# US 7,811,269 B2 · Negative pressure assisted tissue treatment system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,811,269 B2 - Document ID: US7811269B2 - Status: Granted - Kind: B2 - Application number: 11/364,264 - Filed: 2006-02-28 - Published: 2006-07-06 - Granted: 2010-10-12 - Earliest claimed: 2001-08-24 - Assignees: KCI Licensing, Inc. - Inventors: Thomas A. Boynton; Teryl Blane Sanders; Keith Patrick Heaton; Kenneth William Hunt; Mark Stephen James Beard; David M. Tumey; Lawrence Tab Randolph - Web page: https://patentgrep.com/patent/US7811269B2 ## CPC - A61M 1/74: {Suction control (underwater drainage A61M1/61)} - A61M 1/73: {comprising sensors or indicators for physical values} - A61M 1/75: {Intermittent or pulsating suction (A61M1/63, A61M1/772 take precedence)} - A61M 1/78: {Means for preventing overflow or contamination of the pumping systems (combined with drainage containers A61M1/60)} - A61M 1/784: {by filtering, sterilising or disinfecting the exhaust air, e.g. swellable filter valves} - A61M 1/80: {Suction pumps (A61M1/64, A61M1/71, A61M60/00 take precedence)} - A61M 1/96: {Suction control thereof} - A61M 39/04: having pierceable self-sealing members - A61M 2039/0202: {for taking samples} - 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)} ## Abstract A system for stimulating the healing of tissue comprises a porous pad positioned within a wound cavity, and an airtight dressing secured over the pad, so as to provide an airtight seal to the wound cavity. A proximal end of a conduit is connectable to the dressing. A distal end of the conduit is connectable to a negative pressure source, which may be an electric pump housed within a portable housing, or wall suction. A canister is positioned along the conduit to retain exudates suctioned from the wound site during the application of negative pressure. A first hydrophobic filter is positioned at an opening of the canister to detect a canister full condition. A second hydrophobic filter is positioned between the first filter and the negative pressure source to prevent contamination of the non-disposable portion of the system by exudates being drawn from the wound. An odor filter is positioned between the between the first and second hydrophobic filters to aid in the reduction of malodorous vapors. A securing means is supplied to allow the portable housing to be secured to a stationary object, such as a bed rail or intravenous fluid support pole. A means for automated oscillation of pressure over time is provided to further enhance and stimulate the healing of an open wound. A means for varying pump drive frequency and a means for managing a portable power supply are provided to increase battery life and improve patient mobility. ## Claims ### Claim 1 A system for stimulating healing of tissue at a wound site comprising: a porous pad; a pump for applying negative pressure to the wound site through said porous pad that varies over time; and a controller regulating the negative pressure applied by the pump by changing the negative pressure in predefined pressure intervals, the controller comparing the negative pressure to a target pressure and incrementing the target pressure toward a maximum target pressure when the negative pressure has risen to or is greater than the target pressure. ### Claim 2 (depends on 1) The system of claim 1, further comprising a drape for covering the porous pad when the porous pad is positioned at the wound site. ### Claim 3 (depends on 2) The system of claim 2, wherein the drape forms an airtight seal around the porous pad. ### Claim 4 (depends on 1) The system of claim 1, further comprising means for deactivating a backlight to a display after a predetermined time interval. ### Claim 5 (depends on 1) The system of claim 1 further comprising a clamp for securing said system to a pole. ### Claim 6 (depends on 1) The system of claim 1, wherein said porous pad is comprised of a polyvinyl alcohol foam. ### Claim 7 (depends on 1) The system of claim 1 further comprising a control system to determine an optimum drive frequency for variably driving the pump in order to maximize pump flow. ### Claim 8 (depends on 7) The system of claim 7, further comprising a pressure sensor for measuring the pressure. ### Claim 9 (depends on 8) The system of claim 8, further comprising a variable frequency drive circuit for driving said pump at said optimum drive frequency. ### Claim 10 (depends on 1) The system of claim 1, wherein said controller is further adapted to compare the target pressure to the maximum target pressure and begin decreasing the negative pressure when the target pressure has reached the maximum target pressure. ### Claim 11 (depends on 10) The system of claim 10, wherein said controller is further adapted to decrement the target pressure toward a minimum target pressure when the negative pressure has fallen to or is less than