be equal when the baby applies a secondary pressure. Milk therefore flows from the space between the nipple dome and the mother's breast, through the orifice or orifices, and into the baby's mouth. Since the diameter of the orifice or orifices is known, the pressure difference allows the milk flow rate to be determined. Even if the diameter of the orifice or orifices is not known, a simple pre-calibration procedure can be used to determine the relationship between the measured pressure and the milk flow rate through the orifice or orifices. Integrating these varying flow rates over time gives the total milk flow rate through the orifice or orifices to the baby. This application describes structures and methods that allow the measurement of this pressure difference, and thus the flow of milk from the mother to the baby.

[0016] In its simplest form, a nipple device of the type shown in this disclosure requires a pair of pressure sensors (or differential pressure sensors) whose inputs are connected by passages to each of two regions of the milk flow where it is desired to measure the pressure. The pressure sensor or sensors may be located at the outer periphery edge of the base layer of the device so that they are not obscured by the baby's mouth. Using a generic nipple shield model, this may be achieved by forming narrow passages in the nipple shield material. One of the passages leads from an opening in the outer surface of the dome-shaped convexity of the device, near its top end, down the passage to a first pressure sensor input to convey the pressure generated in the baby's mouth, and the other of the passages leads from an opening in the inner surface of the dome-shaped convexity of the device to a second pressure sensor input to convey the pressure present in the dome-shaped convexity's internal volume. This internal volume is the space in which milk drained from the mother's breast accumulates before being drawn in by the baby through the feeding orifice or orifices. As long as the resistance of the orifice or orifices remains constant, the measured pressure differential gives an indication of the fluid flow rate of milk from the mother to the baby. These passages are sealed at their outer ends so that ingress of milk into the passages is minimised and the pressure of the milk flow is transmitted to the pressure sensor input by a layer of trapped air in the passages. The presence of this layer of trapped air in the passages is important as it provides a gas barrier preventing milk from contacting the pressure sensor itself which could cause malfunction over time.

[0017] According to another exemplary embodiment of the device and method of the present disclosure, the material layer of the nipple dome region of the device of the present disclosure includes a pair of chambers embedded therein. Although using only a pair of chambers is the simplest implementation, similar measurement systems may also use more than one pair. The chambers may be located at any circumferential position of the nipple dome where the baby sucks to obtain milk, but advantageously, but not necessarily, each chamber may extend around an opposing portion of the circumference of the nipple dome region of the device. The positions of the chambers relative to the centerline of the thickness of the material layer of the nipple are configured differently. One chamber of the pair of chambers (herein known as the first chamber) is located closer to the outer surface of the material layer of the nipple region of the device than to the inner surface. The other of the pair of chambers, the second chamber, is located closer to the inner surface of the material layer of the nipple region of the device than to the outer surface. The placement of the chambers near one or the other surface of the nipple layer naturally results in a partition between the chamber and the nearby surface. This partition is thinner and therefore more flexible than the partition between the chamber and the surface remote from it. This thin partition may be considered as a thin flexible membrane. That is, each chamber has a thin wall that easily flexes in response to pressure changes on its outer surface, and a thick wall that may be considered semi-rigid, not flexing under pressure changes in its outer volume. Once the outer wall of the chamber is considered fixed due to the relative stiffness of its rear wall, application of external pressure to the thin opposing wall of the chamber will cause the thin wall to deflect inwardly or outwardly depending on the level of external pressure applied, whether above or below ambient pressure. The terms "outer" or "outside" as used in this paragraph are intended to relate to the orientation of the thin wall relative to the material of the nipple, whether facing the mother's breast or the real "outside" world in which the baby resides from the mother's perspective.

[0018] That is, when the pressure outside the nipple is lower than the ambient pressure, such as in the normal situation when a baby is nursing, the thin walls of the chambers exposed to the lower pressure in the baby's mouth will expand outward, and the volume inside the chamber will increase. Since the chamber is a closed volume, the pressure inside the chamber will decrease. Similarly, for the chambers whose thin walls face the mother's breast, when the pressure inside the volume of the dome-shaped nipple structure decreases, the thin walls of the chambers will bow away from the wall into the inner volume of the dome-shaped nipple structure, and since the chamber is also a closed body, the pressure inside the chamber will decrease accordingly. As a result, a pressure difference is created between the first and second chambers. This is because the thin outer wall of the first chamber will expand outward more than the thin wall between it and the second chamber, and the inner side of the nipple dome will expand inward due to the secondary pressure from the outside caused by the baby's sucking, so that the pressure inside the first chamber will be lower than the pressure inside the second chamber. This analysis makes the approximation that the stiffness of the thick wall of each chamber is such that its movement under the influence of pressure applied to the outside of the thick wall is negligible compared to the movement of the thin wall. This difference in pressure developed between the two chambers is proportional to the difference in pressure that exists between the outer surface of the nipple dome structure and its internal volume. Since that pressure difference is substantially equal to the pressure difference across the milk flow orifice(s), and since that pressure difference determines the rate at which milk flows from within the nipple internal volume through the orifice(s) to the baby's mouth on the outer surface, a measurement of that pressure difference provides a measurement of the flow of milk to the baby.

[0019] An alternative way of looking at the interaction of the chambers with the ambient pressure present on the outer and inner surfaces of the nipple dome structure is to consider the reduced pressure in a first chamber, due to the outward movement of its thin wall, to be proportional to the reduced pressure outside of the nipple dome. At the same time, for a second chamber located closer to the inner surface of the nipple dome structure, the pressure generated in that chamber, due to the inward movement of its thin wall, is proportional to the pressure within the interior volume of the nipple dome structure.

[0020] In an alternative to the structure described above, each chamber could be provided with one wall that is more flexible than the opposing wall by fabricating one of the walls from a more flexible material. Such a structure would meet the multiple chamber requirements of this application, but may not be as cost effective or simple to manufacture.

[0021] The nipple device has been described in its simplest form, which is also the most economical way to manufacture the device. In the basic implementation of this device, which shows how the pressure difference between these chambers can be used to give information about milk flow, there is only a single first chamber and a single second chamber. However, it should be understood that the use of a single first chamber and a single second chamber is not intended to limit the device, which may function if either or both of the first and second chambers contain more than a single chamber. These chambers are claimed as "at least a first chamber" and "at least a second chamber" to thus claim structures that use multiple chambers for each pressure measurement, which includes structures that may have different numbers of chambers for pressure measurements of the interior and exterior spaces of the nipple dome structure in the baby's mouth.

[0022] To measure the level of differential pressure, one convenient way is to provide the nipple device with a narrow passageway connecting the two chambers to a remote area, for example a peripheral area around the nipple base. The differential pressure measurement is then made between the two passageways. It should be understood that alternatively, multiple passageways may be used for each input to the differential pressure sensor, with multiple chambers for inner and outer pressure measurements, and is intended to be claimed as such. The differential pressure measurement is then proportional to the measurement of milk flow through one or more orifices into the baby's mouth. Such a differential pressure measurement may be made by connecting two fluid connections of a differential pressure sensor to the passageways from the first and second chambers. Many such pressure sensors are available, including miniature sensors of only a few mm, which do not significantly interfere with the use of the nipple device. Such sensors may operate using piezoresistive or piezoelectric elements, or miniature silicon-based chip sensors, typically based on strain gauge technology, or other physical phenomena as used in many commercially available miniature pressure sensor elements. The output of the differential pressure gauge may be input to a readout monitor that gives an output proportional to milk flow. Calibration of the sensor is required to convert its signal output into a reading that reflects flow rate. The differential pressure measurement may be transferred and analyzed by an external device such as a smartphone.

[0023] Throughout the embodiments shown in the present disclosure, as an alternative to a single differential pressure sensor, individual pressure sensors may be used, one at each end of the two passageways, each pressure sensor sending its output signal to an electronic difference circuit, which outputs the measured differential pressure. Similarly, in devices using more than two chambers, the differential pressure measurement is obtained by measuring the individual pressures between the ends of the passageways from each set of chambers. That is, the pressures in the internal volume of the nipple dome obtained in several passageways from several chambers are measured and subtracted from the pressures obtained from the chambers measuring the pressure in the baby's mouth in the external volume of the nipple dome to obtain a differential pressure on the basis of which the milk flow is determined. As a result, the measurement of individual pressures as claimed is intended to cover the pressures obtained from such combinations as well.

[0024] In order to accurately measure the milk flow, there are a certain number of details of the nipple device's construction that need to be observed. Since the accuracy with which the pressure in each chamber is measured depends on the orderly movement of the thin walls under the effect of pressure, it is important to reduce to a minimum any movement imparted to the shape of the nipple dome, and thus to the shape of the chambers therein, due to the drop in pressure caused by the baby's sucking. If the overall shape of the chambers is distorted by the by-pressure of the baby's sucking or by the physical movement of the baby's tongue or lips, the movement of the thin walls and thus the change in the volume of the chambers will be undeterminable and the pressure reading will be distorted accordingly. To prevent inaccurate pressure readings due to distortion of the nipple shape caused by the baby's sucking, these chambers may be advantageously located near the top of the nipple dome. Here, the material layer undergoes less distortion or shape change due to the increased inherent strength of the tightly curved areas of the dome structure near the peak compared to the less curved walls below the nipple dome structure. Alternatively, the upper region of the nipple dome may be artificially reinforced by using a material or thickness that provides additional stiffness in that area. By such means, these chambers are protected more than they would be otherwise from externally induced mechanical distortions. Moreover, by analysing the signals representative of the pressure in both chambers, it should be possible to determine whether the distortion of the chamber membrane is due to the physical pressure of the baby's tongue or lips, or to an actual downward pressure applied. By analysing the feeding pattern, it is possible to filter out such noise and distinguish the effects of real pressure from other disturbances.

[0025] Additionally, distortion of the nipple shape may be caused directly by the baby's lips contacting the nipple further down the nipple wall rather than near the top of the nipple dome. Thus, for chambers located in the upper regions of the nipple dome structure, or in particularly reinforced regions of the dome structure, the shape of the nipple in the measurement area will not be disturbed by the baby's lips to the same extent as chambers located further down the dome.

[0026] The use of electronic measurement with the nipple device of the present disclosure not only allows measurement of the rate and amount of milk ingested by the infant, but also provides a real-time indication of the infant's sucking and intake patterns, this functionality providing the mother with useful information regarding the progress of the feeding session and the infant's tiredness.

