Diaper sensing device

Abstract

The present invention relates to a sensing device for attachment to an exterior surface of a diaper, the sensing device comprising an expandable member comprised of one or more elastic members extending between a plurality of attachment points configured to fixedly attach the expandable member to the exterior surface of the diaper, the one or more elastic elements configured to stretch as the attachment points move apart such that the expandable member expands in accordance with expansion of the diaper, the sensing device further comprising a detector coupled to the expandable member configured to detect expansion of the expandable member and further configured to determine a diaper fullness parameter based on the expansion detected at the expandable member.

Description

[Technical field]

[0001] The present invention relates to a sensing device for attachment to the exterior surface of a diaper for determining fullness parameters of the diaper. The present invention also relates to a combined diaper-sensing device, wherein each sensing element of the sensing device is attachable to or may be integral with the exterior surface of the diaper.

[0002] Incontinence products, such as diapers, incontinence pads and underwear, allow the wearer to urinate and / or defecate without using a toilet. Incontinence products have an absorbent layer that contains urine or faeces and prevents leakage onto outer clothing. Incontinence products can be used by children (bedwetting) as well as adults, especially those with incontinence-related conditions. [Background technology]

[0003] When diapers or other incontinence products become soiled with urine or faeces, they usually need to be changed by another person (e.g., a caregiver). Because diaper wearers are often unable to change their own diapers, or even communicate that a diaper change is necessary, caregivers must manually check the diaper for soiling periodically throughout the day. This involves changing diapers, possibly unnecessarily, thereby wasting the caregiver's valuable time and associated costs. On the other hand, not changing diapers regularly enough can result in discomfort for the wearer, negative impacts on the wearer's dignity, and / or skin problems such as rashes, pressure sores, and infections.

[0004] Therefore, there is room for improvement in the process of sensing the fullness of a diaper or other incontinence product. Sensing the fullness of a diaper can also be useful for the baby.

[0005] According to a first aspect of the present invention, there is provided a sensing device for attachment to an outer surface of a diaper. The sensing device comprises an expandable member. The expandable member comprises one or more elastic members extending between a plurality of attachment points. The attachment points are configured to fixedly attach the expandable member to the outer surface of the diaper. Preferably, some or all of the attachment points are located at or near an edge of the diaper, such as an elasticated edge. The one or more elastic elements are configured to stretch as the attachment points move apart, thereby causing the expandable member to expand in accordance with diaper inflation (i.e., as the diaper fills). The sensing device further comprises a detector coupled to the expandable member. The detector is configured to detect an expansion of the expandable member. The detector is further configured to determine a diaper fullness parameter based on the expansion detected at the expandable member.

[0006] According to a second aspect of the present invention, there is provided a diaper-sensing device combination comprising a diaper and the sensing device described above. The sensing device further comprises an electronic control and power unit configured to provide power to the sensing device described above. The electronic control and power unit preferably comprises the detection unit described above. The attachment point of the expandable member is fixedly attached to an outer surface of the diaper. Summary of the Invention

[0007] In some examples, the sensing device is attached to the exterior surface of the diaper after manufacture. In other examples, the expandable member of the sensing device is integrated into (i.e., created on) the exterior surface of the diaper during manufacture. The detector may then be attached to the expandable member, for example via a loop.

[0008] The present invention also has other advantageous aspects, which are described in the detailed description that follows. [Brief description of the drawings]

[0009] In order that the present invention may be more readily understood, reference will now be made, by way of example only, to the accompanying drawings, in which: [Figure 1] FIG. 2 is a plan view of an exemplary sensing device attached to the exterior surface of a diaper. [Diagram 2] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Diagram 3] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Figure 4] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Diagram 5] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Figure 6] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Figure 7] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Figure 8] 1A-1C are plan views of alternative configurations of an exemplary sensing device mounted on the exterior surface of a diaper. [Figure 9a] 9a is a cross-sectional view of an exemplary photodetector for use with the sensing device of any of Figures 1 to 8. In Figure 9a, the expandable member of the sensing device is in an unexpanded state. [Figure 9b] FIG. 9b is a plan view of the arrangement of FIG. 9a. [Figure 9c] FIG. 9c is a cross-sectional view of the exemplary photodetector of FIGS. 9a-9b when the expandable member of the sensing device is in an expanded state. [Figure 9d] FIG. 9c is a plan view of the arrangement of FIG. 9c. [Figure 10] FIG. 9 is a plan view of an exemplary alternative photodetector for use with the sensing device of any of Figures 1-8. The photodetector comprises a plurality of links. [Figure 11a] 11a-11c are cross-sectional views of an exemplary alternative photodetector for use with the sensing device of any of Figures 1-8. In Figure 11a, the expandable member of the sensing device is in an unexpanded state. [Figure 11b]FIG. 11b is a cross-sectional view of the exemplary photodetector of FIG. 11a when the expandable member of the sensing device is in an expanded state. [Figure 12] FIG. 9 is a plan view of an alternative photodetector for use with the sensing device of any of FIGS. 1-8. [Figure 13] FIG. 9 is a plan view of a number of exemplary photodetectors for use with the sensing devices of any of FIGS. 1-8. [Figure 14] FIG. 2 is a plan view of an exemplary alternative sensing device attached to the exterior surface of a diaper, the sensing device comprising three sensor elements. [Figure 15] 15 is a partial plan view of the arrangement of FIG. 14, showing additional features of the exemplary sensing device of FIG. 14. [Figure 16] FIG. 1 is a plan view of an exemplary alternative sensing device attached to the exterior surface of a diaper. [Figure 17] FIG. 1 is a plan view of an exemplary alternative sensing device attached to the exterior surface of a diaper. [Figure 18] Figure 16 is a schematic diagram of a Wheatstone bridge used with the representative sensing device to measure resistance. [Figure 19] FIG. 18 is a circuit diagram of a capacitance bridge that measures capacitance and can be used with the exemplary sensing device of FIG. [Figure 20] FIG. 1 is a perspective view of an exemplary electronic control and power supply section that provides power to any exemplary sensing device. [Figure 21] 1 is a representative graph of volume versus time data for determining diaper fullness parameters. [Figure 22] FIG. 2 is a plan view of an exemplary integrated sensor configuration of a sensing device on the exterior of a diaper. [Figure 23a] FIG. 1 is a circuit diagram of a gyroscope that measures motion and can be used with any representative sensing device. [Figure 23b] FIG. 1 is a circuit diagram of an accelerometer that measures motion and can be used with any representative sensing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Described herein are sensing devices suitable for attachment to an outer surface of a diaper. The sensing devices each comprise an expandable member. The expandable member comprises one or more elastic elements extending between a plurality of attachment points. Each attachment point is configured to fixedly attach the expandable member to the outer surface of the diaper. Preferably, some or all of the attachment points are located at or near an edge of the diaper, such as an elasticated edge. The one or more elastic elements are configured to stretch as the attachment points move apart, thereby configuring the expandable member to expand in accordance with (volumetric) expansion of the diaper. The sensing device further comprises a detector coupled to the expandable member. The detector is configured to detect expansion of the expandable member. The detector is further configured to determine a diaper fullness parameter based on the expansion detected at the expandable member. The detector may comprise a gyroscope or an accelerometer configured to detect movement. For example, the gyroscope or accelerometer may detect movement of a diaper wearer during use of the diaper.

[0011] Also described herein is a diaper-sensing device combination comprising a diaper and a sensing device as described above. The sensing device further comprises an electronic control and power unit configured to provide power to the sensing device. The electronic control and power unit preferably comprises a detection unit as described above. Each attachment point of the expandable member is fixedly attached to the outer surface of the diaper. In some examples, the sensing device is attached to the outer surface of the diaper after the diaper is manufactured. In other examples, the expandable member of the sensing device is integrated into (i.e., created on) the outer surface of the diaper during manufacture. The detection unit may then be attached to the expandable member, for example via a loop.

[0012] A nappy may also be referred to herein as a diaper. A diaper may be sized to be worn by an adult, a child, or an infant, and may have any suitable design and absorbency. As mentioned above, the sensing device may be manufactured separately from the diaper, and therefore may be applied to any type of diaper or other incontinence product. The sensing device is attached to the outer surface of the diaper after the diaper is manufactured. Alternatively, the expandable member of the sensing device may be integrated (i.e., created on) the outer surface of the diaper during the diaper manufacturing process, and the detection portion may be attached at a later time. These are in contrast to conventional diaper wetness / fullness sensing technologies, in which active sensing elements (such as electrical and chemical elements) are separately manufactured and incorporated into the interior of the diaper, and the active sensing elements are in physical contact with the urine-absorbing layer of the diaper, which is complex and expensive.

[0013] An example of a sensing device attached to a diaper is shown in Figure 1. Figure 1 shows a plan view of a diaper 1600 prior to wear, having an exterior surface 1590. The diaper 1600 includes a front portion 1530 connected to a waistband portion 31. The front portion 1530 of the diaper 1600 is connected to a rear portion 1570 of the diaper 1600 by a crotch region 1540. When the diaper 1600 is worn, the front portion 1530 of the diaper 1600 is positioned against the wearer's pubic region and abdomen, the rear portion 1570 of the diaper 1600 is positioned against the wearer's buttocks, and the crotch region 1540 of the diaper 1600 is positioned over the wearer's crotch and between the legs. The diaper 1600 has elasticated edges 1560 that extend around the tops of the wearer's legs. The elasticated edges 1560 allow the diaper to stretch so that it is comfortable to wear and conforms to the wearer's body contours, preventing liquids from leaking out of the diaper 1600. The outer surface 1590 of the diaper 1600 is typically made of a non-elastic material. In this case, the diaper 1600 is nevertheless able to expand, thanks to the elasticated edges 1560 and because the outer surface 1590 is configured to be relatively loose when the wearer first puts on the diaper 1600 (i.e., when the diaper is not containing feces / urine). Creases in the diaper material (as described below) also aid in expansion.

