Patent Publication Number: US-2020289346-A1

Title: Wound dressing with electrode multiplexing and related methods

Description:
The present disclosure relates to wound dressings and in particular to wound dressings with sensing and multiplexing capabilities to facilitate monitoring of the wound/wound dressing during use of e wound dressing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The accompanying drawings are included to provide a further understanding of embodiments and are incorporated into and a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. 
         FIG. 1  illustrates an exemplary wound dressing system, 
         FIG. 2  illustrates an exemplary monitor device of the wound dressing system, 
         FIG. 3  is a proximal view of a first adhesive layer of a wound dressing, 
         FIG. 4  is a schematic cross-section of an exemplary wound dressing, 
         FIG. 5  is a proximal view of an exemplary electrode assembly, 
         FIG. 6  is more detailed proximal view of a part of exemplary electrode assembly of  FIG. 5 , 
         FIG. 7  is a schematic cross-section of an exemplary wound dressing, 
         FIG. 8  is a proximal view of an exemplary first support layer, 
         FIG. 9  is a proximal view of an exemplary first masking layer, 
         FIG. 10  is a proximal view of an exemplary second support layer, 
         FIG. 11  is a proximal view of an exemplary second masking layer, 
         FIG. 12  is a distal view of an exemplary second support layer, 
         FIG. 13  is a proximal view of an exemplary second masking layer, 
         FIG. 14  is a distal view of an exemplary first support layer, 
         FIG. 15  is a flow chart of an exemplary method of monitoring a wound dressing, 
         FIG. 16  is a distal view of a part of a wound dressing including a multiplexer and monitor interface, 
         FIG. 17  is a flow diagram of an exemplary method, 
         FIG. 18  is a flow diagram of an exemplary method, 
         FIG. 19  is an exemplary graphical representation of parameter data as a function of time, 
         FIG. 20  is an exemplary graphical representation of parameter data as a function of time, and 
         FIG. 21  is an exemplary graphical representation of parameter data as a function of time. 
     
    
    
     DETAILED DESCRIPTION 
     Various exemplary embodiments and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described. 
     In the following, whenever referring to proximal side or surface of a layer, an element, a device or part of a device, the referral is to the skin-facing side or surface when a user wears the wound dressing. Likewise, whenever referring to the distal side or surface of a layer, an element, a device or part of a device, the referral is to the side or surface facing away from the skin when a user wears the wound dressing. In other words, the proximal side or surface is the side or surface closest to the user when the wound dressing is fitted on a user and the distal side is the opposite side or surface—the side or surface furthest away from the user in use. 
     The axial direction is defined as the direction away from the skin surface of the user when a user wears the wound dressing. Thus, the axial direction is generally perpendicular to the skin or abdominal surface of the user. 
     The radial direction is defined as perpendicular to the axial direction. In some sentences, the words “inner” and “outer” may be used. These qualifiers should generally be perceived with respect to the radial direction, such that a reference to an “outer” element means that the element is farther away from a centre portion of the wound dressing than an element referenced as “inner”. In addition, “innermost” should be interpreted as the portion of a component forming a centre of the component and/or being adjacent to the centre of the component. In analogy, “outermost” should be interpreted as a portion of a component forming an outer edge or outer contour of a component and/or being adjacent to that outer edge or outer contour. 
     The use of the word “substantially” as a qualifier to certain features or effects in this disclosure is intended to simply mean that any deviations are within tolerances that would normally be expected by the skilled person in the relevant field. 
     The use of the word “generally” as a qualifier to certain features or effects in this disclosure is intended to simply mean—for a structural feature: that a majority or major portion of such feature exhibits the characteristic in question, and—for a functional feature or an effect: that a majority of outcomes involving the characteristic provide the effect, but that exceptionally outcomes do no provide the effect. 
     The present disclosure relates to a wound dressing system and devices thereof, such as a wound dressing, a monitor device, and optionally one or more accessory devices. Further, methods related to the wound dressing system and devices thereof are disclosed. An accessory device (also referred to as an external device) may be a mobile phone or other handheld device. An accessory device may be a personal electronic device, e.g. a wearable, such as a watch or other wrist-worn electronic device. An accessory device may be a docking station. The docking station may be configured to electrically and/or mechanically couple the monitor device to the docking station. The docking station may be configured for charging the monitor device and/or configured for transferring data between the monitor device and the docking station. The wound dressing system may comprise a server device. The server device may be operated and/or controlled by the wound dressing system manufacturer and/or a service centre. 
     A wound dressing system comprising a wound dressing and/or a monitor device is disclosed, wherein the monitor device is a monitor device as described herein. 
     The present disclosure provides a wound dressing system and devices thereof, such as a wound dressing, a monitor device, and optionally one or more accessory devices which either alone or together facilitate reliable monitoring of the wound dressing and operating state thereof. Accordingly, the wound dressing system and devices thereof enable providing information to the user about the operating state of the wound dressing, and in turn optionally enable providing an indication to the user or a caretaker of the remaining time frame for replacing the wound dressing without experiencing leakage and/or to provide optimum wound healing conditions. 
     A wound dressing is disclosed, the wound dressing comprising a first adhesive layer with a proximal surface configured for attachment of the wound dressing to the skin surface of a user; an absorbent core layer; an electrode assembly comprising a plurality of electrodes optionally arranged on a distal side of the absorbent core layer; and a top layer on a distal side of the electrode assembly. 
     It is an advantage of the present disclosure that an optimum or improved use of a wound dressing is enabled and facilitated. In particular, the present disclosure facilitates that a wound dressing is not changed too early (leading to increased costs and/or material waste) nor too late (leading to adhesive failure, leakage and/or unsatisfactory wound healing conditions). Accordingly, the user or a health care professional is able to monitor and plan the use of the wound dressing. 
     Further, determination of moisture or wetting pattern types and classification of operating states of the wound dressing is useful in helping to reduce the risk of a user experiencing leakage from a wound dressing and/or in helping reduce the risk of unsatisfactory wound healing conditions. The present disclosure provides a simple, efficient, and easy-to-use wound dressing system with a high degree of comfort for a user. 
     In addition, it is an advantage of the present disclosure that the wound dressing with multiplexer capabilities disclosed herein facilitates a wound dressing with many electrodes, e.g. nine or more, while keeping the number of monitor terminals to a reasonable number, e.g. eight or less, such as four, five, six or seven. 
     The wound dressing comprises a first adhesive layer having a proximal surface configured for attachment of the wound dressing to the skin surface of a user. The first adhesive layer may comprise or be made of a first composition. The first composition may comprise silicone. The first adhesive layer may comprise a support layer with an adhesive material made of a first composition molded onto or otherwise attached to the support layer. The first composition may be a thermoset, curable adhesive material. An example of such adhesive material may be a silicone based adhesive material. The first composition may be a two-component system. Preferably, the first composition contains no solvent. Preferred first compositions include polyurethane, acrylic, silicone or polyethylene or polypropylene oxide based cross-linking types, e.g. as described in WO 2005/032401. The first composition may be a hotmelt type, which initially is heated to flow and subsequently cooled to gel or crosslink. Instead of curing upon cooling, the first composition may in some embodiments cure upon application of thermal energy. 
     The support layer of the first adhesive layer may be any suitable layer being water impermeable but vapour permeable. A suitable support layer may be a polyurethane film. 
     The first adhesive layer may have perforations or through-going openings arranged within an absorbing region, e.g. for allowing exudate from the wound to pass or flow through the perforations of the first adhesive layer to be absorbed by absorbent core layer arranged on the distal side of the first adhesive layer. 
     The perforations of the first adhesive layer may be made by punching, cutting or by applying high frequency mechanical vibrations, for example as disclosed in WO 2010/061228. The perforations may be arranged in a regular or random array, typically separated by 0.5 mm to 10 mm. The number of holes per cm 2  may be between 1 and 100, such as between 1 and 50 or even between 2 and 20. 
     The perforations of the first adhesive layer may have a diameter in the range from 0.5 mm to 10 mm, such as in the range from 1 mm to 8 mm. In one or more exemplary wound dressings, the perforations of the first adhesive layer have a diameter in the range from 1 mm to 5 mm, e.g. from 1.5 mm to 5 mm, and even in the range from 2 mm to 4 mm. 
     The wound dressing comprises an absorbent core layer also denoted an absorbent pad. The absorbent core layer may be a uniform material, or it may be a composite, for example in the form of a layered construction comprising layers of different texture and properties. The absorbent core layer may comprise foam, cellulose, super absorbent particles and/or fibres. The absorbent core layer may comprise a layer of foam facing the wound. 
     The absorbent core layer may comprise a polyurethane foam. The absorbent core layer may comprise a super absorbing layer. 
     The absorbent core layer and/or the first adhesive layer may contain active ingredients, such as ibuprofen, paracetamol, silver compounds or other medically active ingredients configured to reduce pain and/or to improve the healing of a wound. In one or more exemplary wound dressings, the absorbent core layer comprises a silver compound with antimicrobial properties. 
     The wound dressing comprises a top layer also denoted a backing layer. The top layer may be any suitable layer being water impermeable but vapour permeable. A suitable top layer may be a polyurethane film. The top layer is a protective layer protecting the absorbent core layer and other parts of the wound dressing from external strains and stress when the user wears the wound dressing. The electrodes, e.g. some or all the electrodes, may be arranged between the first adhesive layer and the top layer. The top layer may have a thickness in the range from 0.01 mm to 1.0 mm, e.g. in the range from 0.02 mm to 0.2 mm, such as 0.04 mm. 
     The wound dressing may comprise a release liner, such as a one-piece, two-piece or a three-piece release liner. The release liner is a protective layer that protects adhesive layer(s) during transport and storage and is peeled off by the user prior to applying the wound dressing on the skin. 
     The electrode assembly comprises a plurality of sensor points or sensor zones distributed along a distal surface or distal side of the absorbent core layer. 
     The plurality of electrodes optionally comprises a first set of first electrodes and optionally a second set of second electrodes, wherein a sensing part of a first electrode and a sensing part of the second electrode may form a sensor point. The electrodes are electrically conductive and may comprise one or more of metallic (e.g. silver, copper, gold, titanium, aluminium, stainless steel), ceramic (e.g. ITO), polymeric (e.g. PEDOT, PANI, PPy), and carbonaceous (e.g. carbon black, carbon nanotube, carbon fibre, graphene, graphite) materials. 
     A set of electrodes, such as the first set of electrodes and/or the second set of electrodes, may comprise one or a plurality of electrodes. In one or more exemplary electrode assemblies, a set of electrodes, such as the first set of electrodes and/or the second set of electrodes, may comprise one, two, three, four, five, or more electrodes. In one or more exemplary electrode assemblies, a first electrode of the first set of first electrodes forms a part of a first sensor point and a second sensor point of the plurality of sensor points. In one or more exemplary electrode assemblies, a first electrode of the first set of first electrodes forms a part of at least two sensor points, such as at least three sensor points. In one or more exemplary electrode assemblies, each of at least two first electrodes of the first set of first electrodes forms a part of at least two sensor points, such as at least three sensor points. 
     The first set of first electrodes may comprise one, two, three, or more electrodes. In one or more exemplary electrode assemblies, the first set of first electrodes comprises at least three electrodes, such as at least five electrodes. 
