Wound dressing device and associated method for fabricating the same

Abstract

In summary, the present disclosure provides an approach which combines active DC-electrostimulation with active AC measurements, all performed using a disposable wound dressing device 1. The DC-electrostimulation and the AC-measurements can be automatically performed by a circuitry 10 of as system 23 comprising said device 1, and the circuitry 10 can adapt the stimulation, in particular parameters such as DC current strength, DC pulse duration, or waiting time m1 based on the active AC measurements. For achieving biocompatibility and long-term stability, the device 1 features laser-induced graphene (LIG) stimulation electrodes 3a, 3b which are covered with a conductive polymer 15. All electrodes 3a, 3b, 5, 6 as well as electrical contact pads 19 and wirings 16 can be defined in a single laser processing step (c.f. Figure 7).

Description

[0001] PC 25 0970 G August 22 , 2025

[0002] WOUND DRESSING DEVICE and associated method for fabricating the same

[0003] The present disclosure relates to the field of electrical DC stimulation of wounds , in which DC pulses with durations in the order of seconds to minutes are applied . In particular, the present disclosure concerns a wound dressing device , designed for covering a wound and configured for DC-electro- stimulation of said wound, the device comprising : a substrate sheet for being positioned on the wound and at least one pair of stimulation electrodes , which are spaced apart from each other and arranged on an upper side of said substrate sheet to the left and to the right of a stimulation area . The two stimulation electrodes forming a / the respective pair are arranged and designed for providing a flow of direct current ( DC ) between each other over the stimulation area for the purpose of DC-electrostimulation of said wound . The disclosure further concerns a system comprising such a wound dressing device , and a speci fic method for fabricating the device .

[0004] Wound healing is the naturally occurring process by which skin cells repair damaged tissue . This process involves di f ferent cell types and several communication mechanisms that orchestrate the correct healing process . Wounds can be divided into acute or chronic depending on how long it takes for the healing process . Chronic or non-healing wounds are lesions that take longer than six weeks to cure and can evolve into li fe-threatening conditions i f adequate treatment is not provided . Chronic wounds are a prevalent condition that derives from several comorbidities like diabetes ( e . g . diabetic foot ulcers ) , circulatory problems (venous ulcers ) , or mobility deficiencies (pressure ulcers ) . These wounds are di f ficult to heal through conventional methods and result in a clear reduction in quality of li fe for individuals suf fering from them . Additionally, long treatment durations , in PC 25 0970 G 2 / 46 August 22, 2025 combination with costly materials and treatments, result in a significant monetary burden for the patient and society.

[0005] Electrical stimulation acts on a wound on different fronts, including: the increment in tissue perfusion through blood vessel dilation, antimicrobial effects due to current flow and changes in the environment and the directed migration of skin cells (e.g., macrophages, fibroblasts, keratinocytes ) in an electric field (i.e., Electrotaxis) . Electrotaxis is the biological process by which cells direct their movement along an electric field and it has been demonstrated to play a significant role in the natural healing process of skin.

[0006] Conventional wound care relies on support mechanisms that mainly focus on preventing infection while providing an adequate environment for the natural wound-healing process to occur (e.g., bandages, ointments, biologies, pressure relief) . They do not actively accelerate the healing process, resulting in long treatment times and varying degrees of success. Research has been mainly focused on improving these support materials to e.g. reduce the chance of infection.

[0007] Furthermore, current products for wound assessment and monitoring rely on the direct observation and manual measurement of the wound. This approach requires periodic visits from patients to healthcare professionals, which remove any therapeutic device in place to observe the wound and determine whether the current approach is working or not. If a patient is incapable of visiting or being visited by a healthcare professional (e.g., during a lockdown or due to poor mobility) then the state of the wound can drastically deteriorate without any alarm or change to the treatment. Accordingly, the wound healing devices of the present art are not efficient enough. Existing wound healing devices which rely on electrical stimulation fail to effectively accelerate PC 25 0970 G 3 / 46 August 22 , 2025 healing and / or provide biocompatibility and / or reduce manual burden . It is therefore an obj ect of the present invention to provide a wound healing device that is more ef ficient compared to the wound healing devices of the prior art . Speci fically, there is a need for a wound healing device which reduces manual burden ( i . e . the need for manual control / supervising) when applying the device , which improves healing, and which is biocompatible .

[0008] It is therefore an obj ect of the present disclosure to alleviate at least some of the mentioned drawbacks to provide a wound dressing device , an associated system, and a method for producing such a wound dressing device . The present disclosure is at least partly based on the insight that a wound dressing device which utili zes direct current ( DC ) to stimulate a wound will accelerate healing of said wound by stimulating / complementing the naturally occurring electric fields , and, in particular, by inducing Electrotaxis through the DC stimulation .

[0009] In accordance with the present invention, a device is provided according to claim 1 , which solves the afore-mentioned problem . In particular the invention proposes a device as introduced at the beginning, which is further characteri zed in that the stimulation electrodes are integrally formed as laser-induced graphene electrodes and these laser-induced graphene electrodes are covered with an electrically conductive polymer coating formed from a doped polymer . The LIG electrodes can exhibit a desired high roughness in the order of at least 1 . 0 pm ( rms-value ) . And for promoting the adhesion of the polymer coating on the LIG electrodes , polyurethane ( PU) may be applied as an adhesion promoter .

[0010] Without limitation to the scope of the invention, the substrate sheet must not necessarily be a single piece PC 25 0970 G 4 / 46 August 22 , 2025

[0011] (however, it can be ) ; instead, multiple independent portions to be each applied onto the skin of the patient to be treated can also be defined . In the latter case , care must be taken as the placement of the individual parts of the ( then multi-part- ) substrate sheet will determine the distance between the stimulation electrodes (which can thus be distributed on several parts of the sheet ) .

[0012] As one typical example , a Kapton foil with a thickness in the range of [ 75 . . 125 ] pm may be used as suitable substrate sheet and this sheet may be cut into appropriate dimensions to be able to cover a particular wound . In other words , wound dressing devices according to the invention may be delivered in di f ferent prefabricated shapes and si zes , such that a suitable shape and si ze may be easily chosen to cover a wound in the skin of a particular patient .

[0013] Preferably, the outer surface of the LIG electrodes (which is to be brought into electrical contact with the skin of a patient during application of the wound dressing device ) is fully covered by the conductive polymer coating ( CPC ) such that all charge trans fer into the wound ( resulting from the DC-electro-stimulation) is performed via the polymer coating ( thereby avoiding any direct contact between the skin / wound and the LIG-material ) . As will be detailed below with respect to Figure 7 , from a fabrication perspective , an area onto which the CPC will be deposited must be pre-defined .

[0014] Therefore , it is recommendable to define all LIG-structures of the device first and then to apply an electrically insulating layer, which leaves an area of the respective LIG-stimulation electrode freely exposed, which is slightly smaller than the total area of said electrode . In a final step, the CPC can then be applied onto the total area of the electrode that is still exposed ( and due to fabrication tolerances also with an overlap onto said insulating layer ) . PC 25 0970 G 5 / 46 August 22 , 2025

[0015] The LIG electrodes may have a width spanning at least 80% of a length of the wound . Through this approach, the DC-pulses can be applied as an electrical surface current over a wide cross- sectional area of said wound .

[0016] The wound dressing device may optionally comprise a wound supporting membrane positioned between the stimulation electrodes ( in particular above said stimulation area ) and intended to cover the open wound . For this purpose , the wound supporting membrane may be attached on the upper side of the substrate sheet , on which side the stimulation electrodes are formed and which is to be brought into skin contact during use of the device . The wound supporting membrane may also comprise a cellulose-based material ( for taking up moisture from a weeping wound) or a hydrogel ( for providing moisture to a dry wound) .

[0017] For example , one particular embodiment of the wound dressing device proposes that it comprises said substrate sheet for being positioned on a wound ( so to cover a wound at said site ) ; a pair of spaced apart electrodes attached to said substrate , the pair of electrodes being arranged to provide a flow of DC between each other for stimulating said wound and thus can be used as DC stimulation electrodes ; a wound supporting membrane positioned between the electrodes ( e . g . such that the electrodes at least partially surround the wound supporting membrane ) . Moreover, the wound dressing device may be completed by a control circuitry to form a DC electrostimulation system . The control circuitry can be configured to control said pair of electrodes , based on a stimulation protocol , to provide a flow of ( a plurality of / a train of ) DC pulses across said wound . Thereby, the DC pulses are operable to electrically stimulate a wound .

