# US 10,307,516 B2 · Apparatuses and methods for detecting leaks in a negative pressure wound therapy system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,307,516 B2 - Document ID: US10307516B2 - Status: Granted - Kind: B2 - Application number: 15/472,672 - Filed: 2017-03-29 - Published: 2017-09-14 - Granted: 2019-06-04 - Earliest claimed: 2011-10-31 - Assignees: Smith & Nephew, Inc. - Applicants: Smith & Nephew, Inc. - Inventors: Paul Aceto; Kealoha Young Deutch; Joseph Gordon; Luke Hagan; William Joseph Jaecklein; Bill Kane; Dino Kasvikis; Corey Libby; Jacob A. Marks; Michael Salame; Jared Schneider - Web page: https://patentgrep.com/patent/US10307516B2 ## CPC - G01M 3/24: using infrasonic, sonic or ultrasonic vibrations - A61M 1/73: {comprising sensors or indicators for physical values} - A61M 1/90: {Negative pressure wound therapy devices, i.e. devices for applying suction to a wound to promote healing, e.g. including a vacuum dressing} - A61M 1/985: {the dressing itself forming the collection container} - A61M 1/912: {Connectors between dressing and drainage tube} - A61M 1/913: {having a bridging element for transferring the reduced pressure from the connector to the dressing} - A61M 1/916: {specially adapted for deep wounds} - A61M 2205/15: Detection of leaks - A61M 2205/18: with alarm - A61M 2205/3375: Acoustical, e.g. ultrasonic, measuring means - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract Leak location devices and methods of using leak location devices that can be used in conjunction with negative pressure wound therapy systems are disclosed. In some embodiments, a leak location device can include a microphone for detecting sound pressure produced by a leak. Detected sound pressure can be compared to a threshold, which can correspond to background or ambient sound pressure. Background or ambient sound pressure can correspond to sound produced by a negative pressure source. The leak detection device can include a display configured to visually depict the detected sound, and a light source which creates a visual depiction of the coverage angle of the microphone. ## Claims ### Claim 1 An apparatus for applying negative pressure to a wound, comprising: a dressing configured to be placed over the wound to create a substantially fluid impermeable seal over the wound; a negative pressure source configured to be coupled to the dressing; a directional microphone configured to detect sound produced by an airflow associated with the dressing; and a controller configured to determine a location and/or presence of a leak, the controller further configured to: receive sound from the directional microphone; and limit interference from one or more background noise sources based on a comparison of the sound to a threshold determined based on measurement of ambient noise produced when the negative pressure source provides negative pressure. ### Claim 2 (depends on 1) The method of claim 1, wherein the controller is configured to communicate with the directional microphone through a wired or wireless connection. ### Claim 3 (depends on 1) The apparatus of claim 1, further comprising a display configured to visually depict sound waves detected by the directional microphone. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the directional microphone is further configured to measure a plurality of sound pressures over a period of time and the controller is further configured to compute a representative sound pressure based on the plurality of measured sound pressures. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the controller is configured to compute the representative sound pressure based on an average of the plurality of measured sound pressures. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein the controller is configured to compute the representative sound pressure based on low-pass filtering the plurality of measured sound pressures. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the controller is further configured to activate an alarm configured to alert a user to a detected leak. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the directional microphone is configured to eliminate at least some off-axis sound waves to identify the location of the leak. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the directional microphone comprises sound pressure cancellation slits configured to eliminate at least some of the off-axis sound waves. ### Claim 10 A method of detecting a leak in a negative pressure wound therapy system comprising a controller, a directional microphone, and a negative pressure source, the method comprising: utilizing the directional microphone to detect sound waves produced by an airflow associated with the negative pressure source; by the controller, limiting interference from background noise sources by comparing the detected sound waves to a threshold determined based on measuring background sound level and substantially eliminating from the detected sound waves the background sound level; and by the controller, detecting a location and/or presence of the leak based on the sound waves from which the background sound level has been substantially eliminated. ### Claim 11 (depends on 10) The method of claim 10, wherein the controller communicates with the directional microphone through a wired or wireless connection. ### Claim 12 (depends on 10) The method of claim 10, further comprising providing an alert to indicate the presence and/or location of the leak. ### Claim 13 (depends on 10) The method of claim 10, further comprising providing a visual indication of the leak. ### Claim 14 (depends on 10) The method of claim 10, further comprising visually depicting sound detected by the directional microphone. ### Claim 15 (depends on 10) The method of claim 10, further comprising measuring a plurality of sound levels over a period of time and computing a representative sound level based on the plurality of measured sound levels. ### Claim 16 (depends on 15) The method of claim 15, wherein computing the representative sound level comprises averaging the plurality of measured sound levels. ### Claim 17 (depends on 15) The method of claim 15, wherein computing the representative sound level comprises low-pass filtering the plurality of measured sound levels. ### Claim 18 (depends on 10) The method of claim 10, further comprising eliminating at least some off-axis sound waves and identifying the location of the leak. ### Claim 19 (depends on 18) The method of claim 18, wherein eliminating at least some off-axis sound waves is performed at least partially by sound pressure cancellation slits of the directional microphone. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein the directional microphone comprises sound pressure cancellation slits configured to eliminate at least some of the off-axis sound waves. ### Claim 21 An apparatus for applying negative pressure to a wound, comprising: a negative pressure dressing configured to be placed over the wound to create a substantially fluid impermeable seal over the wound; a negative pressure source configured to be coupled to the negative pressure dressing through a negative pressure adaptor; a fluid flow path configured to connect the negative pressure source to the negative pressure dressing, the fluid flow path including the negative pressure adaptor; a directional microphone configured to detect sound produced by an airflow in the fluid flow path; and a processor configured to determine a location and/or presence of the leak, the processor further configured to: obtain sound from the directional microphone; and limit interference from one or more background noise sources based on a comparison of the sound to a threshold determined by measuring ambient sound produced by the negative pressure source providing negative pressure. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the directional microphone is configured to eliminate at least some off-axis sound waves to identify the location of the leak.