[0014] 1 also shows a sensing device attached to the diaper 1600. The sensing device comprises an expandable member 1602 coupled to a detector 5. The expandable member 1602 comprises an elastic element 1604 extending between a plurality of attachment points 45, 1510. Each attachment point is configured to fixedly attach the expandable member 1602 to an exterior surface of the diaper 1600.

[0015] The sensing device may be attached to the diaper through the attachment points after the diaper is manufactured, in which case it is removable and reusable. Alternatively, the expandable member may be integrated (i.e., created on) the outer surface of the diaper during manufacture. In this case, the expandable member is created on top of the diaper's outer material as an integral part of the diaper during the diaper manufacturing process. This may be accomplished in a variety of ways. For example, it is well known that some diapers include a top layer of non-stretchable material that is placed on top of and adhered to a bottom layer material of a stretchable polymer (e.g., rubber-like). During the diaper manufacturing process, the two layers may be crimped in selected areas to create a stretchable, wearable diaper. For example, the crimped portion of the diaper will stretch when worn. If the diaper does not include a stretchable bottom layer, the composition of the top material may be modified to make it elastic (the entire top material may be elastic or only selected areas may be elastic). During the manufacturing process of the diaper, the expandable members may be fabricated (e.g., integrated) into these fold regions on the outer surface of the diaper. The fold regions are preferably fabricated in the machine direction of the manufacturing process. An example of an integrated sensor configuration is shown in FIG. 22. As the fold regions 318 stretch as the diaper expands, the central element 402 is pulled. The zigzag solid lines represent a top layer of non-stretchable material. The zigzag dashed lines represent an underlying material of stretchable polymer. The central element 402 may be integrated into (i.e., fabricated on) the outer surface of the diaper. Pulling on the central element 402 exerts a pulling force on the sensing element 5, which changes the detection signal generated by the sensing element 5. This expansion measurement is described in more detail below.

[0016] If the outer surface of the diaper 1600 is made of a non-elastic material (as is generally the case), it is important that at least a portion of each attachment point is located at or near an edge of the diaper 1600 (e.g., elasticated edge 1560) so that expansion of the diaper can be detected. In this regard, it will be understood that FIG. 1 is only a schematic diagram, and that the corner attachment points 1510 may actually be located very close to the lateral (elasticated) edge 1560 of the diaper. Alternatively, there may be additional attachment points connecting the elastic elements 1604 to the elasticated edge 1560 of the diaper 1600. However, if an expandable member is created on the outer surface of the diaper during the manufacturing process, it is not necessary that each attachment point be located at or near the edge of the diaper. This is because the creased areas of the diaper will naturally expand as the volume of the diaper increases (e.g., as the diaper fills with urine and feces). Thus, it is not necessary to utilize elasticated edges of the diaper. The detector 5 is attached to the waistband portion 31 of the diaper 1600. Alternatively, the detector 5 may be attached to any other suitable portion of the outer surface 1590 of the diaper 1600 near the waistband portion 31, such as the front portion 1530 of the diaper 1600. The detector 5 is coupled to the expandable member 1602. For example, in FIG. 1, each attachment point includes a detector attachment point 45 directly coupled to the detector 5. The detector attachment point 45 is located in the center of the front portion 1530 of the diaper 1600, immediately below or at the waistband portion 31 of the diaper 1600. The detector 5 is configured to detect the expansion of the expandable member 1602 as the diaper 1600 expands. The detector 5 may comprise an optical detector, a resistive detector, a capacitive detector, or other detector suitable for sensing the expansion of the expandable member 1602. There may also be additional electronics for data storage and internal communication of the detection unit 5, such as a gyroscope or accelerometer configured to detect the movement of the diaper wearer when the diaper is in use.

[0017] The elastic element 1604 of the expandable member 1602 is an elastic patch in FIG. 1. The attachment points include respective attachment points 1510 at the corners of the elastic patch. Thus, the expandable member 1602 in FIG. 1 includes only one elastic element 1604 in the form of a rectangular elastic patch that extends between the attachment points 45, 1510 and is centrally located over a substantial area of ​​the front 1530, crotch region 1540, and rear 1570 of the diaper 1600. Two of the attachment points 1510 are located at the first two corners of the elastic patch at the front 1530 of the diaper 1600, equidistant from the waistband portion 31. Two more attachment points 1510 are located at the remaining two corners of the elastic patch at the rear 1570 of the diaper 1600. There may be additional attachment points connecting the elastic patch 1604 to the elastic edge 1560 of the diaper. The elastic patch can expand according to the volume expansion of the diaper 1600 when urine or feces infiltrates inside the diaper 1600. In Fig. 1, the elastic patch is rectangular. Of course, the elastic patch can be any suitable shape, such as square, circular, or oval. The attachment points 1510 may be located at the corners or around the edges / periphery of the elastic patch.

[0018] The expandable member 1602 is sized and shaped to cover a substantial area of ​​the exterior surface 1590 of the diaper 1600 of FIG. 1. In some examples, the expandable member may cover a substantial portion of each of the front of the diaper, the back of the diaper, the crotch region of the diaper, the elasticated edge of the diaper, or a combination thereof. For example, in FIG. 1, the expandable member 1602 covers a substantial portion of the front 1530 of the diaper 1600, a substantial portion of the crotch region 1540 of the diaper 1600, and a substantial portion of the back 1570 of the diaper 1600. In other examples, the expandable member 1602 may be sized and shaped to extend across the entire width of the crotch region 1540 of the diaper 1600 (see FIG. 7 for an example).

[0019] The attachment points 45, 1510 are configured to fixedly attach the expandable member 1602 to the exterior surface 1590 of the diaper 1600. For example, the attachment points 45, 1510 may be fixedly attached using an attachment mechanism such as adhesives, sticky substances, ultrasonic bonds, hook-and-loop pads, poppers, magnets, stitching, riveting, welding, or any other suitable attachment mechanism. As mentioned above, the fastening may occur during or after the manufacture of the diaper. The attachment points 45, 1510 of the expandable member 1602 may be fixedly attached to the front 1530 of the diaper 1600, the back 1570 of the diaper 1600, the crotch region 1540 of the diaper 1600, the elasticated edge 1560 of the diaper 1600, or a combination thereof.

[0020] As the diaper 1600 expands, the attachment points 45, 1510 move further apart, creating a pulling force on the detector attachment point 45 in a direction away from the detector 5, as will be described in more detail below. The elastic element 1604 is configured to stretch as the attachment points 45, 1510 move apart, thereby allowing the elastic element 1604 to expand with the expansion of the diaper 1600. In other words, the elastic element 1604 is free to change length and width with the expansion of the diaper 1600 as the diaper 1600 fills with urine and feces. To facilitate stretching, the elastic element 1604 may be made of an elastomeric material, for example an elastomeric material with a low Young's modulus and high breaking strain. The material properties of the elastomer are selected to function in accordance with the diaper material. For example, the elastomeric material closely follows the expansion properties of the diaper material, especially at the elastic edge 1560 of the diaper 1600. The elastic element 1604 may be made from a conductive or non-conductive polymer. A conductive elastomeric material is particularly useful when the sensing device is configured to detect a change in resistance or capacitance as the material expands with the diaper 1600 upon ingress of urine or feces into the diaper 1600 (see examples below in connection with Figures 16 and 17).

[0021] During use, the sensing device is configured to determine a diaper fullness parameter based on the expansion detected at the expandable member 1602. As the diaper 1600 fills with urine and feces, it begins to expand. As the diaper 1600 expands, the attachment points 45, 1510 move away from each other, causing a relative displacement between the attachment points 45, 1510. This in turn causes the elastic element 1604 to stretch. The detection unit 5 is configured to detect the expansion of the expandable member 1602 by (indirectly) detecting the relative displacement between the attachment points 45, 1510. For example, as the diaper 1600 expands and the attachment points 45, 1510 move away from each other, causing a relative displacement between the attachment points 45, 1510. As the elastic element 1604 stretches, a pulling force is applied to the detection unit 5 via the detection unit attachment point 45, which results in a change in the detection signal generated by the detection unit 5. In other words, the detection unit 5 detects the pulling of the detection unit 5 as the diaper 1600 expands. The change in the detection signal is proportional to the overall volumetric expansion of the diaper 1600 due to the ingress of urine and feces into the diaper 1600. As described in more detail below with reference to Figures 9-17, the detection unit 5 generates an output signal, either an analog or digital electrical signal, that represents the displacement and thus the expansion of the diaper. The detected expansion of the expandable member 1602 is proportional to the overall expansion of the diaper that occurs as urine and feces enter the diaper 1600. Thus, the detection unit 5 responds indirectly to the change in displacement between the attachment points 45, 1510 on the outer surface 1590 of the diaper 1600. This is in contrast to conventional approaches that use a moisture sensor inside the diaper to sense the wetness / wetness of the diaper or a pressure sensor to sense the increase in radial pressure between the wearer and the diaper to determine the fullness of the diaper. The sensing portion 5 may detect displacement using any displacement or strain detector technology, but preferred examples described below include optical detectors, capacitive detectors, and / or resistive detectors.