[0018] Advantageously, the wound dressing device / said system is able PC 25 0970 G 6 / 46 August 22 , 2025 to accelerate wound healing based on the DC pulses which are provided across the wound . This is because the DC stimulates the cellular migration and proli feration at the wound and thereby accelerates the healing .

[0019] The mentioned ( electro- ) stimulation protocol may be a pre- determined / conf igured stimulation protocol . The stimulation protocol may be obtained from a database or a memory unit of the control circuitry . The stimulation protocol may be adapted for said wound ( i . e . to certain characteristics of said wound) . In other words , the wound may be characteri zed ( colour, dimensions , edges , depth) in the first place , in particular by a doctor, and then, based on the characterization, a suitable stimulation protocol may be selected ( i . e . manually, or autonomously / automatically retrieved) . Accordingly, a storage means of said circuitry may comprise a plurality of stimulation protocols , each adapted for a speci fic wound characteri zation so that the simulation protocol utili zed is optimal for the speci fic wound .

[0020] The stimulation protocol may define DC values over time . For example , the stimulation protocol may be derived by an algorithm, in particular by an algorithm that has been trained by machine learning based on training data, and the algorithm may be configured to , based on image data ( or other suitable data ) of the wound, determine said stimulation protocol ( that is suitable for electrostimulating such a wound) . The algorithm may be an image processing algorithm configured to receive image data of the wound, wherein the algorithm is configured to filter, segment and define wound dimensions and further parameters / characteristics of said wound . To process the image data more easily, a reference marker may be placed on the skin at the site of the wound to facilitate the appliance of the algorithm . PC 25 0970 G 7 / 46 August 22 , 2025

[0021] The term wound dressing may be understood, in particular, as meaning "wound cover" or "band-aid" or "wound covering device" .

[0022] The DC pulses may be provided / transmitted in di f ferent directions intermittently, so to ensure homogeneous closure / healing of the wound . In other words , the current polarity of the DC pulses applied via the electrical stimulation electrodes of the device may be alternated to reverse the current flow direction and to ensure homogenous closure of the wound .

[0023] Further advantageous implementations will now be described :

[0024] For example , it is highly beneficial for biocompatibility and for achieving long-term stable DC-electrostimulation, i f the polymer coating is chosen such that it provides a nanoscale mesh that can absorb and release ions , such as Na+ and Ka+ , which are present in body fluids . Such ions can serve to deliver electrical charges to the wound or from the wound, as soon as they are embedded in the mesh provided by the polymer coating . In other words , the main function of the polymer coating is to enable DC-stimulation via an ionic current that results from ions which are embedded into or released from the polymer coating ( depending on polarity) - rather than electrical stimulation via electron-based currents , which is not recommended as it leads to harmful changes of the cell biology . In other words , the polymer coating can act as an " ion-exchange reservoir" during electrical use of the device , enabling long-term stable and safe DC-electrostimulation without introducing bio-hazards .

[0025] The substrate sheet preferably comprises a carbon-based material , in particular polyimide Kapton, polydimethylsiloxane ( PDMS ) , Parylene-C, or cellulose . In this case , the PC 25 0970 G 8 / 46 August 22 , 2025 laser-induced graphene ( LIG) electrodes can be grown from said carbon-based material by a laser induced technique , as will be detailed with reference to the Figures . The formation of the LIG electrodes can be such that the stimulation electrodes are integrally formed from the carbon-based material and / or such that they are grown into a bulk volume of said carbon-based material . This growth into the bulk volume can preferably be performed into a depth of at least 10% , most preferably of at least 25% , of a thickness of the substrate sheet . In practice , said depth may thus be at least 2 pm, most preferably at least 5 pm . The depth may be controlled by appropriate parameters ( in particular laser pulse duration and average laser power and / or a velocity of moving the laser beam in x- / y-directions ("rastering velocity" ) ) of the laser radiation used in the laser induced technique .

[0026] The term " integrally formed from the substrate sheet" may be understood here , in particular, in that the stimulation electrodes are not formed as a separate layer or added onto the substrate sheet but are rather made entirely from the same starting material , namely the carbon-based material comprised in the substrate sheet . In particular, the substrate sheet may completely consist of / may be formed from the carbon-based material ( such as polyimide ) . In other words , the LIG electrodes can be formed by a laser-induced chemical conversion of a top layer of the carbon-based material of the substrate sheet . This may be achieved, in particular, by a laser-induced pyrolysis technique that extracts carbon atoms of the carbon-based material and trans forms them into Graphene , a technique that is well known in the state-of-the- art .

[0027] A typical laser that may be employed for forming the LIG electrodes may be a CO2-laser . The laser-induced electrode formation process is mainly characteri zed in that carbon from PC 25 0970 G 9 / 46 August 22, 2025 the carbon-based material is converted to graphene oxide. By applying the laser radiation to certain areas of the substrate sheet, the electrode formation can be spatially controlled. As will be detailed below, also electrical contact pads as well as electrical supply lines / wirings (electrically connecting the contact pads with the LIG electrodes) can be formed by the same laser-induced process.

[0028] According to an embodiment, which results in excellent charge transfer, the doped polymer used for said coating may be Poly ( 3 , 4-ethylene-dioxythiophene ) polystyrene sulfonate (PEDOT-PSS) . As a good working alternative, the doped polymer may be chosen as Polyaniline. It has been found, however, that PEDOT-PSS provides superior stability when performing DC- electrostimulation over long periods of time (days / weeks) as intended by the invention.

[0029] The invention also suggests several preferred and specific ways of depositing PEDOT-PSS as the conductive polymer coating (CPC) when fabricating the device: Depositing PEDOT-PSS may be done by electropolymerisation, by spot-casting (see below) , by spray coating, by spin coating or by embedding the PEDOT-PSS into a doped hydrogel such as PDMAAp and depositing said doped hydrogel as the CPC.

[0030] Most preferably, PEDOT-PSS may be applied as a pure PEDOT-PSS hydgrogel, because blending with non-conductive polymer can compromise the mechanical or (even worse) electrical properties of the resulting hydrogel. In particular, the CPC may be formed from a network of interconnected PEDOT:PSS nanofibrils, resulting in a high-performance pure PEDOT:PSS hydrogel. Such a network may be formed by mixing volatile additive dimethyl sulfoxide (DMSO) into an aqueous solution of PEDOT-PSS, depositing said solution on the LIG electrodes, and dryannealing and rehydrating the resulting deposited layer. PC 25 0970 G 10 / 46 August 22 , 2025

[0031] Through this method, a CPC can be achieved that of fers excellent electrical and electrochemical stability, as required for long-term stable DC-electrostimulation .

[0032] As will become evident from the Figures , the wound dressing device may feature electrical contact pads and / or electrical wirings , and these electrical components may be formed from the same laser-induced-graphene ( LIG) material as the stimulation electrodes . All of these LIG structures may be fabricated by the same laser-induced process as the laser- induced stimulation electrodes . This approach is highly of advantage for enabling rapid and cost-ef fective mass production of the wound dressing device with a limited number of processing steps .

[0033] As an important aspect of the invention, the wound dressing device may further comprise at least two monitoring electrodes , which are intended for providing alternating currents to a wound ( at various frequencies ) for allowing a live-monitoring through live and active AC measurements . During DC-electrostimulation, said DC pulses and said flow of AC (used in the active measurements ) can be provided in an alternating manner, in particular such that during waiting intervals between the DC pulses , active AC measurements can be performed using the at least two monitoring electrodes .

[0034] For a similar purpose , and as a technical alternative or in addition to using such monitoring electrodes , the wound dressing device can also comprise a pH-sensor and / or a temperature sensor . These sensors , which may be placed on the upper side of the substrate sheet , ideally in direct vicinity to the stimulation area (which will contact the wound, when the device is applied onto the wound) may be formed as integrated parts of the wound dressing device or as separate , in particular miniaturi zed, devices which are attached to the PC 25 0970 G 11 / 46 August 22 , 2025 wound dressing device ; such sensors can be used to detect inflammations or infections in a tissue on which surface the device is applied to . Preferably, the respective sensor may be electrically connected to electrical contact pads of the wound dressing device , such that the respective sensor can be readout by the mentioned control circuitry, as soon as the latter is electrically connected to the wound dressing device . In other words , said pH-sensor and / or said temperature sensor can be important sensory parts of the system described herein . Depending on demand, such a sensor / such sensors can also replace one or two of the monitoring electrodes described herein .

