阅读说明：本技术 基于微传感器的母乳喂养的乳量测量装置 (Milk quantity measuring device for breast feeding based on micro-sensor ) 是由 弗朗西丝卡·索吉尼 詹姆斯·特拉弗斯 朱塞佩·图西文德 于 2019-07-18 设计创作，主要内容包括：一种安装有传感器的乳头护罩,具有关联的电子接口和互连件,用于测量和显示母乳喂养期间的母乳流量和容量。传感器安装在乳头护罩的尖端,以尽量减少母婴之间的侵扰。根据所选的传感技术,传感器可以垂直于或平行于通道内的母乳流动安装。所述传感器和相关电缆的尺寸使得该装置看起来与单独的乳头护罩没有明显不同,从而在哺乳期间产生最小的影响。微升级别流量由传感器直接测量,以便将母乳容量的准确、实时信息反馈给哺乳母亲。电子单元放大传感器输入并使用软件算法对数据进行数字处理以确定液体容量,可以直接集成在护罩中,也可以根据集成在流动通道中的传感技术的性质组成外部模块。(A sensor-mounted nipple shield having an associated electronic interface and interconnect for measuring and displaying milk flow and volume during breastfeeding. The sensor is mounted at the tip of the nipple shield to minimize intrusion between mother and baby. Depending on the sensing technology chosen, the sensor may be mounted perpendicular or parallel to the flow of breast milk within the channel. The size of the sensor and associated cables is such that the device appears not to be significantly different from a nipple shield alone, thereby producing minimal impact during lactation. Microliter-scale flow is measured directly by a sensor to feed accurate, real-time information of breast milk volume back to the nursing mother. The electronic unit amplifies the sensor input and digitally processes the data using software algorithms to determine the liquid volume, either directly integrated in the shroud or constituting an external module depending on the nature of the sensing technology integrated in the flow channel.)

1. A flow measuring device for breast feeding comprising a flexible nipple shield adapted to operatively conform to the shape of a nipple, the shield defining a flow passage through which an amount of breast milk is to be delivered from the nipple to a feeding infant(ii) a Characterized in that the device further comprises a sensor module with a flow sensor provided in the teat cup, said flow sensor comprising a temperature dependent heatable resistor in the middle part of the flow channel, wherein the resistor is operatively heated to a first temperature T₁Above the ambient temperature T of the milk flowing in the flow channel₂The flow of milk produces a measurable cooling effect on the resistor, and the device is configured to use the measurable cooling effect to generate an output signal indicative of milk flow in the channel.

2. The device of claim 1, wherein the flow sensor is a non-mechanical sensor that does not include a component that moves relative to the flow of breast milk.

3. The device of claim 1 or 2, wherein the flow sensor is positioned perpendicular to the flow channel.

4. The device of claim 1, wherein the flow sensor is positioned parallel to the flow channel.

5. The device of any preceding claim, wherein the resistor is operatively heated by its own electrical connection or is coupled to a secondary heat source to raise its temperature above the ambient temperature of breast milk.

6. An apparatus as claimed in any preceding claim, comprising anemometry circuitry coupled to the resistor and arranged to monitor electrical characteristics of the resistor and to use changes in those monitored electrical characteristics to generate an output signal.

7. The apparatus of claim 6, wherein the anemometry circuitry is selected from one of a Constant Temperature Anemometry (CTA) circuitry, Constant Current Anemometry (CCA) circuitry, or Constant Voltage Anemometry (CVA) circuitry.

8. The apparatus of any preceding claim, wherein the resistors are coupled to a power supply, the resistors being operable to be continuously powered by an analogue bridge circuit, or pulsed by a digital modulation scheme such as Pulse Width Modulation (PWM) or sigma-delta (Σ Δ) modulation.

9. The apparatus of any preceding claim, wherein the resistor is a thin wire, thin film, RTD, thermistor, bulk silicon device, junction silicon device or any other resistive component with a measurable temperature coefficient of resistance.

10. The device of any preceding claim, wherein the sensor module comprises a plurality of sensing elements arranged in an array along the flow channel.

11. The device of any preceding claim, comprising a memory element for storing calibration coefficients for the flow sensor.

12. An apparatus as claimed in any preceding claim, comprising a storage element for storing historical suckling data.

13. A device according to any preceding claim, comprising a memory element for storing sensor wear and/or usage information.

14. The device of any preceding claim, comprising a cable extending from the nipple shield, wherein the storage element is located on or embedded in the cable.

15. The apparatus of any preceding claim, comprising a cable extending from the nipple shield and connected to a processing unit.

16. The apparatus of any preceding claim, wherein the apparatus comprises a transmitter.

17. The apparatus of any preceding claim, wherein the transmitter communicates with a remote apparatus using a wireless communication protocol.

18. A measurement system comprising a processing unit for receiving flow sensor data from a device and providing a visual indication of the measured flow in a visual display, a visual display and a device as claimed in any preceding claim.

19. The system of claim 18, comprising a data logger configured to collate the received flow sensor data with at least one of personal information, time of day, and medical records.

20. A system according to claim 18 or 19, characterised in that the processing unit is integrated in the wrist unit so as to be worn during nursing.

21. The system of any one of claims 18 to 20, wherein the system is configured to provide storage of historical feed records for subsequent retrieval and display numerically or graphically.

22. The system of any one of claims 18 to 21, wherein the system is configured to allow measurement from a selected one of the left or right breast, so as to track milk flow from each breast independently.

23. The system of any one of claims 18 to 22, wherein the visual display provides a graphical representation of the milk flow pulses, including a bar chart, dial chart, or corresponding percentage display, in reverse when responding to dynamic readings in response thereto.

24. The system of any one of claims 18 to 23, wherein the processing unit is configured to provide a real-time accuracy range for a given measurement numerically or graphically, the real-time accuracy range being displayed on a visual display.

25. A system according to any of claims 18 to 24, wherein the system is arranged to track usage of the device and provide an indication of when actual usage is approaching pre-calibrated expected usage.

26. The system of claim 18, wherein the processing unit is a smartphone and the visual display is a screen of the smartphone, the smartphone executing application software thereon that receives and processes flow sensor data from the sensor and provides a visual indication of the measured flow in the visual display.

27. A nursing bra adapted to house at least a sensor module of a device according to any one of claims 1 to 17.

Technical Field

The present invention relates to breast feeding milk volume measuring devices, and in particular to a device provided with a sensor operable to provide a measured indication of the amount of breast milk produced.

Background

In nursing mothers, there is a need to accurately measure the amount of breast milk delivered to the baby; in the absence of this information, many mothers are turning to supplementation or giving up breastfeeding entirely due to concerns about the nutrition of the infant.

There is significant prior art in this field and for purposes of this detailed description we have classified these known devices into three broad categories:

1. and (4) offline indirection. Obtaining a measurement without directly measuring flow or volume; the calculated volume is only displayed after the end of the feeding period. The most important method in this category is to measure the weight of the infant before and after feeding. This is the only method that seems to be currently accepted by various national health service agencies, but studies have shown that its accuracy is very low.

2. Indirect in real time. Also, a proxy measurement is used to obtain the amount of milk delivered. Methods employing this technique can be used to deliver any measurement to the mother in real time. There are many patents and products in this field, mainly focusing on the measurement of the amount of maternal milk. The methods employed involve the use of various techniques such as doppler blood flow, skin conductance, physical volume, etc. One approach that does not involve direct breast measurements relies on the acoustic characteristics of infant swallowing to obtain volume. These methods tend to be very complex and accuracy information has been ignored as an example of product entry into the market and is often poorly accepted due to reporting inaccuracies.

3. And (4) direct real-time. Such devices utilize the actual direct measurement of breast milk flow from mother to baby and display the corresponding volumetric information to the mother in real time. A typical example includes a breast cup with a sensor that is mounted in or beside the milk channel and then leads to an artificial nipple. Many sensor types have been proposed, such as piezo-resistive forces, thermal gradients, mechanical turbine/reciprocating piston devices. The physical volume of the sensor or the required channel length must be divided in each case. While in some cases these devices may be more accurate than previous devices, they also present the problem of separation of the baby from the mother's breast. The physical capacity of the sensor or the required channel length has to be divided in each case.