[0022] FIG. 2 shows an alternative configuration of the expandable member 1602 of the sensing device attached to the outer surface 1590 of the diaper 1600. In this configuration, each attachment point includes a first attachment point 4080 connected to the detector attachment point 45 via a longitudinal elastic element 4010. For example, the detector attachment point 45 is located next to the detector 5 as in FIG. 1. The first attachment point 4080 is located in the center of the rear 1570 of the diaper 1600. The longitudinal elastic element 4010 can be a central elastic string or thread attached to the diaper 1600 at the first attachment point 4080 and the detector attachment point 45. The remaining length of the longitudinal elastic element 4010 is free to expand. Each attachment point also includes one or more second attachment points 4005 connected to the longitudinal elastic element 4010 via one or more lateral elastic elements 4015, 4030, 4060. The second attachment point 4005 is located near the lateral (elastic) edge 1560 of the diaper 1600. In Fig. 2, the lateral elastic elements 4015, 4030, 4060 are arranged such that there is one 4015 at the front 1530 of the diaper 1600, one 4030 at the crotch region 1540 of the diaper 1600, and one 4060 at the rear 1570 of the diaper 1600. The lateral elastic elements 4015, 4030, 4060 extend towards the elastic edge 1560 of the diaper 1600 so as to be able to sense the expansion of the diaper at the elastic edge 1560 of the diaper 1600. The lateral elastic elements 4015, 4030, 4060 may also be elastic strings or threads, which are free to expand between the respective attachment points 4005 at their ends. As the diaper expands, the transverse elastic elements 4015, 4030, 4060 exert additional force on the longitudinal elastic elements 4010 and thereby on the detection unit 5. Advantageously, these transverse elastic elements 4015, 4030, 4060 allow a more accurate measurement of the expansion of the diaper 1600 since the expandable member 1602 covers more of the outer surface 1590 of the diaper 1600. The elastic elements 4010, 4015, 4030, 4060 extend in two different directions (horizontal and vertical in FIG. 2). Thus, the relative displacement of the attachment points 45, 4080, 4005 can be more accurately detected and the volumetric expansion of the diaper 1600 can be more accurately determined.In one example, the lateral elastic elements 4030 may extend all the way to the elasticated edges 1560 of the diaper 1600. In this case, the expansion of the lateral elastic elements 4030 follows the expansion of the elasticated edges 1560, thereby helping to account for the wearer's body movements. Figure 2 relates to an example where the sensing device is attached to the outer surface of the diaper after the diaper is manufactured, and an example where the expandable member of the sensing device is integrated into the outer surface of the diaper during manufacture.

[0023] 3 shows an alternative configuration of the expandable member 1602 of the sensing device. In this configuration, there is a central junction 4045 connected to the detector attachment point 45 via a central elastic element 4010. The central junction 4045 (shown as a shaded circle in FIG. 3) is not fixedly attached to the exterior surface 1590 of the diaper 1600 and is therefore free to move as the diaper 1600 expands. In FIG. 3, the central junction 4045 is located above the center of the front 1530 of the diaper 1600 and the central elastic element 4010 extends across the center of the front 1530 of the diaper 1600 between the central junction 4045 and the detector attachment point 45. Each attachment point also includes multiple attachment points 4070, 4080 spaced around the central junction 4045, with each multiple attachment point 4070, 4080 connected to the central junction 4045 via a radial elastic element 4025. In FIG. 3, the multiple attachment points 4070, 4080 are primarily located in the crotch region 1540 of the diaper 1600, close to the elastic edge 1560 of the diaper 1600. Also, some of the multiple attachment points 4070, 4080 are located in the rear 1570 of the diaper 1600, close to the elastic edge 1560 of the diaper 1600. The spacing between the attachment points 4070, 4080 aids in detecting inflation, as each radial elastic element 4025 increases the force experienced by the central elastic element 4010, and thus the detection unit 5. The elastic elements 4010, 4025 are free to expand between the attachment points 45, 4080, 4070. The expandable member 1602 may also include another elastic element connected between multiple attachment points 4070, 4080. For example, in Fig. 3, another lateral elastic element 4075 is connected between each attachment point 4070 at the rear 1570 of the diaper 1600, close to the elastic edge 1560 of the diaper 1600. Fig. 3 relates to an example where the sensing device is attached to the outer surface of the diaper after the diaper is manufactured, and an example where the expandable member of the sensing device is integrated into the outer surface of the diaper during manufacture.

[0024] 4-6 show other alternative configurations of the expandable member of the sensing device. In these configurations, each elastic element of the expandable member comprises multiple elastic elements arranged in a polygon with attachment points at one or more corners of the polygon. For example, in FIG. 4, multiple elastic elements 3050 are arranged in a diamond shape with two attachment points 3070 at two corners of the diamond. These two attachment points 3070 are located in the crotch region 1540, one near the left elastic edge 1560 and the other near the right elastic edge, and are fixedly attached to the outer surface 1590 of the diaper 1600. There are also two junction points 3111 (shown as hatched circles in FIG. 4) connected to the expandable element 3050 at the other two corners of the diamond. The two junction points 3111 are not attached to the outer surface 1590 of the diaper 1600 and are therefore free to move as the diaper 1600 expands. One of the two junctions 3111 is a front junction located above the center of the front 1530 of the diaper 1600, and the other is a rear junction located above the center of the rear 1570 of the diaper 1600. This diamond shape is mainly located in the center of the crotch region 1540 of the diaper 1600 and extends partially across the front 1530 and rear 1570 of the diaper 1600. There is also a longitudinal elastic element 3090 located in the center of the diaper 1600 (similar to the longitudinal elastic element 4010 in FIG. 2). The longitudinal elastic element 3090 is attached to the diaper 1600 between the rear attachment point 3040 located in the center of the rear 1570 of the diaper 1600 and the detector attachment point 45 located in the center of the front 1530 of the diaper 1600 and next to the detector 5. The rear attachment point 3040 and the detector attachment point 45 are both fixedly attached to the outer surface 1590 of the diaper 1600. The longitudinal elastic element 3090 is also connected to the front and rear junction 3111. There may also be additional elastic elements 3020 connected to the longitudinal elastic elements 3090 and attached to the outer surface 1590 of the diaper 1600 at each attachment point 3010. For example, in FIG. 4, the additional elastic elements 3020 are attached to the outer surface 1590 of the diaper 1600 at each attachment point 3010 on the front 1530 of the diaper 1600 near the elastic edge 1560 so as to be orthogonal across the longitudinal elastic elements 3090.

[0025] As shown in FIG. 5, there is again a longitudinal central elastic element 3090 attached to the diaper 1600 between the detector attachment point 45 and the rear attachment point 3040. The rear attachment point 3040 is located in the center of the rear 1570 of the diaper 1600, as in FIG. 4. The central elastic element 3090 is also connected to at least one of the multiple elastic elements 3050 arranged in a polygonal configuration. In FIG. 5, the multiple elastic elements 3050 are arranged in a rectangle with an attachment point 3070 at each corner of the rectangle. In this configuration, each of the attachment points 3070, 3040, 45 is fixedly attached to the exterior surface 1590 of the diaper 1600 near the edge of the diaper 1600. The rectangle is located in a location generally similar to the elastic patch 1604 of FIG. 1. Specifically, the rectangle has a first transverse elastic element disposed across the front 1530 of the diaper 1600 and generally parallel to the waistband of the diaper 1600. There are two longitudinal elastic elements that extend generally perpendicularly from the first transverse elastic element across the crotch region 1540 of the diaper 1600 to the rear 1570. There is also a second transverse elastic element across the rear 1570 of the diaper 1600 and generally parallel to the first transverse element. Any suitable polygonal configuration may be used, such as a square, pentagon, hexagon, etc.

[0026] FIG. 6 shows the same configuration of the expandable member 1602 as FIG. 5, except that in FIG. 6, the expandable member 1602 further includes a plurality of lateral elastic elements 3005 extending between two longitudinal elastic elements. Additionally, the lateral elastic elements are concentrated within a polygonal designated area 515. For example, in FIG. 6, the designated area 515 is a substantial portion of the crotch region 1540 and a substantial portion of the rear portion 1570 of the diaper 1600. The lateral elastic elements 3005 are concentrated in this area 515 to enhance sensitivity in detecting expansion of the diaper 1600. When urine (e.g., 50-100 ml) first enters the diaper 1600, expansion of the diaper 1600 first occurs in this area 515. However, the expansion may be very small. The lateral elastic elements 3005 allow for a more accurate capture of the expansion force in this area 515. Alternatively, as shown in FIG. 1, each elastic element may comprise an elastic patch which serves a similar purpose.

[0027] 7 shows another alternative configuration of the expandable member 1602 of the sensing device. In this configuration, the elastic element is made of an elastic net 5480 with the attachment points 5160 at the periphery of the elastic net 5480. The attachment points also include a detector attachment point 45 (similar to the detector attachment point 45 described above) located in the center of the front 1530 of the diaper 1600 and adjacent to the detector 5 (attached to the waistband of the diaper 1600). Each elastic element also includes a longitudinal elastic element 4010 located in the center of the front 1530 of the diaper 1600. The longitudinal elastic element 4010 extends between a front junction point 5050 located above the center of the front 1530 of the diaper 1600 and the detector attachment point 45. The front junction 5050 (shown as a hatched circle in FIG. 7) is not attached to the outer surface 1590 of the diaper 1600 and is therefore free to move as the diaper 1600 expands. The detector attachment point 45 is fixedly attached to the outer surface 1590 of the diaper 1600. The elastic net 5480 is connected to the central longitudinal elastic element 4010 at the front junction 5050. The elastic net 5480 is also attached to a rear junction 5055 located above the center of the rear 1570 of the diaper 1600. The rear junction 5055 (shown as a hatched circle in FIG. 7) is not attached to the outer surface 1590 of the diaper 1600 and is therefore free to move as the diaper 1600 expands. From the rear junction 5055, a short elastic element 4015 extends to another attachment point 5060 located further up at the rear 1570 of the diaper 1600. The attachment point 5060 is fixedly attached to the outer surface 1590 of the diaper 1600. The peripheral attachment points 5160 of the elastic net 5480 are located along the elastic edge 1560 of the diaper 1600, i.e., the attachment points 5160 are located at the two curved edges of the crotch region 1540 where the diaper 1600 fits snugly around the legs of the wearer. The attachment points 5160 are fixedly attached to the outer surface 1590 of the diaper 1600. Between the attachment points 5160 and the junctions 5050, 5055, the elastic net 5480 is free to stretch. The elastic net 5480 may cover a substantial portion of the crotch region 1540 of the diaper 1600 .For example, the elastic net 5480 may be sized and configured to extend across the entire width of the crotch region 1540 of the diaper 1600, as shown in Figure 7. In the alternative, the elastic net 5480 may also cover a significant portion of the surface of the front 1530 and back 1570 of the diaper 1600. Advantageously, the use of the elastic net 5480 allows for greater forces (from the expanding diaper 1600) to be captured and transferred to the central elastic element 4010, as detected by the detection unit.

