Absorbent articles and methods for detecting body fluids
The absorbent article with strategically placed conductive members addresses the conductivity issues in metal-based urine sensors, enabling reliable detection of urine leakage by maintaining stable current flow, particularly suitable for mild urinary incontinence.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- NIPPON PAPER CRECIA CO LTD
- Filing Date
- 2024-10-24
- Publication Date
- 2026-05-12
AI Technical Summary
Existing absorbent articles, such as those described in Patent Document 1, fail to accurately detect mild urinary incontinence due to issues with conductivity in metal-based urine sensors, which can be hindered by electrolytic reactions with sodium chloride in urine.
An absorbent article with conductive members spaced apart in the width direction, allowing for stable current flow through metal conductive members, even in the presence of electrolyte solutions, by using thread-like members made of metal or alloys like iron, arranged in a straight line parallel to the longitudinal direction.
Enables reliable detection of urine leakage by ensuring stable current flow, accurately detecting both the timing and volume of urination.
Smart Images

Figure 2026076664000001_ABST
Abstract
Description
[Technical Field]
[0001] This disclosure relates to an absorbent article equipped with a mechanism for detecting bodily fluids such as urine, and to a method for detecting bodily fluids in an absorbent article. [Background technology]
[0002] Patent Document 1 discloses a wearable article with a sensor. This wearable article with a sensor has a urination sensor attached to one of the sheets that make up the wearable article. The urination sensor is composed of a printed substrate made of a resin film, a plurality of printed electrodes that form a sensor element using conductive ink applied to the surface of the printed substrate, a conductive wire portion that connects these plurality of printed electrodes, and a terminal portion to which the conductive wire portion is connected. The printed substrate has ventilation openings that function as ventilation areas. The urination sensor has printed electrodes in close contact with the surface of the back sheet of the urine absorption pad, and is covered with a covering sheet coated with adhesive, and attached to the back sheet of the urine absorption pad. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 2017-189348 [Overview of the project] [Problems that the invention aims to solve]
[0004] However, conventional technologies, including the wearable item with a sensor described in Patent Document 1, are based on the premise of detecting severe urinary incontinence, and have the problem that they are not suitable as a mechanism for mild urinary incontinence because they have difficulty detecting mild urinary incontinence.
[0005] Furthermore, when metal is used as a urine sensor (conductive component), the electrolytic reaction of sodium chloride in urine can cause the metal to oxidize, potentially hindering conductivity. If conductivity is hindered, the electrical state cannot be accurately detected, making it impossible to accurately detect urine leakage.
[0006] Therefore, the present disclosure aims to provide an absorbent article and a bodily fluid detection method that can reliably detect urine leakage by ensuring stable current flow through a metal conductive member. [Means for solving the problem]
[0007] To solve the above problems, a first aspect of the present invention provides an absorbent article comprising a liquid-permeable skin-side sheet, a liquid-impermeable non-skin-side sheet, and an absorbent disposed between the skin-side sheet and the non-skin-side sheet, wherein the absorbent article is provided with at least one conductive member on one side and at least one conductive member on the other side, spaced apart in the width direction of the absorbent article with respect to the center line in the width direction of the absorbent article, and the conductive members are capable of continuous current flow in an electrolyte aqueous solution.
[0008] A second aspect of the present invention is an absorbent article according to the first aspect, wherein the distance between at least one of the conductive members on one side and at least one of the conductive members on the other side is 10 mm or more and less than 50 mm.
[0009] A third aspect of the present invention is an absorbent article according to the first or second aspect, wherein the conductive member is a thread-like member.
[0010] A fourth aspect of the present invention is an absorbent article according to the third aspect, wherein the thread-like member is made of metal only.
[0011] A fifth aspect of the present invention is an absorbent article according to the fourth aspect, wherein the filamentous member is plated with metal.
[0012] A sixth aspect of the present invention is an absorbent article according to the fourth aspect, wherein the thread-like member is an alloy mainly composed of iron.
[0013] A seventh aspect of the present invention is an absorbent article according to the third aspect, wherein the thread-like members are arranged substantially in a straight line parallel to the longitudinal direction of the absorbent article.
[0014] An eighth aspect of the present invention is an absorbent article according to the first or second aspect, wherein the current supplied to the conductive member on one side and the conductive member on the other side is 1 mA or less.
[0015] A ninth aspect of the present invention is a method for detecting body fluids in an absorbent article comprising a liquid-permeable skin-side sheet, a liquid-impermeable non-skin-side sheet, and an absorbent disposed between the skin-side sheet and the non-skin-side sheet, wherein at least one conductive member is disposed between the absorbent and the non-skin-side sheet, spaced apart in the width direction of the absorbent article with respect to the center line in the width direction, and at least one conductive member is disposed on the other side, and body fluids are detected based on the time-series change in the degree of current flow between the conductive member on the one side and the conductive member on the other side. [Effects of the Invention]
[0016] According to this disclosure, it is possible to provide an absorbent article and a bodily fluid detection method that can reliably detect urine leakage by ensuring stable current flow through a metal conductive member. [Brief explanation of the drawing]
[0017] [Figure 1] This diagram schematically shows the overall configuration of the body fluid detection device in the embodiment. [Figure 2] This is a cross-sectional view taken along arrow II in Figure 1(A) of a light incontinence pad for a body fluid detection device, which is an embodiment of the present invention. [Figure 3]It is a plan view schematically showing a formation mode of a conductive part of a light incontinence pad according to an embodiment. [Figure 4] It is a plan view explaining the interval between conductive members of a light incontinence pad according to an embodiment. [Figure 5] It is a side view of the connector in FIG. 1, where (A) shows the closed state and (B) shows the open state respectively. [Figure 6] It is a perspective view of the connector in the open state. [Figure 7] It is a plan view of the terminal part of the connector. [Figure 8] It is a cross-sectional view taken along the arrow VIII-VIII in FIG. 7. [Figure 9] It is an enlarged view of the IX part in FIG. 7. [Figure 10] It is a plan view schematically showing a state where the connector in FIG. 5 is attached to an end part in the longitudinal direction of a light incontinence pad according to an embodiment. [Figure 11] It is a figure showing the result of this verification test.
Mode for Carrying Out the Invention
[0018] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, an absorbent article according to the present invention (specifically, the light incontinence pad 2) is incorporated into the body fluid detection device 1 shown in FIG. 1. Further, in the following embodiments, the body fluid detection method according to the present invention is applied to the detection of body fluid in the absorbent article (specifically, the light incontinence pad 2) of the body fluid detection device 1 shown in FIG. 1. Note that each figure does not define the mutual size relationship and shape of the dimensions of each component.
[0019] In the following explanation, the following definitions apply: Wearing the light incontinence pad 2 means the state in which the light incontinence pad 2 is attached to the body (specifically, the lower body, lower abdomen), regardless of whether or not bodily fluids have been absorbed. The light incontinence pad 2 is attached to the body inside clothing, but it may also be attached to the body so that at least a part of it is exposed to the outside. The longitudinal direction is the direction that runs from the front to the back of the body through the wearer's crotch when the light incontinence pad 2 is worn, and is the X-axis direction in each figure. The width direction is the direction perpendicular to the longitudinal direction, and is the Y-axis direction in each figure. The thickness direction is the direction perpendicular to the longitudinal and width directions, and is the direction in which each component is stacked, and is the Z-axis direction in each figure. A plane is the XY plane along the X-axis and Y-axis in each figure. A longitudinal side is the side along the longitudinal direction, and is the XZ plane along the X-axis and Z-axis in each figure. The longitudinal section is a section along the longitudinal direction, and is the XZ section along the X and Z axes in each figure. The width side is a side along the width direction, and is the YZ plane along the Y and Z axes in each figure. The skin side is the surface that comes into contact with the wearer's skin when the light incontinence pad 2 is worn, or the surface facing the skin, and is the side in the direction of the Z-axis arrow in each figure. The non-skin side is the surface that comes into contact with the wearer's clothing when the light incontinence pad 2 is worn, or the surface facing the clothing, and is the side opposite to the direction of the Z-axis arrow in each figure. Body fluids refer to liquids that are expelled from the body to the outside, such as urine, blood, and water in loose stools.