A related example of a device for measuring the amount of milk when breastfeeding is mentioned in the following prior art.

Us 20080167579a1 to Ezra discloses a breastfeeding device consisting of a nipple shield in which a thermodilution is mounted in a flow passage embedded in the shield.

Us patent 7887507B2 to Tulsa discloses a device for breast feeding, which device comprises a brassiere in which a breast milk channel is fitted, and in which a temperature gradient sensor or a mechanical flow meter is provided, as well as sensors for monitoring other parameters, such as temperature, viscosity, fat content and chemicals present.

Us patent 2013073211(a1) to Hershkovich discloses a breastfeeding device comprising a nipple shield equipped with a microcontroller-based breastmilk flow meter, an on-board dielectric detector board assembly and a pressure resistance sensor assembly.

Japanese patent 4634402B2 to Kaizen discloses a breast feeding device that measures the amount of milk from a breast during feeding by the amount of milk present in a transparent tube. It does not contain any flow sensors in the bra or breast ducts.

U.S. patent 20130096461A1 to Sella discloses an apparatus and method for determining and monitoring the flow and volume of excreted or secreted fluids from the human body. The sensor mode includes thermistors and measures the flow of fluid through the channel, calculating the difference in resistance of the two thermistors. The device of Sella includes a thermal flow meter sensor.

Us patent 8521272B2 to Yeda Research and Development Co Ltd discloses a device for monitoring breast feeding by capacitance measurement, determining the change in breast capacitance during breast feeding, and placing a device on the breast that correlates the change in capacitance with the amount of milk consumed by the infant through the electrodes.

EP patent 2388026a1 to Tritsch-Olian discloses a device for assisting breast feeding which is applied to the mother's breast and in which a flow meter may be embedded to measure the amount of breast milk taken by the baby. It consists of a nipple shield, a milk storage tank is arranged on the nipple shield, and the nipple shield is connected with a milk pump. It does not measure the amount of breast milk of the mother that is directly supplied to the baby and the presence of the flow meter is not specified but is described in a general way.

WO patent WO2014087343a1 to momik discloses a device for assessing the amount of milk remaining in the breast by measuring the impedance of the breast tissue by placing electrodes directly on the breast or embedded in the shell or bra. This patent describes a volumetric indirect measurement method.

Us patent 20100217148a1 to Inolact discloses an apparatus for monitoring the amount of fluid in an organ, including breast milk. It consists of electrodes placed on the breast to allow volumetric assessment thereof. The patent also describes the addition of a sound sensor to detect the possibility of swallowing by an infant.

Us patent 8280493B2 to Mamsense discloses a device for volumetric assessment of the amount of milk secreted by a breast during breastfeeding by performing an ultrasonic doppler transmitter probe on the breast. This patent describes a volumetric indirect measurement method.

Us patent 20150223755a1 to Digisense describes a device for estimating the amount of milk taken by an infant by an indirect method. It details the use of a system applied to diapers that includes an optical sensor to calculate the amount of food taken by the infant.

U.S. patent 7607965B1 to Frazier describes a device consisting of a tube and a nipple shield that allows milk to flow directly from a mother's breast to an artificial nipple placed in the mouth of the baby for feeding. The purpose of the device is to allow the mother to feed the baby without using a pump and without exposing himself during breastfeeding. The device physically isolates the infant from the breast and does not involve any sensors for flow measurement.

Japanese patent No. jph0788112a to Etsuno-Hirose Electric describes a device for measuring the amount of milk taken during breastfeeding, which is equipped with a microphone capable of detecting when the baby sucks on the breast. The connected CPU will count the number of inspirations to determine the amount of breast milk ingested. An ultrasonic sensor is added to detect the change of movement of the baby when sucking breast milk. This does not take into account the direct measurement of milk flow.

U.S. patent 20160235353A1 to Momsense-Nakar again describes a device that detects swallowing by a microphone placed in the throat of the infant, and an ear plug worn by the mother to monitor the amount of breast milk provided during breastfeeding. The described techniques can indirectly measure the amount of breast milk ingested by an infant.

U.S. patent No.20080264180A1 to Kimberly-Clark world wide Inc describes an apparatus for detecting the amount of breast milk provided using an acoustic method. It includes an audio transducer and a receiver for detecting, discerning and counting the amount of liquid ingested to determine the amount of liquid ingested.

US8413502B2 to Zemel describes a device for measuring the feeding performance of an infant, the device comprising a body portion having one end for receiving fluid from a reservoir and the other end connected to a teat, the second end having a larger cross-section than the first end, a conduit in communication with the first and second ends including a pressure sensor, monitoring the pressure indicative of the flow of liquid in the passage. The pressure sensor described in this invention is based on the venturi principle, since the liquid flows through a channel having a narrower cross section at the head end relative to the end portion.

WO2011/117859 describes a lactation measurement device which uses first and second thermistors disposed upstream and downstream relative to each other and relative to a flow passage. The elements are mounted to the walls or sides of the flow channel. Heating a thermistor above the expected temperature of the milk, the invention discloses using a constant absolute temperature for the heated element, and the cooling effect of the milk gives an indication of the measured flow of milk.

Although these known methods fall into the broad category of "real-time direct" measurements, there remains a need for a system and method for breast milk volume measurement that does not require a large number of physical sensors and associated electronics.

Disclosure of Invention

These and other problems are solved by the present device, which includes a flexible nipple shield adapted to operatively conform to the shape of a nipple, the shield defining a flow passage through which an amount of milk will be delivered from the nipple to a feeding infant; the device also includes a flow sensor disposed in the flow passage in the nipple shield in contact with the flowing breast milk.

In one embodiment, the flow sensor includes a member mounted in the flow passage and perpendicular to the direction of flow of the milk. Mounted on the member is a thermistor element which can be heated above ambient flow temperature, either self-thermally or by an external source, by its own power supply. The movement of liquid over the element will have the effect of cooling the element, which measurably changes the resistance of the element and thus gives a flow value. The method may be implemented to keep the current, voltage or temperature of the element constant, the latter being the most commonly used in schemes commonly referred to as Constant Current Anemometry (CCA), Constant Voltage Anemometry (CVA) and Constant Temperature Anemometry (CTA), respectively. In each case, the change in resistance, the required compensation for this change or the element power are measured by a circuit and converted algebraically into a flow measurement.

In another embodiment, the flow sensor comprises two members mounted in the flow channel and perpendicular to the direction of flow of the breast milk, both members having a thermistor element mounted or integrated therein. One component remains unheated, thus enabling measurement of the ambient temperature of the milk, while the other component is heated to a known temperature rise or increment above that ambient value. According to this arrangement, unlike previous arrangements using absolute temperature measurement, this technique uses a known temperature increment between the two sensors, thereby allowing accurate flow measurements at varying ambient temperatures.

In another embodiment, the flow sensor comprises two members mounted horizontally in a flow channel and parallel to the direction of milk flow, the flow channel comprising a flow restrictor, the larger part of the flow restrictor being close to the nipple and the smaller part being close to the baby's mouth, the first member of the sensor being placed in the larger part of the channel and the second member in the smaller part. The first and second members are each adapted to sense a change in pressure caused by the flow of milk through itself, and the pressure measurements detected by each member then define a differential pressure measurement produced by bernoulli's principle and provide an indication of the flow of milk in the channel. This type of flow sensor is commonly referred to as a venturi meter.

In another embodiment, the flow sensor includes a member mounted at an angle "θ" to the flow channel and the direction of milk flow that transmits a frequency to the flow channel and detects the signal reflected by the flow channel. The frequency shift caused by the doppler effect provides an indication of the flow rate of milk in the channel. A range of frequency sources may be used, such as ultrasound, visible light and infrared.

