# US 11,076,997 B2 · Restriction of sensor-monitored region for sensor-enabled wound dressings > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,076,997 B2 - Document ID: US11076997B2 - Status: Granted - Kind: B2 - Application number: 16/633,828 - Filed: 2018-07-25 - Published: 2021-05-20 - Granted: 2021-08-03 - Earliest claimed: 2017-07-25 - Assignees: Smith & Nephew, Inc. - Applicants: Smith & Nephew PLC - Inventors: Allan Kenneth Frazer Grugeon Hunt; Felix Clarence Quintanar - Web page: https://patentgrep.com/patent/US11076997B2 ## CPC - A61F 13/023: {wound covering film layers without a fluid retention layer} - A61B 5/0537: Measuring body composition by impedance, e.g. tissue hydration or fat content - A61B 5/6833: {Adhesive patches} - A61F 13/00055: {Saturation indicators} - A61F 13/02: Adhesive bandages or dressings - A61F 13/0236: {characterised by the application/handling support layer} - A61B 5/0531: Measuring skin impedance - A61B 5/445: {Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore} - A61B 5/6802: {Sensor mounted on worn items} - A61B 5/746: {Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms} - A61B 2562/12: Manufacturing methods specially adapted for producing sensors for in-vivo measurements - A61F 2013/00442: {using electrodes} - A61F 2013/00944: {humidity; moisture} - A61F 2013/00961: {electrical conductivity} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A wound dressing that incorporates a number of sensors can be utilized in order to monitor characteristics of a wound as it heals or to identify one or more risk factors or conditions that may precipitate a wound. The wound dressing can include at least one sensor, such as an impedance sensor, that may be restricted from sensing in a direction away from the wound when the wound dressing is positioned in contact with the wound. ## Claims ### Claim 1 A wound monitoring apparatus comprising: a wound dressing comprising a wound contact layer configured to be positioned in contact with a wound; one or more sensors incorporated onto or into the wound contact layer, the one or more sensors being supported by a substrate; and a mask layer supported by the substrate, the mask layer being configured to restrict sensing by the one or more sensors in a direction away from the wound when the wound dressing is positioned in contact with the wound. ### Claim 2 (depends on 1) The wound monitoring apparatus of claim 1, wherein an output signal from the one or more sensors is usable to determine whether a tissue of or around the wound is living or dead. ### Claim 3 (depends on 1) The wound monitoring apparatus of claim 1, wherein the one or more sensors comprises an impedance sensor. ### Claim 4 (depends on 3) The wound monitoring apparatus of claim 3, wherein the impedance sensor is separated from the wound by an insulator and configured to measure an impedance of the wound without directly contacting the wound. ### Claim 5 (depends on 1) The wound monitoring apparatus of claim 1, wherein the one or more sensors comprises a driving pad and a measuring pad, and the mask layer extends in a direction parallel to a line that joins a center of the driving pad and a center of the measuring pad when viewing a cross-section of the one or more sensors. ### Claim 6 (depends on 1) The wound monitoring apparatus of claim 1, wherein the mask layer is floating rather than connected to ground. ### Claim 7 (depends on 1) The wound monitoring apparatus of claim 1, wherein the mask layer is connected to ground rather than floating. ### Claim 8 (depends on 1) The wound monitoring apparatus of claim 1, wherein when the wound dressing is positioned in contact with the wound, the mask layer is configured to prevent the one or more sensors from sensing a tissue positioned on an opposite side of the wound dressing from the wound. ### Claim 9 (depends on 1) The wound monitoring apparatus of claim 1, wherein when the wound dressing is positioned in contact with the wound, the mask layer is configured to permit sensing by the one or more sensors in a direction toward the wound. ### Claim 10 (depends on 1) The wound monitoring apparatus of claim 1, wherein the one or more sensors is positioned on an opposite side of the substrate from the mask layer. ### Claim 11 (depends on 1) The wound monitoring apparatus of claim 1, wherein the one or more sensors is positioned on a common side of the substrate as the mask layer. ### Claim 12 (depends on 1) The wound monitoring apparatus of claim 1, wherein the substrate comprises a substantially flexible printed circuit. ### Claim 13 (depends on 1) The wound monitoring apparatus of claim 1, further comprising a hardware processor configured to: determine a characteristic of the wound from an output signal from the one or more sensors; and activate an alarm responsive to the characteristic. ### Claim 14 A wound monitoring method comprising: collecting, with a wound dressing, fluid aspirated from the wound, the wound dressing comprising a wound contact layer positioned in contact with the wound; activating one or more sensors incorporated onto or into the wound contact layer, the one or more sensors being supported by a substrate; and restricting, with a mask layer supported by the substrate, sensing by the one or more sensors in a direction away from the wound. ### Claim 15 (depends on 14) The wound monitoring method of claim 14, further comprising outputting an output signal from the one or more sensors, the output signal being usable to determine whether a tissue of or around the wound is living or dead. ### Claim 16 (depends on 14) The wound monitoring method of claim 14, wherein the one or more sensors comprises an impedance sensor, and said activating comprises activating the impedance sensor. ### Claim 17 (depends on 16) The wound monitoring method of claim 16, wherein the impedance sensor is separated from the wound by an insulator, and further comprising measuring an impedance of the wound using the impedance sensor without directly contacting the wound. ### Claim 18 (depends on 14) The wound monitoring method of claim 14, wherein said restricting comprises preventing the one or more sensors from sensing a tissue positioned on an opposite side of the wound dressing from the wound. ### Claim 19 (depends on 14) The wound monitoring method of claim 14, further comprising permitting, with the mask layer, sensing by the one or more sensors in a direction toward the wound. ### Claim 20 (depends on 14) The wound monitoring method of claim 14, further comprising: determining, with a hardware processor, a characteristic of the wound from an output signal from the one or more sensors; and activating, with the hardware processor, an alarm responsive to the characteristic.