     In one or more exemplary electrode assemblies, a second electrode of the second set of second electrodes forms a part of a first sensor point and a third sensor point of the plurality of sensor points. In one or more exemplary electrode assemblies, a second electrode of the second set of second electrodes forms a part of at least two sensor points, such as at least three sensor points. In one or more exemplary electrode assemblies, each of at least two second electrodes of the second set of second electrodes forms a part of at least two sensor points, such as at least three sensor points. 
     The second set of second electrodes may comprise one, two, three, or more electrodes. In one or more exemplary electrode assemblies, the second set of second electrodes comprises at least three second electrodes, such as at least five electrodes. 
     A first set of first electrodes with N 1  first electrodes E_ 1 _ 1 , E_ 1 _ 2 , . . . , E_ 1 _N 1  and a second set of second electrodes with N 2  second electrodes E_ 2 _ 1 , E_ 2 _ 2 , . . . , E_ 2 _N 2  allow for an electrode assembly with N 1  times N 2  sensor points. In one or more exemplary wound dressings, the number N 1  of first electrodes in the first set of first electrodes is in the range from 1 to 30, such as in the range from 3 to 25, or in the range from 4 to 20. The number N 1  of first electrodes in the first set of first electrodes may be larger than 4, such as larger than 5 or even larger than 6. In one or more exemplary wound dressings, the number N 2  of second electrodes in the second set of second electrodes is in the range from 1 to 30, such as in the range from 3 to 25, or in the range from 4 to 20. The number N 2  of second electrodes in the second set of second electrodes may be larger than 4, such as larger than 5 or even larger than 6. 
     The electrode assembly comprises a plurality of sensor points optionally distributed along a distal surface of the absorbent core layer. In one or more exemplary electrode assemblies, the plurality of sensor points comprises at least nine sensor points. The plurality of sensor points may be arranged in a matrix configuration. The plurality of sensor points may comprise at least 20 sensor points. Two electrodes of the electrode assembly may form a sensor point. A first electrode E_ 1 _ 1  and a second electrode E_ 2 _ 1  may form a (first) sensor point SP_ 1 _ 1  (first electrode pair). The first electrode E_ 1 _ 1  and a second electrode E_ 2 _ 2  may form a (second) sensor point SP_ 1 _ 2  (second electrode pair). The first electrode E_ 1 _ 1  and a second electrode E_ 2 _ 3  may form a (third) sensor point SP_ 1  _ 3  (third electrode pair). A first electrode E_ 1 _ 2  and the second electrode E_ 2 _ 1  may form a (fourth) sensor point SP_ 2 _ 1  (fourth electrode pair). The first electrode E_ 1 _ 2  and the second electrode E_ 2 _ 2  may form a (fifth) sensor point SP_ 2 _ 2  (fifth electrode pair). The first electrode E_ 1 _ 2  and the second electrode E_ 2 _ 3  may form a (sixth) sensor point SP_ 2 _ 3  (sixth electrode pair). A first electrode E_ 1 _ 3  and the second electrode E_ 2 _ 1  may form a (seventh) sensor point SP_ 3 _ 1  (seventh electrode pair). The first electrode E_ 1 _ 3  and the second electrode E_ 2 _ 2  may form a (eighth) sensor point SP_ 3 _ 2  (eighth electrode pair). The first electrode E_ 1 _ 3  and the second electrode E_ 2  _ 3  may form a (ninth) sensor point SP_ 3 _ 3  (ninth electrode pair). 
     A distance, such as a center-to-center distance, between two neighbouring sensor points may be in the range from 2 mm to 50 mm, such as about 30 mm. In one or more exemplary electrode assemblies, a distance, such as a center-to-center distance, between two neighbouring sensor points is in the range from 3 mm to 20 mm, such as in the range from 4 mm to 15 mm, e.g. about 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm. 
     The electrode assembly may comprise one or more support layers including a first support layer. The first support layer may have a plurality of sensor point openings, e.g. for allowing exudate to pass through the first support layer. A sensor point opening of the first support layer may form a part of one or more sensor points of the electrode assembly. 
     The first set of electrodes may be printed or arranged on the first support layer. In one or more exemplary electrode assemblies, the first set of electrodes are printed on a proximal surface of the first support layer. The first set of electrodes may be printed on a distal surface of the first support layer. 
     The second set of electrodes may be printed or arranged on the first support layer. In one or more exemplary electrode assemblies, the second set of electrodes are printed on a proximal surface of the first support layer. The second set of electrodes may be printed on a distal surface of the first support layer. The second set of electrodes may be printed or arranged on a support layer surface different than the support layer surface on which the first set of electrodes is printed or arranged. Arranging the first set of electrodes and the second set of electrodes on different support layer surfaces allows for provision of a larger number of sensor points using a smaller number of electrodes. 
     The electrode assembly may comprise a second support layer. The second set of electrodes may be printed or arranged on the second support layer. In one or more exemplary electrode assemblies, the second set of electrodes are printed on a proximal surface of the second support layer. The second set of electrodes may be printed on a distal surface of the second support layer. 
     The second support layer may have a plurality of sensor point openings, e.g. for allowing exudate to pass through the second support layer. A sensor point opening of the second support layer may form a part of one or more sensor points of the electrode assembly. 
     A support layer, such as the first support layer and/or the second support layer, may comprise polymeric (e.g. polyurethane, PTFE, PVDF) and/or ceramic (e.g. alumina, silica) materials. In one or more exemplary wound dressings, the first support layer and/or the second support layer is/are made of thermoplastic polyurethane (TPU). The support layer material may be made of or comprise one or more of polyester, a thermoplastic elastomer (TPE), polyimide, polyimide, Ethylene-vinyl acetate (EVA), polyurea, and silicones. 
     Exemplary thermoplastic elastomers of the first support layer and/or the second support layer are styrenic block copolymers (TPS, TPE-s), thermoplastic polyolefin elastomers (TPO, TPE-o), thermoplastic Vulcanizates (TPV, TPE-v), thermoplastic polyurethanes (TPU), thermoplastic copolyester (TPC, TPE-E), and thermoplastic polyamides (TPA, TPE-A). 
     The electrode assembly may comprise a spacing layer between the first support layer and the second support layer. A spacing layer between the first support layer and the second support layer may reduce the risk of false positives when detecting and/or determining moisture/liquid patterns or distributions. The spacing layer may have a plurality of sensor point openings, e.g. for allowing exudate to pass through the spacing layer. The spacing layer may be made of an absorbent material. The spacing layer may have a thickness in the range from 1 μm to1 mm. 
     The electrode assembly/wound dressing may comprise one or more masking layers including a first masking layer isolating electrode parts of the plurality of electrodes. The first masking layer may isolate electrode parts of first electrodes of the first set of first electrodes. A masking layer may be made of a masking layer material, such as 
     The first masking layer may be printed on the first support layer and optionally cover one or more parts of electrodes printed or arranged on the first support layer. In one or more exemplary electrode assemblies, the first masking layer is printed on the proximal side of the first support layer and covering one or more parts of first electrodes and/or second electrodes. In one or more exemplary electrode assemblies, the first masking layer is printed on the distal side of the first support layer and covering one or more parts of first electrodes and/or second electrodes. 
     The first masking layer may be printed on the second support layer and optionally cover one or more parts of electrodes printed or arranged on the second support layer. In one or more exemplary electrode assemblies, the first masking layer is printed on the proximal side of the second support layer and covering one or more parts of second electrodes. In one or more exemplary electrode assemblies, the first masking layer is printed on the distal side of the second support layer and covering one or more parts of second electrodes. 
     The first masking layer may be divided in a plurality of first masking layer parts. The first masking layer may be arranged between the absorbent core layer and at least parts of the first electrodes to electrically isolate the parts of the first electrodes from the absorbent core layer. The first masking layer may be arranged between the absorbent core layer and at least parts of the second electrodes to electrically isolate the parts of the second electrodes from the absorbent core layer. 
     The first masking layer may comprise one or more, such as a plurality of, sensor point openings. A sensor point opening of the first masking layer optionally overlaps at least one electrode of the electrode assembly when seen in the axial direction, e.g. to form a sensor point. For example, a sensor point opening of the first masking layer may overlap a (sensing) part of a first electrode of the first set of electrodes and a (sensing) part of a second electrode of the second set of electrodes. 
     The electrode assembly may comprise a second masking layer isolating electrode parts of the plurality of electrodes. 
     The second masking layer may be printed on the first support layer and optionally cover one or more parts of electrodes printed or arranged on the first support layer. In one or more exemplary electrode assemblies, the second masking layer is printed on the distal side of the first support layer and covering one or more parts of second electrodes. 
     The second masking layer may be printed on the second support layer and optionally cover one or more parts of electrodes printed or arranged on the second support layer. In one or more exemplary electrode assemblies, the second masking layer is printed or arranged on the proximal side of the second support layer and covering one or more parts of second electrodes. In one or more exemplary electrode assemblies, the second masking layer is printed or arranged on the distal side of the second support layer and covering one or more parts of second electrodes. 
     The second masking layer may be divided in a plurality of second masking layer parts. The second masking layer may be arranged between the absorbent core layer and at least parts of the second electrodes to electrically isolate the parts of the second electrodes from the absorbent core layer. The second masking layer may be arranged between the first support layer and at least parts of the second electrodes to electrically isolate the parts of the second electrodes from the first support layer. The second masking layer may be arranged between the spacing layer and at least parts of the second electrodes to electrically isolate the parts of the second electrodes from the spacing layer. 
     The second masking layer may comprise one or more, such as a plurality of, sensor point openings. A sensor point opening of the second masking layer optionally overlaps at least one electrode of the electrode assembly when seen in the axial direction, e.g. to form a sensor point. For example, a sensor point opening of the second masking layer may overlap a (sensing) part of a first electrode of the first set of electrodes and/or a (sensing) part of a second electrode of the second set of electrodes. 
     A masking layer, e.g. the first masking layer and/or the second masking layer, may comprise one or more, such as a plurality of, terminal openings. A terminal opening may overlap with one or more connection parts of electrodes. In one or more exemplary wound dressings, each terminal opening overlaps with a single connection part of an electrode. A masking layer, e.g. the first masking layer and/or the second masking layer, may comprise polymeric (e.g. polyurethane, PTFE, PVDF) and/or ceramic (e.g. alumina, silica) materials. In one or more exemplary wound dressings, the first masking layer and/or the second masking layer is/are made of or comprises thermoplastic polyurethane (TPU). In one or more exemplary wound dressings, the first masking layer and/or the second masking layer is made of or comprises polyester. The masking element material may be made of or comprise one or more of polyester, a thermoplastic elastomer (TPE), polyamide, polyimide, Ethylene-vinyl acetate (EVA), polyurea, and silicones. 
     Exemplary thermoplastic elastomers of the first masking layer and/or the second masking layer are styrenic block copolymers (TPS, TPE-s), thermoplastic polyolefin elastomers (TPO, TPE-o), thermoplastic Vulcanizates (TPV, TPE-v), thermoplastic polyurethanes (TPU), thermoplastic copolyester (TPC, TPE-E), and thermoplastic polyamides (TPA, TPE-A). 
     The wound dressing comprises a monitor interface. The monitor interface may be configured for electrically and/or mechanically connecting the wound dressing (electrode assembly) to the monitor device. The monitor interface may be configured for wirelessly connecting the wound dressing to the monitor device. Thus, the monitor interface of the wound dressing is configured to electrically and/or mechanically couple the wound dressing and the monitor device. 