[0028] FIG. 8 shows another alternative configuration of the expandable member 1602 of the sensing device. In this configuration, the attachment points 580 are connected via one or more elastic elements 590 to form a serpentine pattern, with each attachment point 580 located at each turn of the serpentine pattern. The detector 5 is attached to the waistband portion of the diaper 1600. The attachment points include a detector attachment point 45 located in the center of the front of the diaper 1600 next to the detector 5. The other attachment points 580 consist of six front attachment points arranged generally linearly and laterally across the front of the diaper 1600 and five rear attachment points arranged generally linearly and laterally across the rear of the diaper 1600. The six front attachment points are fixedly attached to the front outer surface of the diaper 1600 near the front top edge of the diaper (i.e., near the waistband). The five rear attachment points are fixedly attached to the rear exterior surface of the diaper 1600 near the rear top edge of the diaper (i.e., near the rear waistband). One of the elastic elements 590 extends downward from the central detector attachment point 45 laterally across the front of the diaper 1600 to the two front exterior attachment points 580. The remaining elastic elements 590 extend generally longitudinally (lengthwise) in a serpentine pattern above the exterior surface of the diaper 1600. Specifically, two separate elastic elements 590 extend longitudinally (lengthwise) from each of the two front exterior attachment points 580, down the front, crotch region and up the rear of the diaper 1600 to the two rear exterior attachment points 580. The elastic elements 590 then connect to the remaining attachment points 580 in a serpentine pattern between the front and rear attachment points, with an attachment point at each turn. Each elastic element 590 is free to stretch between each attachment point 580, 45 as the diaper 1600 expands. Each elastic element 590 is thinner than the elastic elements of Figures 1-7 so that it can snake more easily. For example, in Figure 8, each elastic element 590 may be made from a thin string, thread, or wire of elastic material. Figures 4-8 relate to examples in which the sensing device is attached to the outer surface of the diaper after the diaper is manufactured, and examples in which the expandable member of the sensing device is integrated into the outer surface of the diaper during manufacture.

[0029] During use, in all of the above configurations, the detector 5 may be configured to detect the expansion of the expandable member 1602 by sensing a relative displacement between the detector attachment point 45 and at least one other attachment point. For example (see FIG. 2), as the diaper 1600 expands, the attachment point 4080 may move away from the detector attachment point 45, causing a relative displacement between the attachment points 45, 4080. The relative displacement between the detector attachment point 45 and at least one other attachment point 4080 causes the expandable member 1602 to pull the detector attachment point 45 away from the detector 5. This creates a proportional pulling force on the detector 5, resulting in a change in the detection signal at the detector 5. In other words, the detector detects the pulling of the detector caused by the expansion of the diaper. The change in the detection signal is proportional to the volumetric expansion of the entire diaper 1600 due to the ingress of urine or feces into the diaper 1600. Various examples for detecting the expansion of the expandable member 1602 will now be described.

[0030] <Photodetector> Figures 9a-9d show examples of a detector 2 comprising a photodetector for use with any of the sensing devices described above. Figures 9a and 9b respectively show a front cross-sectional view and a plan view of the detector 2 disposed on a diaper 1 in an uninflated state, where the diaper 1 is worn on the body but not in use, i.e., there is no urine or feces in the diaper 1, and so there is no additional stretch in the diaper 1 (except for the stretch required to fit the diaper to the wearer, e.g., the stretch of the elasticated edges around the tops of the wearer's legs and the stretch of the elasticated waistband). The diaper 1 is equivalent to the diaper 1600 described above with respect to Figures 1-8.

[0031] The detector 2 comprises a housing 10, a light source 6, a photodetector 140, a first tube 70, a second tube 100, an optical fiber 50, and a link 56 to a detector attachment point 45 on an expandable member (e.g., expandable member 1602 as in Figs. 1-8 above). For simplicity, the expandable member is not shown in Figs. 9a-9d, except for the detector attachment point 45. The light source 6 may be a light emitting diode (LED). The photodetector 140 may be a light sensor. The housing 10 is attached to the diaper 1. For example, the housing 10 may be attached to a waistband of the diaper 1.

[0032] The housing 10 is a two-part housing, the two parts of the housing 10 being separated by an opening 34. The housing 10 has two ends, one at the distal end of the first part of the housing 10 and the other at the distal end of the second part of the housing 10. The light source 6 is mounted at one end of the housing 10 and the photodetector 140 is mounted at the other end of the housing 10 opposite the light source 6. The first tube 70 and the second tube 100 are coaxially mounted within the housing 10 along respective portions of the path between the light source 6 and the photodetector 140. Thus, the first tube 70 is disposed within the first part of the housing 10 and the light source 6 is disposed at a first end of the first tube 70. The second tube 100 is disposed within the second part of the housing 10 and the photodetector 140 is disposed at a second end of the second tube 100. The two parts of the housing 10, as well as the first tube 70 and the second tube 100, are spaced apart (e.g., by up to 4 cm) by the opening 34. Similarly, the first tube 70 and the second tube 100 are spaced apart across the opening 34 .

[0033] The optical fiber 50 extends through the first tube 70 and the second tube 100. A first end of the optical fiber 50 is disposed adjacent to the light source 6 and fixed in front of the light source 6. A second end of the optical fiber 50 is disposed near the light detector 140 but is not fixed in position. There is a gap 120 between the second end of the optical fiber 50 and the light detector 140. At least a central portion of the optical fiber 50 is exposed at the opening 34 between the tubes 70, 100 (i.e., the central portion of the optical fiber 50 is not contained within either of the tubes 70, 100 or within the housing 10). The inner diameter of the tubes 70, 100 is preferably slightly larger than the outer diameter of the optical fiber 50 so that movement of the optical fiber 50 within the tubes 70, 100 is somewhat limited and the majority of the optical fiber 50 remains in the same position during use.

[0034] As previously mentioned, the detector attachment point 45 forms part of the expandable member, the remainder of which is not shown in Figures 9a-9d. The detector attachment point 45 is used to connect the expandable member to the detector 2. Specifically, an inelastic link 56 extends between the detector attachment point 45 and the exposed portion of the optical fiber 50.

[0035] In use, the detector 2 is powered by an electronic control and power unit (not shown), which may be an internal or external power source, such as a battery. When the detector 2 is powered, light from the light source 6 passes through the optical fiber 50 and the gap 120 to the photodetector 140. The photodetector 140 is configured to generate an output signal corresponding to the amount of light received from the light source 6. When the diaper 1 is worn and in an uninflated state (i.e., no urine or feces in the diaper 1, as in Figures 9a and 9b), the expandable members and links 56 are only minimally taut, and the photodetector 140 generates an output signal corresponding to the uninflated state of the diaper 1. In this uninflated state, the gap 120 has a length d1.

[0036] 9c and 9d show a front cross-sectional view and a plan view of the detector 2 and the diaper 1 in an expanded state as the diaper 1 fills with urine and feces and begins to expand (i.e., the volume of the diaper 1 expands). This causes the expandable member attached to the outer surface of the diaper 1 to expand. As previously mentioned, the expandable member is not shown in FIGS. 9a-9d, except for the detector attachment point 45. This expansion is measured by the detector 2. The detector 2 is configured such that the amount of light reaching the photodetector 140 from the light source 6 varies in response to the relative displacement between the detector attachment point 45 and at least one other attachment point (e.g., the relative displacement between attachment point 4080 and the detector attachment point 45 in FIG. 2), thereby causing a change in the output signal from the photodetector 140. In other words, as the diaper 1 expands, the attachment points of the expandable member are displaced from one another, stretching the elastic elements of the expandable member (e.g., the longitudinal elastic element 4010 in FIG. 2). This in turn pulls on the detector attachment point 45 and the link 56. The link 56 pulls the exposed central portion of the optical fiber 50 towards the detector attachment point 45, i.e., away from the housing 10 of the detector 2, such that the optical fiber 50 flexes. The optical fiber 50 is constrained from moving only when a force is applied to the optical fiber 50 by the expandable member. The flexing of the optical fiber 50 is most clearly seen in FIG. 9d, and results in a change in the gap 120 between the second end of the optical fiber 50 and the photodetector 140. Because the second end of the optical fiber 50 is not fixed in position, it is free to move longitudinally through the second tube 100, thereby changing the gap 120. The gap 120 increases from d1 (in the unexpanded state of FIGS. 9a and 9b) to a larger value d2 (in the expanded state of FIGS. 9c and 9d). This increase in the gap 120 reduces the amount of light received by the photodetector 140 from the light source 6. The proportion of emitted light that strikes the photodetector 140 decreases as the size of the gap 120 increases. Thus, when urine or feces enters the interior of the diaper 1, the output signal generated by the photodetector 140 decreases, indicating that the diaper 1 has expanded. Specifically, the optical signal received by the photodetector 140 is inversely proportional to the expansion of the diaper. Based on this, a fullness parameter of the diaper can be determined.

[0037] Similarly, as the expansion of the diaper 1 decreases (e.g., due to urine leakage from the diaper 1), the tension on the exposed central portion of the optical fiber 50 decreases. As a result, the exposed portion of the optical fiber 50 moves back in a direction away from the detector attachment point 45, i.e., toward the detector 2. This reduces the gap 120 between the optical fiber 50 and the photodetector 140. As a result, the amount of light that the photodetector 140 receives from the light source 6 through the optical fiber 50 increases. Thus, the output signal generated by the photodetector 140 increases, indicating that the diaper 1 has shrunk.

[0038] The change in gap 120 depends on the properties of the material from which the diaper 1 is made, the material properties of the expandable member, and the properties of the optical fiber 50. The deflection of the optical fiber 50 in the exposed area in the pulling direction is given by:

number

[0039] In an alternative example, the second end of the optical fiber 50 may be fixed in front of the photodetector 140, and the first end of the optical fiber 50 may be disposed adjacent the light source 6 but not fixed in position and allowed to move longitudinally within the first tube 70. As a result, the gap 120 is disposed between the light source 6 and the first end of the optical fiber 50. Equation (1) applies equally to this example.