[0027] A further advantage of determining the sucking behaviour of an infant in real time is that the sinusoidal tracking of the infant's sucking gives important information about the baby's health and fitness, at least as far as its sucking ability is concerned, and by comparing the sinusoidal measurements with normal standards an indication of the infant's development is obtained. Electronic data tracking of feeding sessions also allows the infant's development to be easily followed over time.

[0028] As mentioned above, the electronic nipple device of the present disclosure can also be used as a nipple for a baby bottle, thereby converting any baby bottle into a "smart baby bottle" in a very simple manner at a substantially lower cost than other methods of measuring the amount and rate of milk intake by the baby. In addition to the additional advantages available for the electronic nipple device of the present application, especially in the area of ​​determining the time-dependent pattern of the baby's feeding and the associated characteristics of the baby's feeding habits, the electronic nipple device is more accurate than any method that involves checking the level of milk in the bottle that drops during a feeding session. The other advantages mentioned above are also applicable to the "smart baby bottle" nipple, not only the amount and rate of intake, but also the pattern of the baby's milk intake and the clinical or developmental information that can be derived therefrom.

[0029] According to further implementations of the device of the present application, a number of structural improvements are proposed to the simple orifice used in the prior art device to avoid the influence of the baby's mouth or tongue movements from interfering with the shape or form of the orifice orifices and thus the magnitude of the flow resistance of the orifice orifices, affecting the accuracy of the differential pressure measurement and thus the flow rate measurement. According to a first embodiment, the material in which the orifice orifices are formed is connected to the rest of the dome-shaped nipple structure by a thin and thus flexible layer of nipple material, so that the area of ​​the orifice itself can remain stiffer than the area surrounding it. As a result, even if the baby applies mechanical force to the orifice, the degree of deformation of the orifice orifices themselves is reduced, and the flow resistance of the orifice orifices is better maintained, even if the orifice area moves or tilts. This implementation allows the orifice or orifices to effectively "float" relative to the rest of the domed nipple structure, such that forces applied to the upper end of the nipple structure are essentially not transferred to the structural form of the orifice or orifices themselves, or at least have a reduced effect on the orifice or orifices. Similarly, the area of ​​the orifice or orifices can be made from a harder material than the rest of the nipple device, and not experience the same level of strain when forces are applied as if it were made from the same material.

[0030] According to yet another implementation, the inner side of the dome-shaped nipple structure may include a thickened region having a number of channels within the thickness of that region that open into the region around the inner orifice opening so that breast milk can flow to the orifice or orifices in the event that the mother's nipple is in contact with the inner side of the dome-shaped structure and would otherwise block the orifice or orifices.

[0031] To avoid any of the above mentioned interferences with the measurement of the milk flow at the orifice or orifices, according to yet another embodiment of the present disclosure, the milk flow itself may not flow directly from the inner side of the domed nipple structure through the orifice to the baby's mouth, but may be conveyed by a fluid transfer passage to a location near the outer edge of the device, remote from the protruding domed nipple structure. At this location, a constriction is formed in the flow path, which acts as a fluid flow resistor where the differential pressure is measured. After flowing through the flow resistor, the milk is conveyed through a second fluid transfer passage, through the orifice or orifices to the outside of the domed nipple structure and back to the baby's mouth. In this embodiment, the orifice or orifices do not have any function as a flow resistor of the device in this case, but simply serve to convey the milk from the nipple device to the baby. The passages may be implemented as more than one passage in each direction to minimize the resistance to the milk flow between the domed nipple structure and the flow resistor. A pressure sensor is placed either at or within the end region of the fluid resistor and the differential pressure across the resistor is measured and the milk flow rate is determined from this pressure difference. By using a fluid flow resistor in a location remote from the feeding orifice, an accurate measurement of flow rate can be obtained that is essentially independent of baby interference with the flow out of the feeding orifice or orifices.

[0032] As in the implementation described above, contact between the milk flow and the pressure sensor can be prevented by using a layer of air trapped in the passage between the milk flow itself and the pressure sensor. According to another method to prevent the milk from contracting the pressure sensor itself, a pair of pressure transmission chambers can be used: one for the milk flowing into the flow resistor and the other for the milk flowing out of the flow resistor. Each chamber has a flexible diaphragm that divides each chamber into two separate subchambers. The first pair of subchambers is in contact with the milk, one for the input side of the flow resistor and the other for the output side. The second pair of subchambers is in contact with the pressure sensor itself, one for the pressure on the input side of the flow resistor and the other for the pressure on the output side of the flow resistor. The flexible diaphragm deflects in response to the pressures applied by the milk flow subchambers and acts as a pressure transmission mechanism, transmitting those pressures to the pressure sensor in the second pair of subchambers. Milk is prevented from entering the second pair of sub-chambers by the flexible diaphragm so that the pressure sensor is protected from contact with the milk itself but senses the fluid pressure of the milk stream by extension of the flexible diaphragm.

[0033] In the above-mentioned US Patent Publication 5,549,563 for "Breast Milk Flow Detection Device," various implementations of a multitasking device for measuring various breast milk characteristics are shown in Figs. 10-12 in the form of a generic nipple shield flexible base unit that is attached to the mother's nipple with various attachment heads available for various different tasks related to breast milk feeding. The attachment heads are adapted to plug into fluid connection ports located remotely from the nipple area of ​​the device. A number of different attachment heads are shown in Fig. 10 of the publication, the common feature being that the connection of the head to the fluid connection port completes a breast milk circuit between a passage or passages leading from a breast milk source inside the flexible nipple shield and a passage or passages returning to the feeding orifice that supplies breast milk to the baby. One of the attachment heads disclosed in the publication is a flow indicating head. The flow indicating head provides an indication to the mother that the baby is receiving a flow of milk through the nipple shield by indicating the flow in a visually transparent tubing section. Similarly, attachment heads are disclosed herein. Here, milk flow is determined by incorporating a flow resistor together with a pressure sensor and electronic circuitry in the attachment head. The pressure sensor determines the differential pressure across the flow resistor, and the electronic circuitry converts this differential pressure into a measure of milk flow. An electronic display may be incorporated in the attachment head, or alternatively, a wireless connection for transmitting the measured flow rate to a remote device such as a mobile phone. Additionally, a pressure transmission chamber as described herein above may be incorporated in the head.

[0034] The above mentioned devices are described assuming that the flow of milk to the baby is continuous, without considering the pulsatile flow pattern of milk to the baby through the nipple orifices. The present application also describes further novel features of feeding nipples, which provide a more stable flow of milk to the baby and reduce the effort required by the baby to feed through the nipple, making every feeding session less strenuous for the baby and worry-free for the mother. This feature can be advantageously applied to the measuring nipples described hereinbefore, but may also be applied to improve any type of nipple in which the feeding orifice has a limited fluid conductance (e.g. nipples in which the pressure drop across the orifice is necessary to be able to determine the flow through the orifice). These improved nipples include a partial area of ​​the nipple convex surface intended to enter the baby's mouth, which has a higher flexibility than the rest of the nipple. This flexible area can be most easily formed by making the partial area a thinner or softer material than the rest of the nipple area. The flexible area then acts as a pressure equaliser for the sucking action of the baby, as explained herein below.

[0035] According to the prior art nipple, when the baby sucks, a negative pressure is generated in the baby's mouth, which is transferred to the inner volume of the nipple protrusion, from where the milk accumulated in the space between the mother's breast and the inner surface of the nipple is drawn. The flow of milk from the mother to the baby occurs because the negative pressure in the baby's mouth, generated by the baby's sucking, has a higher level of negative pressure, i.e. a more negative absolute pressure, than the negative pressure in the inner volume. In the time between the baby's periodic sucking actions, the baby releases the low pressure in its mouth, and the pressure in the mouth returns substantially to atmospheric pressure. In this case, the pressure in the inner space of the nipple is lower than the pressure in the baby's mouth, so that milk flows back from the baby's mouth to the accumulated milk in the inner volume of the nipple. The amount of milk that flows back is proportional to the difference in pressure between the baby's mouth, which approaches atmospheric pressure between sucking, and the inner space of the nipple. In the nipples of the present disclosure described herein, the flexible membrane area acts to reduce the pressure differential between the baby's mouth and the nipple internal space by flexing in response to changes in the pressure differential between the baby's mouth and the nipple internal space. That is, while the baby is in the sucking portion of the pulsatile feeding process, the flexible membrane moves outward in the direction of milk flow toward the lower pressure of the baby's mouth. However, when the baby releases the sucking, the flexible membrane bulges inward toward the mother's breast, as the pressure in the baby's mouth increases toward atmospheric pressure, creating a higher absolute pressure than in the mother's internal space. This inward movement of the membrane effectively reduces the volume of the space between the nipple and the mother's breast, and also reduces the degree of negative milk pressure accumulated there (i.e., the absolute pressure increases), thus reducing the pressure differential across the nipple orifice and thus reducing the backflow of milk from the baby into the nipple internal volume. The rise in pressure from the mother's side to the baby's side occurs more quickly than would be obtained without the flexible membrane, as the tendency for these two pressures to equalize depends on the flow rate of milk through the feeding orifice or orifices.

[0036] An alternative and graphic way of looking at this step is to consider the inwardly bulging membrane as expanding the volume available for milk at the baby's mouth, making room to contain any milk not swallowed by the baby, rather than flowing back to the mother's side of the nipple. Once the baby resumes sucking, the membrane reverses its bulging shape and moves in an outward direction, since there is now a negative pressure on the baby's side of the membrane. This results in an increased pressure differential across the orifice, and a continued flow of milk to the baby. That is, the oscillatory motion of the membrane results in a reduced pressure differential across the orifice when the baby is relaxed in the non-sucking phase of the sucking cycle, and an increased or maintained pressure differential across the orifice when the baby resumes sucking. The net effect of the membrane is therefore to increase the net flow of milk from the mother to the baby, and to reduce the degree of backflow of milk from the baby's mouth back into the interior space of the nipple convexity. This then achieves the dual benefit of reducing the effort required for the baby to feed and reducing the "noise" in the differential pressure measurements required to determine milk flow rate by smoothing the net flow pattern of milk from mother to baby.