In another embodiment, the flow sensor includes a separate frequency source and a detector, both mounted at an angle 'θ' relative to the flow path and the direction of milk flow. One component emits a frequency towards the flow channel and the other component detects a signal reflected from the flow of milk, the frequency shifted frequency being indicative of the flow rate of milk as in the previous method.

In another embodiment, the flow sensor comprises two members mounted horizontally in the flow channel and parallel to the direction of flow of milk, a first member emitting an electromagnetic or mechanical frequency to the flow channel, and a second member disposed behind the first member in the direction of flow of milk, detecting signals reflected from opposite sides of the channel, the offset phase of the signals being produced by the time of flight of the flow of milk and providing an indication of the speed of milk in the channel. In such an arrangement, each member may also act as both an emitter and a detector to provide time-of-flight information in both forward and reverse flow directions, thereby achieving more accurate flow resolution.

In another embodiment, the flow sensor comprises two pairs of members having a known separation distance in the direction of flow, the members being mounted on opposite sides of the flow channel, the member on one side emitting an optical signal into the flow channel and the other optical member on the opposite side detecting the optical signal. For each pair of members, the signal is interrupted or disturbed by the presence of particles, bubbles or other impurities in the liquid flow, the time of flight of which provides an indication of the flow rate of milk in the channel.

In another embodiment, the flow sensor includes two members mounted on opposite sides of the flow channel and the direction of flow of milk, a first member transmitting an electromagnetic or mechanical frequency to the flow channel, a second member located behind the first member along the direction of flow of milk and detecting a signal propagated by the flow of milk, the time of flight between the two signals providing an indication of the flow rate of milk in the channel. In this embodiment, each member may also act as both an emitter and a detector to provide time-of-flight information in both forward and reverse flow directions, thereby achieving more accurate flow resolution.

In another embodiment, the flow sensor comprises one or more pairs of members mounted perpendicular to the flow path and in the direction of flow of milk, a first member of each pair emitting an acoustic or ultrasonic signal towards the flow path, a second member being disposed in front of the first member in the direction perpendicular to the flow path and detecting a signal having a phase shift as a function of time of flight through the milk, the movement of the detected ultrasonic signal providing an indication of the flow rate of milk in the path. In the case of multiple pairs of sensors, the combined signal can be decomposed into spatial cross-sectional images from which point and total flows can be derived. This field is widely referred to as tomography.

In another embodiment, the flow sensor comprises a member in the form of a highly curved airfoil or hydrofoil profile mounted in the flow passage and held in place relative to the direction of flow of milk by a pivot placed at the trailing edge of the member, held in place by two flexible elements placed above and below the member, the flow rate being measured by the difference in elongation of the two flexible elements relative to a rest state and sensed by strain gauges on said elements.

According to the present invention, such a device provides a real-time direct measurement of the amount of milk delivered to the infant while solving the separation problems associated with the prior art by minimizing the physical dimensions and the length of the flow path of the sensor.

Accordingly, there is provided an apparatus as detailed in the claims.

Drawings

Fig. 1 is a schematic view of an apparatus according to the invention positioned on a breast and coupled to a measurement system.

FIG. 2A is a schematic cross-sectional detail view of the apparatus of FIG. 1 using a single element anemometer according to an embodiment of the present invention.

Fig. 2B is a front schematic view of the device of fig. 2A.

FIG. 2C is a schematic cross-sectional detail view of the apparatus of FIG. 1, in which an anemometer having a separate temperature reference element is used, according to an alternative embodiment of the present invention.

Fig. 2D is a front schematic view of the device of fig. 2C.

Fig. 2E is a schematic diagram illustrating the apparatus of fig. 1 coupled to a processing unit.

Fig. 2F is an example of a flexible cable that may be advantageously used in the context of the present invention.

Fig. 2G is a schematic diagram showing how the pattern of the flat flexible cable is designed to fit the geometry of the shield.

Fig. 2H shows a plan view of how the flex cable connects between the sensor module and the connected processing unit.

Fig. 3 is a schematic detail of the device of fig. 1 using another alternative embodiment of a pressure sensor according to the present invention.

Figure 4A is a schematic detail of the apparatus of figure 1 using another alternative embodiment of a single doppler sensor in accordance with the present invention.

Figure 4B is a schematic detail of the apparatus of figure 1 using another alternative embodiment of a doppler sensor pair in accordance with the present invention.

Figure 5A is a schematic detail of the dealer of figure 1 using a planar time-of-flight optical sensor including two emitter/detector pairs, according to another alternative embodiment of the present invention.

Fig. 5B is a schematic detail of the apparatus of fig. 5A, the planar time-of-flight sensor consisting of only one pair of emitters/detectors, according to a different arrangement of sensing elements using the planar time-of-flight sensor.

FIG. 5C is a schematic detail of the apparatus of FIG. 5B according to different placements of sensing elements.

Fig. 5D is a front schematic view of the device of fig. 5C.

Fig. 5E is a front view schematic diagram of the apparatus of fig. 5C adapted for multiple time-of-flight sensor pairs to achieve flow tomography.

FIG. 6 is a schematic detail of the apparatus of FIG. 1 using an airfoil or hydrofoil according to another embodiment of the invention.

FIG. 7 is an example of a Wheatstone bridge circuit which may be advantageously used to control a CTA circuit in accordance with the invention.

Fig. 8 is an example of a digital pulse circuit for applying a fixed voltage to a heater circuit over a measured time window.

Fig. 9 shows an example window of signals used in a PWM circuit.

Fig. 10 is an example of the output of the delta-sigma modulation circuit.

FIG. 11A is a schematic illustration of a front view of a first portion of a mold for making a device according to the present invention.

Fig. 11B is a schematic side view of a first portion of a mold for manufacturing a device according to the present invention.

Fig. 12A is a schematic illustration of a front view of a second portion of a mold for making a device according to the present invention.

Fig. 12B is a schematic side view of a second portion of a mold for manufacturing a device according to the present invention.

Fig. 13A is a side view schematically illustrating the final step of the injection molding process for manufacturing the device according to the invention when enclosing the incomplete shield with integrated components in the mold.

Fig. 13B is a schematic representation of a side view of the device according to the invention when extracted from the mould after the last injection step.

Detailed Description

With reference to fig. 1, a device is provided comprising a nipple shield/nipple protector (1) made of silicone rubber, TPE or similar elastomeric material. It will be appreciated that the nature of this material imparts flexibility to the shield and is operable to conform to the shape of a female nipple. A flow passage (4) is defined in and extends through the shroud. The flow passage has a proximal teat end which, in use, is adjacent the teat when the shield is located on the breast. The flow passage also has a distal nipple end which, in use, is presented in the mouth of the infant when the shield is positioned on the breast.

The device further comprises a sensor module (2), the sensor module (2) being located in a flow channel (4) defined in the shroud. To facilitate the placement of the sensor module in the channel, the sensor may be manufactured on a plastic (or other food-contact safety material) support and may be integrated into the polymer shield (1) by glue or other clamping means during the molding process. In another embodiment, it may be integrated in the shield (1) by means of an adhesive (or other clamping means) after the moulding process. The flow passage comprises an inlet (3A) at the proximal end of the teat and an outlet (3B) at the distal end of the teat of the flow passage (4), the flow passage providing a liquid communication path therebetween.

The sensor module is placed within the flow channel to extend, according to a selected embodiment, along a direction perpendicular or parallel to the flow of milk flowing from the inlet (3A) to the outlet (3B). In some embodiments of the invention, the sensor module is oriented at a defined angle 'θ' relative to the flow channel and is in a fixed position relative to the flow of breast milk from the inlet (3A) to the outlet (3B). The inlet (3A) communicates with and is normally in close contact with the teat and, in the case of breastfeeding, receives milk delivered into the flow channel and passes through the sensor module (2) before flowing out of the outlet (3B).