[0040] FIG. 10 is an alternative example of the photodetector 2 of FIGS. 9a-9d. Similar to the photodetectors of FIGS. 9a-9d, a light source 400 injects light into an optical fiber 425 at a first end of the optical fiber 425. The first end of the optical fiber 425 is fixed relative to the light source 400. The light travels through the optical fiber 425 to a photodetector 410 located at a second end of the optical fiber 425. The second end of the optical fiber 425 is not fixed in position relative to the photodetector 410. The optical fiber 425 provides a substantially straight path between the light source 400 and the photodetector 410 in FIG. 10. However, in FIG. 10, there are four tube sections 480, 490, 500, and 510 disposed along respective portions of the substantially straight path between the light source 400 and the photodetector 410 through which the optical fiber 425 passes. The tube sections 480, 490, 500, 510 act as light guides for the optical fiber 425. Between the four tube sections 480, 490, 500, 510 are openings that expose three portions of the optical fiber 425. Three links 550, 460, 570 couple the detector attachment point 45 to the three exposed portions of the optical fiber 425. It will be appreciated that the use of four tube sections and three links is merely exemplary and a different number of tube sections (e.g., three or more) can be used to provide a different number of exposed portions of the optical fiber 425 (e.g., two or more). The number of links used corresponds to the number of exposed portions of the optical fiber 425. Advantageously, having multiple, spaced apart links 550, 460, 570 allows the detector attachment point 45 to pull the optical fiber 425 more uniformly along its length. As a result, this configuration is more stable and produces a larger deflection δ.

[0041] Figures 11a and 11b show yet another example of an optical detector configured for use with any one of the sensing devices described above. For simplicity, the expandable member is not shown in Figures 11a-11b, except for the detector attachment point 45. In Figures 11a and 11b, the optical detector is made of a laminated structure having the following layers from top to bottom (as shown in Figure 11a): a lamination layer 233, an optical fiber with two coaxial sections 285 and 430 separated by a gap 410, a rigid spacer made of two sections 324, 325 separated by a spacer gap, and a flexible substrate 125. The optical fiber is made of a fiber core 250 and a fiber cladding 256, as is well known. The lamination layer 233 is a thin flexible plastic layer that protects the top of the laminated structure. The gap 410 between the two coaxial sections 285 and 430 is located above and next to the first end of the section 325 of the rigid spacer. A first end of the rigid spacer portion 325 is vertically aligned with a first end of the coaxial section 430 of the optical fiber and horizontally adjacent to the spacer spacing. As a result, section 270 of the first optical fiber section 285 is not fixed and can bend when a force is applied. The unfixed section 270 of the first optical fiber section 285 is connected to the detector attachment point 45 via an inelastic link 56. Figures 11a and 11b show cross-sectional views of the optical fiber, the rigid spacer, and the flexible substrate 125, where the link 56 actually extends substantially vertically all the way from the optical fiber to the detector attachment point 45 (i.e., extends substantially all the way in the plane of the outer surface of the diaper). The detector attachment point 45 is part of an expandable member (e.g., one of the expandable members 1602 described above). The expandable member is fixedly attached to the outer surface of the diaper (e.g., diaper 1600).

[0042] The detector of FIG. 11a may be fabricated by placing a rigid spacer on the flexible substrate 125, placing a single optical fiber on the rigid spacer, and then placing a lamination layer 233 on top of the optical fiber. The lamination layer is then laminated (e.g., using heat or ultrasound) on top of the structure. A vertical cut is made in the unfixed section 270 of the optical fiber using a sharp tool (e.g., a blade) to form a void 410 at one end of the spacer space such that the void 410 and the spacer space form a single air space. The vertical cut, and thus the void 410, separates the optical fiber into two coaxial sections 285 and 430 by extending through each of the lamination layer 233, the fiber coating 256, and the fiber core 250. The vertical cut does not penetrate the substrate 125. The distal (left) end (not shown) of the first optical fiber section 285 is coupled to a light source (not shown), and the distal (right) end of the second optical fiber section 430 is coupled to a photodetector (not shown).

[0043] In use, when a light source shines light into the distal end of the first optical fiber section 285, the light passes through the gap 410 into the second optical fiber section 430. Figure 11a shows the configuration of the detector when the diaper is in an uninflated state. In this configuration, the expandable member and inelastic links 56 are minimally taut and the photodetector produces an output signal corresponding to the uninflated state of the diaper. Due to the gap 410, there is a small loss in light transmission (e.g., on the order of 20%).

[0044] FIG. 11b shows the configuration of the detector when the diaper is in an expanded state. In this configuration, expansion of the diaper causes the expandable member to pull the detector attachment point 45 further away from the detector. Because the link 56 is inelastic, the pull from the expandable member is transferred to the optical fiber, thereby pulling the loose section 270 of the optical fiber away from the second optical fiber section 430. This pull causes the optical fiber sections 285, 430 to shift position. Thus, the signal transmission is significantly degraded (up to 80%). The greater the pull, the greater the signal drop at the photodetector. The signal drop is directly proportional to the expansion of the diaper volume as more urine and feces enter the diaper. The sensitivity of the photodetector depends on the material properties of the optical fiber and the rigid spacer, the force exerted by the detector attachment point 45, and the dimensions of the loose section 270 of the optical fiber.

[0045] FIG. 12 shows an alternative example of a light detector for use with any one of the sensing devices described above. In this configuration, the detector 600 is constructed on a small footprint circular printed circuit board 655. The detector 600 includes a light source 621 (such as a light emitting diode), a light detector 601 (such as a photodetector), an optical fiber 642, two linear guide rails 625, and a link 666 connecting the optical fiber 642 to a detector attachment point 675. The detector attachment point 675 may be equivalent to the detector attachment point 45 described above, and is one of the attachment points of an expandable member (e.g., expandable member 1602). For simplicity, the expandable member is not shown in FIG. 12 except for the detector attachment point 675.

[0046] The light source 621 is disposed near one end of the printed circuit board 655. The photodetector 601 is disposed next to the light source 621. The optical fiber 642 is disposed in a U-shape over a substantial area of ​​the printed circuit board 665. A first end of the optical fiber 642 is disposed in front of the light source 621 such that there is a first gap between the first end of the optical fiber 642 and the front of the light source 621. A second end of the optical fiber 642 is disposed in front of the photodetector 601 such that there is a second gap between the second end of the optical fiber 642 and the front of the photodetector 601. Two straight guide rails 625 are disposed in parallel on the printed circuit board 655 to guide two straight sections of the U-shape of the optical fiber 642, i.e., one guide rail forms a first straight line to the light source 621, and the other guide rail forms a second straight line to the photodetector 601. An optical fiber 642 is inserted into each guide rail 625. Each guide rail 625 is configured to keep optical fiber 642 aligned with the optical axis of each of light source 621 and light detector 601. Link 666 is connected to optical fiber 642 at the center of the bottom of the U-shape.

[0047] The light source 621 shines light onto the optical fiber 642. The light travels through the U-shaped optical fiber 642 and is detected by the photodetector 601. When the expandable member pulls the detector attachment point 675 away from the detector 600, the optical fiber 642 moves further away from the light source 621 and / or the photodetector 601, thereby increasing the size of the first gap and / or the second gap. This causes the detected signal to decrease. The decrease in the detected signal is proportional to the tension, which is proportional to the amount of urine or feces in the diaper (e.g., diaper 1600). Therefore, the change in the detected signal is indicative of diaper expansion.

[0048] Thus far, only one sensing device has been shown attached to the diaper. However, any suitable number of sensing devices may be used on the same diaper. For example, the diaper may be combined with one or more additional sensing devices. The sensing device and the one or more additional sensing devices are configured to detect inflation at different locations on the exterior surface of the diaper. In FIG. 13, there is a first detector 513, a second detector 530, and a third detector 542. Each of the three detectors 513, 530, 542 are equivalent to the detectors described in FIGS. 9a-9d and operate in a similar manner. For example, the first detector 513 comprises a link 50 connecting the light source 400, the optical fiber 425, the first tube 440, the second tube 450, the photodetector 410, and the optical fiber 425 to a detector attachment point 715. The detector attachment point 715 may be equivalent to the detector attachment point 45 described above. The detector attachment point 715 forms part of an associated expandable member, the remainder of which is not shown in FIG. 13.

[0049] Each of the detectors 513, 530, 542 may be attached to the waistband of the same diaper (e.g., diaper 1600). The optical fibers of the detectors 513, 530, 542 are connected to detector attachment points 701, 715, 725 by separate inelastic links 460, 576, 585, respectively. The detector attachment points 701, 715, 725 are each fixedly attached to the exterior surface 1590 of the diaper 1600, preferably near the waistband of the diaper 1600. As mentioned above, the detector attachment points 701, 715, 725 each form part of a respective expandable member (only the detector attachment points 701, 715, 725 of the expandable members are shown in FIG. 13). Each of the expandable members may be fixedly attached to a different location on the exterior surface 1590 of the diaper 1600. For example, a first expandable member may be located at the front 1530 of the diaper 1600, a second expandable member may be located at the crotch region 1540 of the diaper 1600, and a third expandable member may be located at the rear 1570 of the diaper 1600. In FIG. 13, only a photodetector is shown. However, any suitable type of detector may be used. Advantageously, the use of more than one sensing device increases signal generation and sensitivity to diaper expansion. The use of multiple sensing devices, where separate expandable members are fixedly attached to different locations on the exterior surface 1590 of the diaper 1600, increases the accuracy of indicating the fullness of the diaper 1600. Furthermore, the displacements measured by the multiple sensing devices may be used to determine whether the diaper 1600 is filled with liquid (e.g., urine) or solids (e.g., feces). FIG. 13 relates to an example where the sensing device is attached to the exterior surface of the diaper after the diaper is manufactured, and an example where the expandable member of the sensing device is integrated into the exterior surface of the diaper during manufacturing.