[0037] The above-mentioned methods for providing an easy feeding for the baby and generally reducing the pulsatility of the feeding process of the baby have been described using one or more areas of the nipple region as a flexible membrane to generate the desired effect resulting from a significant change in volume available on both sides of the nipple convexity as the membrane flexes back and forth in response to the sucking pattern of the baby. Similarly, according to further embodiments of the device described in the present disclosure, it is possible to achieve the same change in volume between the mother's side and the baby's side of the nipple convexity when the baby is feeding by manufacturing the entire nipple convexity from a material that has a substantially higher flexibility than is accepted in the art. Currently available baby nipples or flow measurement devices based on baby nipple devices use flexible materials with a hardness in the region of 50 Shore A, or materials with some lower flexibility, in order to provide good resistance of the nipple material to the baby's jaw movements, especially for older babies, and thus good wear quality and long life for the nipple. According to the proposed nipple device, the entire nipple protrusion is made of silicone or other flexible layer having a hardness of 40 Shore A or less, e.g. 35 Shore A or 30 Shore A. This allows easier feeding and less pulsation, as the nipple protrusion has less resistance to pressure changes caused by the sucking or relaxing of the baby. It may also be advantageous to manufacture the entire nipple device from such flexible material to reduce manufacturing costs.

[0038] The size of the feeding orifice or orifices should be a compromise between being small enough so that the pressure differential across the orifice is high enough for the expected milk flow to be accurately measured by a pressure sensor, but not so small that the orifice provides so much resistance to the flow of milk to the baby that the baby cannot comfortably feed. The optimal size or sizes may be measured experimentally or determined from the size of the orifice or orifices used in nipples in general use. However, it should be understood that the need to measure the pressure differential places additional constraints on the upper size of the nipple orifice or orifices.

[0039] In fact, the membrane section may be located on any portion of the nipple convex, whether in the region around the orifice of the dome or on the upper sidewall of the nipple convex, provided that it is located in the baby's mouth when in use. The area or dimensions of the pressure sensitive membrane are limited by the need to maintain sufficient strength so that the membrane does not burst when pulled beyond its designed limits.

[0040] The entire nipple device can be manufactured at very low cost and in high volume by any suitable polymer molding process. The differential pressure sensing device and its controller may be formed on a single miniature electronics board, with no electronic readout unit taking up a significant amount of space on or adjacent to the nipple device.

[0041] Since the operation of the device described herein involves negative or subatmospheric pressures generated by the sucking action of the infant and transmitted to the mother's nipple, in order to avoid any uncertainty as to the levels of these negative pressures, references to increasing or decreasing the negative pressure are understood to mean increasing or decreasing the degree of negative pressure even if the pressure is negative. That is, terms such as "decreasing the negative pressure" are not to be construed in this disclosure as meaning to further decrease the absolute level of negative pressure, but rather to mean decreasing the degree of negative pressure expressed in negative levels of pressure which means increasing the absolute pressure.

[0042] Although throughout this application the infant's mother is referred to as the milk provider and is claimed as such, it should be understood that this is the normal situation and the reference to the mother is not intended to exclude women other than the infant's mother who provide milk, and the disclosure and claims are not intended to be construed as limited to use of the device by mothers to breastfeed their babies.

[0043] In addition, the orifice through which the baby draws milk from the interior volume of the dome of the nipple structure may be a single opening or several openings, and references in this disclosure and claims to "an orifice" or "the orifice" are intended to be interpreted as the total passage of milk from the inside of the nipple to the baby's mouth, whether a single orifice or several orifices.

[0044] It is further recognized that differential pressure measurements can be performed through the use of a dedicated differential pressure sensor, or through two separate pressure sensors with subtraction circuitry to provide an output proportional to the difference in pressure between them. As a result, in this disclosure and claims, any reference to differential pressure measurements or differential pressure sensors is intended to include measurements performed by a single differential pressure measurement probe or by two separate pressure measurement probes.

[0045] The nipple device described above has been shown in its simplest form, but this is also the most economical way to manufacture the device in the sense that in the basic implementation of the device, there is only a single flexible membrane that provides pressure compensation to overcome the tendency of milk to flow back into the mother's side of the nipple structure. However, it should be understood that the use of a single flexible membrane is not intended to limit the device, and that the use of two or more flexible membranes may also function, provided that both are positioned in a position that is substantially inside the baby's mouth during feeding. Thus, the flexible membrane is claimed as "at least one area of ​​material of the nipple device that is more flexible than the remainder of the nipple device" or "at least one area of ​​the dome-shaped convexity". Such claim language or similar language is intended to include claimed structures that use more than one flexible membrane to provide milk backflow compensation. Furthermore, the term "single flexible membrane" may be understood in some embodiments to refer to the entire nipple convexity of the device.

[0046] Thus, according to an exemplary embodiment of the device described in the present disclosure, there is provided a device for monitoring the flow of milk drawn in by an infant during feeding, the device comprising: a nipple device that is drawn in by the infant during feeding to monitor milk flow, the device comprising: a base layer including a dome-shaped protrusion having an inner surface and an outer surface, the inner surface defining an interior volume of the dome-shaped protrusion, the dome-shaped protrusion adapted to be inserted into the infant's mouth; at least one first passageway from the interior volume of the dome-shaped protrusion to an area of ​​the base layer remote from the dome-shaped protrusion; a second at least one passageway from the area of ​​the base layer remote from the dome-shaped protrusion to at least one location on the outer surface of the dome-shaped protrusion; Including, The first at least one passage and the second at least one passage are fluidly connected by a section of a passage having a first pressure sensor and a second pressure sensor in the region of the base layer remote from the dome-shaped convex portion, and a differential pressure between the first pressure sensor and the second pressure sensor can be determined.

[0047] In such a nipple device, the flow of milk from within the interior volume of the dome-shaped convex to at least one location on the outer surface of the dome-shaped convex can be determined by a pressure difference between the first and second pressure sensors. Additionally, the first and second sensors may be incorporated into a differential pressure module. The differential pressure module may include a subtraction circuit operating between the outputs of the pressure sensors.

[0048] In any of the nipple devices described above, the connection between the first at least one passageway and the second at least one passageway has a constricted bore to generate an increased fluid flow resistance to the flow of milk therethrough. Furthermore, the flow of milk to the baby is determined from the differential pressure measured between these pressure sensors using a known relationship. The output of the pressure measuring device can also determine the pattern of milk intake of the baby. Additionally, the base layer of the nipple device may be shaped to be mounted to the breast of a mother feeding the baby, or may be adapted to be mounted to a baby bottle. Furthermore, the region of the base layer remote from the dome-shaped convexity may be a peripheral region of the base layer of the nipple device.

[0049] According to further implementations of the devices of the present disclosure, in any of the devices described above, the pressure sensor or differential pressure module may be located in a separate head adapted to be attached to the periphery of the nipple device through a fluid flow port. In such a case, the separate head may include either a display indicating the level of milk flow or wireless equipment to transmit the flow rate to a remote receiver.

[0050] Additionally, in any of the nipple devices described above, the first and second at least one passageway are each connected to a chamber having a flexible diaphragm dividing its internal volume into two sealed compartments, and pressure communication between each of the first and second at least one passageway and its associated pressure sensor is across the flexible diaphragm. In such devices, the first at least one passageway is connected to a first of the two sealed compartments, and the first pressure sensor is connected to a second of the two sealed compartments. The second of the two sealed compartments is filled with liquid.

[0051] In further implementations of the nipple device of the present disclosure, the diameter of the passageway may be selected to be small enough so that milk entering the passageway at pressures generated in the device does not mix with air already in the passageway. Optimally, the passageway has an inner diameter of no more than 4 mm.

[0052] According to yet a further implementation of the device described herein, there is also provided a nipple device for feeding an infant, the nipple device comprising: a flexible layer having a dome-shaped convex region; at least one orifice in the dome-shaped convex region of the flexible layer, the at least one passageway being formed connecting an interior volume within the dome-shaped convex region to an exterior surface, allowing milk to flow from the interior volume of the dome-shaped convex region outwardly through the at least one orifice; at least one highly flexible area of ​​the dome-shaped convex region having a flexibility selected to be higher than the flexibility of the material of the remaining areas of the dome-shaped convex region, the area being disposed at a location of the dome-shaped convex region adapted to be worn in the mouth of the baby during feeding; Includes.

[0053] In such a nipple device, the at least one highly flexible area is deflected inwardly or outwardly of the dome-shaped convex region in response to a pressure difference between two opposite sides of the at least one highly flexible area. The at least one highly flexible area is arranged in an area adapted to enter the baby's mouth during feeding. The at least one highly flexible area may be arranged either in the area of ​​the at least one orifice or at a location in the wall of the dome-shaped convex region of the nipple device. The deflection of the at least one highly flexible area is adapted to reduce the change in pressure difference between the opposite sides of the at least one highly flexible area by reducing the volume of the side of the flexible membrane that has a lower pressure and increasing the volume of the side of the flexible membrane that has a higher pressure.

[0054] The inward deflection of the flexible membrane when the baby relaxes the sucking action may be adapted to reduce the degree of backflow of milk from the baby's mouth into the internal space of the dome-shaped nipple protrusion, in the process expanding the volume available for the baby to keep milk in his mouth. Alternatively, the outward deflection of the flexible membrane when the baby starts to suck may be adapted to expand the degree of milk flow from the internal space of the dome-shaped nipple protrusion to the baby's mouth, by expanding the volume of the internal space of the dome-shaped nipple protrusion. Also, the differential pressure sensor unit may be pre-calibrated such that the measured differential pressure is related to the milk flow through at least one orifice of the nipple device.

[0055] According to yet another implementation of these nipple devices, the differential pressure sensor unit comprises: A single differential pressure sensor, or Pressure sensors for each set of passages from the inner and outer surfaces of the dome-shaped protrusion, respectively. a subtraction circuit operates between the outputs of the pressure sensors.

[0056] In any such device, the base layer of the nipple device may be adapted to be mounted to a mother's breast to breastfeed the baby, or may be adapted to be mounted to a baby bottle.Furthermore, advantageously, the at least one differential pressure sensor unit may be located in a peripheral region of the base layer of the nipple device.

[0057] According to yet a further implementation of the device described herein, there is also provided a nipple device for feeding an infant, the nipple device comprising: a flexible layer having a dome-shaped convex region; at least one orifice in the dome-shaped convex region of the flexible layer, the at least one passageway being formed connecting an interior volume within the dome-shaped convex region to an exterior surface, and allowing milk to flow from the interior volume of the dome-shaped convex region outwardly through the at least one orifice; Including, At least the material of the dome-shaped protrusion has a hardness of less than 40 Shore A.