     The monitor interface of the wound dressing may comprise, e.g. as part of a first connector of the monitor interface, a coupling part for forming a mechanical connection, such as a releasable coupling between the monitor device and the wound dressing. The coupling part may be configured to engage with a coupling part of the monitor device for releasably coupling the monitor device to the wound dressing wound dressing. 
     The monitor interface of the wound dressing may comprise, e.g. as part of a first connector of the monitor interface, a plurality of terminals, such as two, three, four, five, six, seven, eight or more terminals, for forming electrical connections with respective terminals of the monitor device. The monitor interface may comprise a ground terminal element forming a ground terminal. The monitor interface may comprise a first terminal element forming a first terminal, a second terminal element forming a second terminal and optionally a third terminal element forming a third terminal. The monitor interface may comprise a fourth terminal element forming a fourth terminal and/or a fifth terminal element forming a fifth terminal. The monitor interface optionally comprises a sixth terminal element forming a sixth terminal. The terminal elements of the monitor interface may contact respective electrodes (connection parts) of the wound dressing/electrode assembly. In one or more exemplary wound dressings, a first intermediate element may be arranged between the terminal elements and the first adhesive layer. The first intermediate element may cover or overlap terminal element(s) of the wound dressing when seen in the axial direction. Thus, the first adhesive layer may be protected or experience more evenly distributed mechanical stress from the terminal elements of the wound dressing, in turn reducing the risk of terminal elements penetrating or otherwise damaging the first adhesive layer. The first intermediate element may protect or mechanically and/or electrically shield the first adhesive layer from the terminal elements of the wound dressing. 
     A terminal element, such as the ground terminal element, the first terminal element, the second terminal element, the third terminal element, the fourth terminal element, the fifth terminal element and/or the sixth terminal element, may comprise a distal end and a proximal end. A terminal element, such as the ground terminal element, the first terminal element, the second terminal element, the third terminal element, the fourth terminal element, the fifth terminal element and/or the sixth terminal element, may comprise a distal part (with a distal end), a centre part, and/or a proximal part (with a proximal end). The centre part may be between the distal part and the proximal part. The proximal end/proximal part of a terminal element may contact a connection part of an electrode. A terminal element, such as the ground terminal element, the first terminal element, the second terminal element, the third terminal element, the fourth terminal element, the fifth terminal element and/or the sixth terminal element, may be gold plated copper. 
     In one or more exemplary wound dressings, connection parts of electrodes of the electrode assembly form respective terminals of the monitor interface. 
     The wound dressing may comprise a multiplexer. The multiplexer may comprise a number of N input pins and a number of M output pins. The number N of input pins may be larger than the number M of output pins, i.e. N&gt;M. For example, the multiplexer may comprise at least nine input pins and one or two output pins. As another example, the multiplexer may comprise at least sixteen input pins and one or two output pins. 
     The N input pins may include a first set of first input pins for connection to first electrodes of the first set of first electrodes, the first set of first pins including a first primary input pin and a first secondary input pin, and the M output pins include a first output pin. The first primary input pin may be connected to a first primary electrode of the first set of first electrodes and the first secondary input pin may be connected to a first secondary electrode of the first set of first electrodes, and the first output pin may be connected to the first terminal of the monitor interface. The multiplexer may be configured to connect the first primary input pin to the first output pin in a first multiplexer configuration and to connect the first secondary input pin to the first output pin in a second multiplexer configuration. A wound dressing with said multiplexer facilitates a wound dressing with many electrodes, e.g. ten or more, while keeping the number of monitor terminals to a reasonable number, e.g. eight or less, such as four, five, six or seven. 
     The monitor interface may comprise a second terminal, wherein the M output pins may include a second output pin connected to the second terminal. 
     The plurality of electrodes may comprise a second set of second electrodes including a second primary electrode and a second secondary electrode. The N input pins may comprise a second set of second input pins for connection to second electrodes of the second set of second electrodes. A second primary input pin of the second set of second input pins may be connected to the second primary electrode and a second secondary input pin of the second set of second input pins may be connected to the second secondary electrode. The multiplexer may be configured to connect the second primary input pin to the second output pin in the first multiplexer configuration and to connect the second secondary input pin to the second output pin in the second multiplexer configuration. 
     The first set of first electrodes may comprise a first tertiary electrode. And, a first tertiary input pin of the first set of first input pins may be connected to the first tertiary input pin. The multiplexer may be configured to connect the first tertiary input pin to the first output pin in a third multiplexer configuration. 
     The second set of second electrodes may comprise a second tertiary electrode. A second tertiary input pin of the second set of second input pins may be connected to the second tertiary input pin. The multiplexer may be configured to connect the second tertiary input pin to the second output pin in a third multiplexer configuration. 
     The multiplexer may comprise a first control pin. The multiplexer may be configured to select a multiplexer configuration based on a first control signal received by the first control pin. 
     The multiplexer may comprise a second control pin. The multiplexer may be configured to select a multiplexer scheme based on a second control signal received by the second control pin. 
     The multiplexer may be embedded in the electrode assembly. Alternatively, the multiplexer may be embedded in the coupling part of the monitor interface. 
     A method of manufacturing a wound dressing is also disclosed. The method may comprise providing a first adhesive layer having a proximal surface configured for attachment of the wound dressing to a skin surface of a user. The method may further comprise arranging an absorbent core layer on a distal side of the first adhesive layer. The method may further comprise arranging an electrode assembly on the distal side of the absorbent core layer. The electrode assembly may comprise a plurality of electrodes and a multiplexer. The plurality of electrodes may comprise a first set of first electrodes, wherein a first primary electrode of the first set of first electrodes may be connected to a first primary input pin of the multiplexer and a first secondary electrode of the first set of first electrodes being may be connected to a first secondary input pin of the multiplexer. The method may further comprise arranging a monitor interface on the distal side of the absorbent core layer. The monitor interface may comprise a coupling part and a plurality of terminals including a first terminal for forming mechanical and electrical connection with a monitor device, such that a first output pin of the multiplexer is connected to the first terminal. Manufacturing a wound dressing having the above stated multiplexer will enable a wound dressing with many electrodes, e.g. ten or more, to connect with a monitor device having fewer monitor terminals, e.g. eight or less, such as four, five, six or seven. 
     A method of monitoring a wound dressing is also disclosed. The wound dressing may comprise a first adhesive layer, plurality of electrodes on a distal side of the first adhesive layer, a multiplexer, and a monitor interface. A first output pin of the multiplexer may be connected to a first terminal of the monitor interface and the plurality of electrodes may include a first set of first electrodes. The method may comprise selecting a first multiplexer configuration of the multiplexer. A first primary electrode of the first set of first electrodes may be connected to the first output pin in the first multiplexer configuration. The method may further comprise obtaining a first sensor signal from the first terminal of the monitor device. The method may further comprise selecting a second multiplexer configuration of the multiplexer. A first secondary electrode of the first set of first electrodes may be connected to the first output pin in the second multiplexer configuration. The method may further comprise obtaining a second sensor signal from the first terminal of the monitor device. Similar to above, this method allows sensor signals from many electrodes of the wound dressing to be monitored by a reasonable number of monitor terminals. 
     The monitor device comprises a processor and one or more interfaces, such as a first interface and/or a second interface. The monitor device may comprise a memory for storing wound data and/or parameter data based on the wound data. 
     The first interface is connected to the processor and the memory. The first interface is configured for collecting wound data from the wound dressing coupled to the first interface. The wound data, also denoted WD, comprises wound data from sensor points of the wound dressing, e.g. first wound data WD_ 1  from a first sensor point, e.g. a first electrode pair, of the wound dressing, second wound data WD_ 2  from a second sensor point, e.g. a second electrode pair, of the wound dressing, and optionally third wound data WD_ 3  from a third sensor point, e.g. a third electrode pair, of the wound dressing. In one or more exemplary monitor devices, the wound data comprises wound data for each sensor point of the wound dressing. For example, for a wound dressing with N sensor points, the wound data WD may comprise WD_ 1 , WD_ 2 , . . . , WD_N. The number N of sensor points of the wound dressing may be at least 9, such as at least 20 or even larger than 50. 
     The processor is configured to apply a processing scheme. To apply a processing scheme comprises to obtain parameter data based on the wound data, e.g. the first wound data WD_ 1 , the second wound data WD_ 2 , and the third wound data WD_ 3 ; and to determine an operating state of the wound dressing based on the parameter data. The parameter data may comprise one or more of first parameter data, also denoted P_ 1 , based on the first wound data WD_ 1 , second parameter data, also denoted P_ 2 , based on the second wound data WD_ 2 , and third parameter data, also denoted P_ 3 , based on the third wound data WD_ 3 . 
     The operating state of the wound dressing is optionally indicative of a degree of wetting of the absorbent core layer of the wound dressing. The operating state is optionally indicative of a degree of wetting of the distal surface of the absorbent core layer. The operating state may be indicative of a wetting pattern or wetting distribution on the distal surface or distal side of the absorbent core layer. 
     The monitor device is optionally configured to, in accordance with a determination that the operating state is a first operating state, transmit a first monitor signal comprising monitor data indicative of the first operating state of the wound dressing via the second interface. The first operating state of the wound dressing may correspond to a situation wherein the absorbent core layer is wetted to a first degree on the distal surface of the absorbent core layer and/or wherein a first wetting pattern is detected on the distal surface of the absorbent core layer. 
     The monitor device is optionally configured to, in accordance with a determination that the operating state is a second operating state, transmit a second monitor signal comprising monitor data indicative of the second operating state of the wound dressing via the second interface. The second operating state of the wound dressing may correspond to a situation wherein the absorbent core layer is wetted to a second degree (different from the first degree) on the distal surface of the absorbent core layer and/or wherein a second wetting pattern is detected on the distal surface of the absorbent core layer. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a first criteria set based on first parameter data and/or second parameter data of the parameter data, wherein the operating state is determined to be the first operating state if the first criteria set is satisfied. The first criteria set optionally comprises a first primary criterion based on the first parameter data, and a first secondary criterion based on the second parameter data. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a first threshold set comprising one or more first threshold values. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a second criteria set based on first parameter data and second parameter data of the parameter data, wherein the operating state is determined to be the second operating state if the second criteria set is satisfied. The second criteria set optionally comprises a second primary criterion based on the first parameter data, and a second secondary criterion based on the second parameter data. Applying first and second criteria set based on first parameter data and second parameter data allows for a distinction between different degrees and/or patterns of wetting. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a second threshold set comprising one or more second threshold values. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a default criteria set based on the parameter data, wherein the operating state is determined to be the default operating state if the default criteria set is satisfied, and optionally in accordance with a determination that the operating state is the default operating state, transmit a default monitor signal comprising monitor data indicative of the default operating state of the wound dressing. The default operating state may correspond to no wetting or a low degree of wetting of the (distal surface or side of) absorbent core layer. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a third criteria set based on third parameter data of the parameter data, wherein the operating state is determined to be the third operating state if the third criteria set is satisfied. The third operating state of the wound dressing may correspond to a situation wherein the absorbent core layer is wetted to a third degree on the distal surface of the absorbent core layer and/or wherein a third wetting pattern is detected on the distal surface of the absorbent core layer. 
     The monitor device is optionally configured to, in accordance with a determination that the operating state is the third operating state, transmit a third monitor signal comprising monitor data indicative of the third operating state of the wound dressing. 