[0035] It is to be mentioned here already, that the control circuitry of the system presented herein can be configured to regularly read-out said pH-sensor and / or said temperature sensor for monitoring the environment of the device . Moreover, the circuitry can be configured to adapt at least one parameter of the stimulation protocol ( to change the DC-pulses applied during the DC-electrostimulation) based on an environmental change that is detected / detectable with the respective ph- and / or temperature sensor . Such an adaption may be done alternatively to or additionally to an adaption that is performed based on a change of electro-chemical ( ec ) properties of tissue detected via an active AC measurement that is performed with said monitoring electrodes . An environmental change , which is happening in the direct environment of the wound dressing device , may be a change of the pH-level or a temperature change . Through this approach, the system can actively adapt the applied DC electrostimulation to changes occurring in the direct vicinity of the wound dressing device , in particular in tissue below the device .

[0036] In particular, the wound dressing device may comprise a first and a second set of monitoring electrodes , the first set PC 25 0970 G 12 / 46 August 22 , 2025 comprising at least one first electrode , the second set comprising at least one second electrode , and the first and the second set being distributed oppositely relative to the wound supporting membrane . In other words , such monitoring electrodes may be distributed about / around the wound supporting membrane / said stimulation area .

[0037] The control circuitry mentioned before may be configured to control said at least two monitoring electrodes , in particular said first and second set of monitoring electrodes , to provide a flow of alternating current (AC ) therebetween, i . e . across said wound as soon as the wound is covered with the device . Moreover, the control circuitry may be configured to monitor changes of electrochemical properties such as impedance of said wound based on said flow of AC .

[0038] Advantageously, by monitoring changes of electrochemical properties , a user and / or the system may obtain data indicative of changes of certain wound characteristics . For example , based on active AC measurements , it is possible to determine i f the circumference of the wound is becoming smaller, or i f the wound is less deep, etc . , which are all indicators of a progression of wound healing .

[0039] The monitoring electrodes may be distributed oppositely or in any suitable manner that allows a flow of alternating current to be trans ferred between them, in particular between corresponding respective pairs of first and second electrodes ( at least partially) , across the wound . The first set may comprise a plurality of first monitoring electrodes and the second set may comprise a plurality of second monitoring electrodes , thus enabling multi-directional AC measurements , as illustrated in Figure 2 .

[0040] The DC pulses ( resulting from a DC flowing through the PC 25 0970 G 13 / 46 August 22 , 2025 stimulation electrodes ) and said flow of AC ( resulting from an AC flowing through the separate monitoring electrodes ) may be provided ( continuously) in an alternating / intermittent manner . Accordingly, during transmittal of each DC pulse , the monitoring electrodes may be passive / idle so to not transmit any AC (which would impede the DC electrostimulation) . Hence , transmittal of AC may be performed between subsequent transmitting of DC pulses ( i . e . , when the stimulation electrodes are idle ) . Accordingly, DC pulses and AC pulses may preferably not transmitted simultaneously .

[0041] Advantageously, according to this approach, the wound dressing device may electrostimulate a wound with the dedicated DC stimulation electrodes while simultaneously ( i . e . in between) monitoring wound healing with di f ferent monitoring electrodes with minimal / no signal interference .

[0042] As mentioned, the first set of monitoring electrodes may comprise a plurality of first monitoring electrodes , wherein the second set of electrodes may comprise a plurality of second electrodes . The control circuitry may then be configured to switch said plurality of first monitoring electrodes and said plurality of second monitoring electrodes into a plurality of di f ferent monitoring electrode configurations and provide , respectively, a flow of AC between the first monitoring electrodes and the monitoring second electrodes for each configuration, respectively .

[0043] Such an approach allows active and multi-path-AC measurements to be performed with the system and advantageously, this allows for a greater amount of electro-chemical property data to be obtained, thereby being able to monitor healing of the wound with more detail / certainty, in particular in di f ferent spatial dimensions ( e . g . in x- and y-directions ) . Accordingly, the control circuitry may be configured to transmit data of PC 25 0970 G 14 / 46 August 22 , 2025 wound progress ( e . g . changes in characteristics of the wound) to a graphical user interface ( GUI ) of a remote user equipment ( e . g . laptop or smartphone ) for allowing an attending physician to review the wound progress using said GUI .

[0044] In particular, the control circuitry may trans form the electrochemical property data gathered in the active AC measurements with the device to a healing map (which may be understood as a 2D-representation of the healing progress over time ) and provide said healing map to the GUI (via a wireless or wired data link) . Such a healing map may be a graph (which e . g . depicts circumf erence / depth progress of the wound over a time-period) or any other suitable graphical representation that indicates healing of the wound over a time-period . In particular, the control circuitry may be configured to predict , based on the electrochemical property data gathered by the active AC measurements , healing of the wound ( to which said device is applied) for a future time-period and to include said predicted healing in said healing map .

[0045] For example , the first set of monitoring electrodes may comprise first monitoring electrodes A, B, C, D and the second set may comprise second monitoring electrodes A' , B' , C' , D' . Accordingly, for each electrode configuration, pairs of first / second monitoring electrodes may be connected in a respective measurement circuit (which can be electronically defined by the control circuitry) . Upon switching (which may be understood as the circuit energi zing di f ferent electrodes by applying AC to the respective monitoring electrode ) , which is performed by the circuit , at least one of said pairs may be changed . For example , a first of a plurality of monitoring electrode configurations may be : A-A' , B-B' , C-C' , and D-D' .

[0046] Hence , upon switching, a second monitoring electrode configuration may be : A-B' , B-A' , C-D' , and D-C' . PC 25 0970 G 15 / 46 August 22 , 2025

[0047] The control circuitry may thus be configured to switch monitoring electrode configurations after a pre-determined timeperiod and / or following each of a number of transmitted DC pulse trains .

[0048] Moreover, during each active AC measurement (performed by the circuit and with the respective pair of monitoring electrodes ) , a respective flow of AC may be provided over a frequency spectrum . The AC pulse may therefore span over a time-period in which a frequency of the AC pulse varies / is alternated over said time-period . Advantageously, such an variable frequency AC measurement may give further detail regarding wound characteristics changes . In other words , monitoring electrodes may be switched by the circuit to measure electrochemical property spectra across di f ferent monitoring electrode combinations and utili zing a range of di f ferent ( e . g . sinusoidal ) frequencies .

[0049] According to another variant , the control circuitry may be configured to , at least one of : adapt said flow of DC pulses ( i . e . adapting the stimulation protocol ) based on said monitored changes of electrochemical properties ; and / or to determine changes in wound dimensions of said wound based on said monitored changes of electrochemical properties , wherein said changes are indicative of a healing at said wound .

[0050] Accordingly, the control circuitry may be configured to create , based on electrochemical property data obtained from the active AC measurements performed using the monitoring electrodes , an electrochemical property map, which may be understood as a 2D-representation of the wound . The changes in wound dimensions may be derivable by monitoring of said electrochemical property map . And therefore , the circuitry may be configured to transmit the determined electrochemical property map to said GUI mentioned earlier . PC 25 0970 G 16 / 46 August 22 , 2025

[0051] The control circuitry may also provide an adequate voltage and DC current required for electrostimulating the wound, and this may be based, in particular, on changes in electrochemical properties , which the circuitry has detected using the monitoring electrodes of the device in an active AC measurement . The control circuitry may (preferably in realtime ) adapt parameters of the DC pulses ( i . e . adapt the stimulation protocol ) to be applied via the stimulation electrodes based on detected changes in electrochemical properties . This adaptive stimulation approach can ensure optimal stimulation at all times and also improved energy management . The adaptation may be performed by use of a stimulation algorithm ( this algorithm may also make use of machine learning) , a look-up table or a pre-defined stimulation model . Said stimulation algorithm may be configured to provide a stimulation protocol , which is adapted to and based on speci fic wound characteristics , which have been determined in an AC-measurement performed with the device . The stimulation algorithm may perform said adaption dynamically or in speci fic intervals ( e . g . every hour ) .

[0052] The AC-measurements may be performed by setting an alternating voltage , and measuring the resulting alternating current , or vice versa, and an impedance may be calculated from the respective combination of current and voltage .

[0053] By contrast , the DC-stimulation can be performed by setting a drive voltage with the aim of maintaining a constant DC current strength . In other words , the circuitry may adapt the drive voltage to maintain a DC as defined and desired according to the stimulation protocol .

[0054] The stimulation electrodes used for providing said DC pulses and the monitoring electrodes , in particular said first and second set of monitoring electrodes , may all be laser-induced PC 25 0970 G 17 / 46 August 22 , 2025 graphene electrodes . Preferably, these LIG structures may be grown on said substrate sheet by a laser pyrolysis technique . Most preferably, the substrate sheet may be formed from or by a carbon-based material , such as , but not limited to , Kapton, Polydimethylsiloxane ( PDMS ) , Parylene-C or Cellulose . Accordingly, a carbon dioxide laser or any other suitable source of high intensity IR radiation may be used to produce the LIG structures thereon .