[0050] 14 and 15 show plan views of an alternative embodiment of a sensing device attached to the outer surface 905 of the diaper 791. As can be seen in FIG. 14, the diaper 791 has the same configuration as the diaper 1600, i.e., a front portion, a crotch region between the elasticated edges of the diaper, and a rear portion. The front portion of the diaper 791 is connected to the waistband section 749. Alternatively, the rear portion of the diaper can be connected to the waistband section 749. The sensing device comprises a detection portion 871 and three sensor elements 1100, 1122, 1133, although a different number of sensor elements (e.g., one or more) can be used if desired. The detection portion 871 is attached to the waistband section. In an alternative embodiment, the detection portion 871 can be attached to another suitable location on the outer surface 905 of the diaper 791. For example, at the front of the diaper 791, near the waistband section 749. The detection portion 871 comprises three light sources and three photodetectors. Each source / detector pair is connected to one of the three sensor elements 1100 , 1122 , 1133 .

[0051] The sensing device also includes one or more expandable members 3334 fixedly attached to the outer surface 905 of the diaper 791 at attachment points 3122. In FIG. 14, the expandable member 3334 includes an elastic element (similar to the elastic patch of FIG. 1) configured to stretch as the diaper 791 expands. The expandable member 3334 is fixedly attached (e.g., by adhesive, Velcro, or the like) to the outer surface 905 of the diaper 791 at each attachment point 3122 located at each corner of the elastic patch. The expandable member 3334 covers a substantial area of ​​the outer surface 905 of the diaper 791. As an alternative to an elastic patch, the expandable member 3334 may be a flexible polymer substrate.

[0052] The sensor elements 1100, 1122, 1133 are each disposed on an elastic element of the expandable member 3334. Although Fig. 14 shows the sensor elements 1100, 1122, 1133 disposed on a single elastic patch, any suitable number of elastic elements may be used. For example, the sensor elements 1100, 1122, 1133 may each be disposed on a dedicated expandable member 3334 (e.g., Fig. 15 shows a single sensor element 1133 disposed on its own dedicated elastic element 3334).

[0053] The sensor elements 1100, 1122, 1133 and the expandable member 3334 may be manufactured together as a disposable patch configured to be placed on the outer surface 905 of the diaper 791 prior to use of the diaper 791. Considering the sensor element 1133 in more detail, the detection portion 871 includes a light source 897 (such as a light emitting diode) and a photodetector 890 (such as a photodetector) associated with the sensor element 1133. The sensor element 1133 includes two optical fibers 865, 828 and a microtube 911 extending between the two optical fibers 865, 828. The microtube 911 may be metal or plastic. A first end of a first optical fiber 865 is disposed in front of the light source 897 and is secured to the detection portion 871 at an attachment point 901. The first optical fiber 865 extends across a portion of the outer surface 905 of the diaper 791. For example, in FIG. 14, the first optical fiber 865 extends across the front of the diaper 791. The second end of the first optical fiber 865 extends partially into the first end of the microtube 911. In FIG. 14, the microtube 911 is disposed at the front of the diaper 791. The first end of the second optical fiber 828 is disposed in front of the photodetector 890 in the detection portion 871. The first end of the second optical fiber 828 is not fixed to the detection portion 891 and is therefore free to move toward and away from the photodetector 890. There is a first gap between the photodetector 890 and the first end of the second optical fiber 828. The second optical fiber 828 extends across a substantial length of the outer surface 905 of the diaper 791. For example, in FIG. 14, the optical fiber 828 extends across the front, crotch region, and back of the diaper 791 and folds back toward the microtube 911. A second end of the second optical fiber 828 extends partially into the second end of the microtube 911 such that the two optical fibers 865, 828 are generally coaxial within the microtube 911. A second gap 855 exists between the second ends of the two optical fibers 865, 828 within the microtube 911. Sensor elements 1100 and 1122 are constructed in a similar manner as sensor element 1133, with their respective microtubes 840 and 920 positioned at different locations relative to the diaper 791.

[0054] The optical fibers 828, 865 of the sensor element 1133 are attached to the expandable member 3334 such that the optical fibers 828, 865 are free to move to allow for the expansion of the diaper 791. For example, the optical fibers 828, 865 may be attached (e.g., glued) to the expandable member 3334 only at specific locations such that the optical fibers 828, 865 are free to move, particularly within the microtubes 911, as the diaper 791 expands. In other examples, the optical fibers 828, 865 may be partially or completely housed within one or more sheaths. Each sheath is attached to the expandable member 3334 with any suitable attachment mechanism (e.g., adhesive). Even if the optical fibers 828, 865 are housed within each sheath, it is possible for the optical fibers 828, 865 to move apart from one another within the microtubes 911 as the diaper 791 expands.

[0055] 15, the expandable member further comprises two elastic polymers 3525 attached between respective attachment points 3233 on the elastic patch 3334 and respective attachment points 3232 on the elastic edge 3324 of the diaper 791. The elastic edge 3324 of the diaper 791 is equivalent to the elastic edge 1560 of the diaper 1600 described above. The elastic polymers 3525 provide increased sensitivity in detecting expansion of the expandable member 3334.

[0056] In use, the sensor element 1133 is configured to provide a sensor signal to the detector 871, the sensor signal varying with the amount of stretch of the elastic element. The additional sensor elements 1100, 1122 are also configured to provide respective sensor signals to the detector 871, each varying with the amount of stretch of the elastic element. For example, the detector 871 is configured such that a relative displacement between the two optical fibers 865, 828 (caused by stretching of the elastic element) results in a change in the amount of light reaching the photodetector 890, thereby causing a change in the output signal from the photodetector 890. In a non-expanded state, the first gap (near the photodetector 890) and the second gap 855 (within the microtube 911) each have a predetermined size, and the detected signal has a predetermined value. As the outer surface 905 of the diaper 791 expands (due to the ingress of urine or feces into the diaper 791) and the elastic element stretches, the second gap 855 in the microtube 911 increases. As the diaper expands, the second end of the optical fiber 828 may move further away from the photodetector 890, thereby increasing the first gap. As these gaps increase, the signal at the photodetector 890 decreases (the detected signal is proportional to the increase in gap and thus the volume of urine or feces inside the diaper), thereby indicating that the diaper 791 has expanded. Advantageously, the combination of the change in the first gap and the change in the second gap 855 provides greater sensitivity to diaper expansion.

[0057] Although the increase in the (each) gap is only a few millimeters, the overall change in distance (from the original position of the diaper) at the outer surface 905 of the diaper 791 as urine or feces enters the interior of the diaper 791 is several centimeters. To accommodate this large change, multiple sensor elements are used as shown in FIG. 14. Three sensor elements 1100, 1122, 1133 are spaced across the outer surface 905 of the diaper 791. For example, a microtube 911 is located at the front of the diaper 791, a second microtube 840 is located at the crotch region of the diaper 791, and a third microtube 920 is aimed at the rear of the diaper 791. The placement of each microtube at different locations on the diaper 791 improves the accuracy of the detected expansion. For example, the microtube 840 located at the crotch region of the diaper 791 is likely to be the first to detect expansion as the diaper 791 fills with urine or feces because it is located in the wearer's groin region. Also, since different parts of the diaper 791 will inflate first depending on the wearer's position, the aforementioned variety of positions is advantageous when the wearer is in different positions, e.g., lying down versus standing.

[0058] <Conductivity detector> 16 and 17 show alternative examples of a sensing device on the exterior of a diaper 1600. The diaper 1600 is equivalent to the diaper 1600,1,791 described above. In these examples, the detector comprises a resistive or capacitive detector, and each elastic element is conductive. For example, each elastic element may be made of a conductive polymer. The detector is configured to detect the expansion of the expandable member by detecting a change in length of at least one of the elastic elements. For example, as the diaper expands, each elastic element stretches, thereby changing in length (as in the case of a resistor). The change in length of each elastic element causes a change in a signal detected at the detector, indicating the expansion of the expandable member.

[0059] In the example shown in FIG. 16, the sensing device comprises a detector 5 directly coupled to the expandable member 1602 at a detector attachment point 45. The detector attachment point 45 may be equivalent to the detector attachment point 45 described above. The expandable member 1602 comprises one or more elastic elements 625 extending between multiple attachment points 617, 45. The attachment points 617 are connected via the elastic elements 625 to form a serpentine pattern. The attachment points 617 are located at each turn of the serpentine pattern. In FIG. 16, the detector 5 is attached to the waistband section of the diaper 1600. However, in some examples, the detector 5 may be located in another location on the diaper 1600, such as below the waistband section. The detector attachment point 45 is located in the center of the front of the diaper 1600, next to the detector 5. The other attachment points 617 consist of six front attachment points arranged generally linearly and laterally across the front of the diaper 1600 and five rear attachment points arranged generally linearly and laterally across the rear of the diaper 1600. The six front attachment points are fixedly attached to the front exterior surface of the diaper 1600 near the front top edge of the diaper (i.e., near the waistband). The five rear attachment points are fixedly attached to the rear exterior surface of the diaper 1600 near the rear top edge of the diaper (i.e., near the rear waistband). Two elastic elements 625 extend in opposite directions from the central detector attachment point 45 across the front of the diaper 1600 to the two outer front attachment points 617. The remaining elastic elements 625 extend in a generally longitudinal (lengthwise) serpentine pattern across the exterior surface of the diaper 1600. Specifically, two separate elastic elements 625 extend longitudinally from each of the two outer front attachment points 617, down the front, crotch region and up the rear of the diaper 1600 to the two outer rear attachment points 617. Each elastic element 625 then snakes between the front and rear attachment points to connect the remaining attachment points 617, with attachment points located at each turn. Each elastic element 625 is free to stretch between the attachment points 617, 45 as the diaper 1600 expands. Each elastic element 625 is thinner than the elastic elements of FIGS. 1-7 so that it can snake more easily.For example, in Figure 16, each elastic element 625 may be made of a thin cloth, thread, or wire of conductive elastic material. Figure 16 includes both examples where the sensing device is attached to the exterior surface of the diaper after the diaper is manufactured, and examples where the expandable member of the sensing device is integrated into the exterior surface of the diaper during manufacture.