[0058] In such nipple devices, pressure changes on either side of the dome-shaped protrusion will cause a larger volume change on the opposite side of the nipple protrusion than would be the case if a material having a higher hardness were used. Furthermore, at least the material of the dome-shaped protrusion may have a hardness of less than 35 Shore A. In any case, the entire flexible layer may comprise a material having a hardness of less than 40 Shore A, or may comprise a material having a hardness of less than 35 Shore A.

[0059] Further provided according to a further embodiment described herein is a device for monitoring the flow of milk drawn in by an infant during feeding, the device comprising: (i) a flexible layer having a domed nipple area adapted to be placed in the mouth of a baby, the flexible layer having at least one orifice connecting an inner surface of the domed nipple area to an outer surface thereof to permit the flow of milk from within the domed nipple area to the baby's mouth; (ii) a first chamber formed in a layer at the domed nipple region spanning a first wall and a second wall opposite the first wall, the first chamber being in a position adapted to be placed in the mouth of a baby when the baby is being fed in the device, the first wall having increased flexibility being positioned adjacent to the outer surface of the domed nipple region and the second wall being positioned adjacent to the inner surface of the domed nipple region; (iii) a second chamber formed in a layer in the domed nipple region spanning a first wall and a second wall opposite the first wall, the first wall having increased flexibility being positioned adjacent to the inner surface of the domed nipple region and the second wall being positioned adjacent to the outer surface of the domed nipple region; (iv) a passageway connecting the first chamber and the second chamber to an input of a differential pressure measurement unit, where a differential pressure between a first pressure in the first chamber and a second pressure in the second chamber is determined; and Includes.

[0060] In such devices, the increased flexibility results from a first wall being thinner than the opposing second wall of each chamber, and at least one of these first walls may have increased flexibility by being formed from a more flexible material than the opposing second wall of each chamber.

[0061] Further, the differential pressure measurement unit may be pre-calibrated such that the measured differential pressure is related to milk flow through at least one orifice of the device. The measured differential pressure may determine milk flow in real time. Additionally or alternatively, the measured differential pressure may be used to determine the feeding pattern of the infant as a function of time.

[0062] In any of these embodiments, the first and second chambers may be located at different circumferential positions in the domed nipple region of the device. At least one of these first walls having increased flexibility is in the form of a thin membrane. Furthermore, at least one of these chambers may be located in an area of ​​the domed nipple region that has a higher stiffness than other areas of the domed nipple region, such that the at least one chamber is resistant to physical obstruction by the baby. The higher stiffness of the area of ​​the domed nipple device may result from the at least one chamber being formed of a material that has stiffer properties than other areas of the domed nipple device.

[0063] Additionally, in any of these above mentioned devices, the differential pressure measurement unit may include two pressure sensors and a subtraction circuit operating at the output of the two pressure sensors. It may also include a small electronic chip mounted on the device. A control unit may be used that is adapted to convert the output of the differential pressure measurement unit into a measurement of the milk flow through the device to the baby. The control unit may be adapted to convert the output of the differential pressure measurement unit to determine the feeding pattern of the baby.

[0064] The base layer of any of the nipple devices described above may be connected to a flexible layer adapted to be mounted to a mother's breast to feed a baby, or alternatively, to a baby bottle, and the differential pressure measurement unit may be sent to a remote system for display or analysis.

[0065] Further, the first chamber may include a plurality of first chambers and the second chamber may include a plurality of second chambers, and the device may further include a plurality of passages connecting the plurality of first chambers to a first input of the differential pressure measurement unit and a plurality of passages connecting the plurality of second chambers to a second input of the differential pressure measurement unit.

[0066] According to yet another implementation of such a device, a nipple shield device for determining the flow of milk drawn by an infant during feeding is disclosed, the nipple shield device comprising: A base layer; a dome-shaped protrusion having a dome layer having an inner surface and an outer surface, the dome-shaped protrusion having at least one orifice extending from the base layer and disposed through the dome-shaped protrusion; Including, The dome-shaped protrusion further comprises: a first chamber formed in the dome layer, the first chamber spanning a first wall having increased flexibility disposed on an outer surface and a second wall disposed on an inner surface; a second chamber formed in the dome layer, the second chamber spanning another first wall having increased flexibility disposed on the inner surface and another second wall disposed on the outer surface; Including, A differential pressure between a first pressure in the first chamber and a second pressure in the second chamber is determined. Such a nipple shield device may further include a pressure measurement unit for determining the differential pressure. Such a device may further include: (i) a first passageway extending from the first chamber to a first output of the pressure measurement unit; (ii) a second passageway extending from the second chamber to a second output of the pressure measurement unit; Including, A differential pressure is measured between a first pressure in the first chamber and a second pressure in the second chamber.In any of these devices, the base layer of the nipple device may be adapted to be mounted to a baby bottle.

[0067] According to a final implementation of the device of the present disclosure, for feeding an infant, such a device comprises: a flexible layer having a dome-shaped convex region; at least one orifice in the dome-shaped convex region of the flexible layer, the at least one passageway being formed connecting an interior volume within the dome-shaped convex region to an exterior surface, allowing milk to flow outwardly from the interior volume of the dome-shaped convex region through the at least one orifice; a fluid connection in an end region of said at least one passage with a differential pressure measuring module; Including, The area of ​​the at least one orifice includes at least one structure that reduces changes in fluid resistance of the at least one passageway induced during breastfeeding.

[0068] In such a device, a region of the dome-shaped convex region surrounding the at least one orifice may have a higher flexibility than the remaining region of the dome-shaped convex region. In such a case, the dome-shaped convex region surrounding the at least one orifice may have either a smaller thickness or different elastic properties than the remaining region of the dome-shaped convex region. In addition, the inside of the dome-shaped convex region surrounding the at least one orifice may include a region of a thickness greater than the thickness of the remaining area, the region having a number of channels within the thickness of the region, the channels communicating with the region around the internal orifice opening. In addition, the at least one orifice may have a first internal opening and a second external opening, both ends of which are fluidly connected to the differential pressure measurement module, the external opening having a larger diameter.

[0069] Finally, references to a differential pressure module or unit or the like for measuring the difference between fluid pressures across a fluid flow resistor may be understood to relate to separate pressure sensors or both pressure sensors incorporated into a single unit, but should be understood to necessarily involve two separate pressure measurements, i.e., the terms may be used interchangeably, but should be understood to relate to the same type of measurement. [Brief description of the drawings]

[0070] The present invention will be more fully understood and appreciated from the following detailed description taken in conjunction with the drawings, in which:

[0071] [Figure 1A] 1 illustrates, diagrammatically, the manner in which a nipple device of the type shown in this disclosure operates; [Figure 1B] 1B shows a cross-section of an example implementation of the nipple device shown diagrammatically in FIG. 1A. [Figure 1C] FIG. 1B is a schematic isometric skeletal diagram of a particular exemplary implementation of a nipple device of the type shown in FIG. 1A. [Diagram 2] 1D shows a cross-sectional view of the dome region of the nipple device of FIG. 1C. [Figure 3A-3B]Figures 3A and 3B are time plots of the pressure change associated with a sinusoidal type sucking action performed by an infant: Figure 3A shows the negative pressure inside and outside the nipple, and Figure 3B shows the differential pressure across the nipple orifice. [Figure 4A-4B] 4A and 4B show schematic diagrams illustrating the functionality of a flexible membrane embodiment of a nipple of the present disclosure to reduce backflow of milk from the baby to the maternal side of the nipple. [Figure 5A] 5A and 5B graphically illustrate the effect of using a nipple with a flexible membrane on the pressure cycle shown in the measured plot of FIG. 3A. [Figure 5B] 5A and 5B graphically illustrate the effect of using a nipple with a flexible membrane on the pressure cycle shown in the measured plot of FIG. 3A. [Figure 5C] 5C and 5D show plots of differential pressure versus time for a conventional nipple device of the present disclosure without a flexible membrane, and for a novel nipple device of the present disclosure with a flexible membrane, respectively. [Figure 5D] 5C and 5D show plots of differential pressure versus time for a conventional nipple device of the present disclosure without a flexible membrane, and for a novel nipple device of the present disclosure with a flexible membrane, respectively. [Figure 6A] 6A and 6B are schematic diagrams of alternative nipple structures using a flexible membrane to reduce the level of milk reflux at the nipple, with FIG. 6A showing the flexible membrane in the dome-shaped region of the nipple device. [Figure 6B] FIG. 6B shows a flexible membrane on the side wall of the nipple device. [Figure 7A-7B] Figures 7A and 7B show schematic examples of two practical implementations of novel orifice structures that can be used to prevent the influence of external forces, such as from the movement of the baby's mouth or tongue, from interfering with the shape or form of the feeding orifice and thus the degree of flow resistance of the orifice or orifices. [Figure 8A-8B]8A and 8B show schematics of novel structures that may be incorporated inside the domed nipple protrusion around the feeding orifice to prevent blocking or partial blocking of the feeding orifice by the tip of the mother's nipple. [Figure 9] One implementation of the milk flow measurement device described herein is shown, where the components and functions required for flow measurement, namely the fluid flow resistor and the pressure sensor, are integrated into a plug-in head. [Figure 10] It is shown how a pressure transmission chamber unit is used to ensure that the pressure sensors are not exposed to contact with the milk flow, and a flexible diaphragm is used to transmit the pressure within the milk in each flow channel to the respective pressure sensor without allowing any of the milk to touch the pressure sensor. [Figure 11] An exemplary replaceable flow resistor suitable for use as part of the orifice through which the baby draws is shown, and which is washable by its exterior flow path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] Reference is first made to FIG. 1A, which shows a schematic diagram of the general manner in which a nipple device of the type shown in this disclosure operates. In FIG. 1A, the flow of milk from the mother's breast, represented by region 1, to the baby's mouth, represented by region 2, occurs through one or more orifices in the nipple device, shown in FIG. 1A as a resistive section 3 of the flow path. As the flow through the resistive section 3 is restricted, a pressure drop occurs in the flow path between the volume on the mother's side 1 of the device and the volume on the baby's side 2 of the device. This pressure difference ΔP is measured by two separate pressure sensors 6, 7 connected by ports 4, 5, respectively, on either side of the resistive section 3 of the flow path, or it can be measured by using a differential pressure sensor (not shown in FIG. 1A). Port 4 measures the pressure P2 on the mother's side and port 5 measures the pressure P1 on the baby's side. As long as the resistance of the orifice or orifices remains constant, the measured pressure difference ΔP gives an indication of the fluid flow rate of milk from the mother to the baby. A specific implementation of this model is given below.