The milk flows through the sensor module and is conveyed via a channel (4) to an outlet (3B) which communicates with the baby's mouth in order to convey milk from the mother to the baby. The sucking action of the infant is transferred through the pliable nature of the nipple shield to encourage milk flow through the flow passage.

Preferably, the sensor module (2) comprises a temperature sensor or a frequency detector, respectively, mounted vertically or at a defined angle 'θ' with respect to the liquid flow and in a fixed position with respect to the flow channel. The present invention uses a change in the resistance of a conductive element due to a change in temperature or due to a delay or frequency shift in a test signal sent in the flow and associated with the flowing entity. The sensor output will provide an accurate measurement of the sensed temperature change or frequency shift on the sensing element, which can be directly attributed to the flow through the sensor, thereby measuring the amount of breast milk passing through the device.

The sensor module may also comprise a mechanical member shaped with a highly curved wing profile, mounted parallel to the flow channel and fixed in the flow channel by two flexible members, on which strain gauges may be mounted. The wing-shaped members may be fixed horizontally or vertically in the flow channel depending on the application requirements. In this configuration, the present invention uses the amount of deflection of the flexible member, which is caused by flow in the channel and sensed by the strain gauge, as a measure of the flow entity.

The electrical signal from the sensor is transmitted out of the shield. Such communication may be achieved using, for example, a Flat Flexible Cable (FFC) (5) embedded in the shield material. By using a flat flexible cable embedded in the shield material, the profile of the shield is minimized. The flexible cable may be designed with a shape that ensures its flexibility and integration in the thin polymer layer of the cover (1). The cable is then connected to a processing unit which can be integrated directly in the lower part of the shroud, as we have described in PCT invention No. PCT/EP2017/067445 on day 11, 7/2017. In another embodiment, the treatment unit is a separate external treatment unit (7), in which configuration the sensor will continue to be co-located with the shield. In case the processing unit is separated from the shield, the cables (5) preferably emerge radially from the shield at the lower part of the breast and are connected to the processing module or processing unit (7) by means of an extension of a flat cable or a connection of a round cable (6). As shown in fig. 1, the processing module will typically include a user interface including buttons (8) or similar types of user interface elements and a display (9), which may be LCD, LED or other suitable type.

To facilitate disengagement of the shield and as a processing unit, a connector may be provided between the sensor and the processing module that is connected to the shield cable (10). The physical location of such connectors may vary according to design constraints.

The operation of the processing module (7) and the possibility of integrating a storage device on the shroud to store data may include the use of a transmitter or transmitter/receiver arrangement to facilitate wireless communication between the sensor module and the processing unit/module, which has been described in our previous invention (PCT/EP 2017/067445 on 11/7/2017) and is also applicable to the present invention.

The processing module includes suitable electronic hardware and/or software to provide signal amplification, digitization and algorithmic processing to accurately display the amount of breast milk to the mother in real time. In some aspects, the functionality of the processing unit may be provided by a smartphone, such as a mobile telecommunications device, which performs many of the functions of a computer, typically having a touch screen interface, Internet access rights, and an operating system capable of running downloaded applications or applications. The processing function of displaying the amount of breast milk to the mother in real time is implemented using hardware already present on the smartphone by providing a software application or application that can be downloaded on the smartphone and then executed. In this way, where the term processing unit is described, it should be understood that this can be thought of as the smart phone executing specialized software that is provided separately to the phone. The executable application will typically be provided to the actual bra through a separate transaction channel, for example it will be accessed through an iOS or Android application store, as will be appreciated by the skilled person.

This may be combined with other electronics, such as a storage device for storing sensor calibration and historical nursing records. As such, the shroud may include dedicated electronics and/or memory, which would facilitate personalization of a particular shroud. It will be appreciated that the accuracy of the measurements may require calibration, and by having a memory associated with each device, a separate calibration routine for a particular device may be uniquely provided and stored. Such a memory may also be used to store historical data indicative of actual measurements made using the sensor. This may allow the use of a device separate from the processing unit. When the connector is reconnected to the processing unit (7), the measurements made during "off-line" may be relayed to the processing unit (7) and the information displayed to the user.

According to the present invention, by embedding memory on the shroud side of the system rather than relying on memory contained only in the processing unit, the present invention facilitates record storage on the shroud itself. As mentioned above, this facilitates the personalization of the shield, while the processing module may be generic in nature, allowing connection to a plurality of sensors provided on different shields. In addition, a data logging module may be provided that is capable of providing reading and collating nursing information based on personal or other data recorded at the obstetrical hospital.

Such a storage unit may be provided as a unit that is physically separate from the cover, but is in electronic communication with the cover. Such communication may be provided by a physical cable, such as shown with respect to the coupling of the processing unit to the shroud. In such an arrangement, the need to provide additional storage on the shroud-the volume associated therewith-may be minimised, but facilities may be provided which provide individualized storage for a particular shroud.

It should be appreciated that such a memory element may be used to store calibration coefficients for the flow sensor. Other uses would include storing historical feeding data or sensor wear and/or usage information. In the latter application, the device may be used to provide a visual indication of actual use and then provide the user with information regarding the possible need to replace the sensor module. The sensor module may be provided as a removable or replaceable component and may, for example, be provided as a component of a nursing bra. Such a brassiere may be designed to receive a first sensor module and a second sensor module that provide an indication of the amount of milk produced by the left and right breasts, respectively. In this way, the amount of breast milk for each breast can be detected and tracked separately for data recording and viewing.

In certain embodiments, the sensor module is directly coupled to the processing unit using a direct cable extending from the shroud. In order to allow flexibility and avoid the need to always physically connect the processing unit, the cable may already be embedded therein or already be coupled to a memory element which advantageously allows storing data during periods of time when no connection to the processing unit is made. This would facilitate the use of the sensor module when no physical connection with the processor is required and provide a more portable sensor arrangement.

Other configurations that avoid an always direct physical connection may be used, including the use of a transmitter or the placement of a transmitter/receiver, to facilitate wireless communication between the sensor module and the processing unit. The transmission may use any of a variety of protocols, such as WiFi^TM，Bluetooth^TMOr ZigBee^TMAt least one of the protocols to communicate with a remote device.

In this manner, it should be appreciated that an overall measurement system provided in accordance with the present invention includes a processing unit for receiving flow sensor data from the sensor modules and providing a visual indication of the measured flow, and a separate sensor module. The processing unit may preferably include a data logger for collating the received flow sensor data with at least one of personal information, time, medical records. The actual physical form of the processing unit may vary. For example, the processing unit may be integrated into a wrist unit to be worn during lactation.

The actual processing of the recorded data may include storing the historical nursing records for later retrieval and display, either numerically or graphically. This may allow a selected one of the left or right breasts to be measured individually in order to track milk flow from each breast independently. A visual display provides a graphical representation of the milk flow pulses, including bar, dial, or corresponding percentage display, in reverse when responsive to dynamic readings. Such data processing is used to provide a range of real-time accuracy for a given measurement, either digitally or graphically, and may be used to track usage of the device and provide an indication of when actual usage is approaching pre-calibrated expected usage.

The configuration of the sensor module may be similar to that shown in fig. 2A-D. The sensing module may be secured within the flow channel in the shroud using a suitable adhesive or mechanical clamping means.

Fig. 2A and 2B show an exemplary embodiment in cross-section and plan view, in which the sensor module (2) is implemented as a single active element (205) and is placed between the inlet (3A) and the outlet (3B) of the flow channel, perpendicular to the flow channel. The active elements (205) of the sensor module may be mounted on a support substrate (210) which is arranged horizontally upwards of the flow channel cross-section by means of a support ring (220) made of metal or other food-safe material. The active element (205) is preferably a heatable resistor, the resistance of which depends on the temperature of the resistor. Preferably, the heatable resistor is located within the intermediate portion of the flow channel, as shown in the schematic diagram of fig. 2B. The inventors have determined this to be a particularly advantageous location because if the resistor is located at an edge or side of the flow channel, the sensed flow is least affected by boundary effects or turbulence. Any fouling effect of the resistor is also minimized by its location away from the side walls. The frequency response of the sensor is also improved because the support substrate (210) is in closer contact with the liquid being measured than would be possible if it were mounted or otherwise placed at the edge of the channel. It is believed that the flow through the resistor in the middle of the channel is more likely to be laminar and not compromised by the side wall surface effects, which, due to fouling, exacerbate any turbulent or fouling effects on the liquid flow.