     The parameter data may be indicative of resistance between the two electrodes of an electrode pair forming a sensor point. For example, the first parameter data, the second parameter data, and the third parameter data, may be indicative of resistance between first electrode pair of the first sensor point, second electrode pair of the second sensor point, and third electrode pair of the third sensor point, respectively. Wetting of the distal surface of the absorbent core layer with exudate, i.e. exudate from the wound being absorbed by the absorbent core layer, is detected by a reduced resistance between the two electrodes of the sensor point(s). The sensor points are arranged or distributed along the distal surface of the absorbent core layer allowing the monitor device to detect and/or derive a degree of wetting and/or a wetting pattern or wetting distribution on the distal surface of the of the absorbent core layer. 
     In one or more exemplary monitor devices, the parameter data are indicative of a rate of change in resistance between the two electrodes of an electrode pair forming a sensor point. The first parameter data, the second parameter data, and the third parameter data may be indicative of a rate of change in resistance between first electrode pair of the first sensor point, second electrode pair of the second sensor point, and third electrode pair of the third sensor point, respectively. In one or more exemplary monitor devices, the first parameter data, the second parameter data, and the third parameter data may be indicative of a rate of change in voltage between the first electrode pair, the second electrode pair, and the third electrode pair, respectively. In one or more exemplary monitor devices, the first parameter data, the second parameter data, and the third parameter data may be indicative of a rate of change in current between the first electrode pair, the second electrode pair, and the third electrode pair, respectively. 
     In one or more exemplary monitor devices, the wound data comprises fourth wound data from a fourth sensor point of the wound dressing, and wherein to apply a processing scheme comprises to obtain fourth parameter data based on the fourth wound data and determine an operating state of the wound dressing based on the fourth parameter data. 
     The monitor device is optionally configured to, in accordance with a determination that the operating state is a fourth operating state, transmit a fourth monitor signal comprising monitor data indicative of the fourth operating state of the wound dressing. The fourth operating state of the wound dressing may correspond to a situation wherein the absorbent core layer is wetted to a fourth degree on the distal surface of the absorbent core layer and/or wherein a fourth wetting pattern is detected on the distal surface of the absorbent core layer. 
     In one or more exemplary monitor devices, to obtain parameter data comprises to obtain common parameter data of the parameter data based on a plurality of the first wound data, the second wound data, and the third wound data, and wherein to determine the operating state of the wound dressing is based on the common parameter data. 
     In one or more exemplary monitor devices, to determine an operating state comprises to determine a degree of wetting of the absorbent core layer, such as a degree of wetting of the distal side or surface of the absorbent core material. To determine a degree of wetting of the absorbent core material may comprising to determine if the degree of wetting satisfies first wetting criterion and/or if the degree of wetting satisfies second wetting criterion. 
     The monitor device is optionally configured to, in accordance with the degree of wetting satisfying first wetting criterion, setting the operating state to be the first operating state and optionally include the degree of wetting in the monitor data. 
     The monitor device is optionally configured to, in accordance with the degree of wetting satisfying a second wetting criterion, setting the operating state to be the second operating state and optionally include the degree of wetting in the monitor data. 
     In one or more exemplary monitor devices, to determine an operating state comprises to determine a wetting pattern of the absorbent core layer, such as a wetting pattern on the distal side or surface of the absorbent core material, and optionally to determine a pattern type of the wetting pattern from a plurality of pattern types. To determine a pattern type of the wetting pattern may comprise to determine if the wetting pattern satisfies first pattern type criterion, wherein the pattern type is determined as being a first pattern type if the first pattern type criterion is satisfied. To determine a pattern type of the wetting pattern may comprise to determine if the wetting pattern satisfies second pattern type criterion, wherein the pattern type is determined as being a second pattern type if the second pattern type criterion is satisfied. 
     The monitor device may be configured to, in accordance with the pattern type being a first pattern type, setting the operating state to be the first operating state and optionally including a pattern representation of the wetting pattern in the monitor data. The pattern representation may comprise a pattern type identifier and/or pattern data indicative of parameter data. 
     The monitor device may be configured to, in accordance with the pattern type being a second pattern type degree, setting the operating state to be the second operating state and optionally including a pattern representation of the wetting pattern in the monitor data. The pattern representation may comprise a pattern type identifier and/or pattern data indicative of parameter data. 
     The monitor device comprises a second interface connected to the processor. The second interface may comprise a loudspeaker connected to the processor, and wherein the processor is configured to transmit a monitor signal via the loudspeaker. In one or more exemplary monitor devices, the second interface comprises an antenna and a wireless transceiver, and wherein the processor is configured to transmit a monitor signal as a wireless monitor signal via the antenna and the wireless transceiver. 
     A wound dressing system is disclosed, the wound dressing system comprising a wound dressing and a monitor device, the wound dressing comprising an absorbent core layer, wherein the monitor device is a monitor device as described herein. 
     To obtain first parameter data based on the first wound data may comprise determining one or more first parameters based on the first wound data. To obtain second parameter data based on the second wound data may comprise determining one or more second parameters based on the second wound data. To obtain third parameter data based on the third wound data may comprise determining one or more third parameters based on the third wound data. In one or more exemplary monitor devices, determination of an operating state may be based on one or more first parameters, such as first primary parameter and/or first secondary parameter of first parameter data. In one or more exemplary monitor devices, determination of an operating state may be based on one or more second parameters, such as second primary parameter and/or second secondary parameter of the second parameter data. In one or more exemplary monitor devices, determination of an operating state may be based on one or more third parameters, such as third primary parameter and/or third secondary parameter of the third parameter data. In one or more exemplary monitor devices, determination of an operating state may be based on one or more fourth parameters, such as fourth primary parameter and/or fourth secondary parameter of the fourth parameter data. 
     Parameter data, P_ 1 , P_ 2 , . . . , P_N, may comprise respective parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  indicative of resistance between the respective two electrodes forming a sensor point of the wound dressing. Parameter data, P_ 1 , P_ 2 , . . . , P_N, may comprise respective parameters p_ 1 _ 2 , p_ 2 _ 2 , . . . , p_N_ 2  each indicative of a rate of change in resistance between the respective two electrodes forming a sensor point of the wound dressing. Accordingly, p_ 1 _ 1  of P_ 1  may be the resistance measured between the first electrode E_ 1 _ 1  and the second electrode E_ 2 _ 1  forming the first sensor point SP_ 1 _ 1 , p_ 2 _ 1  of P_ 2  may be the resistance measured between first electrode E_ 1 _ 1  and the second electrode E_ 2 _ 2  forming the second sensor point SP_ 1 _ 2 . 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a first criteria set based on the first parameter data P_ 1  (p_ 1 _ 1 ) and/or one or more other parameter data P_ 2  (p_ 2 _ 1 ), P_ 3  (p_ 3 _ 1 ), . . . , P_N (p_N_ 1 ), wherein the operating state is determined to be the first operating state if the first criteria set is satisfied. The first criteria set may comprise one or more first criteria based on one or more of P_ 1 , P_ 2 , . . . , P_N. The first criteria set may comprise a first primary criterion based on P_ 1  (p_ 1 _ 1 ). The first criteria set may comprise a first secondary criterion based on P_ 2  (p_ 2 _ 1 ). The first criteria set may comprise a first tertiary criterion based on P_ 3  (p_ 3 _ 1 ). The first criteria set may comprise N first criteria respectively based on P_ 1 , P_ 2 , . . . , P_N. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a second criteria set based on the second parameter data P_ 2  (p_ 2 _ 1 ) and/or one or more other parameter data P_ 1  (p_ 1 _ 1 ), P_ 3  (p_ 3 _ 1 ), . . . , P_N (p_N_ 1 ), wherein the operating state is determined to be the second operating state if the second criteria set is satisfied. The second criteria set may comprise one or more second criteria based on one or more of P_ 1 , P_ 2 , . . . , P_N. The second criteria set may comprise a second primary criterion based on P_ 1  (p_ 1 _ 1 ). The second criteria set may comprise a second secondary criterion based on P_ 2  (p_ 2 _ 1 ). The second criteria set may comprise a second tertiary criterion based on P_ 3  (p_ 3 _ 1 ). The second criteria set may comprise N second criteria respectively based on P_ 1 , P_ 2 , . . . , P_N. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing may comprise to determine the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  having resistances less than a first threshold as a first common parameter of common parameter data. The operating state of the wound dressing may be based on the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  having resistances less than a first threshold. The operating state of the wound dressing may be determined as the first operating state if the first common parameter being the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  having resistances less than a first threshold is in a first range, e.g. from 0.25N to 0.5N. The first operating state may be indicative of a low-wetted absorbent core layer, i.e. a high degree of remaining absorbent capacity of the wound dressing/absorbent core layer. The operating state of the wound dressing may be determined as the second operating state if the first common parameter being the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  having resistances less than a first threshold is in a second range, e.g. from 0.5N to 0.75N. The second operating state may be indicative of a medium-wetted absorbent core layer, i.e. a medium degree of remaining absorbent capacity of the wound dressing/absorbent core layer. 
     The operating state of the wound dressing may be determined as a default operating state if the first common parameter being the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  having resistances less than a first threshold is less than a default threshold. The default threshold may be a fixed value or based on the number N of sensor points. The default threshold may be 0.1 N or 0.25 N. The processor is optionally configured to, in accordance with a determination that the operating state is the default operating state, transmit a default monitor signal comprising monitor data indicative of the default operating state of the wound dressing. The default operating state may be indicative of a substantially non-wetted absorbent core layer, i.e. a very high degree of remaining absorbent capacity of the wound dressing/absorbent core layer. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a default criteria set based on parameter data P_ 1 , P_ 2 , . . . , P_N, wherein the operating state is determined to be the default operating state if the default criteria set is satisfied, and in accordance with a determination that the operating state is the default operating state, transmit a default monitor signal comprising monitor data indicative of the default operating state of the wound dressing. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a third criteria set based on parameter data P_ 1 , P_ 2 , . . . , P_N, wherein the operating state is determined to be the third operating state if the third criteria set is satisfied. The operating state of the wound dressing may be determined as the third operating state if the first common parameter being the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . ., p_N_ 1  having resistances less than a first threshold is in a third range, e.g. from 0.75N to 0.9N. 
     The processor is optionally configured to, in accordance with a determination that the operating state is the third operating state, transmit a third monitor signal comprising monitor data indicative of the third operating state of the wound dressing. In one or more exemplary monitor devices, the third operating state of the wound dressing corresponds to a situation wherein the absorbent core layer is wetted to a third degree on the distal surface. The third degree may be indicative of low degree of remaining absorbent capacity of the wound dressing/absorbent core layer. 
     In one or more exemplary monitor devices, to determine an operating state of the wound dressing is based on a fourth criteria set based on parameter data P_ 1 , P_ 2 , . . . , P_N, wherein the operating state is determined to be the fourth operating state if the fourth criteria set is satisfied. The operating state of the wound dressing may be determined as the fourth operating state if the first common parameter being the number of parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_N_ 1  having resistances less than a first threshold is in a fourth range, e.g. from 0.9N to N. 
     The processor is optionally configured to, in accordance with a determination that the operating state is the fourth operating state, transmit a fourth monitor signal comprising monitor data indicative of the fourth operating state of the wound dressing. In one or more exemplary monitor devices, the fourth operating state of the wound dressing corresponds to a situation wherein the absorbent core layer is wetted to a fourth degree on the distal surface. The fourth degree may be indicative of very low or no degree of remaining absorbent capacity of the wound dressing/absorbent core layer. 