[0073] In its simplest implementation, the method shown in the schematic device of Fig. 1A has a particularly useful form with significant advantages in terms of reusability of the device. Since the differential pressure sensor or the two separate pressure sensors are hermetically connected to the milk flow areas 1, 2 by respective conduits 4, 5, respectively, no pressure leakage occurs at these ports or connecting conduits and thus the accuracy of the pressure measurement is not impaired. The effect of this, however, is that due to the closed volume of the pressure measurement end of the conduit, only a limited amount of milk enters the conduit and the pressure in the conduit is transmitted to the sensor by the air trapped in the conduit. The ends of the conduits connected to the differential pressure sensor or the separate pressure sensors 6, 7 and the pressure sensor or sensors themselves remain free of milk. This limits possible small intrusions into the conduits close to the milk flow area. As a result, the pressure measurement section of the device remains essentially free of milk and can be reused without the need for cleaning or with minimal cleaning procedures that do not damage the sensitive sensors themselves. The remainder of the device, i.e. the flexible teat section with the orifice(s) and the conduit transmitting pressure to the connected pressure sensor(s), may then be washed in any manner deemed sufficiently thorough to provide the teat safe for use again, including for example washing with hot or boiling soapy water.The apparatus and method of use shown diagrammatically in Figure 1A therefore enables a fully reusable milk flow device, rather than some of the prior art devices which must be disposable.

[0074] Reference is now made to Figure 1B, which is a schematic cross-sectional view of one exemplary implementation of a nipple device 10 using the concept shown diagrammatically in Figure 1A. In Figure 1B, a nipple device 10 is shown having an orifice 13 or a number of orifices (not shown in Figure 1B) at the top region of the dome-shaped nipple convex of the nipple device. The nipple device is shown mounted on the nipple region of the mother's breast 8 such that breast milk collects in a volume 1 between the mother's breast and the inner surface of the dome-shaped nipple convex. As the baby sucks on the outer surface of the dome-shaped nipple convex, breast milk flows through the orifice or orifices 13 to the baby's mouth 2. Within the thickness of the flexible material of the dome-shaped nipple convex 10, two passages or conduits 4, 5 are formed, one 4 of which opens into the internal volume of the nipple device in fluid contact with the accumulated breast milk, and the other of which opens into the external space around the nipple dome-shaped structure 10 to be located in the baby's mouth when sucking. These passages lead to connection ports (not shown in FIG. 1B) that run to locations on the outer edge of the base layer of the nipple device where they can be connected to a differential pressure sensor or a separate pressure sensor. Although passages 4, 5 are shown on diametrically opposite sides of the nipple dome in FIG. 1B, this is done merely to clearly show both of the passages in a single cross-sectional view, and it should be understood that the passages may advantageously be located adjacent to one another on one side of the nipple dome-shaped protrusion so that a single differential pressure sensor device can be conveniently connected to both of their remote ends. It should also be understood that one or both of these passages may include multiple passages.

[0075] Reference is now made to FIG. 1C, which is a schematic isometric see-through view of an exemplary nipple device using the general method of the basic device described in FIG. 1A, but in which pressure measurements are made in a completely absent direct contact with milk. FIG. 1C shows the dome area 10 of the nipple device and indicates the pressure transmission passages used to implement the operation of the device. As applied in the simplest implementation as in FIG. 1B, pressure transmission passages 16, 17 lead from the upper area of ​​the dome nipple protrusion, one from the inside of the dome nipple protrusion and one from the outside of said protrusion as shown in FIG. 1B (shown as passages 4 and 5), to a small differential pressure measurement and control module 31 located remotely from the dome nipple protrusion, advantageously in the peripheral area of ​​the device. Module 31 includes a differential pressure sensor 30 and may have a readout display 32 directly on the module 30 itself or may send data to a remote display. This module is configured to use previous calibration measurements made on the device to indicate the flow rate of milk from the mother to the baby.

[0076] A complex controller may be used to output a real-time signal proportional to the flow rate, so that information can be gathered about the nature of the infant's feeding habits, the changes in feeding behavior during the feeding session, and by integrating the signal, the total amount of milk taken by the infant during the entire feeding session. Alternatively and advantageously, the pressure measuring chip or control unit may be adapted to transmit its measurements to a remote smart device, such as a mobile phone, which can analyze and present the data. This has the advantage that the control unit 31 becomes compact and simple, since its only function will be to export the differential pressure readings to an external control system, where all the calculations related to the milk flow rate, milk volume, or the nature of the feeding process can be performed. It also has the advantage that the mother or other interested party can easily read the measurement results in real time on a device separate from the nipple device itself. Moreover, the chip or control unit or both can be manufactured to be portable from nipple device to nipple device, so that the user only needs one chip or control unit with electronics that can be used for many successive nipples.

[0077] The nipple device is advantageously formed from a thin layer of flexible material 12, such as a silicone compound or other suitable flexible polymer, and has a base section 11 from which extends a dome region 10. The exemplary device shown in FIG. 1C is adapted for use by a nursing mother who places the device, like a conventional nipple shield, over the nipple of her breast. Devices for use with a baby bottle (not shown) typically have a flexible, resiliently fitted cover section that matches the top of the bottle, in place of the base section 11 of the device shown in FIG. 1C. Like a conventional nipple shield, the nipple device of the present invention has one or more orifices 13 at or around the tip of the dome region of the nipple device. This allows a nursing infant, with the dome region positioned in his mouth, to draw breast milk from the interior space of the device that is between the mother's breast and the interior volume of the dome region.

[0078] The device shown in FIG. 1C differs from conventional nipple shields in that it includes two internal chambers 14, 15 formed in the material of the dome-shaped convex region of the device in its upper region. Each of these chambers is separately connected by narrow passages 16, 17 to a pressure measurement and control module 31, which is preferably located in the outer part of the base 11 of the device. Each chamber and its narrow passages are filled with air and each constitutes a closed volume. These chambers are formed near the tip of the dome-shaped region and their position is intended to be in the mouth of the baby when he sucks milk. An advantageous configuration of these chambers is in the form of chambers arranged opposite each other around the circumference of the nipple dome. However, the device can also work with the chambers in other suitable positions.

[0079] As clearly shown in the cross-sectional view of FIG. 2 below, these chambers differ from each other in that they are not evenly spaced relative to the centerline of the thickness of the flexible layer in the dome region. The first chamber 14 is located closer to the outer surface of the flexible layer, and the second chamber 15 is located closer to the interior volume of the nipple device dome. As a result of this location within the wall thickness of the nipple dome region, the first chamber 14 is significantly thinner at the wall with the outer surface of the nipple dome than at the wall with the interior volume of the nipple dome. On the other hand, the second chamber 15 is significantly thinner at the wall with the inner surface of the dome than at the wall with the outer surface of the nipple dome. That is, the two thin walls can be considered as pressure sensitive membranes that move perpendicular to the surface of the nipple dome, and the extent of this movement is proportional to the pressure applied across the membrane. The thick wall can be considered as a static wall that is essentially stiff compared to the mobility of the thin membrane wall, and when the baby sucks on the dome structure to obtain milk, the thin wall membrane of the first chamber 14 moves outward from the dome surface, the extent of the outward movement being proportional to the level of negative pressure generated by the sucking force of the baby. As the thin wall membrane moves outward, the air pressure in the system decreases in a manner proportional to the degree of the output movement of the membrane wall, since the first chamber is a closed pneumatic system. That is, the negative pressure generated in the first chamber is proportional to the negative pressure generated by the sucking force of the baby, which is equal to the negative pressure generated at the outer end of the nipple orifice or orifices. In a similar manner, the thin wall membrane of the second chamber 15 moves inward or outward from the dome surface, the extent and direction of the movement being proportional to the level of pressure generated within the nipple volume. The movement of the membrane wall then generates a corresponding pressure in the second chamber 15, which reflects the pressure in the internal volume of the nipple and thus at the internal end of the nipple orifice(s). The difference in pressure between the air in the first chamber 14 and the air in the second chamber 15 is therefore a measure of the difference in pressure along the milk orifice(s). As the orifice(s) have a fixed flow resistance, the difference in pressure along the milk orifice(s) is directly proportional to the flow rate of milk to the baby.As explained above, the pressure difference between the two chambers can be easily measured by mounting a differential pressure sensor on either end of the narrow passages 16, 17 which transmit the pressure levels in the chambers 14, 15 for measurement by the differential pressure sensor 30. Alternatively, separate pressure sensors (not shown in FIG. 1C) may be used to measure each passage pressure separately and the difference in the readings subtracted to obtain a differential pressure measurement. The volumes of the narrow passages 16, 17 are small enough that they do not significantly affect the levels of pressure measured by these chambers.

[0080] Each of these chambers has been described as having a thinner wall towards one of the surfaces of the nipple dome-shaped convex structure and a thinner wall towards the other surface of the dome-shaped convex structure (as shown more clearly in FIG. 2 below). As explained in the previous paragraph, this structure gives the thinner wall of the chamber under consideration a higher flexibility than the opposite wall, so that one chamber gives a pressure indication on one surface of the dome-shaped structure and the other chamber gives a pressure indication on the other surface of the dome-shaped structure. This method of constructing these chambers is advantageous because the different walls can be manufactured simultaneously in one molding process with the same material as the rest of the nipple device. However, it is understood that the same effect can be obtained by making one of the walls of each chamber from a material that is more flexible than the material of the opposite wall. In this way, the essential property of multiple chambers of this nipple structure, namely one wall having a higher flexibility than the opposite wall, can be achieved in this way. An important feature of these chambers is that each has one wall that is more flexible than the opposing wall, with one chamber having its more flexible wall on the inner surface of the nipple convex structure and the other chamber having its more flexible wall on the outer surface of the nipple convex structure.