[0020] (Body fluid detection device) Figure 1 is a schematic diagram showing the overall configuration of a body fluid detection device 1, including a light incontinence pad 2 according to an embodiment, as an example of a specific configuration of the absorbent article according to the present invention.
[0021] It should be noted that the application of the present invention is not limited to light incontinence pads, and the present invention can be applied to various absorbent articles. Examples of absorbent articles to which the present invention can be applied include various articles that have absorbency, whether for babies or adults, such as urine absorbent pads, pant-type disposable diapers, and tape-fastened disposable diapers, in addition to light incontinence pads. For example, a disposable diaper as an outer layer and a light incontinence pad as an inner layer may be combined. Furthermore, absorbent articles to which the present invention can be applied may be absorbent articles in which an absorbent material is integrated into a cloth outer layer (such as absorbent shorts).
[0022] The bodily fluid detection device 1 in this embodiment is a mechanism for detecting bodily fluids (specifically, for example, relatively small amounts of urine associated with mild urinary incontinence) and transmitting data related to the detection of the bodily fluids to an external terminal. The bodily fluid detection device 1 comprises a light incontinence pad (absorbent material) 2 and a bodily fluid detection device 100 that is detachable from the light incontinence pad 2. The bodily fluid detection device 100 has a connector 3 and a transmitter 9. The connector 3 and the transmitter 9 are electrically connected via a connector harness 10.
[0023] (Light incontinence pads) Figure 2 is a cross-sectional view of the light incontinence pad 2 taken along the line II in Figure 1(A). Figure 3 is a schematic plan view showing the formation of the conductive part of the light incontinence pad according to the embodiment. In Figure 2, for clarity, some of the components are shown spaced apart from each other in the thickness direction, but each component is basically in close contact with each other in the thickness direction. However, there may be partial gaps between the components.
[0024] As shown in Figures 2 and 3, the light incontinence pad (absorbent article) 2 according to this embodiment comprises a liquid-permeable skin-side sheet 21, a liquid-impermeable non-skin-side sheet 23, an absorbent body 22 disposed between the skin-side sheet 21 and the non-skin-side sheet 23, and a detection unit 24 for detecting urine leakage. The detection unit 24 is located within the light incontinence pad 2 and has at least one conductive member 24c on one side and at least one conductive member 24c on the other side, spaced apart in the width direction with respect to the center line in the width direction of the light incontinence pad 2. Furthermore, the light incontinence pad 2 of this embodiment comprises a carrier sheet 26 disposed between the absorbent body 22 and the non-skin-side sheet 23, and a second sheet 27 disposed between the absorbent body 22 and the skin-side sheet 21. The light incontinence pad 2 has a structure in which the absorbent body 22 is sandwiched between the skin-side sheet 21 and the non-skin-side sheet 23. Body fluids are absorbed and retained by the absorbent body 22 through the skin-side sheet 21. The light incontinence pad 2 may also be equipped with three-dimensional gathers on the left and right sides. In the following description, one side of the center line in the width direction will be simply referred to as "one side," and the other side of the center line in the width direction will be simply referred to as "the other side."
[0025] Furthermore, the body fluid detection method according to this embodiment is a method for detecting body fluids in a light incontinence pad 2 comprising a liquid-permeable skin-side sheet 21, a liquid-impermeable non-skin-side sheet 23, and an absorbent body 22 disposed between the skin-side sheet 21 and the non-skin-side sheet 23. In the body fluid detection method according to this embodiment, at least one conductive member 24c is placed on one side and at least one conductive member 24c on the other side, spaced apart in the width direction with the center line in the width direction of the light incontinence pad 2 between the absorbent body 22 and the non-skin-side sheet 23. In the body fluid detection method according to this embodiment, body fluids are detected based on the time-series change in the degree of current flow between the conductive member 24c on one side and the conductive member 24c on the other side.
[0026] (Skin-side sheet) The skin-side sheet 21 is a liquid-permeable sheet-like member that allows bodily fluids to pass quickly toward the absorbent 22, and is positioned opposite the non-skin-side sheet 23, with the absorbent 22 in between. The skin-side sheet 21 is not limited to any particular configuration or structure as long as it is liquid-permeable. The shape of the skin-side sheet 21 in plan view is not limited to any particular shape, and may be any shape that covers part or all of the skin-side of the absorbent 22, as necessary to guide bodily fluids toward the absorbent 22 without leakage. When the light incontinence pad 2 is worn, the skin-side sheet 21 is positioned on the skin side of the wearer and constitutes the skin-side of the light incontinence pad 2.
[0027] The base material for the skin-side sheet 21 is not limited to any particular material, as long as it can achieve liquid permeability. Examples of base materials for the skin-side sheet 21 include nonwoven fabrics obtained by processing composite fibers of polyethylene (PE) and polypropylene (PP), or composite fibers of polyethylene (PE) and polyester, using known methods. Examples of known methods include the air-through method, thermal bonding method, spunlace method, and spunbond method.
[0028] (Second row seats) In this embodiment, a second sheet 27 is placed between the absorbent material 22 and the skin-side sheet 21. By placing the second sheet 27, cushioning is increased, improving fit and wearing comfort, and bodily fluids that have permeated through the skin-side sheet 21 can be diffused almost uniformly throughout the absorbent material 22, thereby improving the ability to detect urination.
[0029] The base material of the second sheet 27 is, for example, a bulky nonwoven fabric that allows bodily fluids to permeate faster than the skin-side sheet 21 and quickly diffuse bodily fluids into the absorbent material 22. Air-through nonwoven fabrics and spunbond nonwoven fabrics are preferred as the nonwoven fabric. The shape of the second sheet 27 is not particularly limited, but in a preferred embodiment, it is shaped to completely cover the surface of the absorbent material 22.
[0030] The base material of the second sheet 27 is not particularly limited, but it is preferable that the rate of bodily fluid permeation is faster than that of the skin-side sheet 21 and that bodily fluids are quickly diffused into the absorbent material 22. For example, hydrophilic nonwoven fabrics, and especially air-through nonwoven fabrics, are preferred. The thickness of the second sheet 27 is preferably 0.1 mm or more. The basis weight of the second sheet 27 is preferably 10 g / m². 2 More than 60g / m 2 Preferably, the following conditions apply: The thickness of the second sheet 27 is less than 0.1 mm, or the basis weight of the second sheet 27 is 10 g / m². 2 Less than 60g / m² 2 If the value is greater than this, the liquid will not diffuse sufficiently in the planar direction of the absorbent material 22, and the urine detection capability will decrease. The lower limit of the basis weight range for the second sheet 27 is 15 g / m². 2 It is more preferable that the above conditions are met. Furthermore, the upper limit of the above range for the basis weight of the second sheet 27 is 40 g / m². 2 The following is more preferable:
[0031] Furthermore, the ratio of the basis weight of the skin-side sheet 21 to the second sheet 27 (hereinafter simply referred to as the "basis weight ratio") is preferably 50% or more and 130% or less. By setting the basis weight ratio to 50% or more and 130% or less, the liquid diffusion and liquid permeability when liquid permeates from the skin-side sheet 21 to the second sheet 27 is improved, improving the urination detection ability and making it more difficult for liquid to flow back from the second sheet 27 to the skin-side sheet 21. Furthermore, it is more preferable that the upper limit of the above range for the basis weight ratio is 100% or less.