[0055] Advantageously, by having a substrate sheet formed by a carbon-based material , graphene can be grown on and into the substrate directly, as the carbon from said carbon-based material can be converted to graphene-oxide . Moreover, laser- induced graphene as such can conduct electricity while being biocompatible and it may be manufactured with great design freedom, as will become evident from Figures 7 and 8 . This approach thus enables a low cost and convenient manufacturing of electrodes while maintaining biocompatibility ( thereby allowing the electrodes to contact a skin of a user without irritating / damaging the skin) . Accordingly, all electrodes of the wound dressing device may be arranged to abut the skin of a user wearing the wound dressing device . Also , the wound supporting membrane may be arranged to abut the skin and wound of a user wearing the wound dressing device . The wound supporting membrane may comprise a natural or synthetic material , in particular a cotton material , a hydrogel material or any other suitable material .

[0056] The generation of constant electric fields capable of stimulating Electrotaxis is achieved by applying DC pulses using the stimulation electrodes of the device . This type of stimulation may be challenging to achieve in a biocompatible manner on the long-term with conventional electrode materials as the required electrochemical reactions that sustain current flow eventually result in drastic pH changes ( these may be PC 25 0970 G 18 / 46 August 22 , 2025 monitored using a pH-sensor as part of the wound dressing device / said system) , the formation of reactive oxygen species , the elution of toxic metallic by-products and the corrosion of the electrodes . This is the main reason, why, as detailed before , at least the stimulation electrodes and preferably also the first and a second set of monitoring electrodes should be covered by a conductive polymer coating, preferably a Poly 3 , 4-ethylenedioxythiophene ( PEDOT ) based conductive polymer coating . Such coating of the electrodes with the conducting polymer can be achieved through electrochemical or physical methods ( e . g . , vapour deposition, spot casting, inkj et printing) ; the chosen method should mainly form a uni form layer that is defect- free and shows a constant thickness . The such coated stimulation electrodes ( as well as the monitoring electrodes ) may be additionally insulated to ensure current flow only through desired active areas , as will be explained with reference to an insulation layer illustrated in Figure 7 .

[0057] Concerning spot casting, this is an additive manufacturing step in which a dispersion of the polymer is applied to the surface of the electrodes in tiny droplets ( in the pl volume range ) . After an annealing step, the spotted polymer material bonds and solidi fies into a hydrogel-like material , which thus forms said conductive polymer coating .

[0058] Advantageously, the conductive polymer may act as an ionexchange reservoir, allowing ions to be filled and released from the polymer to avoid unwanted chemical reactions . This quality results in a DC stimulation that is more ef ficient .

[0059] The present disclosure further relates to a method for fabricating a wound dressing device , and the latter may have features as detailed herein or as claimed by one of the device claims . The method may comprise the following steps : providing PC 25 0970 G 19 / 46 August 22 , 2025 a substrate sheet comprising a carbon-based material , in particular wherein the substrate sheet is provided in a predefined and / or standardi zed si ze and shape and / or in the form of a foil of constant thickness ; performing laser processing of the substrate sheet for integrally forming laser-induced graphene stimulation electrodes from the carbon-based material , i . e . from said substrate sheet . Preferably, electrical contact pads and electrical wirings are also integrally formed from the carbon-based material in the same laser processing step ; coating ( 107 ) the laser-induced graphene stimulation electrodes with a doped polymer to form an electrically conductive polymer coating for electrically contacting tissue . The latter step thus defines a biocompatible and long-term stable electrical interface formed from the polymer coated stimulation electrodes for exchanging electrical currents in the form of ionic currents with tissue that is brought in contact with the polymer coating .

[0060] As has been laid out before , a wound supporting membrane , in particular featuring a hydrogel , may be attached on the upper side of the substrate sheet between the pair of spaced apart stimulation electrodes . And for obtaining a system, as laid out below, control circuitry may be connected to said stimulation electrodes , most preferably using connector designed for contacting LIG-contact pads of the device .

[0061] According to one particular embodiment , the method can be adapted for fabricating patient-speci fic wound dressing devices that perfectly fit a speci fic wound on the skin of the patient . For this purpose , the wound of the patient may be imaged and the resulting image of the wound may be characteri zed in a computer-implemented routine to def ine / extract an area of the wound . In this case , the substrate sheet may be provided in a shape and / or si ze that fits the extracted area of the wound . In other words , a PC 25 0970 G 20 / 46 August 22 , 2025 suitable shape and / or si ze of the personali zed wound dressing device may be determined by the computer resulting in a CAD- file that may be used for fabricating, in particular cutting, the substrate sheet into the desired shape and / or si ze .

[0062] Within the scope of the invention, said fabrication process may therefore also comprise the following steps : Imaging, with an imaging device ( e . g . any suitable camera ) , a wound having a wound; Characteri zing, e . g . by the control circuitry or other processing circuitry, the wound to define an area of the wound; providing a substrate based on said area ; Performing, based on said area, a laser-induced technique , e . g . by a laser device , on said substrate to form / to define a pair of spaced apart graphene-based stimulation electrodes thereon, preferably the technique is a laser-induced technique and the stimulation electrodes are graphene based; Optionally attaching a wound supporting membrane between the pair of separated / spaced apart graphene based electrodes ; and coating the separated stimulation electrodes by a conductive polymer ; and finally and optionally : Connecting control circuitry to said stimulation electrodes for forming an electrostimulation system .

[0063] Accordingly, the stimulation electrodes may be coated such that at least a part of the electrodes are coated which deliver electrical currents to the tissue below the wound to which the device is attached to . The coating may be any suitable conducting polymer or hydrogel coating such as PEDOT , polyaniline or any other suitable coating or combinations thereof .

[0064] For solving the afore mentioned problem, a system according to claim 14 is proposed . In particular, the invention proposes a system for supporting local wound healing in a tissue through DC electrostimulation, with the system comprising : a wound PC 25 0970 G 21 / 46 August 22 , 2025 dressing device as detailed herein and / or according to one of claims directed towards such a device ; a control circuitry which is electrically connected to said wound dressing device and which is configured to provide electrical DC driving currents ( in the form of DC pulses ) during stimulation intervals to said pair of stimulation electrodes of the device based on a stimulation protocol . This application of the DC currents may be such that a flow of DC pulses can be provided across a wound covered by said wound dressing device according to the stimulation protocol .

[0065] DC-electrostimulation may be understood here as implying application of DC-pulses ( typically with a rectangular pulse shape , but this may vary) with pulse durations in the order of seconds to minutes ( i . e . not milliseconds as used in AC- electrostimulation approaches ) or even hours .

[0066] Accordingly, the stimulation protocol may define important parameters of the DC-electrostimulation performed with the stimulation electrodes , in particular : current strength and / or DC pulse duration (= duration of an stimulation interval ) and / or waiting time between consecutive DC-pulses ( this is the time available for an intermediate electrical AC-measurement across the wound during an intermediate measurement interval ) ; current direction ( across the wound from left to right or vice versa ) . The paths of the DC-stimulation currents through the tissue , however, are defined by the dimension and positioning of the stimulation electrodes and will therefore remain basically the same unless the wound dressing device is exchanged ( e . g . by a smaller device , in case the healing progresses and the wound is reduced in si ze thanks to the electrostimulation supported healing) or re-attached to the wound .

[0067] The control circuitry may be connected to the wound dressing PC 25 0970 G 22 / 46 August 22, 2025 device using a cable (in particular in the form of a flat band cable) and an electrical connector (which can be part of the wound dressing device or the cable) . The connector can be designed to provide electrical contact to contact pads formed on the upper side of the substrate sheet of the wound dressing device .

[0068] As mentioned, the wound dressing device can preferably be designed as a disposable (one-time-use) product. Hence, the wound dressing device may be exchanged from time to time, while the control circuitry (which may be implemented in a small (external) electronic portable device) may be re-used many times, e.g. until wound healing is successfully completed and / or with multiple patients (e.g. in a hospital) .

[0069] As will be laid out in detail below, the stimulation protocol can be designed patient-specif ically and, maybe even more important, can be adapted on-the-f ly / live during treatment of a patient by the system according to the needs of the patient, based on detected changes of electro-chemical (ec) properties of the tissue in which the wound has formed. Such a detection may be performed, in particular, with an AC-impedance measurement performed by the control circuitry automatically using the monitoring electrodes of the device.