[0081] The operation of the device has been described with the chamber 14 in the vicinity of the orifice or orifices as it would be in the baby's mouth during a feeding session. The chamber should be located in an area that is stiffer than the rest of the nipple dome so that it is not disturbed by physical forces, since the baby may physically squeeze or push against the flexible layer of the dome structure, distorting the flexible layer, distorting the movement of the membranous wall, and thus the pressure level generated in the chamber. As previously mentioned, the location of the curved upper portion of the nipple dome is less prone to distortion than the lower portion of the dome. Increased resistance to distortion can also be achieved by making the material of the upper portion of the nipple dome stiffer than the rest of the dome, either by using a harder material in that area or by making the flexible layer thicker in that area. Of course, it will be understood that this increased stiffness relates to the thicker wall of the chamber and not to the membranous wall, which should maintain the desired flexibility to adequately respond to the variable pressures applied.

[0082] Reference is now made to FIG. 2, which shows a cross-sectional view of the dome region 10 of the nipple device of FIG. 1C. This clearly shows the location of the first and second pressure measuring chambers 14 and 15 relative to the thickness of the nipple material, as well as the position of the orifice or orifices 13. The narrow passages 16, 17 shown in FIG. 1C, which communicate the pressure level in the chambers for measurement by a differential pressure sensor at the edge of the nipple base, are not shown in FIG. 2 to avoid detracting from the purpose of FIG. 2, which is to show the location of the measuring chambers. As can be observed, the first chamber 14 is located closer to the outer surface of the dome nipple structure than to the inner surface, such that the wall 20 between the first chamber 14 and the outer surface of the nipple dome structure is significantly thinner than the wall 21 between the first chamber 14 and the inner surface of the nipple dome structure. As a result, when pressure is applied to the outside of the thin wall 20, the thin wall 20 bulges outward or inward depending on the applied pressure difference, while the inner thick wall 21 is considered to remain stationary and in its position, in a first approximation. The first chamber 14 can therefore be considered as a measuring device for the externally applied pressure. Conversely, since the positions of the thin and thick walls of the second chamber 15 are reversed, the second chamber can be considered as a measuring device for the internal pressure within the nipple dome volume. The pressure difference between the first chamber 14 and the second chamber 15 can therefore be used as a measure of the pressure difference across the orifice 13 and thus as a measure of the milk flow through the orifice 13.

[0083] As previously mentioned, the forward and reverse flow of milk through the nipple orifice caused by the pulsating nature of the baby's sucking creates noise levels that make it difficult to make accurate differential pressure measurements and also increases the effort required for the baby to feed from the mother. Reference is now made to Figures 3A and 3B, which plot the time evolution of pressure resulting from the baby's sinusoidal pulsating type of sucking action on the baby side of the orifice and on the mother side of the feeding orifice. Figure 3A shows the pressure P1 generated by the baby during the sucking routine, together with the pressure P2 generated in the milk accumulated on the breast milk side of the orifice as a result of the baby's sucking action on the outside of the nipple. As can be observed, the side pressure generated in the milk accumulated on the mother side of the orifice tracks the side pressure generated by the baby, but to a smaller extent, due to the pressure drop caused by the milk passing through the nipple orifice. The difference P2-P1 between the two plots shown in FIG. 3A represents the pressure difference across the orifice, which determines the flow of milk through the orifice. At any given time, milk flows from higher absolute pressure to lower absolute pressure. This means that milk flows from a point of lower negative pressure to a point of higher negative pressure. That is, in the graph of FIG. 3A, at the bottom of the pressure depression, milk flows from the mother's side, where pressure is higher, to the baby's side, and at the top peak of the curve, milk flows back from the baby's side to the mother's side. It is noteworthy that the absolute pressure difference P2-P1 at the bottom depression of the baby's sinusoidal pressure cycle shows a larger difference than the absolute pressure difference P2-P1 at the top peak of the baby's pressure cycle. This means that the flow of milk from the inside of the nipple to the baby's mouth is larger than the backflow of milk from the baby's mouth back to the milk accumulated in the nipple volume. This is as expected from the actual situation of the breastfeeding process.

[0084] Reference is now made to FIG. 3B, where the differential pressure P2-P1 between the baby and mother sides of the nipple is plotted as a function of time, with the central horizontal line of the graph representing the zero level of differential pressure. As can be observed from inspection of the graph in FIG. 3A, the difference P2-P1 is clearly greater at the bottom concave of the curve, which represents the point of maximum sucking force of the baby, than at the peak of the curve, which represents the point of maximum relaxation of the baby's sucking force. Since the differential pressure P2-P1 is the driving force for milk flow through the orifice, the area above the zero differential pressure level represents when there is a forward flow of milk, i.e., from the mother to the baby, while the area below the zero line represents when there is a reverse flow from the baby towards the mother side of the nipple. Thus, when the integrated area above the zero line is greater than the integrated area below the zero line, there is a net flow from the mother to the baby. That is the situation in FIG. 3B. It is noted here that the area in the differential pressure curve above the zero line is greater than the area in the differential pressure curve below the zero line, which corresponds exactly to the situation where there is a net flow of milk from the mother to the baby. The objective of additional implementations of the nipple device of the present disclosure is to increase the flow of milk from the mother to the baby as much as possible and reduce the backflow of milk from the baby towards the mother's side of the nipple as much as possible. This is represented in FIG. 3B by reducing the area under the zero differential pressure line as much as possible.

[0085] Reference is now made to Figures 4A and 4B, which show diagrammatically the function of the flexible membrane embodiment of the nipple of the present disclosure, described in the Summary section of the present disclosure. The figures show a representation of a flexible membrane 40 dividing the milk regime into two imaginary chambers. The left chamber 41 represents the mother's side of the nipple where the breast milk accumulates, and the right chamber 42 represents the baby's oral cavity, surrounded by the baby's lips around the nipple. The flexible membrane may be placed in the area of ​​the feeding orifice(s) 43, as shown in the flexible membrane of Figures 4A and 4B, but this location is only shown diagrammatically. In practice, the membrane 40 may be placed as a closed flexible partition in any other upper area of ​​the dome-shaped nipple convexity of the device. This partition divides the representation of the space between the mother's breast and the inside of the nipple 41 from the baby's oral cavity 42. The feeding orifice(s) 43 may be shown in conventional positions other than the membrane 40. In Fig. 4A, the baby is shown in the sucking phase, and milk is drawn from the mother's side 41 of the nipple through the feeding orifice 43 into the baby's mouth 42. The more negative pressure at the baby's mouth 42, the more the flexible membrane 40 bends outward from the surface of the nipple, thus aiding the passage of milk from the mother's side 41 through the orifice 43. On the other hand, in Fig. 4B, when the baby relaxes the sucking action and the negative pressure at the baby's mouth 42 rises towards atmospheric pressure, there is no longer any pressure pulling the membrane 40 towards the baby's mouth 41, and the negative pressure still present at the mother's side 41 of the nipple causes the membrane 42 to reverse direction and bend towards the mother's side 41. This increases the available space for excess milk at the baby's mouth side 42 of the nipple, reducing the tendency for it to flow back into the mother's side 41, while at the same time increasing the absolute pressure at the mother's side 41 of the nipple, reducing the fluid tendency of milk to flow back into the mother's side 41. The result of these features of flexible membrane 40 is twofold: first, flow from mother to baby when the baby is in the sucking phase of the sucking cycle is unimpeded other than by the inherent fluid impedance of a limited orifice opening, and second, milk is less likely to flow back into the mother's side of the nipple when the baby stops the sucking phase and releases its negative pressure.

[0086] Reference is now made to Figures 5A and 5B, which graphically illustrate the effect of using a nipple with a flexible membrane on the pressure cycle shown in the measured plot of Figure 3A. First, Figure 5A shows plots of absolute infant and maternal pressure resulting from the pulsating sucking action of an infant nursing using a conventional nipple without the membrane feature of the present disclosure. Each horizontal division of the plot represents one second. The pressure P1 on the infant side of the nipple in Figure 3A is shown by a curve consisting of small circles, while the pressure P2 on the maternal side within the nipple in Figure 3A is shown by a solid curve. As can be observed, the infant is sucking at a pulsating rate of 2 Hz. The pressure P1 on the infant side of the nipple ranges from -20 mmHg, which is close to atmospheric pressure when the infant is fully relaxed at the breast, to a pressure of approximately -170 mmHg at the peak of the infant's sucking. The resulting maternal pressure ranges from approximately -40 mmHg to -130 mmHg inside the nipple. Two conclusions can be drawn from these results. (i) First, the orifice or orifices connecting the mother's side to the baby's side have a sufficiently high fluid resistance to the flow of milk through said orifice that the pressure changes on the mother's side are significantly lower than the pressure changes generated by the baby. In the case of the pressure measuring nipple of the present invention, this resistance level is deliberately chosen to provide a sufficient pressure difference to allow accurate measurement of the pressure difference, rather than the lowest possible resistance to allow accurate measurement of the milk flow rate. (ii) Secondly, as mentioned above, it is clear that the large pressure difference between the maximum negative pressure generated by the infant, -170mmHg, and the maximum level of negative pressure generated in the maternal nipple, -110mmHg, indicates a large flow of milk from the low negative pressure at the maternal side to the high negative pressure at the infant side. This pressure difference is somewhat larger than that which occurs when the infant is in a relaxation mode, where the flow is from infant to mother, resulting in a relatively small net flow of milk from mother to infant.

[0087] Now, FIG. 5B shows the situation that occurs with a nipple having the flexible membrane feature of the present disclosure. A significant feature is that the use of the flexible membrane allows the mother's pressure to more closely track the pressure generated by the baby at the baby's side. Thus, for example, at the point of maximum suction relaxation, the mother's pressure rises to -20 mmHg, which is very close to the pressure at the baby's relaxation. Similarly, the negative mother's pressure of -130 mmHg is much closer to the baby's point of maximum suction, -165 mmHg, than the nipple without the flexible membrane shown in FIG. 5A. The net result of these two findings is that when the baby relaxes its sucking action, a significantly smaller proportion of the milk flow through the nipple returns to the mother's side. The above-mentioned functionality of the flexible membrane can be illustrated by looking at a graphical plot of the differential pressure generated across the milk flow orifice between the baby's side of the nipple and the mother's side of the nipple. As previously mentioned, the differential pressure is defined as the difference between the pressure P1 on the baby side and the pressure P2 on the mother side, i.e. P2-P1. Such a graphical plot is now shown in Figures 5C and 5D.