[0032] The skin-side sheet 21 and the second sheet 27 are preferably bonded together by heat-seal embossing (embossing by heat fusion). The heat-seal embossing is preferably discontinuous, and the distance between embossings is preferably between 2 mm and 10 mm. By keeping the distance between embossings within the above range, reliable bonding and fixation can be achieved while maintaining good liquid diffusion and a pleasant feel (softness). The lower limit of the above range for the distance between embossings is more preferably 4 mm or more. Furthermore, the upper limit of the above range for the distance between embossings is more preferably 8 mm or less.
[0033] (Absorbent) As shown in Figure 2, the absorbent body 22 is positioned between the skin-side sheet 21 and the non-skin-side sheet 23 to absorb and retain bodily fluids. The absorbent body 22 is not limited to any particular composition or structure, but may be formed, for example, by mixing fluff pulp and a superabsorbent polymer (hereinafter sometimes referred to as "SAP"). The shape of the absorbent body 22 in plan view is not limited to any particular shape, but examples include rectangular, hourglass, I-shaped, a rectangular shape with rounded corners, an elliptical shape, and a teardrop shape.
[0034] (Non-skin side sheet) The non-skin side sheet 23 is a component that prevents bodily fluids held by the absorbent material 22 from wetting clothing or adhering to the skin surface, and is a breathable or non-breathable liquid-impermeable sheet-like component. The non-skin side sheet 23 is not limited to any specific configuration or structure as long as it is liquid-impermeable. In a plan view, the non-skin side sheet 23 is formed to be approximately the same shape and size as the skin side sheet 21, and is positioned opposite the skin side sheet 21, with the absorbent material 22 in between. When the light incontinence pad 2 is worn, the non-skin side sheet 23 is located relatively on the opposite side from the wearer's skin, forming the non-skin side of the light incontinence pad 2.
[0035] The base material for the non-skin side sheet 23 is not limited to any particular material, as long as it can achieve liquid impermeability. Examples of base materials for the non-skin side sheet 23 include resin films made of synthetic resins such as polyethylene (PE).
[0036] An adhesive layer (not shown) is formed on the skin side of the non-skin side sheet 23. The adhesive layer may be formed, for example, by spray application of a rubber-based hot melt adhesive in a mist-like manner or by spiral application of a rubber-based hot melt adhesive in a spiral linear manner on the skin side of the non-skin side sheet 23.
[0037] (Career Sheet) In this embodiment, a carrier sheet 26 is placed between the absorbent 22 and the non-skin side sheet 23 for the purpose of preventing leakage of SAP particles from the absorbent 22 and stabilizing the shape of the absorbent 22. The base material of the carrier sheet 26 can be any hydrophilic material, such as tissue, absorbent paper, airlaid nonwoven fabric, or spunbond nonwoven fabric. Among these, a hydrophilic spunbond nonwoven fabric is preferred as the carrier sheet 26 in this embodiment. Furthermore, if multiple carrier sheets 26 are provided, the base materials of the multiple carrier sheets 26 may be the same or different. Note that the placement position of the carrier sheet 26 is not limited to between the absorbent 22 and the non-skin side sheet 23, but can be provided at any desired position. In addition, although a carrier sheet 26 is provided in this embodiment, it is not necessary to provide a carrier sheet 26.
[0038] (Detection unit) A detection unit 24 for detecting urine leakage is provided inside the light incontinence pad 2. In this embodiment, the detection unit 24 is provided between the absorbent material 22 and the non-skin side sheet 23 (specifically, between the carrier sheet 26 and the non-skin side sheet 23). The detection unit 24 has a pair of conductive parts 24a and 24b.
[0039] Each of the pair of conductive parts 24a and 24b has at least one conductive member 24c. The pair of conductive parts 24a and 24b are arranged between the absorbent body 22 and the non-skin side sheet 23, spaced apart in the width direction with a center line in the width direction in between. That is, the pair of conductive parts 24a and 24b are provided in a manner that they do not contact or intersect with each other, and therefore are not conductive to each other (see Figure 3). Thus, the light incontinence pad 2 has at least one conductive member 24c on one side and at least one conductive member 24c on the other side, spaced apart in the width direction with a center line in the width direction of the light incontinence pad 2. Note that in Figure 3, the skin side sheet 21, the second sheet 27, and the carrier sheet 26 are not shown, and the crimping area 25 is virtually shown by a dashed line.
[0040] A weak current (DC) is continuously supplied from the power supply 5, which will be described later, to the conductive members 24c of the pair of conductive parts 24a and 24b. (Conductive material) The pair of conductive parts 24a and 24b are composed of conductive filamentous conductive members 24c. The conductive members 24c according to this embodiment can conduct electricity continuously in an electrolyte aqueous solution. Specifically, the conductive members 24c are materials that do not fail to conduct electricity within 3 hours, more preferably within 5 hours, and even more preferably within 8 hours when immersed in an electrolyte solution (for example, physiological saline solution with a concentration of 0.9%) and subjected to electricity. Examples of such materials include copper, silver, iron, tin, and the like.
[0041] The conductive member 24c is preferably a thread-like member. When the conductive member 24c is a thread-like member, it is thin and does not hinder the flexibility of the light incontinence pad 2 (it does not become rigid), thus providing excellent fit for the light incontinence pad 2. Examples of conductive members 24c include metal conductors such as tin-plated copper stranded wire (made by bundling together multiple copper wires with tin plating on the surface). Examples of metal conductors include silver-plated wire, which is copper wire with silver plating on the surface, stainless steel wire, and aluminum wire. The metal conductor may be a single wire or a stranded wire made by twisting multiple wires together.
[0042] Examples of metals used for plating the conductive member 24c include silver, gold, iron, and tin. The plating thickness is preferably between 0.1 μm and 3.0 μm. If the plating thickness is less than 0.1 μm, the likelihood of poor electrical conductivity increases. On the other hand, if the plating thickness is greater than 3.0 μm, the conductive member 24c becomes hard, impairing wearing comfort and potentially making it difficult to handle during operation. The upper limit of the above range for the plating thickness is more preferably 1.0 μm or less, and even more preferably 0.5 μm or less.
[0043] The conductive member 24c may be made of metal only. For example, the conductive member 24c may be a metal conductor made of copper, aluminum, or an alloy wire thereof, plated with silver, gold, tin, etc.
[0044] Alternatively, the conductive member 24c may be an alloy mainly composed of iron. For example, the conductive member 24c may be SUS304 or SUS316 (austenitic stainless steel).
[0045] The diameter of the conductive member 24c is preferably 0.03 mm or more and 2 mm or less. If the diameter of the conductive member 24c is smaller than 0.03 mm, the risk of wire breakage increases. On the other hand, if the diameter of the conductive member 24c is larger than 2 mm, the conductive member 24c becomes hard, which impairs wearing comfort and may make it difficult to handle during operation.