     The monitor device comprises a monitor device housing optionally made of a plastic material. The monitor device housing may be an elongate housing having a first end and a second end. The monitor device housing may have a length or maximum extension along a longitudinal axis in the range from 1 cm to 15 cm. The monitor device housing may have a width or maximum extension perpendicular to the longitudinal axis in the range from 0.5 cm to 3 cm. The monitor device housing may be curve-shaped. 
     The monitor device comprises a first interface. The first interface may be configured as a wound dressing interface for electrically and/or mechanically connecting the monitor device to the wound dressing. Thus, the wound dressing interface is configured to electrically and/or mechanically couple the monitor device and the wound dressing. The first interface may be configured as an accessory device interface for electrically and//or mechanically connecting the monitor device to an accessory device. The first interface may be configured for coupling to a docking station of the wound dressing system, e.g. for charging the monitor device and/or for data transfer between the monitor device and the docking station. 
     The first interface of the monitor device may comprise a plurality of terminals, such as two, three, four, five, six, seven or more terminals, for forming electrical connections with respective terminals and/or electrodes of the wound dressing. One or more terminals of the first interface may be configured for forming electrical connections with an accessory device, e.g. with respective terminals of a docking station. The first interface may comprise a ground terminal. The first interface may comprise a first terminal, a second terminal and optionally a third terminal. The first interface may comprise a fourth terminal and/or a fifth terminal. The first interface optionally comprises a sixth terminal. In one or more exemplary monitor devices, the first interface has M terminals, wherein M is an integer in the range from 4 to 16. 
     The first interface of the monitor device may comprise a coupling part for forming a mechanical connection, such as a releasable coupling between the monitor device and the wound dressing. The coupling part and the terminals of the first interface form (at least part of) a first connector of the monitor device. 
     The monitor device comprises a power unit for powering the monitor device. The power unit may comprise a battery. The power unit may comprise charging circuitry connected to the battery and terminals of the first interface for charging the battery via the first interface, e.g. the first connector. The first interface may comprise separate charging terminal(s) for charging the battery. 
     The monitor device may comprise a sensor unit with one or more sensors. The sensor unit is connected to the processor for feeding sensor data to the processor. The sensor unit may comprise an accelerometer for sensing acceleration and provision of acceleration data to the processor. The sensor unit may comprise a temperature sensor for provision of temperature data to the processor. 
     The monitor device comprises a second interface connected to the processor. The second interface may be configured as an accessory interface for connecting, e.g. wirelessly connecting, the monitor device to one or more accessory devices. The second interface may comprise an antenna and a wireless transceiver, e.g. configured for wireless communication at frequencies in the range from 2.4 to 2.5 GHz. The wireless transceiver may be a Bluetooth transceiver, i.e. the wireless transceiver may be configured for wireless communication according to Bluetooth protocol, e.g. Bluetooth Low Energy, Bluetooth 4.0, Bluetooth 5. The second interface optionally comprises a loudspeaker and/or a haptic feedback element for provision of an audio signal and/or haptic feedback to the user, respectively. 
     The wound dressing system may comprise a docking station forming an accessory device of the wound dressing system. The docking station may be configured to electrically and/or mechanically couple the monitor device to the docking station. 
     The docking station may comprise a docking monitor interface. The docking monitor interface may be configured for electrically and/or mechanically connecting the monitor device to the docking station. The docking monitor interface may be configured for wirelessly connecting the monitor device to the docking station. The docking monitor interface of the docking station may be configured to electrically and/or mechanically couple the docking station and the monitor device. 
     The docking monitor interface of the docking station may comprise, e.g. as part of a first connector of the docking monitor interface, a coupling part for forming a mechanical connection, such as a releasable coupling between the monitor device and the docking station. The coupling part may be configured to engage with a coupling part of the monitor device for releasably coupling the monitor device to the docking station. 
     The docking monitor interface of the docking station may comprise, e.g. as part of a first connector of the docking monitor interface, a plurality of terminals, such as two, three, four, five, six, seven or more terminals, for forming electrical connections with respective terminals of the monitor device. The docking monitor interface may comprise a ground terminal. The docking monitor interface may comprise a first terminal and/or a second terminal. The docking station may comprise a third terminal. The docking monitor interface may comprise a fourth terminal and/or a fifth terminal. The docking monitor interface optionally comprises a sixth terminal. 
     The method may comprise mechanically and electrically coupling the first interface to a monitor interface of the wound dressing. 
       FIG. 1  illustrates an exemplary wound dressing system. The wound dressing system  1  comprises a wound dressing  2 , a monitor device  4 , and optionally an accessory device  6  (e.g., a mobile telephone). The monitor device  4  is connectable to the wound dressing  2  via respective first connectors of the monitor device  4  and wound dressing  2 . The monitor device  4  is configured for wireless communication with the accessory device  6 . Optionally, the accessory device  6  is configured to communicate with a server device  8  of the wound dressing system  1 , e.g. via network  10 . The server device  8  may be operated and/or controlled by the wound dressing manufacturer and/or a service centre. Wound data and/or parameter data based on the wound data are obtained from electrodes/sensors of the wound dressing  2  with the monitor device  4 . The monitor device  4  processes the wound data and/or parameter data based on the wound data to determine monitor data that are transmitted to the accessory device  6 . In the illustrated wound dressing system, the accessory device  6  is a mobile phone; however, the accessory device  6  may be embodied as another handheld device, such as a tablet device, or a wearable, such as a watch or other wrist-worn electronic device. Accordingly, the monitor device  4  is configured to determine and transmit monitor data to the accessory device  6 . 
     The wound dressing system  1  optionally comprises a docking station  20  forming an accessory device of the wound dressing system  1 . The docking station comprises  20  comprises a docking monitor interface including a first connector  22  configured for electrically and/or mechanically connecting the monitor device  4  to the docking station  20 . The docking monitor interface may be configured for wirelessly connecting the monitor device  4  to the docking station  20 . The docking station  20  comprises a user interface  24  for receiving user input and/or providing feedback to the user on the operational state of the docking station  20 . The user interface  24  may comprise a touch-screen. The user interface  24  may comprise one or more physical buttons and/or one or more visual indicators, such as light emitting diodes. 
     A user interface refers herein to a graphical representation comprising a collection of user interface objects. A user interface comprises one or more user interface objects. A user interface may be referred to as a user interface screen. 
     A user interface object refers herein to a graphical representation of an object that is displayed on the display of the accessory device. The user interface object may be user-interactive, or selectable by a user input. For example, an image (e.g., icon), a button, and text (e.g., hyperlink) each optionally constitute a user interface object. The user interface object may form part of a widget. A widget may be a mini-application that may be used by the user and created by the user. A user interface object may comprise a prompt, application launch icon, and/or an action menu. An input, such as first input and/or second input, may comprise a touch (e.g. a tap, a force touch, a long press), and/or a movement of contact (e.g. a swipe gesture, e.g. for toggling). The movement on contact may be detected by a touch sensitive surface, e.g. on a display of an accessory device. Thus, the display may be a touch sensitive display. An input, such as first input and/or second input, may comprise a lift off. An input, such as first input and/or second input, may comprise a touch and a movement followed by a lift off. 
     The display of the accessory device may be configured to detect touch (e.g. the display is a touch-sensitive display), the input comprises a contact on the touch sensitive display. A touch-sensitive display provides an input interface and an output interface between the accessory device and a user. A processor of the accessory device may be configured to receive and/or send electrical signals from/to touch-sensitive display. A touch-sensitive display is configured to display visual output to the user. The visual output optionally includes graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). For example, some or all the visual output may be seen as corresponding to user-interface objects. 
     The processor of the accessory device may be configured to display, on the display, one or more user interfaces, such as user interface screens, including a first user interface and/or a second user interface. A user interface may comprise one or more, such as a plurality of user interface objects. For example, the first user interface may comprise a first primary user interface object and/or a first secondary user interface object. A second user interface may comprise a second primary user interface object and/or a second secondary user interface object. A user interface object, such as the first primary user interface object and/or the second primary user interface object, may represent an operating state of the wound dressing. 
       FIG. 2  is a schematic block diagram of an exemplary monitor device  4 . The monitor device  4  comprises a monitor device housing  100 , a processor  101 , and one or more interfaces, the one or more interfaces including a first interface  102  (wound dressing interface) and a second interface  104  (accessory interface). The monitor device  4  comprises a memory  106  for storing wound data and/or parameter data based on the wound data. The memory  106  is connected to the processor  101  and/or the first interface  102 . The first interface  102  is configured as a wound dressing interface for electrically and/or mechanically connecting the monitor device  4  to the wound dressing, e.g. wound dressing  2 . The first interface  102  comprises a plurality of terminals for forming electrical connections with respective terminals of the wound dressing. The first interface  102  comprises a first terminal  110 , a second terminal  112  and a third terminal  114 . The first interface  102  optionally comprises a fourth terminal  116 , a fifth terminal  118  and/or sixth terminal  119 . The first interface  102  of the monitor device  4  comprises a coupling part  120  for forming a mechanical connection, such as a releasable coupling, between the monitor device  4  and the wound dressing. The coupling part  120  and terminals  110 ,  112 ,  114 ,  116 ,  118 ,  119  of the first interface  102  form (at least part of) a first connector of the monitor device  4 . Terminals  110 ,  112 , and  114  may be respectively coupled to first electrodes  210 A,  210 B,  210 C via the monitor interface of the wound dressing, and terminals  116 ,  118 ,  119  may be respectively coupled to second electrodes  212 A,  212 B,  212 C via the monitor interface of the wound dressing. 
     The monitor device  4  comprises a power unit  121  for powering the monitor device and active components thereof, i.e. the power unit  121  is connected to the processor  101 , the first interface  102 , the second interface  104 , and memory  106 . The power unit comprises a battery and optionally charging circuitry. The charging circuitry is optionally connected to the battery and terminals of the first interface  102  for charging the battery via terminals of the first interface, e.g. terminals of the first connector. 
     The second interface  104  of monitor device  4  is configured as an accessory interface for connecting the monitor device  4  to one or more accessory devices such as accessory device  6 . The second interface  104  comprises an antenna  122  and a wireless transceiver  124  configured for wireless communication with accessory device(s). Optionally, the second interface  104  comprises a loudspeaker  126  and/or a haptic feedback element  128  for provision of respective audio signal and/or haptic feedback to the user. 
     The monitor device  6  optionally comprises a sensor unit  140  connected to the processor  101 . The sensor unit  140  comprises a temperature sensor for feeding temperature data to the processor and/or a G-sensor or accelerometer for feeding acceleration data to the processor  101 . 