[0088] 5C shows a plot of differential pressure versus time for a conventional nipple device without a flexible membrane of the present disclosure. As can be observed, the differential pressure ranges from approximately 70 mmHg, signifying flow from the mother's side to the baby's side, to -30 mmHg, signifying flow from the baby's side of the nipple to the mother's side, but an important feature of this plot is that a significant portion of the integrated pressure plot falls below the zero level of differential pressure, signifying that there is a significant flow of milk from the baby back to the mother's side of the nipple.

[0089] Please refer to FIG. 5D. FIG. 5D shows a plot of differential pressure against time for the novel flexible membrane nipple device of the present disclosure, showing that the differential pressure now varies between two much closer pressure levels over a range of only 40 mmHg. This suggests that the maternal side side pressure tracks the infant side side side pressure, which is the driving force of the maternal side side side pressure, more closely than the nipple device without the flexible membrane of FIG. 5C. This immediately suggests that the infant will experience less resistance to feeding when using the nipple device shown in FIG. 5D with the flexible membrane. However, more importantly, the differential pressure, defined as P2-P1, is zero at the infant's maximum relaxation level and only transitions to a positive value when the infant begins the negative pressure of the sucking action. This means that by using the flexible membrane of the present application, the backflow of milk from the infant to the maternal side of the nipple has been dramatically reduced. This feature is also evident from the plot of FIG. 5B, where it is observed that when the infant is at the peak of the relaxation period, the maternal side pressure is essentially equal to the infant side pressure. This result explains the previously mentioned result that the resistance to feeding by an infant using a nipple with a flexible membrane is less than when feeding from the conventional nipple device of the present disclosure without a flexible membrane.

[0090] That is, Figures 5A to 5D show how the use of the flexible membrane of the present application significantly improves the ease of infant feeding, and furthermore, the backflow of milk from the infant towards the maternal side of the nipple is sufficiently reduced that accurate measurement of sensitive differential pressure measurements can be achieved.

[0091] Reference is now made to Figures 6A and 6B, which show in schematic form two practical implementations of the novel use of a flexible membrane in a nipple structure to achieve the advantageous effects described above. The flexible membrane is shown in Figures 6A and 6B and is installed in a nipple as shown in Figures 1C and 2, for measuring milk flow by measuring the differential pressure of two pressure sensing chambers as described in connection with Figure 2. It should be understood that the flexible membrane feature of the present disclosure, with its attendant advantages, can also be applied to conventional prior art nipples that do not have any flow measuring features, although such use may be unnecessary, since in such nipples the feeding orifice or orifices can be enlarged in size to provide the baby with a high fluid conductance path commensurate with a reasonably controlled feeding rate. On the other hand, in the pressure measuring nipple structures of the present disclosure, where the orifice fluid conductance must be limited to ensure that a sufficiently large differential pressure exists across the orifice or orifices to enable accurate differential pressure measurements to be obtained, the use of a flexible membrane is highly advantageous.

[0092] The only difference between Figure 6A and Figure 6B is the location of the flexible membrane in the nipple structure, the method of operation is the same in the two examples shown. In Figures 6A and 6B, the flexible membrane is incorporated into the type of nipple shown in Figure 2, and the features of the nipple device are generally labeled similarly to Figure 2. In Figure 6A, a flexible membrane 61 is incorporated into the side wall of the material of the nipple convexity. It should cover as much of the circumference of the nipple convexity as possible to provide maximum variation in the volume of the space through which the nipple projects, but the area should not be so large that the physical strength of the nipple device is unnecessarily reduced. Furthermore, it should be in the area of ​​the wall that is intended to be within the mouth of the baby when feeding on the nipple, so that it is considered to be within the baby's oral cavity. In other words, it should be within the area where the baby's lips will grasp the nipple. This flexible area can be most easily formed by making an area of ​​thinner or softer material than the rest of the nipple area. Such a thin area can be easily formed in the molding process of the entire nipple. In FIG. 6B, a flexible membrane 62 is incorporated into the material at the tip of the nipple dome and surrounds the feeding orifice or orifices.

[0093] Although in Figures 6A and 6B the flexible membrane is shown applied to an implementation in which pressure measurements are made using a thin-walled chamber as shown in Figure 2, it is emphasized that this is only one example of the application of a flexible membrane in a nipple device and that the flexible membrane may also be placed in a nipple device having any other form of pressure measurement, such as a simple direct measurement embodiment as shown in Figure 1B.

[0094] Reference is now made to Figures 7A and 7B, which show in schematic form two practical implementations of novel orifice structures that can be used to prevent the influence of external forces, such as from the movement of the baby's mouth or tongue, from interfering with the shape or configuration of the feeding orifice or orifices, and thus the degree of flow resistance of the orifice or orifices. In Figure 7A, an enlarged cross section of the tip of the nipple device is shown, with an orifice 71 formed in the nipple device material having a normal thickness, which is also shown below the side 70 of the nipple dome convexity. The orifice region of the dome convexity device is connected to the rest of the device by a thin region 72 of flexible material, such that the orifice region is flexibly attached to the rest of the device such that forces applied to the orifice region may move or reorient the orifice region, but essentially do not distort or compress its shape, thus maintaining the accuracy of the fluid flow resistance through the orifice. In Figure 7A, a single orifice is shown. However, it should be understood that multiple orifices may be used to feed an infant and the same requirement that the orifices not deform or compress applies to such multiple orifices.

[0095] Now, FIG. 7B shows an alternative or additional method to prevent the baby's tongue from blocking the orifice of the dome-shaped nipple structure during feeding. In FIG. 7B, the orifice 75 acting as a flow resistor generating a pressure difference for flow measurement is shown to be located at the base of a deep and slightly wide hole 76. This hole 76 ensures a safe distance between the baby's tongue and the feeding orifice 75, preventing the tongue from reaching the feeding orifice and blocking it. FIG. 7B also shows a passage 78 used to communicate the pressure of the milk in the baby's mouth to a pressure sensor that determines the pressure on the baby's side of the flow resistor 75. The passage 78 should be relatively narrow, with a typical inner diameter of 4 mm or less. This ensures that milk from the baby does not easily pass through the passage and mix with the air already trapped in the passage, thus preventing the air layer from acting as a gaseous buffer or cushion intended to prevent milk from reaching the pressure sensor, where contact with milk may be undesirable, as far as possible.

[0096] Just as the baby's tongue can block the feeding orifice from its outer end, the tip of the mother's nipple can inadvertently block the feeding orifice from its inner end. Reference is now made to Figures 8A and 8B, which show, in schematic form, a novel structure that can be incorporated inside the dome-shaped nipple protrusion 80 around the feeding orifice 81 to prevent blocking or partial blocking of the feeding orifice 81 by the tip of the mother's nipple. Inside the dome-shaped nipple protrusion, the device is formed with an area 83 of increased thickness surrounding the feeding orifice or orifices 81, and has a number of channels 86 within the thickness of that area that connect to the area around the internal orifice opening 81. As a result, even if one or two of these channels are blocked by the mother's nipple, the others are open and milk can flow freely from the mother's nipple to the feeding orifice. The layer of increased thickness 83 may be formed into the device material itself or may be added as a separately manufactured insert. Figure 8A also shows a passageway 84 that conveys the pressure of milk 85 on the maternal side of the nipple structure towards a pressure sensor that determines the pressure on the maternal side of the feeding orifice, which acts as a flow resistor.

[0097] Reference is now made to FIG. 9, which shows a schematic implementation of the multitasking milk measuring device shown in the above-mentioned US Pat. No. 5,399,363 for electronically measuring milk flow from a mother to a baby. The device includes a nipple shield flexible base unit 90 and a plug-in measuring unit 99 including a differential pressure measuring arrangement. The plug-in measuring unit is connected to the flexible base unit 90 by a set of connection ports 94. At the top of the dome-shaped convex, a pair of passages are provided which are connected to an orifice 91. One of these passages 93 is for transporting the breast milk from the inner space of the dome-shaped convex to a standard attachment port 94, and the second passage 92 is for returning the breast milk to the feeding orifice at the top of the dome-shaped convex after flow measurement in the plug-in unit 99. The bottom close-up of FIG. 9 shows a fluid flow resistor 95 connecting the inlet passage 93 and the return passage 92. The pressure sensor P H and P Lis shown connected to the inlet passage 93 and the return passage 92. H measures the milk pressure at the input side of the fluid flow resistor 95, P L measures the pressure of the milk after it has passed through the fluid flow resistor 95. The measurement unit 99 is shown diagrammatically as a circular unit, but it should be understood that it may be of other shapes. In addition, the pressure sensor needs to be connected to electronic circuitry (not shown in FIG. 9) that converts the differential pressure measurement into a measured flow level, and an electronic display may also be incorporated into the measurement unit. Alternately, the unit may include wireless connection provisions to transmit the measured flow rate to a remote device, such as a mobile phone.

[0098] FIG. 9 shows one implementation of the milk flow measurement device described herein, where the components and functions necessary for flow measurement, i.e. fluid flow resistor and pressure sensor, are incorporated in a plug-in head 99. According to a further implementation, these components may be incorporated in a self-contained milk flow nipple device, without the advantage of using different plug-in attachment heads for different milk measurement functions. In such an embodiment, the nipple device may only include a base unit 90. A fluid flow resistor 95 is mounted in the peripheral skirt area of ​​the device, but not on a separate attachable measurement unit. In any of these devices, the fluid flow resistor 95 shown diagrammatically in FIGS. 9 and 10 may be implemented as a replaceable resistor, the function of which is further described herein in connection with FIG. 11. The replaceable resistor may be mounted in the plug-in head 99 where the flow resistor 95 is shown in FIG. 9, or in the area of ​​the fluid attachment port 94 at the tip of the base area of ​​the milk flow measurement device. In either of these cases, a resistor housing is formed in the area where the resistor is inserted, and the resistor may be removably mounted to the base of the device or to the plug-in head so that milk flows through it, in which case it may be periodically removed for cleaning or replacement purposes. Further details are given below with reference to FIG. 11.

[0099] Locating the fluid flow resistor in this manner at the base peripheral region of the device provides an advantageous alternative to using the problematic feeding orifice as the fluid flow resistor. A pressure transmission passage leading to the outer edge of the device base layer measures the pressure drop across the orifice, providing a measurement of the differential pressure at that location.

