US-12616615-B2 - Sensing device for a nappy

US12616615B2US 12616615 B2US12616615 B2US 12616615B2US-12616615-B2

Abstract

There is described a sensing device for attaching to an external surface of a nappy. The sensing device comprises an expandable member comprising one or more elastic elements extending between a plurality of attachment points, wherein the attachment points are configured to fixedly attach the expandable member to the external surface of the nappy, and wherein the one or more elastic elements are configured to stretch as the attachment points move apart such that the expandable member is configured to expand in accordance with expansion of the nappy. The sensing device further comprises a detector unit coupled to the expandable member, wherein the detector unit is configured to detect expansion of the expandable member, and is further configured to determine a nappy fullness parameter based on the detected expansion of the expandable member.

Inventors

Mohamad Yasser AL AIOUBI
Syed Ejazul Huq

Assignees

Oxford Healthtech Ltd.

Dates

Publication Date: 20260505
Application Date: 20220406
Priority Date: 20210408

Claims (20)

1 . A sensing device for attaching to an external surface of a nappy, the sensing device comprising: an expandable member comprising one or more elastic elements extending between a plurality of attachment points, wherein the attachment points are configured to fixedly attach the expandable member to the external surface of the nappy, and wherein the one or more elastic elements are configured to stretch as the attachment points move apart such that the expandable member is configured to expand in accordance with expansion of the nappy; and a detector unit coupled to the expandable member, wherein the detector unit is configured to detect expansion of the expandable member, and is further configured to determine a nappy fullness parameter based on the detected expansion of the expandable member.
2 . The sensing device of claim 1 , wherein the expandable member is sized and shaped to cover a substantial area of the external surface of the nappy, with at least some of the attachment points configured to be disposed on or near to edges of the nappy.
3 . The sensing device of claim 2 , wherein the expandable member is sized and shaped to extend across a full width of a crotch region of the nappy.
4 . The sensing device of claim 1 , wherein the detector unit comprises one of: an optical detector, a resistive detector, or a capacitive detector.
5 . The sensing device of claim 1 , wherein the one or more elastic elements comprise multiple elastic elements arranged in a polygon with the attachment points at one or more corners of the polygon.
6 . The sensing device of claim 5 , wherein the expandable member further comprises one or more transverse elastic elements extending between the multiple elastic elements, wherein the one or more transverse elastic elements are concentrated within a specified area of the polygon.
7 . The sensing device of claim 1 , wherein the one or more elastic elements comprise one of an elastic patch or an elastic net, and wherein the attachment points comprise attachment points at a periphery of the one of an elastic patch or an elastic net.
8 . The sensing device of claim 1 , wherein the detector unit is configured to detect expansion of the expandable member by detecting a relative displacement between the attachment points.
9 . The sensing device of claim 1 , wherein the attachment points comprise a detector unit attachment point directly coupled to the detector unit, wherein: (i) the detector unit is configured to detect expansion of the expandable member by detecting a relative displacement between the detector unit attachment point and at least one other attachment point; (ii) the relative displacement between the detector unit attachment point and the at least one other attachment point is configured to cause the expandable member to pull the detector unit attachment point in a direction away from the detector unit; (iii) the detector unit comprises a light source and a light detector, and wherein the detector unit is configured such that an amount of light reaching the light detector from the light source varies in dependence on the relative displacement between the detector unit attachment point and the at least one other attachment point, thereby producing a change in an output signal from the light detector; (iv) the attachment points further comprise: a first attachment point connected to the detector unit attachment point via a longitudinal elastic element; and one or more secondary attachment points connected to the longitudinal elastic element via one or more transverse elastic elements; and (v) a central junction point is connected to the detector unit attachment point via a central elastic element; and wherein the attachment points further comprise multiple attachment points spaced around the central junction point, the multiple attachment points connected to the central junction point via respective radial elastic elements.
10 . The sensing device of claim 1 , wherein the one or more elastic elements are conductive, and wherein the detector unit 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, further wherein the detector unit 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.
11 . The sensing device of claim 10 , wherein the detector unit is configured to detect expansion of the expandable member by detecting a change in capacitance due to the change in length of the at least one elastic element, wherein: (i) the attachment points comprise a first set of attachment points connected via a first set of the one or more elastic elements so as to form a first digitated pattern, and a second set of attachment points connected via a second set of the one or more elastic elements so as to form a second digitated pattern, and wherein the first and second patterns are arranged in an interdigitated pattern; and (ii) the detector unit is further configured to detect expansion of the expandable member by detecting a change in capacitance due to a change in interdigitation of the first and second patterns.
12 . The sensing device of claim 1 , wherein the attachment points are connected via elastic elements so as to form a meandering pattern, the attachment points positioned at each turn of the meandering pattern.
13 . The sensing device of claim 1 , further comprising a sensor element on the one or more elastic elements, the sensor element configured to provide a sensor signal to the detector unit, wherein the sensor signal varies in dependence on an amount of stretching of the one or more elastic elements, further wherein: the detector unit further comprises a light source and light detector; the sensor element comprises two optical fibres arranged such that stretching of the one or more elastic elements causes a relative displacement between the two optical fibres; the sensing device is configured such that the relative displacement between the two optical fibres results in a change in the amount of light reaching the light detector, thereby producing a change in an output signal from the light detector; and the detector unit comprises a gyroscope or an accelerometer configured to detect movement.