[0070] The wound dressing device of the system may thus comprise at least two monitoring electrodes and / or it may be according to claim 7. In such a case, the control circuitry can be configured: (i) to deliver alternating electrical currents (AC) during measurement intervals to said at least two monitoring electrodes for performing an active AC measurement (respectively) - such a measurement can comprise the circuitry measuring a voltage resulting from said AC applied via the monitoring electrodes. PC 25 0970 G 23 / 46 August 22 , 2025

[0071] Preferably, the circuitry can be further configured ( ii ) to adapt at least one parameter of said stimulation protocol to change the DC-pulses applied during the DC-electrostimulation; this adaption may be based on a change of electro-chemical ( ec ) properties of the tissue , which has been detected via the active AC measurement (by the circuitry without any user interference ) . This adaption may thus be such that the flow of DC pulses provided across the wound is automatically changed by the system over an electrostimulation session (which may comprise numerous stimulation and measurement intervals ) performed with the wound dressing device .

[0072] In particular, the control circuitry may be configured to control said at least two monitoring electrodes , in particular said first and a second set of monitoring electrodes , to provide a flow of alternating current therebetween, in particular across said wound; and to monitor changes of electrochemical properties , preferably an electrical impedance , based on said flow of alternating current .

[0073] Preferably, the control circuitry can be configured to perform the AC measurement as an impedance measurement , in which AC currents of various frequencies are applied to the at least two monitoring electrodes ( as illustrated in Figure 4B ) and resulting voltages are recorded by the control circuitry . The control circuitry, in particular a micro-controller of the same , may then perform calculations of measured impedances based on applied currents and measured voltages and / or detect said changes of the ec properties of the tissue based on characteristic f eatures / changes of the measured impedance ( this may actually be a set of data in the form of an impedance curve plotted over frequency or a comparable table of such data ) .

[0074] These and other features and advantages of the present PC 25 0970 G 24 / 46 August 22, 2025 disclosure will now be further clarified and described in more detail, with reference to the accompanying Figures, wherein:

[0075] Fig. 1A: illustrates a top view of a wound dressing device in accordance with some aspects of the present disclosure as part of an electrical system for supporting local wound healing;

[0076] Fig. IB: illustrates a schematic cross-sectional view of the wound dressing device of Figure 1A;

[0077] Fig. 2: illustrates a first and a second set of monitoring electrodes that may be used on a wound dressing device in accordance with some aspects of the present disclosure ;

[0078] Fig. 3: illustrates a schematic side cross-sectional view of a wound dressing device placed on a skin having a wound;

[0079] Fig. 4A: illustrates DC pulses in a time graph;

[0080] Fig. 4B: illustrates sinusoidal voltage of different frequencies in a graph;

[0081] Fig. 5: illustrates a method depicted schematically in a flowchart ;

[0082] Fig. 6: illustrates some steps of the method of Figure 5 graphically

[0083] Fig. 7: illustrates single steps of a fabrication process according to the invention for defining a wound dressing device,

[0084] Fig. 8: shows details of the laser-induced formation of LIG PC 25 0970 G 25 / 46 August 22, 2025 structures, and

[0085] Fig. 9: illustrates active electrical monitoring of wound healing using a system according to the invention.

[0086] In the following detailed description, some possible embodiments of the present disclosure will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. Even though in the following description, numerous specific details are set forth to provide a more thorough understanding of the present disclosure, it will be apparent to one skilled in the art that the present disclosure may be practiced without these specific details. In other instances, well known constructions or functions are not described in detail, so as not to obscure the present disclosure.

[0087] It should be emphasized that the term "comprises / comprising" when used in this specification is taken to specify the presence of stated features, integers, steps, or components. It does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. The term "and / or" is to be interpreted as meaning "both" as well as each as an alternative.

[0088] Figure 1A illustrates a top view of a wound dressing device 1. Figure 1A illustrates that the wound dressing device 1 comprises a substrate sheet 2 for being positioned on a wound 9 that has formed in the skin of a patient. Further, Figure 1A illustrates a pair of separated stimulation electrodes 3a, 3b attached to / embedded in (or preferably grown) said substrate sheet 2. The pair of stimulation electrodes 3a, 3b being arranged to provide a flow of DC between each other for PC 25 0970 G 26 / 46 August 22, 2025 stimulating said wound 9. Moreover, the wound dressing device 1 comprises a wound supporting membrane 4 positioned between the stimulation electrodes 3a, 3b. The view of Figure 1A discloses an upper surface of the wound dressing device 1 which is arranged to face a skin 18 of a patient.

[0089] Moreover, Figure 1A illustrates schematically that a system 23 may be formed by combining the wound dressing device 1 with adequate control circuitry 10 configured to control said pair of stimulation electrodes 3a, 3b, based on a stimulation protocol, to provide a flow of DC pulses across said wound 9. The control circuitry 10 may be directly positioned on said sheet 2 so to be an integrated control circuitry, but preferably the circuitry 10 is formed as a separate / external unit connected to the wound dressing device 1 by e.g. wires. Accordingly, part or all of the control circuitry 10 (e.g. modules which characterize the wound 9, process image data and / or modules which provide the stimulation protocol) may be external to the wound dressing device 1 (and may be referred to as processing circuitry) while other parts of the control circuitry 10 may be on the wound dressing device 1 (e.g. at least modules or parts (e.g. a signal amplifier) which are operable for controlling electrode output or electrode configurations .

[0090] The substrate sheet 2 may at edge portions thereof comprise an adhesive layer 7 (e.g. in the form of an adhesive strip) for enabling the wound dressing device 1 to be secured to the skin 18. The substrate sheet 2 can also be dimensioned so to be tied about a body part of a user (e.g. a leg, an arm) .

[0091] As illustrated in Figure 1A, the control circuitry 10 may comprise one or more memory devices 14. The memory devices 14 may comprise any form of volatile or non-volatile computer readable memory and / or computer-executable memory devices that PC 25 0970 G 27 / 46 August 22, 2025 store information, data, and / or instructions that may be used by the control circuitry 10. Each memory device 14 may store any suitable instructions, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, algorithms (e.g. algorithm for providing a stimulation protocol) etc. and / or other instructions (such as instructions for switching electrode configurations, controlling the flow of DC pulses, etc.) capable of being executed by the control circuitry 10.

[0092] The control circuitry 10 may further include, for example, one or more central processing units (CPUs) , graphics processing units (GPUs) dedicated to performing calculations, and / or other processing devices. The control circuitry 10 may further comprise one or more interfaces 11 (e.g. input / output interfaces) enabling the control circuitry 10 to output control signals for controlling / energizing the electrodes 3a, 3b, 5, 6 and for receiving data or reading / measuring voltages / currents from the electrodes 3a, 3b, 5, 6 or from other sensor devices such as a temperature sensor and / or a pH- Sensor (which may be both comprised on the device 1, respectively) .

[0093] Further, the control circuitry 10 may comprise one or more modules for monitoring changes of electrochemical properties, controlling stimulation or monitoring electrodes or any other suitable module such as a switching module for switching monitoring electrode configurations, a determining module for determining changes in wound dimensions etc. For example, Figure 1 illustrates that the control circuitry 10 comprises a monitoring module 13 (for reading out the monitoring electrodes 5, 6) and a control module 12.

[0094] The control circuitry 10 may further comprise additional components (not shown) such as a power supply unit (e.g. a PC 25 0970 G 28 / 46 August 22 , 2025 battery pack) to provide voltage and current , at least one switching device to control flow of current and / or voltage , and other suitable electrical components . Accordingly, the control circuitry 10 may be part of a portable / miniature device .

[0095] Figure 1A further illustrates that the wound dressing 1 may further comprise a first and a second set of monitoring electrodes 5 , 6 , the first set comprising at least one first monitoring electrode 5a, the second set comprising at least one second monitoring electrode 6a, the first and the second set 5 , 6 being distributed oppositely relative to the wound stimulation area 21 . Figure 1A illustrates that the first set 5 comprises four monitoring electrodes 5a and the second set 6 comprises four monitoring electrodes 6a which are distributed about the membrane 4 positioned above the stimulation area 21 . The electrodes 5 , 6 may be arranged to be distributed, during an installed state of the device 1 in which it is attached to the skin 18 of a user, around the wound 9 , so that any transmittal of AC from a monitoring electrode 5a of the first set 5 to another monitoring electrode 6a of the second set 6 traverses the wound 9 so to electrically penetrate the wound 9 ( thereby allowing an AC measurement of the wound 9 ) .