By operatively heating the resistor to a first temperature T₁A temperature higher than an ambient temperature T of the breast milk flowing in the flow passage₂When the resistor is exposed to flowing breast milk through the flow channel, it will experience a measurable cooling effect. Preferably, the ambient temperature measurement is from a second temperature sensor, which need not be located in the middle portion of the flow passage. For example, the second temperature sensor may be located within the body of the bra or within the channel wall itself. The second temperature is used to provide an output indicative of an actual temperature of milk flowing within the channel. The indicative actual temperature is more constant over time and there is no need to measure signals with frequency components greater than about 1Hz, so the second sensor can be located outside the channel. In contrast, the first operatively heated resistor will provide an output that rapidly fluctuates over time, with the frequency component of the flow signal typically being up to about 100Hz, and thus being disposed within the actual flow path。

The sensor module is configured to use a measurable cooling effect to generate an output signal indicative of the flow of milk within the pathway, thereby indicating the amount of milk ultimately consumed during any one feeding session.

The circuitry used to sense the effect of this temperature on the resistive properties of the resistor may be collectively referred to as anemometry circuitry coupled to the resistor and arranged to monitor the electrical properties of the resistor and use the monitored changes in the electrical properties to generate an output signal.

The anemometry circuitry is preferably selected from one of a Constant Temperature Anemometry (CTA) circuitry, a Constant Current Anemometry (CCA) circuitry or a Constant Voltage Anemometry (CVA) circuitry. It should be understood that these terms relate to three methods of electronic control of the anemometer elements and can be distinguished as follows:

CTA: the resistance of a heating element is a measure of its temperature. By sensing the resistance through a bridge circuit or similar circuit, a feedback signal can be generated that modifies the excitation of the bridge in order to keep the value (and thus the temperature) constant. Using this method, the excitation voltage is fed back as a measurement quantity.

CCA: a constant current is applied to the heated element. When the resistance of the sensor changes along with the temperature, the voltage at two ends of the sensor also changes correspondingly, so that a measurement quantity is formed.

CVA: a constant voltage is applied across the heated element. When its resistance changes with temperature, the current flowing through it will also change accordingly, forming a measurement.

The CCA and CVA methods do not require any feedback control of the sensor response and can therefore be implemented using simpler electronics. They do, however, allow the temperature of the sensing element to vary with flow, thereby negatively affecting the response time by the thermal time constant of the sensor. Given the relatively low cost of more advanced electronics, the CTA approach is advantageous over selecting smaller, more fragile and more expensive sensor elements to compensate for the response differences of the control methods. Control of such CTA devices can be achieved, for example, by feeding a wheatstone bridge circuit into a differential amplifier (simplified device as shown in fig. 7). The output of the amplifier feeds a power stage that continuously updates the excitation of the bridge to maintain its balance. The excitation voltage forms a measurement quantity and can be read by an analog-to-digital converter (not shown).

In the exemplary arrangement of fig. 7, the resistor R_sIs a heated sensor, where R₁As its balancing resistor. In a non-reference implementation, Ra and Rb will complete the bridge on the other arm, nominally providing a balance between the two sides.

Where temperature compensation is also required, temperature sensing (Rt) and compensation resistance (Rc) are added. They aim to adjust the bridge reference in response to ambient temperature changes so that its effect is gone and only the flow response is measured.

There are many practical problems with this implementation, particularly in a scalable consumer device environment:

although standard resistors can be specified to very tight tolerances, the tolerance range for variable resistors Rs and Rt can be as high as ± 20% or higher. This may unbalance the bridge so that the amplifier or feedback is not within the operable range. A solution to this problem is to individually select the other resistors in the bridge to restore the circuit to normal range. This means that each circuit needs to be uniquely configured, which obviates the need for high volume manufacturing techniques.

Due to the resistance-based factors described above and other variations in the electronics and sensors, the feedback circuit may encounter stability problems, which may result in output resonance. Solutions have been to adjust the design for over-damped response, limiting circuit performance, or to adjust each circuit individually, increasing manufacturing time.

There is also a problem with the temperature compensation circuit in that the response curve of the temperature reference needs to be matched exactly to the response curve of the heating sensor to cancel the temperature signal. This is difficult to achieve for most sensor types. For example, even in the same product family, thermistors will have different characteristic responses (β values), and the responses will also have a specified tolerance range that can vary the curve between the parts. Errors due to mismatch are built into the circuit and later difficult to compensate in the signal path.

The wheatstone bridge resistance and the excitation power stage both consume a large amount of power. Typically, the circuit will be provided with a fixed voltage source and the excitation voltage is generated by a device such as a transistor, which will appear as a resistive load. The heater may only occupy a very small portion of the power budget, which is not ideal for battery powered devices.

An alternative approach to this is the digital pulse approach, where a fixed voltage is applied to the heater circuit over a measured time window, an example of the type of circuit that can be effectively used is shown in fig. 8. In this configuration, the heating resistor (Rs) and the temperature reference (Rt) are in a separate resistive divider arrangement and are represented by R₁And R₂And (4) finishing. The reference arm is permanently connected to an excitation voltage V_excAnd the heater passes through the switch (S)_w) Selectively connected to the reference arm. The outputs of both dividers are fed to a multiplexer (M) which selects one or the other signal to feed to a single-ended ADC for conversion. The advantages are as follows:

now, the signals of the resistor circuit are analyzed in the digital domain and feedback is generated by digital control of the switching device. Since the digital control section has a much higher bandwidth than the analog sensor circuit, the possibility of instability is eliminated.

Since the resistive circuit does not have any direct feedback, its range can be chosen to match that of the ADC, allowing for any tolerance variations. These changes, including changes in the response curves between temperature and heating elements, can then be corrected in the digital domain.

The power requirements are much lower. Although the arrangement of the resistors appears similar to a wheatstone bridge, their values differ greatly since they do not need to be balanced with each other. The reference voltage at the ADC input ranges from 1 to 2V, which means that only a small signal needs to be generated at the input. For the temperature sensor, a high resistance resistor is required, for example, 10k Ω may be selected. When Vexc is in the range of 10 to 20VThis means that the higher value of R2 is about 100sk Ω to produce an output in the ADC range. At the sensing end, the combined resistance is low because the heater consumes power. The power is concentrated in Rs, R₁Again large enough to generate a voltage within the ADC range. Unlike an analog bridge, the heater switches are fully open or closed, thus creating only a small resistive load. With this configuration, it is possible to consume 90% or more of the power in the network where the heating resistor is needed.

Finally, the above architecture fits well into currently available Microcontroller (MCU) chips. These multiplexers and ADC circuits built into the digital processor and our bluetooth radio are readily available. This means that almost all functions can be implemented in a single low cost device and all control and calibration aspects can be modified in firmware.

The anemometry circuitry can be used to measure fluid flow with or without a temperature reference. Resistance temperature (T) of milk in the flow channel without a reference being available₁) And ambient temperature (T)₂) The potential variation in the temperature difference or difference (Δ T) between them with respect to ambient temperature must be large to ensure accuracy. Larger Δ T values in liquid anemometers lead to bubble formation and thus lower sensitivity, so anemometers are preferred. A smaller at also means lower power, which is critical for battery powered devices. The Δ T value is preferably maintained at 20 ℃ or less.