14 . A combined nappy and sensing device comprising: a nappy; and a sensing device comprising: an expandable member comprising one or more elastic elements extending between a plurality of attachment points, wherein the attachment points are configured to fixedly attach the expandable member to an external surface of the nappy, and wherein the one or more elastic elements are configured to stretch as the attachment points move apart such that the expandable member is configured to expand in accordance with expansion of the nappy; a detector unit coupled to the expandable member, wherein the detector unit is configured to detect expansion of the expandable member, and is further configured to determine a nappy fullness parameter based on the detected expansion of the expandable member; and an electronic control and power supply unit configured to power the sensing device; and wherein the attachment points of the expandable member are fixedly attached to the external surface of the nappy.
15 . The combined nappy and sensing device of claim 14 , wherein the electronic control and power supply unit comprises the detector unit and the detector unit is mounted on a waistband of the nappy.
16 . The combined nappy and sensing device of claim 14 , wherein the attachment points of the expandable member are fixedly attached to one of: a front of the nappy, a back of the nappy, a crotch region of the nappy, elasticated edges of the nappy, a waistband of the nappy, or a combination thereof.
17 . The combined nappy and sensing device of claim 14 , further comprising one or more additional sensing devices, wherein the sensing device and the one or more additional sensing devices are configured to detect expansion at different locations on the external surface of the nappy.
18 . The combined nappy and sensing device of claim 14 , wherein the electronic control and power supply unit is further configured to calculate at least one of: a volume of urine and/or feces inside the nappy; a flow rate of urine inside the nappy; and a frequency of urine and/or feces discharge inside the nappy, wherein the electronic control and power supply unit is configured to calculate at least one of the volume, flow rate, or frequency using one or more software algorithms stored on the device, wherein the one or more software algorithms are based on previously collected empirical data.
19 . The combined nappy and sensing device of claim 18 , wherein the electronic control and power supply unit is further configured to display at least one of the calculated volume, flow rate, or frequency.
20 . The combined nappy and sensing device of claim 18 , wherein the electronic control and power supply unit further comprises a wireless transmitter and is further configured to: store at least one of the calculated volume, flow rate, or frequency; and wirelessly transmit at least one of the calculated volume, flow rate, or frequency to a remote device; and further wherein the expandable member of the sensing device is integrated onto the external surface of the nappy.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. national phase application of International Patent Application No. PCT/GB2022/050862, filed on Apr. 6, 2022, which, in turn, is based upon and claims the right of priority to European Patent Application No. 2105043.0, filed on Apr. 8, 2021, the disclosures of all of which are hereby incorporated by reference herein in their entireties by reference for all purposes. FIELD OF INVENTION This invention relates to a sensing device for attaching to an external surface of a nappy so as to determine a nappy fullness parameter. This invention also relates to a combined nappy and sensing device. Sensing elements of the sensing device can be attachable to or integrated onto the external surface of the nappy. BACKGROUND Incontinence products such as nappies/diapers, incontinence pads and underwear allow a wearer to urinate and/or defecate without using a lavatory. The incontinence products comprise an absorbing layer to contain urine and/or feces and prevent leakage onto outer clothing. Incontinence products can be used for children (bed wetting) as well adults, particularly those with illnesses linked to incontinence. When a nappy, or other incontinence product, becomes soiled with urine and/or feces, it requires changing, usually by another person (e.g., a carer). Since nappy wearers may be often unable to replace the nappy themselves, or even be unable to communicate that the nappy requires changing, the carer must manually check the nappy for soiling periodically throughout the day. This involves changing the nappy, possibly unnecessarily, thereby wasting the carer's valuable time and associated costs. On the other hand, failure to change a nappy on a sufficiently regular basis may lead to problems such as the wearer feeling uncomfortable, a negative effect on the wearer's dignity, and/or skin problems, such as rashes, bed sores, and infections. Therefore, there is a need for an improved process for detecting the fullness of a nappy, or other incontinence products. Detecting fullness of a nappy would also be useful for babies. SUMMARY According to a first aspect of the present invention, there is provided a sensing device for attaching to an external surface of a nappy. The sensing device comprises an expandable member. The expandable member comprises one or more elastic elements extending between a plurality of attachment points. The attachment points are configured to fixedly attach the expandable member to the external surface of the nappy. Preferably, some or all of the attachment points are disposed on or near to edges of the nappy, such as elasticated edges. The one or more elastic elements are configured to stretch as the attachment points move apart such that the expandable member is configured to expand in accordance with expansion of the nappy (i.e. as the nappy fills up). The sensing device further comprises a detector unit coupled to the expandable member. The detector unit is configured to detect expansion of the expandable member. The detector unit is further configured to determine a nappy fullness parameter based on the detected expansion of the expandable member. According to a second aspect of the present invention, there is provided a combined nappy and sensing device comprising a nappy and the sensing device described above. The sensing device further comprises an electronic control and power supply unit configured to power the sensing device. The electronic control and power supply unit preferably includes the detector unit described above. The attachment points of the expandable member are fixedly attached to the external surface of the nappy. In some examples, the sensing device is attached to the external surface of the nappy after the nappy has been manufactured. In other examples, the expandable member of the sensing device is integrated onto (i.e., created on) the external surface of the nappy during manufacture. The detector unit may then be attached to the expandable member, e.g., via a loop. There are also other advantageous aspects of the invention described in the detailed description below. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention can be more readily understood, reference will now be made by way of example only, to the accompanying drawings in which: FIG. 1 is a plan view of an exemplary sensing device attached to the external surface of a nappy. FIGS. 2-8 are plan views of alternative configurations of exemplary sensing devices attached to the external surface of a nappy. FIG. 9a is a cross-sectional view of an exemplary optical detector for use with the sensing device of any of FIGS. 1-8. In FIG. 9a, an expandable member of the sensing device is in an unexpanded state. FIG. 9b is a plan view of the arrangement of FIG. 9a. FIG. 9c is a cross-sectional view of the exemplary optical detector in FIGS. 9a-9b, when the expandable member of the sensing device is in an expanded state. FIG. 9d is a plan