[0096] Accordingly, the control circuitry 10 may be configured to control said at least one first monitoring electrode 5a and said at least one second monitoring electrode 6a to provide a flow of alternating current therebetween, across said wound 9 . Further, the control circuitry 10 may be configured to monitor changes of electrochemical properties , preferably an impedance of said wound 9 , based on said flow of AC . Further, the control circuitry 10 is configured to , at least one of adapt said flow of DC pulses based on said monitored changes of electrochemical properties and to determine changes in wound dimensions ( e . g . depth, circumference or any other dimension) PC 25 0970 G 29 / 46 August 22 , 2025 of said wound 9 , based on said monitored changes of electrochemical properties , the changes being indicative of a healing of said wound 9 .

[0097] Each electrode 5a of the first set of monitoring electrodes 5 may be arranged to transmit AC to a corresponding electrode 6a of the second set of monitoring electrodes 6 . I . e . , each monitoring electrode 5a of the first set 5 may be electrically connected to a corresponding monitoring electrode 6a of the second set 6 to form an electrode-pair in a speci fic AC measurement circuit . Hence , in Figure 1A there are four monitoring electrode-pairs , which may each form a respective first electrode configuration .

[0098] The control circuitry 10 may be configured to switch said plurality of first monitoring electrodes 5a and said plurality of second monitoring electrodes 6a into a plurality of di f ferent monitoring electrode configurations and to provide a flow of a respective measurement AC between the first monitoring electrodes and the second monitoring electrodes 6a, 6b for each configuration . Accordingly, there may be at least a first and a second monitoring electrode configuration .

[0099] Figure IB illustrates a cross-sectional view A-A of Figure 1A, also showing an insulation layer 28 , which is not shown in Figure 1A to simpli fy the illustration . Accordingly, Figures 1A- 1B illustrates that the stimulation electrodes 3a-3b may be situated at outer portions ol , o2 of ( a skin facing surface of ) the substrate 2 and the monitoring electrodes 5- 6 may be situated at an inner portion i l of the ( same common) substrate 2 . Also , it is illustrated in Figure IB that the membrane 4 may be in the form of a pad to provide adequate support against the skin 18 . The membrane 4 being intermediate / surrounded by both the stimulation electrodes 3a-3b and the monitoring electrodes 5- 6 . Figures 1A- 1B further illustrates PC 25 0970 G 30 / 46 August 22, 2025 that the wound dressing device 1 comprises an adhesive layer

[0100] 7.

[0101] Figure 2 illustrates schematically the first and second set of monitoring electrodes 5, 6. Figure 2 illustrates that the monitoring electrodes 5, 6 are distributed over a wound 20. Figure 2 further illustrates with the arrows how each monitoring electrode A-D of the first set of monitoring electrodes 5 may form an monitoring electrode-pair with any one of the monitoring electrodes A' -D' of the second set 5, thereby enabling different monitoring electrode configurations. Each monitoring electrode-pair enables flow of AC between the monitoring electrodes of the pair. Thus, impedance spectra may be measured across different combinations of monitoring electrodes, i.e. along different spatial current paths, thereby probing different spatial regions of the wound 9.

[0102] Figure 3 schematically illustrates a side cross-sectional view of the wound dressing device 1. Figure 3 further illustrates with dashed arrows the flow of AC between the monitoring electrodes 5, 6 and with lined arrows the flow of DC between the stimulation electrodes 3a-3b. The DC pulses and said flow of AC may be provided in an alternating manner. The flow of AC may be provided through non-invasive electrochemical impedance spectroscopy (EIS) . In other words, the AC may be provided to measure the impedance of the wound 9 over a range of frequencies. The reference letter 's' represents a stimulation interval 24 and 'm' represents a monitoring or measurement interval 25.

[0103] Figure 4A illustrates DC pulses applied over a time period in a graph where the y-axis represents electrical current, and the x-axis represents time. Accordingly, Figure 4A illustrates that a plurality of DC pulses are provided (sl-s4) , wherein PC 25 0970 G 31 / 46 August 22, 2025 there is dead-time (ml-m4) for a time-period between subsequent DC-pulses (i.e. where IDC= 0) . Accordingly, between consecutive DC pulses, the monitoring electrodes 5, 6 may be activated to provide a flow of AC, thereby preventing interference between stimulation performed with electrodes 3a- 3b and AC measurements performed with electrodes 5-6 (see Figure 1A) .

[0104] The stimulation phases 24 in Figure 4 are DC pulses which may be long duration (hours) or shorter duration (minutes) that are interrupted to perform electrochemical property Admeasurements (such as impedance measurement) before changing the polarity of stimulation. Pulses si, s3 are of positive nature with stimulation electrode 3a being positive and stimulation electrode 3b being negative for example, while pulses s2, s4 are of negative nature, meaning that electrode 3a has now negative polarity while electrode 3b has positive polarity. The alternation of current flow direction elicits the desired biological response of cellular stimulation, while helping the stimulation electrodes 3a, 3b to recharge the ions within their polymeric matrix formed by the polymer coating 8. For the monitoring phases ml-m4, AC pulses of varying frequency and magnitude can be used to measure / obtain information of the tissue impedance over a wide frequency spectrum. This allows for measurement of electrochemical properties of the tissue 26 at different z-depths (see Figure 9a) and regions in combination with the switching of monitoring electrodes 5, 6, as shown in Fig 2.

[0105] The amount of DC-current, the length of each DC-pulse, and the dead-time in between DC-pulses, may differ based on the specific stimulation protocol deployed.

[0106] Figure 4B illustrates AC voltages applied via the monitoring electrodes 5, 6 over time in a graph: Three different signals PC 25 0970 G 32 / 46 August 22 , 2025 with sinusoidal form are provided, each having a frequency f l , f2 , and f3 . Accordingly, the flow of AC may be provided over a frequency spectrum ranging from f l to f3 . The control circuitry 10 may provide the flow of AC over said frequency spectrum during each DC pulse dead-time (ml , m2 , m3 , ... - see Figure 4A) such that a frequency spectrum ( as shown in Figure 4B ) is provided at each dead-time mi , or the control circuitry 10 may provide AC over one respective fixed frequency for each dead-time mi such that the frequency is altered for each subsequent dead-time .

[0107] Figure 5 illustrates , in the form of a flowchart , a method 100 for producing the wound dressing device 1 . The method 100 is not limited to the order as illustrated in Figure 5 and may be performed in any other suitable order . The method comprises the steps of imaging 101 a wound 9 . Further, characteri zing 102 the wound 9 to define at least an area of the wound 9 . Additionally, the characteri zing 102 may also define other characteristics of the wound 9 . Further, the method 100 comprises providing 103 a substrate 2 based on said area and performing 104 , based on said area, a technique on said substrate 2 to define a pair of spaced apart stimulation electrodes 3a, 3b thereon, wherein the technique is a laser induced technique , and the stimulation electrodes are graphene based . Preferably, an electrical insulation layer 28 (which may be prefabricated, see Figure 7 ) may be aligned and attached onto the upper side 22 of the device 1 , to partly electrically insulate the stimulation electrodes 3 .

[0108] Furthermore , the method 100 may comprise attaching 105 a wound supporting membrane 4 between the pair of spaced apart stimulation electrodes 3a, 3b and / or connecting 106 control circuitry 10 to said electrodes 3a, 3b .

[0109] The method 100 also comprises the step of coating 107 the PC 25 0970 G 33 / 46 August 22 , 2025 spaced apart electrodes with a conductive polymer 15 to form the desired electrically conductive polymer coating ( CPC ) . The step of coating 107 may be performed prior to the step 106 , or prior to the step 105 . The area to be coated by the CPC may also be pre-defined by adding said insulation layer 28 first and then performing step 107 .

[0110] Figure 6 illustrates schematically some steps of the method 100 of Figure 5 graphically . Accordingly, Figure 6 illustrates the step of imaging 101 the wound 9 , which may be performed by utili zing a reference marker to facilitate subsequent characteri zing of the wound . Moreover, Figure 6 illustrates characteri zing the wound 9 in a computer-implemented manner and performing 104 , based on said area, a technique on said substrate 2 to define the pair of stimulation electrodes 3a, 3b thereon .

[0111] Further, Figure 6 illustrates that an adhesive layer 7 may be provided . Accordingly, the substrate 2 may be placed onto the adhesive layers 7 . The substrate 2 as such may comprise an adhesive portion . Figure 6 illustrates that the wound dressing device 1 may be dimensioned to be compatible with said wound 9 by determining characteristics of the wound 9 and providing the wound dressing device 1 to comply with said characteristics ( e . g . circumference ) .