Considering that the temperature of breast milk is related to the body temperature of the nursing mother, T is the temperature₂The value is about 37 ℃. Heating the resistor to a value less than or equal to 50 c will provide a sufficient amount of change or delta T value to make the measurement. It will be appreciated that the local heating of the resistor will have a negligible effect on the overall temperature of the milk flowing through the flow channel, so that the milk temperature of the feeding baby does not vary significantly by active heating of the resistor.

In this regard, it should be understood that the size of the heatable resistor or heated element is an important consideration. The larger the element, the larger the thermal mass, and the slower the thermal response time. However, if the element is too largeSmall, durability becomes a factor, and particle fouling in liquids can have a large relative impact on sensor sensitivity. Typical infant suck rates are in the range of 1 to 2Hz, therefore, to detect the entire flow transient range, the sensor bandwidth should be in the range of 10 to 200 Hz. For the type of sensor considered, we find that the size of the sensor falling within this range is 0.3-0.6mm in length, with a preferred but not limited to spherical geometry. The corresponding sensor surface area in thermal contact with breast milk typically ranges from 1-1.5mm²Within the range of (1).

The sensing element will be preferentially placed in the center of the flow channel within the nipple shield. The central position will keep the sensor stable inside the shield material, ensuring that the device is resistant to interference from the baby's mouth during feeding and foreign objects that may be used during device maintenance. As mentioned above, preferably the heatable resistor or sensing element is located within the flow channel and suspended within the flow channel. The suspension structure of the sensor module will reduce the boundary influence of the flow channel walls on the temperature measurement. In this embodiment, the active element (205) is heated and maintained at a constant temperature by associated circuitry (not shown) connected thereto. During breastfeeding, the flow of milk in the channel causes a drop in the temperature of the heating element, which corresponds to a change in the resistance value of the same element detected by a connected measuring circuit (not shown). Such circuits are well known for use in thermistors and similar circuits, for example in temperature measurement circuits using thermistors.

Fig. 2C and 2D show another exemplary embodiment in cross-section and plan view, in which the sensor module (2) is composed of two active elements (205A, 205B) and is placed in the flow channel between the inlet (3A) and the outlet (3B) and perpendicular to the flow channel. The active elements (205A, 205B) of the sensor module may be mounted on a support substrate (210) arranged in a horizontal direction of the cross-section of the flow channel by means of a support ring (220) made of metal or other safe edible material. Similarly, as described above, a separate arrangement of the sensor modules will reduce the boundary influence of the flow channel walls on the temperature measurement. The first element (205A) is heated and maintained at a constant temperature by an electric circuit (not shown) connected thereto, and the second sensing element (205B) placed adjacent to the first heating element (205A) measures a temperature change of the liquid with respect to the heating element temperature by detecting a change in resistance value by the electric circuit (not shown) connected thereto.

In the case of very small flow measurements, the temperature sensing element of the sensor can advantageously shield or isolate the influence of the temperature gradient from the air in the absence of breast milk in the channel.

In the digital domain, to provide active heating of the heated sensor (205), the present invention requires a control method to feed back heater and temperature values to the switch control and maintain the heater at a desired Δ T. Two common methods are Pulse Width Modulation (PWM) and Delta Sigma (Δ Σ) modulation. Generally, PWM describes the bit pattern, while delta-sigma modulation more often describes the entire feedback system. For the purposes of the present invention, we will consider these two cases only in the context of bit patterns. For PWM, a fixed sampling window is selected over which the width of the on pulse is modulated, as shown in fig. 9. For an anemometer, at the beginning of the cycle, the switch will open to power the heater. The response of the heater is then monitored (by an analog to digital converter, ADC) until the heater rises above the set point temperature by self-heating, at which time the switch will be closed until the cycle is over. In this way, the width of the pulse is a measure of the power required to cause the heater to exceed the threshold value during this time.

Delta-sigma modulation is similar in that it uses a fixed period, but differs in that at each period the switch will be continuously opened or closed depending on the threshold used at the beginning of the period. An example output of a sinusoidally varying input is shown in fig. 10.

It will be appreciated from the schematic diagram of fig. 10 that the higher or lower durations are not different cycle lengths, but rather the individual cycles having the same value are grouped together. In this scheme, the measure of power is the number of higher pulses in a given duration, where the duration is an integer multiple of the cycle width. The Δ Σ mode is easier to implement algorithmically and computationally because it requires only one ADC sample and switching decision per cycle, whereas PWM requires constant sampling during the on-phase. However, to obtain the same resolution, Δ Σ requires a smaller period/higher pulse frequency because it is the measured pulse count. In switching scenarios with practical components such as MOSFETs, the frequency is limited due to the rise/fall time and the switching power. To this end, in the context of the present invention, the present inventors have realized that a PWM scheme is preferred: high ADC sampling rates and computational power are readily available, while high frequency switching can be difficult to implement and consumes power, as well as potential electromagnetic interference (EMI) issues.

The device of the invention is more advantageous in use without mains supply. The power components (heatable resistors, etc.) require a power supply to function properly, so the device is usually equipped with a dedicated battery power supply. Preferably, the device comprises a rechargeable (lithium ion) battery, the capacity of which should not cause inconvenience to the user due to frequent charging. Battery life feeding for two reasonable durations (1 hour) corresponds to 1 day of use and up to 1 week or more of use should be considered. The measured electrical power requirements of the anemometer heater circuit is about 10mW, while the digital system and bluetooth power budgets are about 5 mW. In various systems, the battery nominal voltage of 3.7V increases or decreases with associated converter losses, with associated converter losses. To calculate the average current (in mAh) for the cell size,

we will assume that all converters are equivalent to a linear buck to 3V, with a corresponding power loss of 0.7V.

I＝P/V

5mA＝15mW/3V

Wherein, I: current flow; p: power, V: a voltage. The average current was 5mA and the minimum battery capacity for 21 hour power supplies would need to be 10 mAh. To accommodate a 20-40 feed, allowing some users to use a full week, capacities of up to 200mAh may be considered.

Fig. 2E and 2F show how the device of fig. 2A-2D can be coupled to a processing unit 207 through a flat flexible cable 202 integrated in the shroud (1). The present inventors have realised that it is important that the shape of the cable will specifically conform to the shroud profile to easily follow the movement of the apparatus during handling and processing. The selection of an appropriately configured cable will depend on the elongation capabilities of the flexible cable and the necessity for a perfect mechanical match between a polymeric shield. Especially in view of the suction force exerted by the baby on the nipple, the correct geometry of the cable will enable it to follow the elongation/deformation of the polymeric shield avoiding its rupture or detachment from the rubber. Furthermore, for the selected rubber thickness, the specific geometry of the cable will ensure that a break point similar to a polymer shield is reached.

In order to solve the above problems, the flat flexible cable is designed as follows. The upper part of the cable will consist of the connector (201A) of the sensor module (2) placed in the flow channel. The flat flexible cable then extends from said connector (201A) in a straight line (203) of varying length according to the selected dimensions of the shield, said straight line continuing in a wavy line (204), becoming straight again in the lower portion of the shield and ending in a connector (201B) which is inserted into a processing unit (207) in the lower portion of the shield. The lengths of the wavy lines and straight lines will vary accordingly with the selected dimensions of the shield. The number and configuration of the conductive patterns along the flat flexible cable and on the connectors (201A, 201B) will vary accordingly depending on the sensor module mounted in the shroud. By taking a circuitous path, the cable can be flexible in a number of dimensions and can be stretched in these dimensions without breaking. A serpentine shape is easier to apply than a straight path.

The cable should be thin to fit the shield profile (thickness about 100 μm) and will be made of a material that will ensure flexibility of the substrate, such as but not limited to polyimide, and will allow deposition of the conductive pattern. It is important that the material used to make the flat flex cable will ensure a low noise connection to allow for the transmission of weak signals from the sensor module. Due to the sensitivity requirements for very low flow rates (ranging from higher μ l/s to lower ml/s), it may also be necessary to electrically amplify the detected signal in the processing unit.