     The processor  101  is configured to apply a processing scheme, and the first interface  102  is configured for collecting wound data from the wound dressing coupled to the first interface, the wound data comprising wound data from sensor points (electrode pairs) of the wound dressing. The wound data may comprise first wound data WD_ 1  from a first electrode pair (first sensor point) of the wound dressing, second wound data WD_ 2  from a second electrode pair (second sensor point) of the wound dressing, and third wound data WD_ 3  from a third electrode pair (third sensor point) of the wound dressing. In the illustrated monitor device, the processor is configured to collect, WD_ 1 , WD_ 2 , WD_ 3 , . . . , WD_ 9  from nine sensor points of the wound dressing formed by nine electrode pairs being combinations of a first electrode of the first set of first electrodes and a second electrode of the second set of second electrodes. The wound data may be stored in the memory  106  and/or processed in the processor  101  in order to obtain parameter data based on the wound data. The parameter data may be stored in the memory  106 . The processor  101  is configured to apply a processing scheme, wherein to apply a processing scheme comprises obtain first parameter data P_ 1  including p_ 1 _ 1  being the resistance between the two electrodes forming the first sensor point based on the first wound data; obtain second parameter data P_ 2  including p_ 2 _ 1  being the resistance between the two electrodes forming the second sensor point based on the second wound data; obtain third parameter data P_ 3  including p_ 3 _ 1  being the resistance between the two electrodes forming the third sensor point based on the third wound data. In other words, the processor  101  is configured to obtain parameters p_ 1 _ 1 , p_ 2 _ 1 , . . . , p_ 9 _ 1  being resistances based on respective wound data WD_ 1 , WD_ 2 , . . . , WD_ 9  obtained between the two electrodes forming the respective sensor points. To apply a processing scheme comprises to determine an operating state of the wound dressing based on one or more, e.g. all, of the parameter data P_ 1 , P_ 2 , . . . , P_ 9  including p_ 1 _ 1 , p_ 2 _ 1 , . . . ., p_ 9 _ 1 . The operating state is optionally indicative of a degree of wetting or wetting pattern on the distal side of the absorbent core layer of the wound dressing. 
     The monitor device  4  is optionally configured to, in accordance with a determination that the operating state is a first operating state of the wound dressing, transmit a first monitor signal comprising monitor data indicative of the first operating state of the wound dressing via the second interface, the monitor data optionally including including a pattern representation of the wetting pattern and/or the degree of wetting. The pattern representation may comprise a pattern type identifier and/or pattern data indicative of or comprising parameter data. Optionally, the monitor device  4  may be configured to, in accordance with a determination that the operating state is a second operating state of the wound dressing, transmit a second monitor signal comprising monitor data indicative of the second operating state of the wound dressing via the second interface, the monitor data optionally including including a pattern representation of the wetting pattern and/or the degree of wetting. The pattern representation may comprise a pattern type identifier and/or pattern data indicative of or comprising parameter data. 
       FIG. 3  shows a proximal view of an exemplary first adhesive layer of the wound dressing. The first adhesive layer  150  has a proximal surface  150 A configured for attachment of the wound dressing to the skin surface of a user. The first adhesive layer has perforations or through-going openings  152  arranged within absorbing region  154  for allowing exudate from the wound to flow through the perforations of first adhesive layer  150  to be absorbed by absorbent core layer arranged on the distal side of the first adhesive layer. 
       FIG. 4  is a schematic cross-section of an exemplary wound dressing. The wound dressing  2  comprises a first adhesive layer  150  with a proximal surface  150 A configured for attachment of the wound dressing to the skin surface of a user. The wound dressing  2  may form part of wound dressing system  1 . The wound dressing  2  comprises an absorbent core layer  202  with a proximal surface  202 A and a distal surface  202 B; an electrode assembly  204  comprising a plurality of electrodes arranged on a distal side of the absorbent core layer  202 ; and a top layer  206  at least partly on a distal side of the electrode assembly. 
       FIG. 5  is a proximal view of an exemplary and schematic electrode assembly of wound dressing  2 . The electrode assembly  204  comprises a first support layer  208  and a plurality of electrodes printed on a proximal surface  208 A of the first support layer, i.e. the plurality of electrodes is arranged on a distal side of the absorbent core layer of the wound dressing.  202 . The plurality of electrodes comprises a first set  210  of nine first electrodes  210 A, . . . ,  210 I and a second set  212  of a second electrode  212 A. A sensing part of a first electrode and a sensing part of a second electrode forms a sensor point. The electrode assembly  204  comprises nine sensor points  214  arranged on the proximal surface of the first support layer and distributed along a distal surface of the absorbent core layer, e.g. as shown with nine sensor points arranged in a 3×3 matrix sensor point configuration. 
     The electrode assembly  204  comprises a first masking layer  216  covering and isolating electrode parts of the first electrodes  210 A, . . . ,  210 I and the second electrode  212 A. The first masking layer  216  is printed on the first support layer/electrodes and comprises a number of sensor point openings to form respective sensor points of the electrode assembly by exposing sensing parts of first electrodes  210 A, . . . ,  210 I and second electrode  212 A. 
     The second electrode  212 A operates as a reference electrode (ground) for the first electrodes  210 A, . . . ,  210 I and forms a part of the respective sensor points  214  of electrode assembly  204 . The sensor points  214  are arranged with a distance between two neighbouring sensor points in the range from 3 mm to 50 mm, e.g. with a center-to-center distance of 30 mm. 
     Each electrode  210 A, . . . ,  210 I,  212  has a respective connection part (connection parts indicated with dashed box  215  for forming a connection to monitor device via a wired or wireless monitor interface of the wound dressing. 
     The electrode assembly  204  comprises a multiplexer  217  coupled to the connection parts included in the dashed box  215 . The multiplexer  217  connects the connection parts of the electrodes  210 A, . . . ,  210 I,  212  to respective terminals  110 ,  112 ,  114 ,  116 ,  118 ,  119  of the first interface  102  of the monitor device  4 . The monitor device  4  can select a desired multiplexer configuration of the multiplexer  217  by sending one or more control signals to the multiplexer  217 , as described in relation to  FIG. 16 . While the multiplexer  217  is depicted as being embedded in the electrode assembly  204  in alternative embodiments, the multiplexer  217  is embedded in the coupling part  120 . 
       FIG. 6  shows a more detailed view of a sensor point  214  of an electrode assembly, e.g. electrode assembly  204 , see dashed box in  FIG. 5 . The sensor point  214  is formed by a first sensing part  218  of a first electrode and a second sensing part  220  of a second electrode. The first sensing part  218  and the second sensing part  220  are exposed to the absorbent core layer of the wound dressing through sensor point opening  222  of the first masking layer  216 . Thus, exudate or other fluid reaching the distal surface of the absorbent core layer short-circuits the first sensing part  218  and the second sensing part  220 . In the illustrated electrode assembly, the sensor point opening  222  is circular with a radius in the range from 2 to 10 mm. 
       FIG. 7  is a schematic cross-section of an exemplary wound dressing  2 A. The wound dressing  2 A comprises a first adhesive layer  150  with a proximal surface  150 A configured for attachment of the wound dressing to the skin surface of a user. The wound dressing  2 A may form part of wound dressing system  1 . The wound dressing  2 A comprises an absorbent core layer  202  with a proximal surface  202 A and a distal surface  202 B; and an electrode assembly  204 A comprising a plurality of electrodes arranged on a distal side of the absorbent core layer  202 , wherein the plurality of electrodes comprises a first set of first electrodes arranged on a proximal surface  208 A and/or distal surface  208 B of first support layer  208 . The electrode assembly  204 A comprises a second support layer  224 , and the plurality of electrodes comprises a second set of second electrodes arranged on a proximal surface and/or distal surface of second support layer  208 . The electrode assembly  204 A comprises a spacing layer  226  arranged between the first support layer  208  and the second support layer  224 . Further, a top layer  206  is arranged at least partly on a distal side of the electrode assembly  204 A. 
       FIG. 8  shows a proximal view of an exemplary first support layer  208 , e.g. of electrode assembly  204 , electrode assembly  204 A, electrode assembly  204 B. The electrode assembly comprises three first electrodes  210 A,  210 B,  210 C printed on the proximal surface  208 A of the first support layer  208 , wherein each electrode  210 A,  210 B,  210 C comprises three first sensing parts  218  exposed through respective sensor point openings of first masking layer, see  FIG. 9 . The first support layer  208  has a plurality of sensor point openings  250  for allowing exudate to pass through the first support layer (from proximal side to distal side) and reach sensing parts of second electrodes arranged on the distal side or distal surface of the first support layer  208 . Each sensor point opening  250  is optionally centred in a respective first sensing part  218  of a first electrode. Each first electrode  210 A,  210 B, and  210 C has a connection part  252  for connection to or forming part of a monitor interface of the wound dressing. In one or more exemplary electrode assemblies, e.g. electrode assemblies  204 A,  204 B shown in  FIG. 7 , the first electrodes  210 A,  210 B,  210 C may be printed on the distal surface  208 B of the first support layer  208 . 
       FIG. 9  shows a proximal view of an exemplary first masking layer  216  of electrode assembly with first support layer of  FIG. 8 . The first masking layer  216  is printed on the proximal surface/distal surface of first support layer partly covering first electrodes  210 A,  210 B, and  210 C of the electrode assembly. The first masking layer comprises nine sensor point openings  222  arranged to fit a 3×3 matrix sensor point configuration and respectively aligned with first sensing parts  218  of first electrodes  210 A,  210 B,  210 C. 
       FIG. 10  shows a proximal view of an exemplary second support layer  224 , e.g. of electrode assembly  204 A. The electrode assembly comprises three second electrodes  212 A,  212 B,  212 C printed on proximal surface  224 A of the second support layer  224 , wherein each electrode  212 A,  212 B,  212 C comprises three second sensing parts  220  exposed through respective sensor point openings of second masking layer, see  FIG. 11 . Optionally, the second support layer  224  has a plurality of sensor point openings  254  for allowing exudate to pass through the second support layer (from proximal side to distal side). Each sensor point opening  254  is optionally centred in a respective second sensing part  220  of a second electrode. Each second electrode  212 A,  212 B, and  212 C has a connection part  256  for connection to or forming part of a monitor interface of the wound dressing. 
       FIG. 11  shows a proximal view of an exemplary second masking layer  270  of electrode assembly  204 A. The second masking layer  270  is printed on the proximal surface  224 A of the second support layer  224  partly covering second electrodes  212 A,  212 B, and  212 C of the electrode assembly. The second masking layer  270  comprises nine sensor point openings  272  arranged to fit a 3×3 matrix sensor point configuration and respectively aligned with second sensing parts  220  of second electrodes  212 A,  212 B,  212 C. Referring back to  FIGS. 7-11 , the first sensing parts  218  of first electrodes  210 A,  210 B,  210 C are respectively aligned with a second sensing part  220  of second electrodes  212 A,  212 B,  212 C to form sensor points. 
       FIG. 12  shows a distal view of an exemplary second support layer  224 , e.g. of electrode assembly  204 B. The electrode assembly comprises three second electrodes  212 A,  212 B,  212 C printed on distal surface  224 B of the second support layer  224 , wherein each electrode  212 A,  212 B,  212 C comprises three second sensing parts  220  optionally exposed through respective sensor point openings of second masking layer, see  FIG. 13 . The second support layer  224  has a plurality of sensor point openings  254  for allowing exudate to pass through the second support layer (from proximal side to distal side) and reach second sensing parts  220  of second electrodes arranged on the distal side or distal surface of the second support layer  224 . Each sensor point opening  254  is optionally centred in a respective second sensing part  220  of a second electrode. Each second electrode  212 A,  212 B, and  212 C has a connection part  256  for connection to or forming part of a monitor interface of the wound dressing. 