[0046] The weight per unit length of the conductive member 24c is preferably 3 mg / m or more and less than 1000 mg / m. If the weight per unit length of the conductive member 24c is less than 3 mg / m, the risk of wire breakage increases. On the other hand, if the weight per unit length of the conductive member 24c is greater than 1000 mg / m, the conductive member 24c becomes hard, impairing wearing comfort and potentially making it difficult to handle during operation. The upper limit of the above range for the weight per unit length of the conductive member 24c is more preferably less than 500 mg / m, and even more preferably less than 50 mg / m.
[0047] The conductivity of the conductive member 24c is preferably 1000 Ω / m or less, and more preferably 500 Ω / m or less. If the conductivity of the conductive member 24c is greater than 1000 Ω / m, even if bodily fluids penetrate / permeate to the absorbent body 22, the degree of current flow through the conductive parts 24a and 24b will be small, and proper urination detection will not be possible.
[0048] Each of the conductive members 24c of the pair of conductive parts 24a and 24b in this embodiment is in contact with the skin side of the non-skin side sheet 23 and the non-skin side of the carrier sheet 26. In this embodiment, the conductive members 24c are provided on the skin side of the non-skin side sheet 23 along the entire length of the absorbent body 22, each parallel to the other along the longitudinal direction, in a pair of linear shapes in a plan view. That is, the conductive members 24c in this embodiment are arranged in a substantially linear shape parallel to the longitudinal direction of the light incontinence pad 2. If the conductive members 24c are not arranged in a linear shape, the feel against the skin will be poor, which may impair the fit of the light incontinence pad 2, and stable urination detection in the longitudinal direction along the entire length of the light incontinence pad 2 will not be possible.
[0049] In this embodiment of the light incontinence pad 2, each of the pair of conductive parts 24a and 24b is made up of one conductive member 24c, but this is not limited to this. For example, at least one of the pair of conductive parts 24a and 24b may be made up of multiple (for example, about 2 to 5) conductive members 24c (see Figures 4(B) to (G)).
[0050] Here, the absorbent material 22, the non-skin side sheet 23, and the carrier sheet 26 (hereinafter sometimes referred to as "absorbent material 22, etc.") have low conductivity. Therefore, when the absorbent material 22, etc. is dry, there is no conductivity between the pair of conductive parts 24a and 24b, and current does not flow easily. In contrast, when bodily fluids penetrate / permeate into the absorbent material 22 in a way that straddles the pair of conductive parts 24a and 24b in a plan view, or connects at least a part of the conductive parts 24a and 24b, a change occurs in the ease with which current flows through the pair of conductive parts 24a and 24b. That is, when bodily fluids penetrate / permeate and the absorbent material 22, etc. becomes wet, there is conductivity between the pair of conductive parts 24a and 24b that are in contact with the absorbent material 22, etc., and current flows more easily through the pair of conductive parts 24a and 24b compared to when bodily fluids do not penetrate / permeate. In other words, the ease with which current flows through the pair of conductive parts 24a and 24b can be described as the degree of current flow between the pair of conductive parts 24a and 24b.
[0051] (Spacing of conductive members) Figure 4 is a plan view illustrating the spacing between conductive members of a light incontinence pad according to an embodiment.
[0052] The distance W between at least one conductive member 24c on one side and at least one conductive member 24c on the other side (hereinafter sometimes simply referred to as "the distance W between the pair of conductive parts 24a and 24b") is preferably 10 mm or more and less than 50 mm. If the distance W between the pair of conductive parts 24a and 24b is less than 10 mm, when the cumulative amount of absorbed bodily fluids increases due to repeated absorption, the response (fluctuation) of the current value tends to become difficult to observe clearly. On the other hand, if the distance W between the pair of conductive parts 24a and 24b is 50 mm or more, the distance W is too large compared to the diffusion area of urination, so even if urination occurs, there is a risk that no current will flow between the pair of conductive parts 24a and 24b, making it impossible to properly detect urination. The lower limit of the above range for the distance W between the pair of conductive parts 24a and 24b is more preferably 20 mm or more. The upper limit of the above range for the distance W between the pair of conductive parts 24a and 24b is more preferably less than 40 mm. Therefore, the distance W between the pair of conductive parts 24a and 24b is preferably, for example, 10 mm or more and less than 50 mm, more preferably 10 mm or more and less than 40 mm, and even more preferably 20 mm or more and less than 40 mm. When the distance W between the pair of conductive parts 24a and 24b is less than 40 mm, urination can be detected more appropriately.
[0053] For example, the distance W between a pair of conductive parts 24a and 24b is the distance between the two conductive members 24c when each of these conductive parts 24a and 24b is composed of one conductive member 24c, as shown in Figure 4(A).
[0054] Furthermore, at least one of the pair of conductive parts 24a and 24b may be composed of a plurality of conductive members 24c, in which case the distance W between the pair of conductive parts 24a and 24b is the distance between at least one of the conductive members 24c constituting one of the conductive parts 24a and at least one of the conductive members 24c constituting the other conductive part 24b.
[0055] For example, as shown in Figures 4(B) and 4(C), the distance W between the pair of conductive parts 24a and 24b may be the distance between the closest conductive members 24c between the conductive member 24c constituting one conductive part 24a and the conductive member 24c constituting the other conductive part 24b.
[0056] Furthermore, as shown in Figures 4(D) and (E), the distance W between the pair of conductive parts 24a and 24b may be the distance between the conductive member 24c that constitutes one conductive part 24a and is closest to the other conductive part 24b, and at least one of the conductive members 24c that constitute the other conductive part 24b.
[0057] Furthermore, as shown in Figure 4(F), the distance W between the pair of conductive parts 24a and 24b may be the distance between the conductive members 24c that are neither closest nor furthest apart from each other, which constitute one conductive part 24a and the other conductive part 24b.
[0058] Furthermore, as shown in Figure 4(G), the distance W between the pair of conductive parts 24a and 24b may also be the distance between the conductive members 24c that are furthest apart from each other, between the conductive members 24c that constitute one conductive part 24a and the conductive members 24c that constitute the other conductive part 24b.
[0059] Furthermore, the conductive members 24c (metal conductors in this embodiment) that constitute each of the pair of conductive parts 24a and 24b may be arranged symmetrically with respect to the center line in the width direction of the absorber 22 (a straight line along the longitudinal direction at the position indicated by arrow C in Figure 4) (Figure 4(A)(C)(F)(G)), or they may be arranged asymmetrically with respect to the center line (Figure 4(B)(D)(E)).
[0060] By setting the distance W between the pair of conductive parts 24a and 24b to the above range, it becomes possible to detect the timing and volume of urination with particularly high accuracy.
[0061] When providing a pair of conductive parts 24a and 24b on the skin-facing side of the non-skin-facing sheet 23 or carrier sheet 26, for example, an adhesive layer (not shown) is formed on the skin-facing side of the non-skin-facing sheet 23 or carrier sheet 26, and the conductive members 24c of the pair of conductive parts 24a and 24b are placed on the adhesive layer and fixed in place by adhesive. However, the method of providing a pair of conductive parts 24a and 24b on the skin-facing side of the non-skin-facing sheet 23 or carrier sheet 26 is not limited to the above.
[0062] (Crimping area) As shown in Figure 1, a pressure-sealing area 25 is formed at each of the longitudinal ends of the light incontinence pad 2, where the skin-side sheet 21, the detection section 24, and the non-skin-side sheet 23 are laminated. The pressure-sealing area 25 is formed as a sealing area by heat embossing with a knurled pattern to prevent leakage of bodily fluids. The pressure-sealing area 25 is formed to a thickness of, for example, about 0.1 mm. However, the formation of the pressure-sealing area 25 at the ends of the light incontinence pad 2 is not an essential configuration in this invention, and the pressure-sealing area 25 may be omitted.