The specific geometry designed for the flat flexible cable will help ensure its integration in the flexible shield to ensure resistance and flexibility of the conductive pattern within the polymeric material of the shield. Referring to fig. 2G and 2H, the pattern of the flat flexible cable is designed to accommodate the geometry of the shield (1). The upper connector (201A) of the flat flexible cable will be in communicating contact with the sensor module (2) in the flow channel (4), while the lower straight part (203) of the cable will extend in the flow direction as far as the conical part (206) of the shield to be placed on the nipple. The straight portion of the cable will then bend at the junction between the flow channel (4) and the conical portion (206) of the shield and will continue to undulate (204). The undulations of the cables will extend radially along a conical portion (206) of the shield and a curved portion (209) which is placed on the breast, towards an embedded processing module (207) located in the lower part of the device. Once the housing of the processing unit is reached, the flat flexible cable will straighten again (205). The connector (201B) at the lower part of the flat flexible cable will be inserted into the processing unit in order to transmit the measurement signal from the flow sensor (2) to the processing unit (207).

The integration of the sensor module, the processing unit and the flat flexible cable in the brassiere is achieved by a manufacturing method comprising a two-step injection molding. The manufacturing method will ensure that the components are advantageously placed in the flexible bra.

Fig. 3 shows another exemplary arrangement, in which the sensor module (305) is constituted by a differential pressure module placed in the flow channel into which the restrictor (301) has been introduced. The sensor module comprises a first pressure sensor (305A) in a larger part of the flow channel near the inlet (3A), and a second pressure sensor (305B) in a smaller part of the flow channel near the outlet (3B). The differential pressure calculated from the measurements of the two sensors gives an indication of the milk flow in the channel via a connected circuit (not shown).

Fig. 4A shows another exemplary arrangement, in which the sensor module (405) is composed of one active element (405A) that is fixed in a stable position and oriented at a defined angle "θ" with respect to the flow channel and the breast milk flow. The active element is adjacent to the inlet (3A) of the flow channel and acts as a frequency source, for example a light beam which can be used to illuminate breast milk. The sensor module further comprises a detector co-located with the active element (405A) in this arrangement and configured to receive signals reflected by liquid moving in the channel. Based on the doppler effect, the velocity of the liquid is known to be proportional to the frequency shift, and with knowledge of the frequency of the emitted light and the detected light, the processing circuitry can then determine the actual velocity.

Fig. 4B shows another exemplary arrangement having the same functionality as fig. 4A, but in which the sensor module (405) is comprised of a separate frequency source (405A) and a detector (405B) fixed in a stable position, both disposed on opposite sides of the milk flow channel, at a defined angle 'θ' to the flow channel.

Fig. 5A shows another exemplary arrangement, in which the sensor module (505) is made up of four optically active elements (505A-D). The pair of elements on the same side of the flow channel may be, interchangeably, two optical emitters (505A, 505B) or two optical detectors (505C, 505D). Since the optical signal is transmitted by one emitter, the presence of particles, bubbles or other means in the liquid stream affects the optical signal received by the corresponding opposing detector. When the other pair of elements detects the same particle, the time-of-flight difference between the two pairs of elements will be measured, thereby providing a flow measurement.

Fig. 5B shows another exemplary arrangement instead of the arrangement shown in fig. 5A, wherein the sensor module (505) is composed of two active elements (505A, 505B). These elements may interchangeably be one of an ultrasound emitter or an ultrasound detector. When an ultrasonic wave is transmitted through one element, its incidence on the other element will be influenced by the velocity of the fluid in the channel, so that the flow between them can be measured. The downstream/upstream directions of these may be interchanged to measure the time-of-flight difference between the two, thereby providing flow measurements. Since the path arrangement of the elements is planar, the transmission of the signal depends on the reflection of the channel against the walls.

Fig. 5C shows an alternative to the exemplary arrangement shown in fig. 5B, in which the sensor module (505) is made up of two active elements (505A, 505B) fixed in a stable position and oriented at an angle 'θ' relative to the flow channel and milk, and arranged on opposite sides of the flow channel. This configuration provides a direct time-of-flight signal path through the liquid, and therefore does not require signal reflection.

Fig. 5D shows a front view of a channel having the same arrangement as fig. 5C, with a pair of active elements (505) fixed in diametrically opposite stable positions and oriented at an angle 'θ' with respect to the flow channel (4) and the flow of breast milk. The sensor is integrated in the silicone rubber of the nipple shield (1).

Fig. 5E shows a front view of a channel having the same arrangement as fig. 5C, with more (three) pairs of active elements (505) fixed in diametrically opposite stable positions and oriented at an angle 'θ' relative to the flow channel and milk. The sensor is integrated in the silicone rubber of the nipple shield (1) and can be used in this arrangement for flow tomography.

The introduction of a sensing element without a component that moves relative to the liquid will advantageously eliminate the effect of the sensor mass on the flow estimation. Indeed, when mounted perpendicular to the liquid flow, the thermal sensing unit will comprise a lightweight support, while the other sensing techniques described herein will be mounted in parallel, or at an angle 'θ' relative to the liquid, and fixed in a fixed position on the opposite side of the flow channel, making the measurement independent of gravity.

Fig. 6 shows a further exemplary arrangement, in which the sensor module (602) is formed by a component (605) in the form of a high-curvature wing profile which is mounted horizontally in the flow channel and is close to the inlet (3A) of the flow channel with respect to the flow direction of the milk. The member is anchored to the flow channel by a pivot (606) on its rear edge and is held in place in the flow channel by two flexible elements (607), one acting on the upper part of the element and one on the lower part of the element. Flow over the sensing element will cause deflection of the flexible element on which strain gauges are mounted, wherein the amount of deflection from a quiescent state is measured by a connected circuit (not shown) and is indicative of the flow rate. In another arrangement, the aerofoil member (605) may be placed vertically in the flow channel, anchored to its trailing edge by means of one flexible element on the top and one on the bottom, and the sensor is mounted thereon. This vertical configuration compensates for the shock that the device may be subjected to during operation.

Due to the sensitivity requirements for very low flow rates (ranging from higher μ l/s to lower ml/s), it is desirable for the measurement circuitry to use a sensing component whose characteristics do not interfere with the measurement signal. As will be apparent to those skilled in the art, this optimization of the measurement circuit may take various forms.

In all of the described embodiments, it should be understood that additional elements may also be added depending on the desired sensitivity of the sensor module.

Referring to fig. 1, signals from the sensing elements may be transmitted along wires in a bonded portion of a flexible material (not shown) and ejected from the sensor module at a location convenient for unit design. If the manufacturing method allows, all or some of the sensor components, support members, connected circuitry and flat flexible cables can be combined into a single unit, simplifying the device and its components. The sensor unit is required to allow only approved food grade materials to contact the milk flow channel. If other materials are desired, they may need to be encapsulated in a food grade material such as silicone or PTFE (e.g., materials sold under the brand name Teflon). Other substances of interest in infant feeding, such as bisphenol a, should also be excluded, regardless of their approved status.

In use, the shield will be located on the breast and the power/communication cable coupled to the processing unit (7). The operation of the sensing shield (1) and the processing unit (7) has been described in the previous invention (PCT/EP 2017/067445 on 7, 11, 2017) and is also applicable to the present invention.

1. The unit is powered on and the sensor reaches a baseline value within a certain preheating time. This would be a value where there is no liquid in the channel, which would be expected to be different from the zero flow value where breast milk is present due to temperature, convection, etc. For purposes of explanation, this value may be assumed to be 100.

2. The feeding phase begins and the first and subsequent pulses increase as milk flow is sensed in the channel. The output value will increase above the 0 value, for example to 1000. It will be appreciated that the output of the sensor meter will be a series of pulse values in response to the induced flow of breast milk from a nursing mother. Between each maximum pulse value, the sensed value does not fully return to the original value due to the time constant of the sensor or the residual flow between pulses. Thus, assume that these pulses have a peak-to-peak value of 900 and show the corresponding capacity.