       FIG. 13  shows a proximal view of an exemplary and optional second masking layer  270 A of electrode assembly  204 B or a second masking layer  270 A of electrode assembly  204 . The second masking layer  270 A is printed on the distal surface  224 B of the second support layer  224  or on distal surface  208 B of the first support layer  208  partly covering second electrodes  212 A,  212 B, and  212 C of the electrode assembly. The second masking layer  270 A comprises nine sensor point openings  272  arranged to fit a 3×3 matrix sensor point configuration and respectively aligned with second sensing parts  220  of second electrodes  212 A,  212 B,  212 C. Referring back to  FIGS. 4 and 7-11 , the first sensing parts  218  of first electrodes  210 A,  210 B,  210 C are respectively aligned with a second sensing part  220  of second electrodes  212 A,  212 B,  212 C to form sensor points. 
       FIG. 14  shows a distal view of an exemplary first support layer  208  of an electrode assembly, e.g. of electrode assembly  204 . The electrode assembly comprises three second electrodes  212 A,  212 B,  212 C printed on distal surface  224 B of the first support layer  208 , wherein each second electrode  212 A,  212 B,  212 C comprises three second sensing parts  220  optionally exposed through respective sensor point openings of second masking layer, see  FIG. 13 . The first support layer  208  has a plurality of sensor point openings  250  for allowing exudate to pass through the first support layer (from proximal side to distal side) and reach second sensing parts  220  of second electrodes arranged on the distal side or distal surface of the first support layer  208 . Each sensor point opening  250  is optionally centred in a respective second sensing part  220  of a second electrode. Each second electrode  212 A,  212 B, and  212 C has a connection part  256  for connection to or forming part of a monitor interface of the wound dressing. 
       FIG. 15  shows a flow chart of an exemplary method of monitoring a wound dressing comprising an absorbent core layer. The method  1000  comprises, at a monitor device comprising a processor configured to apply a processing scheme; memory; a first interface connected to the processor and the memory; and a second interface connected to the processor, collecting  1002  wound data from the wound dressing, the wound data comprising first wound data from a first sensor point of the wound dressing, second wound data from a second sensor point of the wound dressing, and third wound data from a third sensor point of the wound dressing; applying a processing scheme comprising obtaining  1003  parameter data based on the wound data; and determining  1011  an operating state of the wound dressing based on the parameter data, wherein the operating state is indicative of wetting of the absorbent core layer of the wound dressing; in accordance  1012  with a determination that the operating state is a first operating state, transmitting  1014  a first monitor signal comprising monitor data indicative of the first operating state of the wound dressing via the second interface; and in accordance  1016  with a determination that the operating state is a second operating state, transmitting a second monitor signal comprising monitor data indicative of the second operating state of the wound dressing via the second interface. Obtaining  1003  parameter data optionally comprises obtaining  1004  first parameter data based on first wound data and indicative of resistance between two electrodes of a first sensor point, obtaining  1006  second parameter data based on second wound data and indicative of resistance between two electrodes of a second sensor point, obtaining  1008  third parameter data based on third wound data and indicative of resistance between two electrodes of a third sensor point, and obtaining  1010  fourth parameter data based on fourth wound data and indicative of resistance between two electrodes of a fourth sensor point. 
       FIG. 16  schematically shows a part of an exemplary wound dressing  2 B including the multiplexer  217 A and a monitor interface  102 . The wound dressing  2 B comprises a first set of first electrodes including electrodes  210 A, . . . ,  210 G and a second set of second electrodes including electrodes  212 A, . . . ,  212 C. Each of the electrodes  210 A, . . . ,  210 G,  212 A, . . . ,  212 C is connected to a respective input pin  302 A, . . . ,  302 G,  303 A, . . . ,  303 C of N input pins included in the multiplexer  217 A. That is, each electrode of the first set of first electrodes is connected to a respective input pin of a first set of first input pins  302 A, . . . ,  302 G and each electrode of the second set of second electrodes is connected to a respective input pin of a second set of second input pins  303 A, . . . ,  303 C. 
     For example, in the configuration shown, a first primary electrode  210 A of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first primary input pin  302 A of the first set of first input pins  302 A, . . . ,  302 G. A first secondary electrode  210 B of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first secondary input pin  302 B of the first set of first input pins  302 A, . . . ,  302 G. A first tertiary electrode  210 C of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first tertiary input pin  302 C of the first set of first input pins  302 A, . . . ,  302 G. A first quaternary electrode  210 D of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first quaternary input pin  302 D of the first set of first input pins  302 A, . . . ,  302 G. A first quinary electrode  210 E of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first quinary input pin  302 E of the first set of first input pins  302 A, . . . ,  302 G. A first senary electrode  210 F of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first senary input pin  302 F of the first set of first input pins  302 A, . . . ,  302 G. A first septenary electrode  210 G of the first set of first electrodes  210 A, . . . ,  210 G is connected to a first septenary input pin  302 G of the first set of first input pins  302 A, . . . ,  302 G. A second primary electrode  212 A of the second set of second electrodes  212 A, . . . ,  212 C is connected to a second primary input pin  303 A of the second set of second input pins  303 A, . . . ,  303 C. A second secondary electrode  212 B of the second set of second electrodes  212 A, . . . ,  212 C is connected to a second secondary input pin  303 B of the second set of second input pins  303 A, . . . ,  303 C. A second tertiary electrode  212 C of the second set of second electrodes  212 A, . . . ,  212 C is connected to a second tertiary input pin  303 C of the second set of second input pins  303 A, . . . ,  303 C. 
     The multiplexer  217 A also comprises a first output pin  304  connected to a first terminal  110  of the monitor interface  102 . The multiplexer  217 A comprises a second output pin  306  connected to a second terminal  112  of the monitor interface  102 . The multiplexer  217 A comprises a first control pin  308  connected to a third terminal  114  of the monitor interface  102 . The multiplexer  217 A comprises a second control pin  310  connected to a fourth terminal  116  of the monitor interface  102 . The multiplexer  217 A comprises a third control pin  312  connected to a fifth terminal  118  of monitor interface  102 . The multiplexer  217 A comprises a fourth control pin  314  connected to a sixth terminal  119  of the monitor interface  102 . 
     The control pins  308 ,  310 ,  312 ,  314  are configured to receive control signals from the monitor device  4  via the respective terminals  114 ,  116 ,  118 ,  119  to which they&#39;re connected. Depending on the control signals received, the sensor signals from the different electrodes  210 A, . . . ,  210 G,  212 A, . . . ,  212 C can be output via the first output pin and/or the second output pin  306  to the monitor device  4 . Wth the wound dressing  2 B including the multiplexer  217 A, it is possible to collect data from ten (or more) different electrodes in various multiplexer configurations via a six-terminal connector of the monitor interface  102 . 
     In a first multiplexer configuration example, the multiplexer  217 A receives a control signal to connect the first primary electrode  210 A, via the first primary input pin  302 A, to the first output pin  304 . In the first multiplexer configuration, the multiplexer  217 A may additionally receive a control signal to connect the second primary electrode  212 A, via the second primary input pin  303 A, to the second output pin  306 . 
     In a second multiplexer configuration example, the multiplexer  217 A receives a control signal to connect the first secondary electrode  210 B, via the first secondary input pin  302 B, to the first output pin  304 . In the second multiplexer configuration, the multiplexer  217 A may additionally receive a control signal to connect the second secondary electrode  212 B, via the second secondary input pin  303 B, to the second output pin  306 . 
     In a third multiplexer configuration example, the multiplexer  217 A receives a control signal to connect the first tertiary electrode  210 C, via the first tertiary input pin  302 C, to the first output pin  304 . In the third multiplexer configuration, the multiplexer  217 A may additionally receive a control signal to connect the second tertiary electrode  212 C, via the second tertiary input pin  303 C, to the second output pin  306 . 
       FIG. 17  is a flow chart of an exemplary method  400  of manufacturing a wound dressing of a wound dressing system. The method  400  comprises providing a first adhesive layer (e.g., a first adhesive layer  150 ) including a proximal surface configured for attachment of the wound dressing (e.g. wound dressing  2 ,  2 A,  2 B) to a user (block  402 ). The method  400  further comprises arranging an absorbent core (e.g., the absorbent core  202 ) on a distal side of the first adhesive layer  150  (block  404 ). 
     The method  400  further comprises arranging an electrode assembly (e.g., electrode assembly  204 ) on a distal side of the absorbent core (block  406 ). The electrode assembly includes a plurality of electrodes and a multiplexer. The plurality of electrodes includes a first set of first electrodes (e.g., first electrodes  210 A, . . . ,  210 I) and optionally a second set of second electrodes (e.g., second electrodes  212 A, . . . ,  212 C). The method  400  comprises arranging the electrode assembly on the distal side of the absorbent core such that each electrode of the first and second sets of electrodes are connected to a respective input pin of N input pins of the multiplexer. That is, each electrode of the first set of first electrodes is connected to a respective input pin of a first set of first input pins (e.g., first set of first input pins  302 A, . . . ,  302 G) and each electrode of the second set of second electrodes is connected to a respective input pin of a second set of second input pins (e.g., second set of second input pins  303 A, . . . ,  303 C). 
     In addition, the multiplexer includes a first output pin (e.g., first output pin  304 ), a second output pin (e.g., second output pin  306 ), a first control pin (e.g., first control pin  308 ), a second control pin (e.g., second control pin  310 ), a third control pin (e.g., third control pin  312 ), and a fourth control pin (e.g., fourth control pin  314 ). 
     The method  400  further comprises arranging a monitor interface (e.g., monitor interface  102 ) on the distal side of the first adhesive layer (block  408 ). The monitor interface includes a first terminal (e.g., first terminal  110 ), a second terminal (e.g., second terminal  112 ), a third terminal (e.g., third terminal  114 ), a fourth terminal (e.g., fourth terminal  116 ), a fifth terminal (e.g., fifth terminal  118 ), and a sixth terminal (e.g., sixth terminal  119 ). The monitor interface is arranged on a distal side of the first adhesive layer such that: the first output pin of the multiplexer is connected to the first terminal of the monitor interface, the second output pin of the multiplexer is connected to the second terminal of the monitor interface, the first control pin of the multiplexer is connected to the third terminal of the monitor interface, the second control pin of the multiplexer is connected to the fourth terminal of the monitor interface, the third control pin of the multiplexer is connected to the fifth terminal of the monitor interface, and the fourth control pin of the multiplexer is connected to the sixth terminal of the monitor interface. 
       FIG. 18  is a flow chart of an exemplary method  500  of monitoring a wound dressing (e.g. wound dressing  2 ,  2 A,  2 B) of a wound dressing system. The wound dressing comprises a first adhesive layer (e.g. first adhesive layer  200 ), a plurality of electrodes on a distal side of the first adhesive layer, a monitor interface, and a multiplexer (e.g. multiplexer  217 ,  217 A). A first output pin of the multiplexer is connected to a first terminal of the monitor interface and a second output pin of the multiplexer is connected to a second terminal of the monitor interface. 
     The plurality of electrodes includes a first set of first electrodes (e.g. first electrodes  210 A, . . . ,  210 I), and optionally a second set of second electrodes (e.g. second set of second electrodes  212 A, . . . ,  212 C). Each electrode of the first set of first electrodes is connected to a respective input pin of a first set of first input pins (e.g., first set of first input pins  302 A, . . . ,  302 G) of the multiplexer and each electrode of the second set of second electrodes is connected to a respective input pin of a second set of second input pins (e.g., second set of second input pins  303 A, . . . ,  303 C) of the multiplexer. 
     The method  500  comprises selecting  502  a first multiplexer configuration of the multiplexer (block  502 ). The first multiplexer configuration includes a first primary electrode of the first set of first electrodes being connected, via a first primary input pin of the first set of first input pins, to the first terminal (e.g., a terminal  110 , . . . ,  119 ) of the monitor interface, via the first output pin. 