[0063] In this embodiment, the pair of conductive parts 24a and 24b are arranged substantially parallel and in a substantially straight line along the longitudinal direction of the light incontinence pad 2, including the pressure-sensitive area 25. Therefore, the pair of conductive parts 24a and 24b are heat-embossed together with the various sheets of the light incontinence pad 2 in the pressure-sensitive area 25. It is preferable that the distance W between the pair of conductive parts 24a and 24b is a constant width along the entire length in the longitudinal direction.
[0064] <Body fluid detection device> As shown in Figure 1, the bodily fluid detection device 100 according to this embodiment comprises a transmitter 9 and a connector 3. The transmitter 9 and the connector 3 are electrically connected via a connector harness 10.
[0065] (connector) Figure 5 is a side view of the connector in Figure 1, where (A) shows the closed state and (B) shows the open state. Figure 6 is a perspective view of the connector in the open state. Figure 7 is a plan view of the terminal portion of the connector. Figure 8 is a cross-sectional view taken along the line VIII-VIII in Figure 7. Figure 9 is an enlarged view of portion IX in Figure 7. Note that in each figure, the connector 3 is shown based on the orientation when the connector 3 is attached to the light incontinence pad 2 (hereinafter referred to as the "connector attached state").
[0066] As shown in Figure 1, the connector 3 is detachably attached to the end of the light incontinence pad 2 in the longitudinal direction (crimping area 25 in this embodiment), and is a mechanism for electrically connecting the detection unit 24 of the light incontinence pad 2 and the transmitter 9 via the connector harness 10. The connector 3 may be attached to the crimping area 25 on both sides of the longitudinal direction of the light incontinence pad 2, which is located on the front (abdominal) side of the wearer's body when the pad is attached to the wearer's body, or it may be attached to the crimping area 25 located on the rear (dorsal) side of the wearer. When attaching the connector 3 to the light incontinence pad 2, the predetermined direction of the connector 3 is attached parallel to the longitudinal direction of the light incontinence pad 2. In the following description, the predetermined direction of the connector 3 along the longitudinal direction of the light incontinence pad 2 when the connector is attached is referred to as the "reference direction".
[0067] As shown in Figures 5 and 6, the connector 3 has a non-conductive (e.g., made of resin) bottom part 3a and a non-conductive top part 3b. One end of the bottom part 3a in the reference direction (the longitudinal direction of the light incontinence pad 2 when the connector is attached) and one end of the top part 3b in the reference direction are connected to each other so as to be tiltable about a hinge axis (axis) CL that extends in a direction perpendicular to the reference direction (the width direction of the light incontinence pad 2 when the connector is attached). The bottom part 3a and the top part 3b are connected to each other so as to be rotatable so as to be able to open and close their other ends in the reference direction (the side that is attached to the crimping area 25 of the light incontinence pad 2 (hereinafter referred to as the "tip side")). As shown in Figure 5, the connector 3 can be in a closed state with the tip side closed (see Figure 5(A)) and an open state with the tip side open (see Figure 5(B)). Thus, the connector 3 is formed so that its tip can be opened and closed around the hinge axis CL, and can be attached to and detached from the light incontinence pad 2 as described later. The method of connecting the bottom part 3a and the top part 3b so that they can tilt around the hinge axis CL is not particularly limited. For example, as in this embodiment, the bottom part 3a and the top part 3b may be connected via a rod-shaped member extending in the width direction (such as the hinge pin 3c described later), or one end of the bottom part 3a and the top part 3b may be integrally molded via a deformable thin-walled portion.
[0068] (Bottom parts) As shown in Figures 5 and 6, the bottom part 3a is formed as a non-conductive part. In this embodiment, the bottom part 3a has a pair of terminal portions 4 on its skin side. The material of the bottom part 3a is not limited to any particular type as long as it can achieve non-conductivity. Examples of materials for the bottom part 3a include non-conductive synthetic resins such as ABS resin.
[0069] A wall portion 3d is formed on the tip side of the bottom part 3a, extending in the axial direction of the hinge axis CL (hereinafter referred to as the "hinge axis direction") while protruding toward the skin side. A pair of terminal portions 4 are provided in a region 3e where the height on the hinge axis CL side is lower than that of the wall portion 3d. In addition, a bottom-side locking portion (not shown) for locking the top part 3b is provided on the hinge axis CL side surface of the wall portion 3d.
[0070] (Top part) As shown in Figures 5 and 6, the top part 3b is formed as a non-conductive part. In this embodiment, the top part 3b is rotatably connected to the bottom part 3a via a hinge pin 3c. The material of the top part 3b is not limited to any particular type, as long as it can achieve non-conductivity. Examples of materials for the top part 3b include a synthetic resin such as ABS resin, which is non-conductive, similar to the bottom part 3a.
[0071] As shown in Figure 5(B), the thickness t of the top part 3b is set to approximately the same value as the height h of the wall portion 3d of the bottom part 3a. The length of the top part 3b in the hinge axis direction is set to approximately the same length as the length of the bottom part 3a in the hinge axis direction. The length of the top part 3b in the reference direction when it is closed is set to approximately the same length as the length of the region 3e in the reference direction which is lower in height than the wall portion 3d of the bottom part 3a. As shown in Figure 5(A), when the top part 3b is closed, it fits into the region 3e which is lower in height than the wall portion 3d of the bottom part 3a, and the surface of the top part 3b is located on approximately the same plane as the surface of the wall portion 3d of the bottom part 3a. A top-side locking portion 3f (see Figure 6) that locks the bottom-side locking portion is provided on the tip side of the top part 3b when it is closed.
[0072] (Hinge pin) The hinge pin 3c is positioned along a direction perpendicular to the reference direction, with its axis (hinge axis CL) perpendicular to the reference direction. The hinge pin 3c connects the bottom part 3a and the top part 3b so that the top part 3b can rotate circumferentially relative to the bottom part 3a with the hinge axis CL as the pivot point.
[0073] (terminal part) As shown in Figure 6, the connector 3 has a pair of terminal portions 4 that are electrically connected to a pair of conductive portions 24a, 24b (conductive members 24c) of the light incontinence pad 2 when the connector is attached. Each of the pair of terminal portions 4 is formed as a conductive metal part and is electrically connected to the power supply 5 via the conductors of the connector harness 10. In this embodiment, the pair of terminal portions 4 are arranged on the inner surface of the bottom part 3a spaced apart from each other in the hinge axis direction. That is, the pair of terminal portions 4 are held in the bottom part 3a in a state where they are not in contact with each other, and consequently, where they are not conductive to each other. The inner surface of the bottom part 3a is the surface that faces the top part 3b when it is closed, and in this embodiment, it is the surface that faces the skin when the connector is attached.
[0074] (Dimensions of the terminal section) As shown in Figure 7, the length L1 of the terminal portion 4 in the reference direction is preferably 1.5 mm or more and 6.0 mm or less. If the length L1 of the terminal portion 4 in the reference direction is less than 1.5 mm, it becomes difficult to align the terminal portion 4 in the reference direction (longitudinal direction) for electrically connecting it to the pair of conductive portions 24a, 24b (conductive members 24c) of the light incontinence pad 2 when the connector is attached. On the other hand, if the length L1 of the terminal portion 4 in the reference direction is greater than 6.0 mm, the connector 3 itself may also become larger. If the connector 3 becomes larger, when attaching the connector, it becomes necessary to sandwich the connector 3 not only the crimping area 25 of the light incontinence pad 2 but also the absorbent material 22, which may make it difficult to connect the terminal portion 4 to the pair of conductive portions 24a, 24b. The lower limit of the above range for the length L1 of the terminal portion 4 in the reference direction is more preferably 2.0 mm or more, and even more preferably 2.5 mm or more. Furthermore, the upper limit of the above range for the length L1 of the terminal portion 4 in the reference direction is more preferably 5.5 mm or less, and even more preferably 4.5 mm or less.