3. The inability to deliver breast milk for a relatively long period of time is a characteristic of the breastfeeding stage. When the first is encountered, the output returns to a steady value of 200, indicating a zero flow value for the presence of breast milk. It is now clear that the initial pulse peak is at 800 instead of 900, so the recalculated volume can be calculated based on an algorithm implemented within the processing unit 7.

4. It will be appreciated that displaying the recalculated value immediately may result in a reduction in the capacity of the display, which appears to be erroneous and may be of concern. Thus, the unit 7 may delay providing a visual indication of the first measurement value until the additional data is processed. Other settings would include providing an indication of increased precision over time or a measurement lock type symbol on the display to provide the user with visibility as to the accuracy provided.

From the above, it will be appreciated that the present invention provides a breastfeeding milk flow measuring device that senses milk flow based on changes in the electrical characteristics of a flow sensor disposed within the flow channel of a flexible nipple shield. The device compares the sensed electrical characteristics of the sensor to calibration data to estimate the flow of breast milk through the channel and thus the amount of breast milk flowing to the feeding infant during any feeding session. In a preferred arrangement, the sensed electrical characteristic is dependent upon the thermal characteristic of the sensor-the sensor being operable to respond to the cooling effect caused by the passage of milk through the sensor.

Given the electrical assembly and mechanical tolerances of the component parts of the device, there can be some variation between the flow responses of the sensors, and to ensure the accuracy of the measurements, calibration protocols are required. In a preferred embodiment, the protocol is performed as part of the production process. It will be appreciated that the flexible nipple shield includes electrical components provided in a device that is fully molded or sealed within the flexible elastomer that defines the material of the shield. To provide for calibration of these components, they must be interfaced with without actually using a physical connection to load calibration values. From a process perspective, it is desirable not to customize each firmware image to be loaded into a device to a calibration value.

To solve these problems, the present invention provides a calibration procedure based on the provision of a complete electronic assembly comprising a sensor. This is typically in the form of a printed circuit board PCB, and an associated microcontroller MCU chip. During this stage, no housing or mold is assembled on the PCB of the MCU chip. The generic firmware image is loaded by an electronic test device with a physical (pin) connector. The image contains all the functions, including bluetooth wireless operation, bluetooth service programming with null "features" (bluetooth variants) for holding calibration values. The electronic assembly is then inserted into the device housing and mold and the device is manufactured. The complete device is connected to a calibration line and operated in accordance with the known flow pattern achieved by the flow channels of the device. The range of flow patterns to be achieved includes subtle variations in the amount of liquid in the breastfeeding flow rate range (0.007-2.8ml/s) and will perform in a few minutes. A computer connected to the calibration line converts the response to the flow pattern into calibration coefficients and loads these coefficients Over The Air (OTA) to the device via a bluetooth interface connected to the computer. These values are then set to read only by subsequent bluetooth commands. With this operation, only a generic firmware image is used and no physical connection to the device is required for calibration.

It will be appreciated that the nipple mount sensors described thus far, with associated electronic interfaces and interconnects, conveniently allow for measurement and display of breast milk flow and volume during breastfeeding. The sensors are mounted at the tip of the nipple shield to minimize intrusion between mother and baby. The size of the sensor and associated cables is such that the device appears not to be substantially different from a single nipple shield, thereby having minimal impact on the nursing session. The micro-liter flow is directly measured by a sensor, so that the accurate and real-time information of the breast milk volume is fed back to the nursing mother. The electronics unit amplifies the sensor input and digitally processes the data using software algorithms to determine the liquid volume. It should be appreciated that examples of such measuring devices that provide an indication of a real-time measurement of the flow of breast milk from a mother to her infant are provided to aid in understanding the present invention.

As described above, the sensor module of the present invention can preferably be integrally formed in the elastomeric nipple. The integration of the sensor module and associated processing components and connecting cables (such as the flat flex cable described above) in the nipple shield may be accomplished using injection molding techniques. A particularly advantageous mechanism is to use a two shot mechanism. The manufacturing method will ensure that all components are advantageously placed in the flexible nipple shield.

Fig. 11A and 11B show front and side views, respectively, of a first portion of a mold used in a manufacturing process to make an integrated breastfeeding device. The proposed manufacturing method comprises an injection molding process, the number of injection molding steps starting from two steps and depending on the type of component to be integrated in the shield. For the first step of injection molding, the sensor module (1101), the flat flexible cable (1102) and the processing unit (1103) are placed in a dedicated housing (1104) of a mold (1105), the shape and dimensions of the housing allowing to maintain the position of the assembly by clamping (or other fastening method).

The special housing (1104) will mold the flat flexible cable into the final configuration within the shroud, the flexible substrate of the cable allowing it to be easily bent into a mold without the need for pre-stretching. The housings may be sized to fit precisely to the geometry of the components or to leave a certain tolerance (i.e., free space) around them. In some cases, it is desirable to leave the housing of the flat flexible cable with micron-scale tolerances in order to allow a degree of freedom in the polymeric material of the shield and to avoid cable separation during handling and processing of the device.

During manufacture, to integrate all of the components into the shroud, the individual components may be assembled together to facilitate their incorporation into the mold, or they may be placed separately in the mold by clamping (or other fastening method).

To facilitate the active components being disposed in the shield, two or all of them or a single component may be encapsulated in a polymeric material, which may be (but is not limited to) the same as the shield. The individual components (or assemblies) of the package may then be integrated into the polymeric shroud by clamping (or other fastening method) in a first step of the injection molding process.

Fig. 12A and 12B show front and side views, respectively, of a second portion of a mold used in a manufacturing process to make an integrated breastfeeding device. Once the assembly (1101 and 1103 in FIGS. 11A-B) is placed in the first portion (1105 in FIGS. 11A-B) of the mold, the second portion (1106) of the mold is placed in the first portion (1105 in FIGS. 11A-B). The special housing (1102) will close the assembly (1101-1103 in fig. 11A-B) and the holes (1107) that coincide with the holes on the other side of the mold will close the two parts together by screws (or other fastening method).

Referring to fig. 13A, once the assembly (1101- & 1103) is clamped in the dedicated housing (1104), the first portion (1105) and the second portion (1106) of the mold are brought together through the aperture (1107) and then a first batch of polymeric material is injected into the mold. The polymer is then subjected to a first processing step in which the time and temperature/humidity/pressure conditions are determined by the rubber selected.

Once cured, the first mold is opened and the polymeric shroud/measurement unit assembly is separated from the mold used for the first injection step and placed in another mold for another injection step. In some cases the last step, the second injection step will ensure that the polymer uncovered components on the side that the mold contacts during the previous injection step can be completely encapsulated. The parts of the second mould, similar to those already described (1105, 1106), will conform to the shape of the assembly obtained by the previous injection step (or will be subject to some degree of tolerance).

Referring to fig. 13B, once the assembled shield is placed in the mold by clamping (or other fastening method), the mold is closed using screws (or other fastening method) through the mold holes (1107) and then the same polymer or other material as previously injected is injected. The polymer is then cured under appropriate curing time and temperature/humidity/pressure conditions. Once the material has cured, the mold is opened in its two parts (1105, 1106) and the integrated shield (1108) is ready for use.

In some cases, it may be desirable to create a hollow channel for insertion of a flat flexible cable. In this case the housing dedicated to accommodate the flexible cable in the first mould will be replaced by a filling channel, the shape and dimensions of which will correspond to those of the cable with a certain tolerance (in the order of μm). Said negative mould of the cable channel will allow the formation of a hollow channel after the polymer has cured. The shape of the hollow channel may be similar to the shape of a flat flexible cable or may simply be a straight cylinder.

Thus, for another solution for developing an electrical connection between the flow sensor and the processing unit, the hollow channel may be filled with a low noise conductive ink by an additional injection step.

Although details have been described, it will be understood that modifications may be made without departing from the scope of the invention.

When used in this specification, the terms "comprises" and "comprising" are intended to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.