     The method  500  further comprises obtaining a first sensor signal from the first terminal of the monitor interface when the multiplexer is in the first multiplexer configuration (block  504 ). 
     The method further comprises selecting a second multiplexer configuration of the multiplexer (block  506 ). The second multiplexer configuration includes a first secondary electrode of the first set of first electrodes being connected, via a first secondary input pin of the first set of first input pins, to the first terminal of the monitor interface, via the first output pin. 
     The method further comprises obtaining a second sensor signal from the first terminal of the monitor device when the multiplexer is in the second multiplexer configuration (block  508 ). 
       FIG. 19  shows an exemplary graphical representation of parameter data as a function of time. In this example, the parameter data in the y-axis is in Volts and time is in the x-axis. Curve  1100  shows, as a function of time, a first parameter data indicative of voltage measured by the first electrode pair of the wound dressing. Curve  1102  shows, as a function of time, a second parameter data indicative of voltage measured by the second electrode pair of the wound dressing. Curve  1104  shows, as a function of time, a third parameter data indicative of voltage measured by the third electrode pair of the wound dressing. Curves  1108 ,  1116 ,  1118  show, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing. Curves  1110 ,  1112 ,  1114  show, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing.  FIG. 19  shows the upper voltage threshold value represented as curve  1050 , the medium voltage threshold value represented as curve  1052 , the lower voltage threshold value represented as curve  1054 , and curve  1056  is a gradient limit. 
     Curves  1108 ,  1116 ,  1118  as well as curves  1110 ,  1112 ,  1114  show that no moisture is detected at the proximal side of the first adhesive layer by the fourth electrode pair. 
     At a time less than 5 h, curve  1100  shows that moisture is detected by the first electrode pair as the first parameter data crosses the upper voltage threshold value while curve  1102  shows that moisture is not detected by the second electrode pair as the second parameter data has not crossed the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a first operating state. 
     At time between 5 h and 10 h, curve  1101  shows that moisture is detected by the second electrode pair as the second parameter data crosses the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a second operating state. 
     At time around 45 h, curve  1104  shows that moisture is detected by the third electrode pair as the third parameter data crosses the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a third operating state. 
       FIG. 20  shows an exemplary graphical representation of parameter data as a function of time. In this example, the parameter data in the y-axis is in Volts and time is in the x-axis. Curve  1202  shows, as a function of time, a first parameter data indicative of voltage measured by the first electrode pair of the wound dressing. Curve  1204  shows, as a function of time, a second parameter data indicative of voltage measured by the second electrode pair of the wound dressing. Curve  1200  shows, as a function of time, a third parameter data indicative of voltage measured by the third electrode pair of the wound dressing. Curves  1206 ,  1208 ,  1210  show, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing. Curves  1212 ,  1214 ,  1216  show, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing.  FIG. 20  shows the upper voltage threshold value represented as curve  1050 , the medium voltage threshold value represented as curve  1052 , the lower voltage threshold value represented as curve  1054 , and curve  1056  represents a gradient limit. 
     Curves  1206 ,  1208 ,  1210  as well as curves  1212 ,  1214 ,  1216  show that moisture is detected at the proximal side of the first adhesive layer by the fourth electrode pair at a time starting at 60 h until 90 h. As the three parts of the fourth electrode pair are trigger as shown by the decreases shown by  1206 ,  1208 ,  1210  and as the curves  1212 ,  1214 ,  1216  show a gradient below 80%, this is indicative of the presence of moisture (e.g., sweat, exudate, etc.) at the proximal side of the first adhesive layer. 
     At a time of  30 min, curve  1202  shows that moisture is detected by the first electrode pair as the first parameter data crosses the upper voltage threshold value while curve  1204  shows that moisture is not detected by the second electrode pair as the second parameter data has not crossed the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a first operating state. 
     At time around 40 h, curve  1204  shows that moisture is detected by the second electrode pair as the second parameter data crosses the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a second operating state. 
       FIG. 21  shows an exemplary graphical representation of parameter data as a function of time. In this example, the parameter data in the y-axis is in Volts and time is in the x-axis. Curve  1300  shows, as a function of time, a first parameter data indicative of voltage measured by the first electrode pair of the wound dressing. Curve  1302  shows, as a function of time, a second parameter data indicative of voltage measured by the second electrode pair of the wound dressing. Curve  1304  shows, as a function of time, a third parameter data indicative of voltage measured by the third electrode pair of the wound dressing. Curves  1306 ,  1308 ,  1310  show, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing. Curves  1312 ,  1314 ,  1316  show, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing.  FIG. 21  shows the upper voltage threshold value represented as curve  1050 , the medium voltage threshold value represented as curve  1052 , the lower voltage threshold value represented as curve  1054 , and curve  1056  is a gradient limit. 
     Curves  1306 ,  1308 ,  1310  as well as curves  1312 ,  1314 ,  1316  show that moisture is detected at the proximal side of the first adhesive layer by the fourth electrode pair at a time starting at around 25 h. As the three parts of the fourth electrode pair are trigger as shown by the decreases shown by  1306 ,  1308 ,  1310  and as the curves  1312 ,  1314 ,  1316  show a gradient above 80%, this is indicative of the presence of moisture at the proximal side of the first adhesive layer. This may indicate a low degree of remaining absorbent capacity of the wound dressing/absorbent core layer. 
     At a time of 5 h, curve  1300  shows that moisture is detected by the first electrode pair as the first parameter data crosses the upper voltage threshold value while curve  1302  shows that moisture is not detected by the second electrode pair as the second parameter data has not crossed the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a first operating state. 
     At time around  1 5 h, curve  1302  shows that moisture is detected by the second electrode pair as the second parameter data crosses the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a second operating state. 
     At time around 30 h, curve  1304  shows that moisture is detected by the third electrode pair as the third parameter data crosses the upper voltage threshold value. At this stage, it is determined that the wound dressing is in a third operating state. 
     As of note, the graphical representations of parameter data as a function of time represented in  FIGS. 19-21  are presented for illustration purposes and the times may vary depending on the size and severity of the wound to which the wound dressing is applied. 
     The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order but are included to identify individual elements. Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa. 
     Although particular features have been shown and described, it will be understood that they are not intended to limit the claimed invention, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the claimed invention. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed invention is intended to cover all alternatives, modifications, and equivalents. 
     LIST OF REFERENCES 
       1  wound dressing system 
       2 ,  2 A,  2 B wound dressing 
       4  monitor device 
       6  accessory device 
       8  server device 
       10  network 
       20  docking station 
       22  first connector 
       24  user interface 
       100  monitor device housing 
       101  processor 
       102  first interface (wound dressing interface) 
       104  second interface (accessory interface) 
       106  memory 
       110  first terminal 
       112  second terminal 
       114  third terminal 
       116  fourth terminal 
       118  fifth terminal 
       119  sixth terminal 
       120  coupling part 
       121  power unit 
       122  antenna 
       124  wireless transceiver 
       126  loudspeaker 
       128  haptic feedback element 
       140  sensor unit 
       150  first adhesive layer 
       150 A proximal surface of the first adhesive layer 
       152  perforations of first adhesive layer 
       154  absorbing region 
       200  wound dressing 
       202  absorbent core layer 
       204 ,  204 A,  204 B electrode assembly 
       206  top layer 
       208  first support layer 
       208 A proximal surface of first support layer 
       208 B distal surface of first support layer 
       210  first set of first electrodes 
       210 A,  210 B,  210 C,  210 D,  210 E,  210 F,  210 G,  210 G,  2101  first electrode 
       212  second set of second electrodes 
       212 A,  212 B,  212 C second electrode 
       214  sensor point 
       215  connection parts of plurality of electrodes 
       216  first masking layer 
       217 ,  217 A multiplexer 
       218  first sensing part of first electrode 
       220  second sensing part of second electrode 
       222  sensor point opening of first masking layer 
       224  second support layer 
       224 A proximal surface of second support layer 
       224 B distal surface of second support layer 
       226  spacing layer 
       250  sensor point opening of first support layer 
       252  connection point of first electrode 
       254  sensor point opening of second support layer 
       256  connection point of second electrode 
       270 ,  270 A second masking layer 
       302  first set of first input pins 
       302 A,  302 B,  302 C,  302 D,  302 E,  302 F,  302 G first input pins 
       303  second set of second input pins 
       303 A,  303 B,  303 C second input pins 
       304  first output pin 
       306  second output pin 
       308  first control pin 
       310  second control pin 
       312  third control pin 
       314  fourth control pin 
       400  method of manufacturing a wound dressing 
       402  provide a first adhesive layer 
       404  arrange an absorbent core on a distal side of the first adhesive layer 
       406  arrange an electrode assembly on the distal side of the first adhesive layer 
       408  arrange a monitor interface on the distal side of the first adhesive layer 
       500  method of monitoring a wound dressing 
       502  select a first multiplexer configuration of the multiplexer 
       504  obtain a first sensor signal from the first terminal of the monitor device 
       506  select a second multiplexer configuration of the multiplexer 
       508  obtain a second sensor signal from the first terminal of the monitor device 
       1000  method of monitoring a wound dressing comprising an absorbent core layer 
       1002  collecting wound data 
       1003  obtaining parameter data 
       1004  obtaining first parameter data 
       1006  obtaining second parameter data 
       1008  obtaining third parameter data 
       1010  obtaining fourth parameter data 
       1011  determining operating state of wound dressing 
       1012  in accordance with a determination that the operating state is a first operating state 
       1014  transmitting a first monitor signal 
       1016  in accordance with a determination that the operating state is a second operating state 
       1018  transmitting a second monitor signal 
       1050  curve representing the upper voltage threshold value 
       1052  curve representing the medium voltage threshold value 
       1054  curve representing the lower voltage threshold value 
       1056  curve representing a gradient limit 
       1100  curve showing, as a function of time, a first parameter data indicative of voltage measured by the first electrode pair of the wound dressing 
       1102  curve showing, as a function of time, a second parameter data indicative of voltage measured by the second electrode pair of the wound dressing 
       1104  curve showing, as a function of time, a third parameter data indicative of voltage measured by the third electrode pair of the wound dressing 
       1108  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1110  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1112  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1114  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1116  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1118  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1200  curve showing, as a function of time, a third parameter data indicative of voltage measured by the third electrode pair of the wound dressing 
       1202  curve showing, as a function of time, a first parameter data indicative of voltage measured by the first electrode pair of the wound dressing 
       1204  curve showing, as a function of time, a second parameter data indicative of voltage measured by the second electrode pair of the wound dressing 
       1206  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1208  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1210  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1212  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1214  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1216  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1300  curve showing, as a function of time, a first parameter data indicative of voltage measured by the first electrode pair of the wound dressing 
       1302  curve showing, as a function of time, a second parameter data indicative of voltage measured by the second electrode pair of the wound dressing 
       1304  curve showing, as a function of time, a third parameter data indicative of voltage measured by the third electrode pair of the wound dressing 
       1306  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1308  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1310  curve showing, as a function of time, a fourth parameter data indicative of voltage measured by the fourth electrode pair of the wound dressing 
       1312  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1314  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing 
       1316  curve showing, as a function of time, a gradient of fourth parameter data indicative of voltage gradient measured by the fourth electrode pair of the wound dressing