[0075] As shown in Figure 7, the length L2 of the terminal portion 4 in the hinge axis direction is preferably 5 mm or more and 25 mm or less. If the length L2 of the terminal portion 4 in the hinge axis direction is less than 5 mm, it becomes difficult to align the terminal portion 4 in the hinge axis direction (width direction) for electrically connecting it to the pair of conductive portions 24a, 24b (conductive members 24c) of the light incontinence pad 2 when the connector is attached. On the other hand, if the length L2 of the terminal portion 4 in the hinge axis direction is greater than 25 mm, the distance between the pair of terminal portions 4 may become shorter, making it difficult to align the pair of terminal portions 4 in the hinge axis direction (width direction) with respect to the pair of conductive portions 24a, 24b. For example, if the distance W between the pair of conductive portions 24a, 24b is 10 mm to 50 mm, it becomes difficult to align the pair of terminal portions 4 in the hinge axis direction (width direction) with respect to the pair of conductive portions 24a, 24b. Furthermore, the lower limit of the above range for the length L2 of the terminal portion 4 in the hinge axis direction is more preferably 10 mm or more, and even more preferably 12 mm or more. Also, the upper limit of the above range for the length L2 of the terminal portion 4 in the hinge axis direction is more preferably 20 mm or less, and even more preferably 18 mm or less.
[0076] (protrusion) As shown in Figures 7 to 9, the pair of terminal portions 4 have a plurality of protrusions 6 that project toward the top part 3b when closed. The plurality of protrusions 6 are formed in the shape of a regular square pyramid that project toward the top part 3b when closed. The plurality of protrusions 6 are arranged linearly in a first direction A (direction A shown in Figure 7) and linearly in a second direction B (direction B shown in Figure 7) which is perpendicular to the first direction A. The plurality of protrusions 6 constitute a plurality of rows aligned in the first direction A and a plurality of rows aligned in the second direction B. In other words, the plurality of protrusions 6 are arranged in a grid where the two directions (first direction A and second direction B) are perpendicular to each other.
[0077] As shown in Figures 7 and 9, the first direction A and the second direction B that constitute the grid-like arrangement of the multiple protrusions 6 are inclined (not parallel) with respect to both the reference direction and the hinge axis direction. That is, the two directions (first direction A and second direction B) that constitute the grid-like arrangement of the multiple protrusions 6 are inclined with respect to the reference direction. By inclining the two directions that constitute the grid-like arrangement of the multiple protrusions 6 with respect to the reference direction, when the connector is attached, the vertex P of any of the multiple protrusions 6 is more likely to come into contact with the pair of conductive parts 24a, 24b (conductive member 24c) of the light incontinence pad 2.
[0078] (Angle relative to the reference direction) The angle θ1 of one of the first direction A and the second direction B (the first direction A in Figure 9) with respect to the reference direction (longitudinal direction) is preferably greater than 0 degrees and 45 degrees or less. The angle θ1 of the above one direction refers to the smallest angle θ1 of the angles of the first direction A and the second direction B that intersect with respect to the reference direction. By setting the angle θ1 of the above one direction with respect to the reference direction within the above range, when the connector is attached, the vertex P of any of the multiple protrusions 6 is more likely to come into contact with the pair of conductive parts 24a, 24b (conductive members 24c) of the light incontinence pad 2. The lower limit of the above range for the angle θ1 of the above one direction with respect to the reference direction is more preferably 10 degrees or more, and even more preferably 20 degrees or more.
[0079] (Angle of the vertex) As shown in Figures 8 and 9, the angle θ2 of the vertex P in the cross-section (a cross-section perpendicular to the base) along the opposing side edges 6a of the multiple square pyramidal protrusions 6 is preferably 30 degrees or more and 60 degrees or less. If the angle θ2 of the vertex P of the protrusion 6 is less than 30 degrees, the height of the protrusion 6 will increase in relation to the numerical range of the base length L3 of the protrusion 6, which will be described later. If the height of the protrusion 6 increases, the conductive member 24c will have difficulty reaching the base of the protrusion 6 when the connector is attached, and the contact of the protrusion 6 with the conductive member 24c may become insufficient. On the other hand, if the angle θ2 of the vertex P of the protrusion 6 is greater than 60 degrees, the protrusion 6 will have difficulty piercing the non-skin side sheet 23 and will have difficulty contacting the conductive member 24c. The upper limit of the above range for the angle θ2 of the vertex P of the protrusion 6 is more preferably 50 degrees or less, and even more preferably 40 degrees or less.
[0080] (Length of the base) As shown in Figure 9, the base length L3 of the multiple square pyramidal protrusions 6 is preferably 0.2 mm or more and 1.0 mm or less. If the base length L3 of the protrusions 6 is less than 0.2 mm, the height of the protrusions 6 will be reduced in relation to the above numerical range of the angle θ2 of the vertex P, and there is a possibility that the protrusions 6 will not reach the conductive member 24c when the connector is attached. On the other hand, if the base length L3 of the protrusions 6 is greater than 1.0 mm, the distance L4 between the vertices P of adjacent protrusions 6 will be increased, and there is a possibility that the contact of the protrusions 6 with the conductive member 24c will be insufficient. The upper limit of the above range for the base length L3 of the protrusions 6 is more preferably 0.8 mm or less, and even more preferably 0.5 mm or less.
[0081] (Distance between vertices) As shown in Figure 9, the distance L4 between the vertices P of adjacent protrusions 6 is preferably 100% or more and 150% or less of the base length L3 (100%) of the protrusion 6. If the distance L4 between the vertices P of adjacent protrusions 6 is greater than 150% of the base length L3 of the protrusion 6, the vertices P of the multiple protrusions 6 will be less likely to come into contact with the pair of conductive parts 24a, 24b (conductive members 24c) of the light incontinence pad 2 when the connector is attached. The lower limit of the above range for the distance L4 between the vertices P of adjacent protrusions 6 is more preferably 110% or more, and even more preferably 120% or more. The upper limit of the above range for the distance L4 between the vertices P of adjacent protrusions 6 is more preferably 140% or less, and even more preferably 130% or less.
[0082] (Attaching the connector to the light incontinence pad) Next, we will describe how to attach the connector 3 to the light incontinence pad 2. Figure 10 is a schematic plan view showing the state in which the connector shown in Figure 5 is attached to the end in the longitudinal direction of the light incontinence pad according to the embodiment.
[0083] To attach the connector 3 to the light incontinence pad 2, first, open the connector 3 (see Figure 5(B)). Next, insert the end portion of the light incontinence pad 2 in the longitudinal direction (crimping area 25 in this embodiment) between the bottom part 3a and the top part 3b so that the reference direction of the connector 3 coincides with the longitudinal direction (X direction) of the light incontinence pad 2, and the center of the connector 3 in the hinge axis direction coincides with the center of the light incontinence pad 2 in the width direction (Y direction). Then, close the connector 3 (see Figure 5(A)) to lock the bottom locking portion and the top locking portion 3f together, and sandwich the crimping area 25 of the light incontinence pad 2 between the bottom part 3a and the top part 3b. In this embodiment, the bottom part 3a is positioned on the non-skin side of the light incontinence pad 2, and the top part 3b is positioned on the skin side of the light incontinence pad 2. However, the connector 3 may be attached to the light incontinence pad 2 so that the bottom part 3a is on the skin side and the top part 3b is on the non-skin side. Furthermore, the method of holding the connector 3 in a closed state is not limited to the method of locking the bottom locking part and the top locking part 3f, but various methods can be applied to hold the connector 3 in a closed state. When removing the connector 3 from the light incontinence pad 2, the connector 3 should be opened before removal.