[0060] In use, the detection portion 5 is configured to detect the expansion of the expandable member 1602 by detecting a change in resistance of the expandable member 1602 due to a change in length. Each elastic element 625 is constructed from a conductive material such that the elastic element 625 has a resistance R given by the following equation:

number

[0061] In another example, as shown in FIG. 17, each elastic element is conductive and acts as an electrode such that the sensing device forms a variable capacitor. For example, each elastic element can be made of a conductive polymer and can be up to 0.3 mm thick. In FIG. 17, the sensing device comprises a detector 5 directly coupled to an expandable member 1602 at detector attachment points 45. The detector attachment points 45 can be equivalent to the detector attachment points 45 described above. The expandable member 1602 comprises a number of elastic elements extending between a number of attachment points. Each attachment point includes a first set of attachment points 710 connected to form a first finger pattern 700 via one or more first elastic elements. The one or more first elastic elements form one or more first elastic elements of the first set. Each attachment point also includes a second set of attachment points 720 connected to form a second finger pattern 705 via one or more second elastic elements. The one or more second elastic elements form one or more second elastic elements of the first set. The first and second finger patterns 700, 705 are arranged in an interdigitating finger pattern. More specifically, the first finger pattern 700 includes a longitudinal elastic element 750 having one end fixedly attached to the front of the diaper 1600 at one attachment point 710 of the first set of attachment points and the other end fixedly attached to the rear of the diaper 1600 at another attachment point 710 of the first set of attachment points. A first end of several transverse elastic elements 755 is connected to the longitudinal elastic element 750. The transverse elastic elements 755 are also each fixedly attached at their other ends to respective attachment points. Thus, the transverse elastic elements 755 effectively form each finger of the first finger pattern 700. Each finger extends toward the centerline of the diaper 1600. The second finger pattern 705 is a mirror image of the first finger pattern 700, but the transverse elastic elements 755, 717 of each of the finger patterns 700, 705 are offset from the first finger pattern 700 such that the fingers interdigitate with each other. The second finger pattern 705 includes a longitudinal elastic element 780 having one end fixedly attached to the front of the diaper 1600 at one attachment point 720 of the second set of attachment points and another end fixedly attached to the rear of the diaper 1600 at another connection point 720 of the second set of attachment points.A first end of some of the lateral elastic elements 717 is connected to a longitudinal elastic element 780. Each of the lateral elastic elements 717 is also fixedly attached at the other end to a respective attachment point 730. Thus, the lateral elastic elements 717 effectively form fingers of the second finger pattern 705. Each finger extends toward the centerline of the diaper 1600. As described above, the first and second finger patterns 700, 705 are interconnected to form a pattern of interlocking fingers. The lateral elastic elements 755, 717 may have a length that covers a significant portion of the width of the diaper 1600 (i.e., each extends beyond the centerline of the diaper 1600 between the elasticized edges 1560 of the diaper 1600). The two longitudinal elastic elements 750, 780 have a length that covers a significant portion of the length of the diaper 1600. For example, the two longitudinal elastic elements 750, 780 cover a substantial length of the front, crotch region and back of the diaper 1600. The two longitudinal elastic elements 750, 780 are connected to the sensing portion 5 by respective conductive links 766 between the sensing portion attachment points 45 and at least one of the respective attachment points 710 of the first pattern 700 and at least one of the respective attachment points 720 of the second pattern 705.

[0062] The first and second patterns 700, 705 are separated by a gap (e.g., gap 740) between the distal ends of the longitudinal elastic elements of one pattern and the transverse elastic elements of the other pattern. For example, as shown in FIG. 17, there is a gap 740 between the longitudinal elastic element 750 of the first pattern 700 and the attachment point 730 of the distal end of one of the transverse elastic elements 717 of the second pattern 705. There is also a vertical gap between the distal ends of each transverse elastic element (e.g., there is a gap between the top transverse elastic element of the first pattern and the top transverse elastic element of the second pattern in FIG. 17). FIG. 17 includes both examples where the sensing device is attached to the exterior surface of the diaper after the diaper is manufactured, and examples where the expandable member of the sensing device is integrated into the exterior surface of the diaper during manufacture.

[0063] During use, the detector 5 is configured to detect the expansion of the expandable member 1602 by detecting a change in capacitance due to a change in length of at least one of the elastic elements 750, 755, 780, 717. For example, as the diaper 1600 expands, the elastic elements 750, 755, 780, 717 change in length as they stretch with the diaper 1600. The change in length of the elastic elements 750, 755, 780, 717 causes a change in the size of the gap 740, which in turn causes a change in capacitance. The change in capacitance indicates that the diaper 1600 has expanded. In other words, the expansion of the diaper causes a change in the size of the gap 740. This change in the gap 740 causes a change in the interdigitation of the fingers of the first and second patterns 700, 705. Thus, the detection unit 5 is configured to detect the expansion of the expandable member 1602 by detecting a change in capacitance due to a change in the interdigitation of the fingers of the first and second patterns 700, 704. For example, as the diaper 1600 expands, the first and second finger patterns 700, 705 move away from each other, changing the amount that the fingers of the patterns 700, 705 interdigitate with each other. The change in capacitance is detected using a capacitance bridge in the detection unit 5. FIG. 19 shows a standard capacitance bridge circuit. Cs is a precise standard capacitor, and Cx is an unknown capacitance provided by the elastic elements 750, 755, 780, 717 that are attached to the diaper 1600 and expand. When urine or feces enters the diaper 1600, the volume of the diaper 1600 expands and the capacitance changes. Q and P are standard resistors, one or both of which can be adjustable. Since an AC power source is used, the zero detector D must be an AC device. A low current rectifier ammeter can be used as the zero detector. Q is adjusted until the zero detector indicates zero. Once this is achieved, the capacitance bridge is balanced. The change in capacitance Cx indicates the volume of urine or feces in the diaper 1600. The change in capacitance is proportional to the volume change, i.e. the amount of urine or feces in the diaper 1600.

[0064] <Body movements> Body movements of the diaper wearer (e.g., standing up, walking around, lying down, etc.) can affect the sensing capability of the sensing device. Body movements can cause changes in the detected signal, which can lead to inaccurate expansion measurements. A MEMS (micro-electromechanical system) capacitor-based gyroscope or accelerometer can be used in the sensing section to record any internal body movements of the diaper wearer. Appropriate corrections can then be applied electronically and / or in software to account for the difference between the actual signal (due to the intrusion of urine or feces and the resulting volumetric expansion) and the signal changes caused by body movements.

[0065] Figure 23a shows a MEMS gyroscope. The MEMS gyroscope is constructed such that an inner frame containing a resonating mass is connected to a substrate by springs at a 90 degree angle to the resonating motion. The Coriolis acceleration is measured through capacitance sensing at electrodes attached between the inner frame and the substrate. The gyroscope measures angular rate (expressed in mV / degrees / sec).

[0066] A MEMS accelerometer is shown in Figure 23b. This is a simple single-axis accelerometer. By keeping more pairs of capacitors at 90 degrees to each other, a dual-axis or triple-axis accelerometer can be fabricated. A movable plate and an outer fixed plate act as capacitor plates. When acceleration is applied, the test mass moves accordingly. This creates a capacitance between the movable plate and the outer fixed plate. When acceleration is applied (due to body movements), the spacing between the two plates changes, causing a change in capacitance. The accelerometer measures linear acceleration (specified in mV / g) along one or more axes.

[0067] <Power supply> FIG. 20 shows a schematic of an electronic control and power unit 1520 that may be used with any of the examples of sensing devices described above. The electronic control and power unit 1520 may house the detectors described above. The electronic control and power unit 1520 may include signal amplifiers, analog-to-digital converters, microcontrollers or other processors, memory, data loggers, wireless transmission systems (e.g., Bluetooth), discrete or integrated electronic components, FPGAs, DSPs, ASICs, etc. The electronic control and power unit may have a digital display 1530 configured to display instantaneous volume measurements. The electronic control and power unit 1520 may also include an audio display to provide an alarm, for example, if the volume of urine or feces in the diaper exceeds a target range. The electronic control and power unit 1520 may be entirely housed within its housing.

[0068] Each measurement determined by the sensing device can be taken at regular intervals and stored in a data logger prior to processing by the microprocessor. Each measurement can be taken and recorded in the data logger as frequently as desired, for example, every minute or hour. Data from the data logger or microprocessor can be transmitted by a transmission system to a remote device or server. This can be a smart phone, laptop, pager, or other device. The remote device can keep a record of the fluid volume data that can be used for clinical evaluation. This data logging can be used by clinicians to monitor the patient's incontinence level.

[0069] The electronic control and power unit 1520 may further include a rechargeable coin cell battery for powering the sensing device and electrical components of the electronic control and power unit 1520. The electronic control and power unit 1520 provides a voltage of 5V or less. The electronic control and power unit 1520 further includes a USB port 1500 through which data may be retrieved from the data logger.

[0070] The electronic control and power unit 1520 may be attached to the diaper via an adhesive pad, a hook-and-loop attachment mechanism, or the like, or may be integrated into the housing or case of the sensing device. Alternatively, the electronic control and power unit 1520 may be communicatively coupled to the sensing device. For example, the electronic control and power unit 1520 may be connected by a cable or other suitable wired or wireless power and communication link and located remotely from the sensing device, such as in a pocket of clothing worn by the wearer or on a bedside pushchair.

[0071] <Analysis> Using any of the sensing devices of the above examples, the detected signal may be used to generate volume versus time data, from which diaper fullness parameters such as a) urine or stool volume, b) urine flow rate, and c) frequency of bowel movements may be calculated using analytical methods, e.g., definite integrals, which are very useful in determining incontinence.

