# US 11,027,051 B2 · Pressure control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,051 B2 - Document ID: US11027051B2 - Status: Granted - Kind: B2 - Application number: 16/141,701 - Filed: 2018-09-25 - Published: 2019-01-24 - Granted: 2021-06-08 - Earliest claimed: 2010-09-20 - Assignees: Smith & Nephew, Inc. - Applicants: Smith & Nephew PLC - Inventors: Derek Nicolini - Web page: https://patentgrep.com/patent/US11027051B2 ## CPC - A61M 5/16831: {Monitoring, detecting, signalling or eliminating infusion flow anomalies (low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066)} - A61F 13/05: specially adapted for use with sub-pressure or over-pressure therapy, wound drainage or wound irrigation, e.g. for use with negative-pressure wound therapy [NPWT] - A61M 1/73: {comprising sensors or indicators for physical values} - A61M 1/74: {Suction control (underwater drainage A61M1/61)} - A61M 1/743: {by changing the cross-section of the line, e.g. flow regulating valves (A61M1/7413 takes precedence)} - A61M 1/75: {Intermittent or pulsating suction (A61M1/63, A61M1/772 take precedence)} - A61M 1/80: {Suction pumps (A61M1/64, A61M1/71, A61M60/00 take precedence)} - 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 1/96: {Suction control thereof} - A61M 5/48: having means for varying, regulating, indicating or limiting injection pressure (A61M5/142 takes precedence {; monitoring pressure in infusion systems A61M5/16854}) - A61M 39/22: Valves or arrangement of valves {(A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405)} - A61F 2013/00174: {possibility of applying pressure} - A61M 1/732: {Visual indicating means for vacuum pressure} - A61M 1/966: {having a pressure sensor on or near the dressing} - A61M 1/985: {the dressing itself forming the collection container} - A61M 2205/15: Detection of leaks - A61M 2205/18: with alarm - A61M 2205/3344: Measuring or controlling pressure at the body treatment site - A61M 2205/42: Reducing noise - A61M 2205/8212: with means or measures taken for minimising energy consumption - 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)} - 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) ## Abstract Methods and apparatuses are disclosed for applying negative pressure to a wound site. In some embodiments, the apparatus comprises a source of negative pressure, a processing element, and a memory comprising instructions configured to, when executed on the processing element, cause the apparatus to attempt to generate, via the source of negative pressure, a desired negative pressure at the wound site. If the desired negative pressure has not been generated after a first predetermined period of time, the instructions cause the apparatus to: deactivate the source of negative pressure for a second predetermined period of time, and subsequently attempt to generate the desired negative pressure at the wound site. ## Claims ### Claim 1 A wound therapy apparatus comprising: a wound dressing configured to be positioned over a wound and absorb wound exudate; a pressure source configured to be in fluid communication with the wound dressing via a fluid flow path; a power source configured to power the pressure source; a pressure sensor configured to measure pressure in the fluid flow path; a button or a switch configured to receive user inputs from a user; a plurality of visual indicators; a controller configured to: responsive to a first user input of the user inputs, activate the pressure source to attempt to generate a first level of negative pressure under the wound dressing, responsive to a second user input of the user inputs, deactivate the pressure source, maintain negative pressure under the wound dressing in a negative pressure range by repeatedly deactivating and activating the pressure source, and with the plurality of visual indicators, separately indicate (i) a normal operating condition, (ii) a leak condition, (iii) a remaining capacity or life of the power source, and (iv) an end of life state in which the pressure source is permanently deactivated; and a housing configured to support the pressure source, the power source, the pressure sensor, the plurality of visual indicators, the controller, and the button or the switch, wherein the controller, the pressure source, and the wound dressing are configured to operate together to provide negative pressure wound therapy without use of a fluid collection canister. ### Claim 2 (depends on 1) The wound therapy apparatus of claim 1, wherein the controller is configured to deactivate the pressure source once the first level of negative pressure under the wound dressing is achieved. ### Claim 3 (depends on 2) The wound therapy apparatus of claim 2, wherein the first level of negative pressure is between −75 mmHg and −200 mmHg. ### Claim 4 (depends on 2) The wound therapy apparatus of claim 2, wherein the controller is configured to, subsequent to the first level of negative pressure under the wound dressing being achieved, activate the pressure source once a second level of negative pressure under the wound dressing is reached, the second level of negative pressure being closer to an atmospheric pressure than the first level of negative pressure. ### Claim 5 (depends on 4) The wound therapy apparatus of claim 4, wherein the first level of negative pressure is between −75 mmHg and −200 mmHg. ### Claim 6 (depends on 1) The wound therapy apparatus of claim 1, wherein the power source comprises a battery. ### Claim 7 (depends on 1) The wound therapy apparatus of claim 1, wherein the plurality of visual indicators comprises three separate visual indicators. ### Claim 8 (depends on 1) The wound therapy apparatus of claim 1, wherein the plurality of visual indicators comprises a plurality of light emitting diodes. ### Claim 9 (depends on 1) The wound therapy apparatus of claim 1, wherein the controller is configured to indicate with the plurality of visual indicators that the remaining capacity or life of the power source has reached a threshold. ### Claim 10 (depends on 1) The wound therapy apparatus of claim 1, wherein once the pressure source is activated, the controller is configured to activate and deactivate the pressure source responsive to no inputs from the user other than the user inputs received with the button or the switch. ### Claim 11 (depends on 1) The wound therapy apparatus of claim 1, further comprising a one-way flow valve configured to be positioned in the fluid flow path between the pressure source and the wound dressing. ### Claim 12 (depends on 1) The wound therapy apparatus of claim 1, wherein the wound dressing comprises a film that permits evaporation through the film. ### Claim 13 (depends on 1) The wound therapy apparatus of claim 1, wherein the housing is portable and configured to be carried on the user. ### Claim 14 (depends on 1) The wound therapy apparatus of claim 1, wherein the controller is configured to determine negative pressure under the wound dressing from pressure in the fluid flow path measured by the pressure