[0084] By closing the connector 3, the crimping area 25 of the light incontinence pad 2 is sandwiched between the pair of terminal portions 4 of the bottom part 3a and the non-skin side of the top part 3b. In this state, the multiple protrusions 6 of the pair of terminal portions 4 pierce the crimping area 25 of the light incontinence pad 2. When the multiple protrusions 6 of the pair of terminal portions 4 pierce the crimping area 25 of the light incontinence pad 2, the protrusions 6 reach and contact the conductive portions 24a, 24b (conductive members 24c) of the inner layer of the crimping area 25 (see Figure 10). As a result, the pair of terminal portions 4 lock into the crimping area 25 of the light incontinence pad 2, and the connector 3 is detachably attached to the light incontinence pad 2. In addition, the multiple protrusions 6 of the pair of terminal portions 4 are electrically connected by contact with the conductive portions 24a, 24b (conductive members 24c), and the pair of terminal portions 4 and the detection unit 24 become electrically connected. In other words, one of the pair of terminal portions 4 is electrically connected to only one of the pair of conductive portions 24a, 24b, and the other terminal portion 4 is electrically connected to only the other conductive portion 24b.
[0085] (Transmitter) As shown in Figure 1, the transmitter 9 is a mechanism for detecting bodily fluids in the light incontinence pad 2 and transmitting data related to the detection of the bodily fluids to an external terminal, and has a communication unit 7. In this embodiment, in addition to the communication unit 7, the transmitter 9 includes a power supply 5 and a measurement unit 8. The transmitter 9 is used, for example, by being attached to the clothing of the wearer of the light incontinence pad 2. In this embodiment, the power supply 5 and the measurement unit 8 are integrated into the transmitter 9 for transmitting data to an external terminal, but this is not limited to this, and the power supply 5 and the measurement unit 8 may be provided separately from the transmitter 9.
[0086] (power supply) The power supply 5 is comprised of, for example, a battery, and its positive or negative terminal is electrically connected to each of the pair of conductive parts 24a and 24b of the light incontinence pad 2 via the connector 3 and the connector harness 10.
[0087] (Measurement Department) The measuring unit 8 measures the ease with which current flows through a pair of conductive parts 24a and 24b (in other words, the degree of current flow between the pair of conductive parts 24a and 24b). The measuring unit 8 may be configured using, for example, a tester, or it may be configured as a mechanism that has the same function as a tester.
[0088] The measurement unit 8, for example, supplies a weak current (in other words, energizes) to one of a pair of conductive parts 24a and 24b, with the other being the positive electrode and the other the negative electrode, and measures the ease with which current flows through these conductive parts 24a and 24b at predetermined time intervals, and outputs an index representing the ease with which current flows. The measurement unit 8 outputs, for example, a current value, a voltage value, and an impedance as an index representing the ease with which current flows.
[0089] The measurement unit 8 detects bodily fluids (for example, a relatively small amount of urination associated with mild urinary incontinence) based on the time-series change of an index representing the ease with which current flows in a pair of conductive parts 24a and 24b. Specifically, the measurement unit 8 detects bodily fluids (for example, a relatively small amount of urination associated with mild urinary incontinence) when the current flows more easily in the pair of conductive parts 24a and 24b, based on an index representing the ease with which current flows in a pair of conductive parts 24a and 24b (between the conductive members 24c) observed in time series. In other words, the measurement unit 8 detects urinary incontinence based on the fact that when the absorbent material 22 etc. becomes wet after absorbing urine, the pair of conductive parts 24a and 24b become conductive and current flows more easily.
[0090] (Communications Department) The communication unit 7 transmits an index representing the ease of current flow output from the measurement unit 8 to an external terminal as data related to the detection of bodily fluids in the light incontinence pad 2. The external terminal may be a mobile information terminal such as a smartphone, mobile phone, or tablet, a fixed terminal such as a personal computer, or a server. The communication unit 7 and the external terminal are connected to each other so as to be able to communicate with each other via a LAN (Local Area Network), WAN (Wide Area Network), the Internet, a wireless communication network, etc.
[0091] (Characteristics of Absorbent Articles and Body Fluid Detection Methods) The results of the verification tests conducted to confirm the characteristics of the absorbent article and the body fluid detection method according to the present invention are organized below.
[0092] In this verification test, light incontinence pads of Example 1, Example 2, and a Comparative Example in which the conductive members are different from each other were produced, and a weak current (DC) was continuously supplied to these light incontinence pads, and the response (or rather, the variation) of the current value was verified.
[0093] The dimensions of the light incontinence pads of Example 1, Example 2, and the Comparative Example were set such that the length in the longitudinal direction was 300 mm and the length in the width direction was 120 mm. Also, the dimensions of the absorbent body were set such that the length in the longitudinal direction was 250 mm and the length in the width direction was 70 mm.
[0094] For the light incontinence pads of Example 1, Example 2, and the Comparative Example, the skin-side sheet, the second sheet, the absorbent body, the carrier sheet, and the non-skin-side sheet were made common to each other. For the light incontinence pads of Example 1, Example 2, and the Comparative Example, the same materials as those of the light incontinence pad 2 according to the above embodiment were used as the skin-side sheet, the second sheet, the absorbent body, the carrier sheet, and the non-skin-side sheet.
[0095] Specifically, for the light incontinence pads of Example 1, Example 2, and the Comparative Example, an air-through non-woven fabric (basis weight 25 g / m 2 ) was used as the skin-side sheet. Also, an air-through non-woven fabric (basis weight 30 g / m 2 ) was used as the second sheet between the skin-side sheet and the absorbent body. Further, as the absorbent body, a material formed by mixing 8 g of SAP into 8 g of fluff pulp as the base material was used. Also, a hydrophilic spunbond non-woven fabric (basis weight 15 g / m 2 ) was used as the carrier sheet between the absorbent body and the non-skin-side sheet. Also, a liquid-impermeable breathable polyethylene sheet (basis weight 32 g / m 2 ) was used as the non-skin-side sheet.
[0096] In the light incontinence pads of Examples 1 and 2 and the Comparative Example, each detection unit (a pair of conductive parts) was composed of a single conductive member (a single metal conductor), and the detection unit was positioned between the non-skin side of the carrier sheet and the skin side of the non-skin side sheet.
[0097] In the light incontinence pad of Example 1, tin-plated soft copper bundled twisted yarn (TA) 13 / 0.08 mm manufactured by Sanshu Electric Wire Co., Ltd. was used as the conductive material (metal conductor).
[0098] In the light incontinence pad of Example 2, NASLON YARN SY 12-100 / 2 manufactured by Nippon Seisen was used as the conductive material (metal conductor).
[0099] In the comparative example of a light incontinence pad, AGposs 100d / 34f manufactured by Mitsufuji Co., Ltd. was used as the conductive material. AGposs is a silver-plated conductive fiber, which is a yarn in which silver is plated on the surface of a nylon fiber.
[0100] In this verification test, 0.9% (w / w%) physiological saline solution was injected into the center of a light incontinence pad (the center of the front, back, left, and right sides) 40 ml each, at 10-minute intervals, six times, and the current values were measured over time, including the time of injection.