[0100] Reference is now made to FIG. 10. FIG. 10 shows a pressure sensor P H , P L This is achieved by using a pressure transfer chamber unit 100, in which a flexible diaphragm is used to transfer the pressure in the milk in each flow channel 93, 92 to the respective pressure sensor P without the milk touching the pressure sensor. H , P L With respect to the inlet flow of the mother's milk in the passage 93, the pressure of the milk is transferred to the sub-chamber 97. H The relatively high pressure of the mother's milk inlet flow is experienced at the diaphragm 96 on the inlet side of the pressure transfer chamber. H The inlet sub-chamber 97 H 98, a pressure proportional to the level of the inlet pressure is applied to the inlet subchamber 98. H The pressure level is transmitted to the pressure sensor P H The same process takes place on the outlet side of the milk flow through fluid flow resistor 95. A level of pressure proportional to the pressure on the outlet side is measured by flexible diaphragm 96. L By the outlet subchamber 98 L and the outlet pressure sensor P L Since the pressure on the outlet side is much lower than the pressure on the inlet side, the outlet side flexible diaphragm 96 L The deflection of the inlet flexible diaphragm is much smaller than the deflection of the inlet flexible diaphragm. This is shown by the arrow length representation of the two flexible diaphragms. The subchamber 98 to which the experienced pressure is transmitted. H and 98 Lmay advantageously be filled with oil or other liquid, the essentially incompressible nature of the liquid providing greater accuracy than those sub-chambers that remain air-filled. Also, the stiffness of the flexible diaphragm must be relatively high so that deflections are limited and non-linear elastic effects are avoided. Using such a pressure transmission chamber unit 100 ensures that the pressure sensor is protected from contact with the milk itself, but senses the fluid pressure of the milk flow by the expansion of the flexible diaphragm.

[0101] Reference is now made to FIG. 11, which illustrates another implementation of the features of the present disclosure in the form of a reusable fluid flow resistor. The need for such a reusable resistor is because in applications where the pressure drop across the nipple orifice is used to determine the flow of milk to the baby, it is important that the resistance to flow of the resistor remains at a predetermined value. Since resistors are precision components, it can be advantageous to have such a reusable fluid flow resistor, rather than being part of a disposable nipple device. Since milk flow can leave residues of fat and other milk components on the walls of the resistor, the flow resistance will change unless the resistor is cleaned periodically. Because the bores of conventional flow resistors are small, it is difficult to clean resistors with an internal bore.

[0102] FIG. 11 shows an exemplary replaceable flow resistor 110 suitable for use as part of an orifice through which an infant sucks. The flow resistor of FIG. 11 differs from previously used flow resistors in that the flow path for milk through the resistor is formed on the outer surface 111 of the flow resistor, rather than as an internal bore. The flow resistor is adapted to be mounted in a dedicated housing, which may be part of the orifice 71 of FIG. 7A, the orifice 75 of FIG. 7B, or the orifice 81 of FIG. 8A and FIG. 8B. The flow resistor 110 is slid into the housing until its shoulder 115 hits its matching seat in the housing. When properly seated, the regions 113 and 114 are positioned opposite the input channel through which milk flows from the mother and the output channel through which milk flows into the outlet end of the orifice and towards the sucking infant, respectively. A passage to a pressure sensor may also be in fluid communication with the regions 113 and 114. The flow resistor flow passage itself 112 is formed on the outer surface 111 of the flow resistor 110. It has a cross section and length such that it provides a resistance to the milk flow that generates the desired pressure difference across it, which can be easily measured by a differential pressure measuring module or a separate pressure sensor. The advantage of the external flow resistor of FIG. 11 is that it can be removed at periodic intervals and thoroughly cleaned to maintain the accuracy of the flow resistance. Such a replaceable resistor can also be implemented in the type of plug-in device shown in FIG. 9. Here, the housing is advantageously arranged horizontally, transverse to the direction of the fluid passage, and this flow is diverted to flow into the resistor 95 in the same way as implemented for the removable resistor mounted on the feeding orifice.

[0103] The exemplary embodiments are provided so that this disclosure will be complete and its scope will be fully conveyed to those skilled in the art. Numerous specific details have been described, such as examples of specific components, devices and methods, to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that the use of specific details is not necessary and that the exemplary embodiments may be embodied in many different forms, none of which should be interpreted as limiting the scope of the present disclosure. It will also be apparent to those skilled in the art that the present invention is not limited by what has been particularly shown and described. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described above, together with variations and modifications that do not exist in the prior art and that would occur to those skilled in the art upon reading the above description.

Claims

1. A nipple device that monitors the flow of milk drawn in by an infant during breastfeeding, A base layer comprising a dome-shaped protrusion having an inner surface and an outer surface, wherein the inner surface defines the internal volume of the dome-shaped protrusion, and the dome-shaped protrusion is adapted to be inserted into the mouth of an infant, A first passage connecting the internal volume of the dome-shaped protrusion and a region of the base layer located remote from the dome-shaped protrusion, A second passage, at least one, connecting the one region of the base layer that is far from the dome-shaped protrusion with at least one position on the outer surface of the dome-shaped protrusion, A third passage having fluid flow resistance, which fluidly connects the first at least one passage and the second at least one passage, and is located remotely from the dome-shaped protrusion, A first pressure sensor and a second pressure sensor arranged in the third passage, wherein the differential pressure between the first pressure sensor and the second pressure sensor can be determined. Nipple devices, including

2. The nipple device according to claim 1, wherein the differential pressure between the first pressure sensor and the second pressure sensor can determine the flow of milk from the internal volume of the dome-shaped protrusion to at least one position on the outer surface of the dome-shaped protrusion.

3. The nipple device according to claim 1, wherein the first pressure sensor and the second pressure sensor are incorporated into a differential pressure module.

4. The nipple device according to claim 3, wherein the differential pressure module includes a subtraction circuit that operates between the outputs of the first pressure sensor and the second pressure sensor.

5. The nipple device according to claim 1, wherein the third passage has a constricted bore that generates increased fluid flow resistance to the flow of milk passing through it.

6. The nipple device according to claim 1, wherein the flow of milk to the infant is determined from the differential pressure measured between the first pressure sensor and the second pressure sensor using a known relationship that depends on the fluid flow resistance of the third passage.

7. The nipple device according to claim 1, wherein the base layer of the nipple device is shaped to be mounted on the breast of a mother who is feeding milk to an infant.

8. The nipple device according to claim 1, wherein the base layer of the nipple device is adapted to be mounted on a baby bottle.

9. The nipple device according to claim 1, wherein the region of the base layer that is far from the dome-shaped protrusion is the peripheral region of the base layer of the nipple device.

10. The nipple device according to claim 3, wherein the first pressure sensor and the second pressure sensor or the differential pressure module are arranged in a separate head adapted to be attached to the periphery of the nipple device through a fluid flow port.

11. The nipple device according to claim 10, wherein the separate head includes either a display for showing the level of the milk flow or wireless equipment for transmitting the milk flow rate to a remote receiver.

12. The nipple device according to claim 1, wherein the first end of the third passage is connected to a first chamber having a first flexible diaphragm that divides its internal volume into a proximal end attached to the first end of the third passage and a distal end having a first pressure sensor, and the second end of the third passage is connected to a second chamber having a second flexible diaphragm that divides its internal volume into a proximal end attached to the second end of the third passage and a distal end having a second pressure sensor, and pressure transmission between the first end of the third passage and the first pressure sensor, and between the second end of the third passage and the second pressure sensor, both occur across the respective flexible diaphragms.

13. The nipple device according to claim 12, wherein the distal ends of the first chamber and the second chamber are filled with liquid.

14. The nipple device according to claim 1, wherein the diameter of the passage is selected to be small enough that the milk entering any of the passages by the pressure generated in the nipple device does not mix with air already present in the passages.

15. The nipple device according to claim 14, wherein the passage has an inner diameter not exceeding 4 mm.

16. The nipple device according to claim 1, wherein the measurement of the differential pressure makes it possible to determine the infant's milk intake pattern.

17. The nipple device according to claim 3, wherein the third passage having fluid flow resistance is located in a peripheral region of the base layer of the nipple device, and the pressure sensor or the differential pressure module is located in a separate head adapted to be attached to the periphery of the nipple device through a fluid flow port.

18. The nipple device according to claim 1, wherein the third passage having fluid flow resistance is located on the outer surface of a resistance element adapted to be removablely mounted in a housing formed in a peripheral region of the base layer of the nipple device, and both ends of the fluid flow resistance located on the outer surface of the resistance element are aligned with the far ends of the first at least one passage and the second at least one passage.

19. The nipple device according to claim 1, wherein the third passage having fluid flow resistance is located on the outer surface of a resistance element adapted to be detachably mounted in a housing formed on a separate head adapted to be attached to the periphery of the nipple device through a fluid flow port in a peripheral region of the base layer of the nipple device.

20. The nipple device according to claim 19, wherein when the resistive element is mounted in its housing, both ends of the fluid flow resistance positioned on the outer surface of the resistive element are aligned and fluidly connected to the first pressure sensor and the second pressure sensor, respectively.

21. A nipple device for monitoring the flow of milk drawn in by an infant during breastfeeding, A base layer comprising a dome-shaped protrusion having an inner surface and an outer surface, wherein the inner surface defines the internal volume of the dome-shaped protrusion, and the dome-shaped protrusion is adapted to be inserted into the mouth of an infant, A first passage between the internal volume of the dome-shaped protrusion near at least one breastfeeding orifice having fluid flow resistance and a region of the base layer far from the dome-shaped protrusion, A second passage between the one region of the base layer that is far from the dome-shaped protrusion and at least one position on the outer surface of the dome-shaped protrusion that is close to the at least one breastfeeding orifice having fluid flow resistance, A first pressure sensor connected to the end of the first at least one passage, which is remote from the at least one nursing orifice, and a second pressure sensor connected to the end of the second at least one passage, which is remote from the at least one nursing orifice, are provided so that the differential pressure across the at least one nursing orifice can be determined. Nipple devices, including

22. The nipple device according to claim 21, wherein the flow rate of milk to the infant can be determined by the differential pressure across at least one breastfeeding orifice.

23. The nipple device according to any one of claims 21 and 22, wherein the material around the at least one breastfeeding orifice reduces the influence of the infant sucking on the nipple device on the shape of the at least one breastfeeding orifice.

24. The nipple device according to claim 23, wherein the reduction in the change in the shape of the at least one breastfeeding orifice reduces the change in the fluid flow resistance of the at least one breastfeeding orifice, and as a result, the change in the measured differential pressure, which is independent of the flow rate of milk to the infant, is reduced.

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