[0112] Figure 7 provides another possible approach according to the invention for defining a wound dressing device 1 , and the fabrication process comprises the following steps :

[0113] ( a ) A substrate sheet 2 formed from a carbon-based material such as polyimide or PDMS or cellulose serves as the basis ;

[0114] (b ) Using a CO2-laser 27 , stimulation electrodes ( 3a, 3b ) are integrally formed as laser-induced graphene ( LIG) electrodes , which are grown by pyrolysis from the substrate sheet 2 and into a bulk volume of said sheet 2 . As illustrated in Figure PC 25 0970 G 34 / 46 August 22, 2025

[0115] 7b, contact pads 19 and electrical wirings 16 as well as monitoring electrodes 5, 6 are also formed by this laser- assisted pyrolysis from the same LIG material, resulting in the LIG device shown in Fig. 7c. Next, an electrical insulation layer 28 (shown in Fig. 7d) , for example formed from Kapton (polyimide) , PDMS, or thermoplastic polyurethane (TPU) , is laser-cut (Fig. 7 e) using the very same CO2-laser 27 (or by any other suitable means) and added on part of the LIG structures (Fig. 7f) .

[0116] As illustrated in Fig. 7f, the electrical insulation layer 28 (which may be defined alternatively by lithography or other 2D-masking techniques or by 3D-printing) covers the wiring 16, while leaving at least parts of the electrodes 3a, 3b, 5 and 6 and the contact pads 19 exposed.

[0117] Next, an electrically conductive polymer coating 8, formed from a doped polymer 15, can be added on top of the stimulation electrodes 3a, 3b, for example by a dispensing process (in particular by a spot casting process) or by printing. This coating 8 may completely cover at least all those parts of the stimulation electrodes 3a, 3b, which are not covered by the insulation layer 28, therefore remain still exposed, and which are intended for electrically contacting the skin. In other words, once the CPC 8 is applied, no exposed surface of the electrodes 3a, 3b remains, as these surfaces are either covered by the insulation layer 28 or the CPC 8. Accordingly, all DC-stimulation currents originating from the wound dressing device 1 will be applied via the electrodes 3a, 3b and the CPC 8 to tissue 26 (once the device 1 is applied onto a wound 9) , and the CPC 8 acts as a reservoir for exchanging mobile ions with said tissue 26. Accordingly, such a design results in a DC-electrostimulation that is solely based on exchange of mobile ions with the tissue 26, but no free electrons (as could be released from PC 25 0970 G 35 / 46 August 22, 2025 uncovered LIG electrodes) .

[0118] If desired (depending on the type of wound 9 to be treated) , the upper side 22 of the stimulation area 21 located between the pair of DC-stimulation electrodes 3a, 3b can be covered by a wound supporting membrane 4, as previously elaborated.

[0119] As another optional step (i) , an adhesive layer 7 may be added to the device 1, such that its upper side 22 can be safely and reversibly attached to a skin 18 of a patient. And electronic components such as a temperature sensor 34 and / or a pH-sensor may be added to the device 1 (c.f. Figure 7i) .

[0120] Figure 8 provides further details of the important step b) , in which the electrical structures 3a, 3b, 16 and 19 are defined one after another by a serial laser processing as LIG- structures. Row a) of Figure 8 provides side-views, while rows b) and c) provide top- and front-views, respectively: A beam 29 of the CO2-laser is guided over the substrate sheet 2 in the x- and y- directions. As can be seen in the side-views A- A, taken at different, proceeding points in time ti-t4 (see row a) , the LIG structures are grown in the xy-plane at the desired location on the substrate sheet 2, but they also grow in the negative z-direction (i.e. into the bulk volume of the substrate 2) and in the positive z-direction (i.e. out of the upper xy-plane / surf ace 22 of the substrate 2) . In other words, the stimulation electrodes 3a, 3b, the monitoring electrodes 5, 6, the contact pads 19 and the wirings 16 are all grown als LIG structures into and out of the material of the substrate sheet 2.

[0121] Figure 9 illustrates (purely schematically) how a system 23 according to the invention, comprising a wound dressing device 1 and an associated control circuitry 10 (in the form of a separate device connected via a cable 17 and connector 20 to PC 25 0970 G 36 / 46 August 22 , 2025 the wound dressing device 1 as illustrated in Figure 1 ) , can adapt an electrical DC-stimulation depending on the progress of wound healing, which is detected by an active Admeasurement using the monitoring electrodes 5 , 6 of the wound dressing device 1 : As illustrated by the dotted lines , the control circuitry 10 is configured to provide an alternating current (AC ) that can flow between the two monitoring electrodes 5 and 6 of the device 1 and through a wound 9 , when the upper side 22 of the device 1 is attached onto the wound 9 . At the same time , circuitry 10 measures the voltage resulting from said AC 32 . Due to using two di f ferent sets of electrodes , one for stimulation ( stimulation electrodes 3a, 3b ) and one for AC-measurements (monitoring electrodes 5 , 6 ) , electrical crosstalk can be avoided such that the AC measurements are not negatively influenced by the electrostimulation and vice versa . As illustrated by the dashed lines in Figure 9a, such an active AC measurement allows to electrically probe regions of tissue 26 below the wound 9 and to measure an electrical impedance of these tissue regions . Based on such an active AC measurement , which can also make use of AC 32 applied at varying frequencies , the control circuitry 10 is configured to detect variations of electrochemical properties of the tissue 26 and to adapt a stimulation protocol , which defines the DC currents 31 that are applied to the wound 9 during stimulation intervals 24 of DC- electro stimulation .

[0122] Such an active AC impedance measurement , i f performed repeatedly over a period of time ranging from hours to days or even weeks , thus allows monitoring of changes of electrochemical properties in and below the wound 9 , which changes are indicative of a wound healing . This is illustrated in Figure 9b, which shows such AC measurements performed at progressive points in time ti , t2 , and ta, over which period a signi ficant wound healing has taken place ( thus closing the PC 25 0970 G 37 / 46 August 22 , 2025 wound 9 slowly) . The setup comprising the device 1 and circuitry 10 thus ef fectively forms an active control loop, in which DC pulses 31 are adapted based on changes of ec properties which are electrically monitored in active ( i . e . implying application of an alternating measurement current ) AC measurements using the device 1 .

[0123] As has been detailed before , the active AC measurements performed by the circuitry 10 and using the monitoring electrodes 5 , 6 of the device 1 can comprise switching between at least two di f ferent monitoring electrode configurations , such that the AC measurements are based on varying AC measurement paths . Such spatially moving active AC or impedance measurements can be performed automatically by the system 23 to provide automatic wound progress observation, and in particular digital data documenting the same ( for evidence based assessment of wound healing) . Such data and information can be forwarded automatically by the system 23 to a GUI on an external device , as detailed before .

[0124] In addition, impedance spectra may be measured for single or each of the current paths employed in said AC measurements . Accordingly, active AC measurements can be performed automatically by the system 23 , which measurements are moving in space and in time .

[0125] In summary, the present disclosure provides an approach which combines active DC-electrostimulation with active AC measurements , all performed using a disposable wound dressing device 1 . The DC-electrostimulation and the AC-measurements can be automatically performed by a circuitry 10 of as system 23 comprising said device 1 , and the circuitry 10 can adapt the stimulation, in particular parameters such as DC current strength, DC pulse duration, or waiting time ml (which can be used for performing an AC measurement in between two DC pulses PC 25 0970 G 38 / 46 August 22, 2025 applied with the device 1) based on the active AC measurements. For achieving biocompatibility and long-term stability, the device 1 features laser-induced graphene (LIG) stimulation electrodes 3a, 3b which are covered with a conductive polymer 15. All electrodes 3a, 3b, 5, 6 as well as electrical contact pads 19 and wirings 16 can be defined in a single laser processing step (c.f. Figure 1A) .