[0072] For example, the volume of urine in the diaper may be calculated using empirical methods. Numerous experiments are performed with a variety of diapers of different sizes and absorbency. A known amount of liquid (e.g., saline) is poured into the diaper and the output signal at the photodetector (e.g., photodetector 140) is recorded. The amount of liquid can be up to several liters. Software is used to convert the output signal to the amount of liquid in the diaper. The result is displayed as a volume. The output signal (mV) is converted (using the empirical method described above) to a volume of liquid (ml), volume versus time data is collected, and a volume versus time graph may be generated. Using a definite integral, the volume of urine discharged by the wearer in any given period of time can be estimated from the area under the curve. The rate of discharge (dml / dt) at any time during the use of the diaper can also be determined. This is particularly useful for determining the incontinence of a patient, which is currently done manually.

[0073] Figure 21 is a representative graph of volume (ml) versus time used to show how the volume of liquid inside the diaper, flow rate, and frequency of discharge are calculated. This can be correlated with experimental results. Software algorithms are used to determine each parameter and the results can be displayed digitally. The volume V of urine / faeces discharged by the user during a given period of time on the graph shown in Figure 21 can be calculated using definite integrals.

number

[0074] Expansion of the diaper due to ingress of urine or faeces exerts pressure on the elastic elements, which can be calculated as follows:

number

[0075] Filtering algorithms may be used to avoid false positives caused by wearer movement. For example, time sampling may be used to remove unwanted signals due to wearer movement. The sensing device may be configured to process the output signal from the detector to remove transient features caused by wearer movement, for example, when walking around or tossing and turning. The sensor data may be recorded over time and processed to determine the frequency, flow rate, and / or volume of the wearer's urination.

[0076] The sensing device may also include an output device, such as a speaker, a display, or a light-emitting component (e.g., LED) that indicates the fullness of the diaper. The output device may include electronic circuitry, such as, for example, a wireless transmitter, configured to transmit a signal, for example, to a smartphone of, for example, a parent, guardian, or caregiver. The indication may be binary (e.g., full or not full) or may indicate the fullness of the diaper.

[0077] The sensing device may be configured to determine when a displacement detected in the diaper exceeds a predetermined threshold. The output device may be configured to indicate, e.g., transmit a signal, when a determination is made that the detected displacement exceeds the predetermined threshold. In this manner, the sensing device may be used to alert a parent, guardian, or caregiver, for example, that a diaper worn by an infant, toddler, child, adult, or animal has filled with, for example, urine or feces and needs to be changed.

[0078] The initial expansion of the expandable member is measured or preset before or immediately after the diaper is put on. This initial expansion represents the state or elongation of the diaper 1600 when the diaper 1600 is in an unsoiled, "empty" or unexpanded state. Over time, the sensing device periodically records another expansion measurement. Each another expansion measurement can be compared to the initial expansion measurement. If the sensing device records an expansion measurement that is greater than the initial expansion measurement by a predetermined threshold, this indicates significant expansion of the diaper, and the sensing device determines that the diaper is filling or has already filled, for example, with urine or feces. The sensing device may therefore be configured to alert a parent or caregiver that the diaper is soiled and needs to be changed, for example by sending a wireless message to an infant monitoring device or an app on the parent's or caregiver's mobile phone. In some examples, more complex processing of the expansion measurements may be performed, for example to remove variations due to wearer movement.

Claims

1. A sensing device attached to the exterior surface of a diaper, an expandable member comprising one or more elastic elements extending between a plurality of attachment points; a detector coupled to the expandable member, the attachment points are configured to fixedly attach the expandable member to an exterior surface of the diaper; one or more of the elastic elements are configured to stretch as the attachment points move apart, thereby causing the expandable member to expand in response to expansion of the diaper; The detector is configured to detect an expansion of the expandable member and is further configured to determine a diaper fullness parameter based on the detected expansion of the expandable member. A sensing device characterized by:

2. The expandable member is sized and shaped to cover a substantial area of ​​the exterior surface of the diaper with at least some of the attachment points located at or near multiple edges of the diaper.

2. The sensing device of claim 1 .

3. The expandable member is sized and shaped to extend across the entire width of the crotch region of the diaper.

3. The sensing device according to claim 2 .

4. The detector is one of an optical detector, a resistive detector, and a capacitive detector. Sensing device according to any one of claims 1 to 3, characterized in that it comprises:

5. the one or more elastic elements comprise a number of elastic elements arranged in a polygon and having said attachment points at one or more corners of the polygon; Optional (i) the expandable member further includes one or more lateral elastic elements extending between a number of the elastic elements; and (ii) one or more of said lateral elastic elements are concentrated within a designated area of ​​said polygon; and Consists of one or more of Sensing device according to any one of claims 1 to 4, characterized in that it comprises:

6. one or more of the elastic elements comprises an elastic patch and the attachment points comprise attachment points on a periphery of the elastic patch; or One or more of the elastic elements comprises an elastic net and the attachment points comprise attachment points on the periphery of the elastic net. Sensing device according to any one of claims 1 to 4, characterized in that it comprises:

7. The detector is configured to detect expansion of the expandable member by detecting relative displacement between the attachment points. Sensing device according to any one of claims 1 to 6, characterized in that it comprises:

8. the attachment points include detector attachment points directly coupled to the detector; Optionally, (i) the detector is configured to detect expansion of the expandable member by detecting a relative displacement between the detector attachment point and at least one other attachment point; (ii) a relative displacement between the detector attachment point and the at least one other attachment point causes the expandable member to pull the detector attachment point away from the detector; (iii) the detection unit includes a light source and a photodetector; the detector is configured such that an amount of light reaching the photodetector from the light source varies in response to relative displacement between the detector attachment point and the at least one other attachment point, thereby causing a change in an output signal from the photodetector; (iv) the attachment point is a first attachment point connected to the detector attachment point via a longitudinal elastic element; one or more second attachment points 4005 connected to said longitudinal elastic elements via one or more transverse elastic elements; (v) a central junction connected to the detector attachment point via a central elastic element; the attachment points further include a number of attachment points spaced apart about the central junction, each of the multiple attachment points being connected to the central junction via a radial elastic element; Consists of one or more of Sensing device according to any one of claims 1 to 7, characterized in that it comprises:

9. one or more of said elastic elements are electrically conductive; The detector is configured to detect expansion of the expandable member by detecting a change in length of at least one of the one or more elastic elements; Optionally, The detector is configured to detect expansion of the expandable member by detecting a change in resistance of the expandable member due to the change in length. Sensing device according to any one of claims 1 to 6, characterized in that it comprises:

10. The attachment points are connected via a plurality of elastic elements to form a serpentine pattern, the attachment points being located at each turn of the serpentine pattern. Sensing device according to any one of claims 1 to 4 and claim 9, characterized in that

11. the detection unit is configured to detect an expansion of the expandable member by detecting a change in capacitance due to a change in length of at least one of the elastic elements; Optionally, (i) the attachment points include a first set of attachment points connected to form a first finger pattern via a first set of elastic elements of the one or more elastic elements, and a second set of attachment points connected to form a second finger pattern via a second set of elastic elements of the one or more elastic elements; the first finger pattern and the second finger pattern are arranged in an interdigitating pattern; and (ii) the detection unit is configured to detect expansion of the expandable member by detecting a change in capacitance due to a change in interdigitation of the first finger pattern and the second finger pattern; and Consists of one or more of 10. The sensing device according to claim 9.

12. further comprising a sensor element on one or more of said elastic elements; The sensor element is configured to provide a sensor signal to the detector; the sensor signal varies in response to an amount of stretch of one or more of the elastic elements; Optionally, (i) the detection unit includes a light source and a photodetector; the sensor element comprises two optical fibers arranged such that elongation of one or more of the elastic elements causes a relative displacement between the two optical fibers; the sensing device is configured such that relative displacement between the two optical fibers causes a change in the amount of light reaching the photodetector, thereby causing a change in an output signal from the photodetector; (ii) the detection unit comprises a gyroscope or an accelerometer configured to detect movement; and Consists of one or more of Sensing device according to any one of claims 1 to 4, characterized in that it comprises:

13. Diapers and A diaper-sensing device combination comprising the sensing device according to any one of claims 1 to 12, the sensing device comprises an electronic control and power unit configured to power itself; The attachment points of the expandable member are fixedly attached to the exterior surface of the diaper.

1. A diaper / sensing device combination comprising:

14. The electronic control and power supply unit is made up of the detection unit and is attached to the waistband portion of the diaper.

14. The combination diaper and sensing device of claim 13.

15. The attachment point of the expandable member is fixedly attached to one of the front portion of the diaper, the back portion of the diaper, the crotch region of the diaper, the elastic edge of the diaper, the waistband portion of the diaper, or a combination thereof.

15. A diaper-sensing device combination as claimed in claim 13 or 14.

16. One or more additional sensing devices according to any one of claims 1 to 12, The sensing device and one or more additional sensing devices are configured to detect expansion at different locations on the exterior surface of the diaper. A combined diaper and sensing device as claimed in any one of claims 13 to 15.

17. the electronic control and power unit is further configured to calculate at least one of a volume of urine or feces within the diaper, a flow rate of urine within the diaper, and a frequency of urine or feces excretion within the diaper; Optionally, (i) the electronic control and power unit is configured to calculate the volume, flow rate, and / or frequency using one or more software algorithms stored in the sensing device; one or more of said software algorithms are based on previously collected empirical data; (ii) the electronic control and power unit is further configured to display at least one of the calculated volume, flow rate, and / or frequency; and (iii) the electronic control and power supply unit further comprises a wireless transmitter; storing the calculated volume, flow rate, and / or frequency; and wirelessly transmitting the calculated volume, flow rate, and / or frequency to a remote device. (iv) an expandable member of the sensing device is integrated into an exterior surface of the diaper; and Consists of one or more of 17. A diaper-sensing device combination as claimed in any one of claims 13 to 16.

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