sensor. ### Claim 15 (depends on 14) The wound therapy apparatus of claim 14, wherein the pressure sensor is configured to measure pressure in the fluid flow path at an input of the pressure source. ### Claim 16 (depends on 1) The wound therapy apparatus of claim 1, wherein the controller is configured to: detect the leak condition; and responsive to detection of the leak condition, deactivate the pressure source and indicate the leak condition with the plurality of visual indicators. ### Claim 17 (depends on 1) The wound therapy apparatus of claim 1, wherein the controller is configured to transition to the end of life state and deactivate the pressure source responsive to determining that a time elapsed from a first activation of the controller or the pressure source has reached an end of life threshold corresponding to the end of life state, and the controller is configured to transition to the end of life state when an energy level of the power source is sufficient to power the pressure source and the controller. ### Claim 18 (depends on 1) The wound therapy apparatus of claim 1, wherein the controller is configured to no longer activate the pressure source responsive to the user inputs once a time elapsed from a first activation of the controller or the pressure source has reached an end of life threshold corresponding to the end of life state. ### Claim 19 A method of providing wound therapy, the method comprising: supporting, by a housing, a controller, a pressure source, a power source, a plurality of visual indicators, and a button or a switch, receiving a first user input by the button or the switch; in response to receiving the first user input, activating, by the controller, a pressure source to attempt to generate a first level of negative pressure under a wound dressing positioned over a wound; absorbing wound exudate with the wound dressing; measuring pressure in a fluid flow path connecting the pressure source and the wound dressing; maintaining, by the controller, negative pressure under the wound dressing in a negative pressure range by repeatedly deactivating and activating the pressure source; receiving a second user input by the button or the switch; in response to receiving the second user input, deactivating, by the controller, the pressure source; powering the pressure source by the power source; and separately indicating, by the plurality of visual indicators, a normal operating condition associated with the fluid flow path, a leak condition associated with the fluid flow path, a remaining capacity or life of the power source, and an end of life state in which the pressure source is permanently deactivated, wherein the method is performed without using a fluid collection canister. ### Claim 20 (depends on 19) The method of claim 19, wherein said maintaining negative pressure in the negative pressure range comprises: deactivating, by the controller, the pressure source once the first level of negative pressure under the wound dressing is achieved; and subsequent to the first level of negative pressure under the wound dressing being achieved, activating, by the controller, the pressure source once a second level of negative pressure under the wound dressing is reached, the second level of negative pressure being closer to an atmospheric pressure than the first level of negative pressure. ### Claim 21 (depends on 20) The method of claim 20, wherein the first level of negative pressure is between −75 mmHg and −200 mmHg. ### Claim 22 (depends on 19) The method of claim 19, wherein the plurality of visual indicators comprises a plurality of light emitting diodes, and said separately indicating the normal operating condition, the leak condition, the remaining capacity or life, and the end of life state comprises selectively activating or deactivating one or more of the plurality of light emitting diodes to indicate the normal operating condition, the leak condition, the remaining capacity or life, and the end of life state. ### Claim 23 (depends on 19) The method of claim 19, further comprising limiting flow in the fluid flow path to one direction. ### Claim 24 (depends on 19) The method of claim 19, wherein said measuring pressure in the fluid flow path comprises measuring pressure at an input of the pressure source. ### Claim 25 A wound therapy apparatus comprising: a pressure source configured to be in fluid communication with a wound dressing via a fluid flow path; a power source configured to power the pressure source; a pressure sensor configured to measure pressure in the fluid flow path; a button or a switch configured to receive user inputs from a user; a plurality of visual indicators; a controller configured to: responsive to a first user input of the user inputs, activate the pressure source to attempt to generate a first level of negative pressure under the wound dressing, responsive to a second user input of the user inputs, deactivate the pressure source, and with the plurality of visual indicators, separately indicate (i) a normal operating condition, (ii) a leak condition, (iii) that a remaining capacity or life of the power source has reached a threshold, and (iv) an end of life state in which the pressure source is permanently deactivated; and a housing configured to support the pressure source, the power source, the pressure sensor, the plurality of visual indicators, the controller, and the button or the switch, wherein the controller, the pressure source, and the wound dressing are configured to operate together to provide negative pressure wound therapy without use of a fluid collection canister. ### Claim 26 (depends on 25) The wound therapy apparatus of claim 25, further comprising a one-way flow valve configured to be positioned in the fluid flow path between the pressure source and the wound dressing. ### Claim 27 (depends on 25) The wound therapy apparatus of claim 25, further comprising the wound dressing, the wound dressing comprising a film that permits evaporation through the film. ### Claim 28 (depends on 25) The wound therapy apparatus of claim 25, wherein the housing is portable and configured to be carried on the user. ### Claim 29 (depends on 25) The wound therapy apparatus of claim 25, wherein the controller is configured to transition to the end of life state and deactivate the pressure source responsive to determining that a time elapsed from a first activation of the controller or the pressure source has reached an end of life threshold corresponding to the end of life state, and the controller is configured to transition to the end of life state when an energy level of the power source is sufficient to power the pressure source and the controller. ### Claim 30 (depends on 25) The wound therapy apparatus of claim 25, wherein the controller is configured to no longer activate the pressure source responsive to the user inputs once a time elapsed from a first activation of the controller or the pressure source has reached an end of life threshold corresponding to the end of life state.