[0126] List of reference numerals

[0127] 1 wound dressing device

[0128] 2 substrate sheet

[0129] 3 stimulation electrode

[0130] 4 wound supporting membrane

[0131] 5 monitoring electrode

[0132] 6 monitoring electrode

[0133] 7 adhesive layer

[0134] 8 (electrically conductive) polymer coating

[0135] 9 wound

[0136] 10 control circuitry

[0137] 11 interface (of 10 for outputting signals)

[0138] 12 control module (part of 10)

[0139] 13 monitoring module (part of 10)

[0140] 14 memory device (part of 10)

[0141] 15 doped polymer (forming 8)

[0142] 16 (electrical) wiring (connecting 19 with 3 or 5 / 6)

[0143] 17 cable (for electrically connecting 10 to 1)

[0144] 18 skin (of a human being)

[0145] 19 (electrical) contact pad

[0146] 20 electrical connector (for connecting 17 with 19; can be attached to 17 or 1; can be a separate component)

[0147] 21 stimulation area

[0148] 22 upper side (of 1 / 2; to be brought in contact with 9 / 18)

[0149] 23 system (for supporting local wound healing; comprising 1 and 10 )

[0150] 24 stimulation interval PC 25 0970 G 39 / 46 August 22, 2025

[0151] 25 measurement interval

[0152] 26 tissue

[0153] 27 CO2-laser

[0154] 28 electrical insulation layer (e.g. formed from Kaption, PDMS or TPU)

[0155] 29 beam (of 27)

[0156] 30 bulk (of 2)

[0157] 31 DC

[0158] 32 AC 33 pH-sensor

[0159] 34 temperature sensor

Claims

PC 25 0970 G 40 / 46 August 22, 2025Claims1. A wound dressing device (1) for covering a wound (9) and for DC-electrostimulation of said wound (9) , comprising:- a substrate sheet (2) for being positioned on the wound (9) and- a pair of stimulation electrodes (3a, 3b) , which are spaced apart from each other and arranged on an upper side (22) of said substrate sheet (2) to the left and to the right of a stimulation area (21) ,- wherein the pair of stimulation electrodes (3a, 3b) is arranged and designed for providing a flow of direct current (DC) between each other over the stimulation area (21) for DC-electrostimulation of said wound (9) ; characterized in that:- the stimulation electrodes (3a, 3b) are integrally formed as laser-induced graphene (LIG) electrodes and- these laser-induced graphene electrodes (3a, 3b) are covered with an electrically conductive polymer coating (8) formed from a doped polymer (15) .

2. The wound dressing device (1) according to claim 1, wherein the polymer coating (8) provides a nanoscale mesh that can absorb and release ions such as Na+ and Ka+ .

3. The wound dressing device (1) according to claim 1 or 2, wherein the substrate sheet (2) comprises, in particular is formed from, a carbon-based material,- in particular polyimide, polydimethylsiloxane(PDMS) , Parylene-C, cellulose or any other biocompatible carbon-based polymer material, and- wherein the laser-induced graphene (LIG) electrodes (3a, 3b) have been grown from said carbon-based material by a laser induced technique,- in particular such that the stimulation electrodes (3a,PC 25 0970 G 41 / 46 August 22, 20253b) are integrally formed from the carbon-based material(2) and / or have been grown into a bulk volume of said carbon-based material (2) , preferably into a depth of at least 10%, most preferably of at least 25%, of a thickness of the substrate sheet (2) .

4. The wound dressing device (1) according to any of the preceding claims, wherein the doped polymer (15) is Poly ( 3 , 4-ethylene-dioxythiophene ) polystyrene sulfonate (PEDOT-PSS) .

5. The wound dressing device (1) according to any of the preceding claims, wherein the conductive polymer coating (8) is formed from a pure PEDOT-PSS hydrogel,- preferably wherein said PEDOT-PSS hydrogel comprises a network of interconnected PEDOT:PSS nanofibrils.

6. The wound dressing device (1) according to any of the preceding claims, wherein the wound dressing device (1) features electrical contact pads (19) and / or electrical wirings (16) which are formed from the same laser-induced- graphene (LIG) material as the stimulation electrodes (3a, 3b) ,- preferably and which have been fabricated by the same laser-induced process as the laser-induced stimulation electrodes (3a, 3b) .

7. The wound dressing device (1) according to any of the preceding claims, wherein the wound dressing device (1) further comprises- at least two monitoring electrodes (5, 6) for performing active AC measurements and / or- at least one of: a pH-sensor or a temperature sensor,PC 25 0970 G 42 / 46 August 22, 2025 for detecting changes in the direct environment of the wound dressing device (1) ,- preferably wherein the wound dressing device (1) comprises a first and a second set of monitoring electrodes (5, 6) , the first set comprising at least two first monitoring electrodes (5a) and the second set comprising at least two second monitoring electrodes (6a) , the first and the second set (5, 6) being distributed oppositely relative to each other or relative to the stimulation area (21) .

8. The wound dressing device (1) according to the preceding claim, wherein the first set of monitoring electrodes comprises a plurality of first monitoring electrodes (5a) , and the second set of monitoring electrodes comprises a plurality of second monitoring electrodes (6a) , such that multiple different spatial current paths can be defined by different pairs of first and second monitoring electrodes (6a, 6b) .

9. The wound dressing device (1) according to claim 7 or 8, wherein the stimulation electrodes (3a, 3b) and the first and second set of monitoring electrodes (5, 6) are all laser-induced graphene electrodes,- preferably which are grown on said substrate sheet (2) by a laser induced technique,- most preferably wherein the substrate sheet (2) is formed from a carbon-based material.

10. A system (23) for supporting local wound healing in a tissue (26) through DC electrostimulation, the system (23) comprising :- a wound dressing device (1) according to one of the preceding claims and a control circuitry (10) electrically connected to saidPC 25 0970 G 43 / 46 August 22, 2025 wound dressing device (1) ,- wherein the control circuitry (10) is configured- to provide electrical DC driving currents during stimulation intervals (24) to said pair of stimulation electrodes (3a, 3b) based on a stimulation protocol,- in particular such that a flow of DC pulses can be provided across a wound (9) covered by said wound dressing device (1) according to the stimulation protocol.

11. The system (23) according to the preceding claim,- wherein the wound dressing device (1) comprises at least two monitoring electrodes (5, 6) and / or is according to claim 7,- preferably and wherein the control circuitry (10) is configured to:(i) deliver alternating electrical currents during measurement intervals (25) to said at least two monitoring electrodes (5a, 6a) for performing an active AC measurement and / or(ii) read-out a pH-sensor (33) or a temperature sensor (34) of the wound dressing device (1) ; and(iii) adapt at least one parameter of the stimulation protocol to change the DC-pulses applied during the DC-electrostimulation, based on a change of electrochemical (ec) properties of the tissue (26) detected via the active AC measurement and / or based on an environmental changed detected with said pH-sensor (33) and / or said temperature sensor (34) ,- in particular such that the flow of DC pulses provided across a wound (9) is automatically changed by the system (23) over an electrostimulation session performed with the wound dressing device (1) .PC 25 0970 G 44 / 46 August 22, 202512. The system (23) according to claim 11,- wherein the control circuitry (10) is configured to provide a flow of AC over a frequency spectrum during the respective active AC measurement, such that impedance spectra can be measured and / or- wherein the wound dressing device (1) is according to claim 7 and wherein the control circuitry (10) is configured :- to switch said plurality of first monitoring electrodes (5a) and said plurality of second monitoring electrodes (6a) into a plurality of different monitoring electrode configurations ,- preferably and to provide a respective flow of AC between the first monitoring electrodes (5a) and the second monitoring electrodes ( 6a) for each configuration, respectively .

13. The system (23) according to claim 11 or 12, wherein the control circuitry (10) is configured to:- adapt a flow of DC pulses applied via the stimulation electrodes (3a, 3b) of the device (1) based on changes of electrochemical properties which are monitored by the circuitry (10) using the at least two monitoring electrodes (5, 6) and / or- determine changes in wound dimensions of a wound (9) to which the device (1) is attached to, based on changes of electrochemical properties, the changes being indicative of a healing at said wound (9) , which are monitored by the circuitry (10) using the at least two monitoring electrodes (5, 6) .

14. A method (100) for fabricating a wound dressing device (1) , in particular wherein the wound dressing device (1) is according to any one of the preceding claims 1-9, the method comprising the following steps:PC 25 0970 G 45 / 46 August 22, 2025- providing (103) a substrate sheet (2) comprising a carbon-based material, in particular wherein the substrate sheet (2) is provided in a pre-defined and / or standardized size and shape;- performing (104) laser processing of the substrate sheet(2) for integrally forming laser-induced graphene stimulation electrodes (3a, 3b) from the carbon-based material / from said substrate sheet (2) ;- coating (107) the laser-induced graphene stimulation electrodes (3a, 3b) with a doped polymer (15) ,- preferably wherein the doped polymer (15) is PEDOT-PSS,- most preferably wherein the resulting electrically conductive polymer coating (8) is formed as a PEDOT-PSS hydrogel .

15. The fabrication method according to claim 14, wherein- electrical contact pads (19) and electrical wirings (16) are also integrally formed from the carbon-based material in the same laser processing step and / or- an electrically insulating coating (28) is applied at least on parts of the stimulation electrodes (3a, 3b) .

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