[0101] In this verification test, one of a pair of conductive parts was designated as the positive electrode and the other as the negative electrode, and a current of 0.6 mA was supplied (in other words, energized). The current flowing between the conductive members of the pair of conductive parts during energization was measured over time.
[0102] Figures 11(A), (B), and (C) show the time-series values of the current flowing between a pair of conductive members as a conductive part during water injection. Figure 11(A) shows the verification results for Example 1, Figure 11(B) shows the verification results for Example 2, and Figure 11(C) shows the verification results for the comparative example. In Figure 11, the horizontal axis represents elapsed time (hours:minutes), and the vertical axis represents the current value (mA). In Figure 11, "1st time" refers to the first water injection, "2nd time" refers to the second water injection 10 minutes later, "3rd time" refers to the third water injection 10 minutes later, "4th time" refers to the fourth water injection 10 minutes later, "5th time" refers to the fifth water injection 10 minutes later, and "6th time" refers to the sixth water injection 10 minutes later.
[0103] As shown in the verification results in Figures 11(A), (B), and (C), in Examples 1 and 2, it was confirmed that the current value gradually decreased after water injection, and then increased with the next water injection. On the other hand, in the comparative example, the current value dropped to the value before water injection within a few minutes after water injection. This is presumed to be because an electrolytic reaction occurred in the urine upon water injection, causing oxidation of the metal plating on the surface responsible for conducting electricity in the silver thread, thereby hindering conductivity and preventing current flow. Furthermore, in the comparative example, the current value did not change after the 2nd, 3rd, 5th, and 6th water injections. This is presumed to be because the electrolytic reaction in the urine caused oxidation of the metal plating on the surface responsible for conducting electricity, hindering conductivity and preventing subsequent current flow.
[0104] Thus, by using conductive materials that can conduct electricity continuously in an electrolyte aqueous solution, such as TA wires and SUS wires, it was confirmed that the current value responds accurately (fluctuations) to repeated injections of water, approximately 40-100 mL, which is assumed to be the relatively small amount of urine excreted in mild urinary incontinence.
[0105] Furthermore, if the cumulative amount of water injected is less than the allowable absorption capacity of the pad's absorbent material, the injected saline solution will be absorbed and retained by the absorbent material, causing the area between the conductive members, which act as a pair of conductive parts, to gradually dry out from a wet state. As a result, in the pad of the embodiment, the area between the conductive members, which act as a pair of conductive parts, will gradually change from a state where current flows easily to a state where it flows less easily, and the current value measured over time will increase before decreasing.
[0106] Furthermore, it was confirmed that the current value increased sharply and then decreased as water was injected. This indicates that even with a weak current of about 0.6 mA supplied to the conductive material, the current value responds accurately (fluctuations) to the injection of water of about 40-100 mL, which is assumed to be the relatively small amount of urine excreted in mild urinary incontinence, by using the conductive material.
[0107] Here, supplying a large current to a pair of conductive parts poses a risk of electric shock to the wearer. However, with a current of approximately 1 mA or less (for example, approximately 0.6 mA as in this verification test), the risk of electric shock to the wearer is considered to be almost negligible. For this reason, it is preferable that the current supplied to the conductive components of the pair of conductive parts be 1 mA or less. Note that when one of the pair of conductive parts is designated as the positive electrode and the other as the negative electrode and a current of 1 mA is supplied (in other words, energized), the actual current is considered to be less than 1 mA due to the electrical resistance of each component and the human body.
[0108] Furthermore, electrolysis of a chloride-containing liquid (in this case, bodily fluids) generates hypochlorous acid, a disinfectant and bactericide, and some of it may be further oxidized and converted into chlorine dioxide, chlorous acid (ClO2-), chloric acid (ClO3-), and perchloric acid (ClO4-). In other words, supplying current to a pair of conductive parts carries the risk of generating harmful substances (especially chlorine species). Therefore, it is preferable that the current supplied to the pair of conductive parts be small. That is, being able to accurately detect the timing and volume of urination by supplying a current of about 1 mA or less (for example, about 0.6 mA as in this verification test) is preferable in that it reduces the amount of harmful substances (especially chlorine species) generated.
[0109] (Effects and Benefits) In the light incontinence pad 2 and body fluid detection method according to this embodiment, at least one conductive member 24c is provided on one side and at least one conductive member 24c on the other side, spaced apart in the width direction from each other, with the center line in the width direction of the absorbent body 22 in between. The conductive members 24c can be continuously energized in an electrolyte aqueous solution. Therefore, even slight urine leakage can be detected.
[0110] Therefore, it has been confirmed that the absorbent article and bodily fluid detection method described herein can ensure stable current flow through a metal conductive member, and can detect minor urinary incontinence.
[0111] Although embodiments of the present invention have been described above, the specific configurations of the present invention are not limited to the embodiments described above. The present invention also includes forms in which modifications and changes are made to the above embodiments without departing from the spirit of the invention.
[0112] For example, in the above embodiment, a light incontinence pad 2, as an example of a specific configuration of the absorbent article according to the present invention, is incorporated into the body fluid detection device 1 shown in Figure 1, but the invention is not limited to this. The absorbent article according to the present invention may be incorporated into various mechanisms for detecting liquids in articles worn by people or animals, for example, that have liquid absorbency and retention properties. That is, for example, the absorbent article according to the present invention is not limited to the light incontinence pad 2 in the above embodiment, and the mechanism by which the absorbent article according to the present invention is electrically connected via the connector harness 10 is not limited to the transmitter 9 in the above embodiment. [Explanation of Symbols]
[0113] 2: Light incontinence pads (absorbent items) 21: Skin-side sheet 22: Absorbent material 23: Non-skin side sheet 24c: Conductive material
Claims
1. An absorbent article comprising a liquid-permeable skin-side sheet, a liquid-impermeable non-skin-side sheet, and an absorbent material disposed between the skin-side sheet and the non-skin-side sheet, Within the absorbent article, at least one conductive member is provided on one side and at least one conductive member on the other side, with the center line in the width direction of the absorbent article in between and spaced apart from each other in the width direction. The conductive member is capable of continuous current flow in an aqueous electrolyte solution. An absorbent article characterized by the following features.
2. The distance between at least one of the conductive members on one side and at least one of the conductive members on the other side is 10 mm or more and less than 50 mm. The absorbent article according to feature 1.
3. The conductive member is a thread-like member. The absorbent article according to claim 1 or 2.
4. The aforementioned thread-like member is made of metal only. The absorbent article according to feature 3.
5. The aforementioned thread-like member is plated with metal. The absorbent article according to feature 4.
6. The aforementioned thread-like member is an alloy mainly composed of iron. The absorbent article according to feature 4.
7. The thread-like members are arranged in a substantially straight line parallel to the longitudinal direction of the absorbent article. The absorbent article according to feature 3.
8. The current supplied to the conductive member on one side and the conductive member on the other side is 1 mA or less. The absorbent article according to claim 1 or 2.
9. A method for detecting bodily fluids in an absorbent article comprising a liquid-permeable skin-side sheet, a liquid-impermeable non-skin-side sheet, and an absorbent disposed between the skin-side sheet and the non-skin-side sheet, Between the absorbent material and the non-skin side sheet, at least one conductive member is arranged on one side and at least one conductive member is arranged on the other side, with the center line in the width direction of the absorbent article in between, and spaced apart from each other in the width direction. Body fluids are detected based on the time-series change in the degree of current flow between the conductive member on one side and the conductive member on the other side. A method for detecting bodily fluids characterized by the following features.