the target pressure. ### Claim 12 (depends on 11) The system of claim 11, wherein said controller is further adapted to increase the negative pressure when the target pressure has reached the minimum target pressure, whereby the negative pressure oscillates over time between the maximum target pressure and the minimum target pressure. ### Claim 13 A system for stimulating healing of tissue at a wound site comprising: a porous pad; a pump for applying negative pressure to the wound site through said porous pad that varies over time; and a controller regulating the negative pressure applied by the pump by comparing the negative pressure to a target pressure, said controller being adapted to vary the target pressure between a maximum target pressure and a minimum target pressure by either (a) increasing the target pressure when the negative pressure has risen to or is greater than the target pressure, or (b) decreasing the target pressure when the negative pressure has fallen to or is less than the target pressure. ### Claim 14 (depends on 13) The system of claim 13, wherein said controller is further adapted to compare the target pressure to the maximum target pressure and begin decreasing the negative pressure when the target pressure has reached the maximum target pressure. ### Claim 15 (depends on 13) The system of claim 13, wherein said controller is further adapted to compare the target pressure to the minimum target pressure and begin increasing the negative pressure when the target pressure has reached the minimum target pressure. ### Claim 16 (depends on 13) The system of claim 13, wherein said controller further adapted to decrease the negative pressure when the target pressure has reached the maximum target pressure and increase the negative pressure when the target pressure has reached the minimum target pressure, whereby the negative pressure oscillates over time between the maximum target pressure and the minimum target pressure. ### Claim 17 A system for stimulating healing of tissue at a wound site comprising: a porous pad; a pump for applying negative pressure to the wound site through said porous pad that varies over time; and a controller regulating the negative pressure applied by the pump and adapted to compare the negative pressure to a target pressure and change the target pressure by (a) incrementing the target pressure toward a maximum target pressure when the negative pressure has risen to or is greater than the target pressure and (b) decrementing the target pressure toward a minimum target pressure when the negative pressure has fallen to or is less than the target pressure. ### Claim 18 (depends on 17) The system of claim 17, wherein said controller is further adapted to (a) decrease the negative pressure when the target pressure has reached the maximum target pressure and (b) increase the negative pressure when the target pressure has reached the minimum target pressure, whereby the negative pressure oscillates over time between the maximum target pressure and the minimum target pressure. ### Claim 19 A system for stimulating healing of tissue at a wound site comprising: a porous pad; a pump for applying negative pressure to the wound site through said porous pad that varies over time; and a controller regulating the negative pressure applied by the pump by changing the negative pressure in predefined pressure intervals, the controller comparing the negative pressure to a target pressure and decrementing the target pressure toward a minimum target pressure when the negative pressure has fallen to or is less than the target pressure. ### Claim 20 (depends on 19) The system of claim 19, further comprising a drape for covering the porous pad when the porous pad is positioned at the wound site. ### Claim 21 (depends on 20) The system of claim 20, wherein the drape forms an airtight seal around the porous pad. ### Claim 22 (depends on 19) The system of claim 19, further comprising means for deactivating a backlight to a display after a predetermined time interval. ### Claim 23 (depends on 19) The system of claim 19 further comprising a clamp for securing said system to a pole. ### Claim 24 (depends on 19) The system of claim 19, wherein said porous pad is comprised of a polyvinyl alcohol foam. ### Claim 25 (depends on 19) The system of claim 19 further comprising a control system to determine an optimum drive frequency for variably driving the pump in order to maximize pump flow. ### Claim 26 (depends on 25) The system of claim 25, further comprising a pressure sensor for measuring the pressure. ### Claim 27 (depends on 26) The system of claim 26, further comprising a variable frequency drive circuit for driving said pump at said optimum drive frequency. ### Claim 28 (depends on 19) The system of claim 19, wherein said controller is further adapted to compare the target pressure to the minimum target pressure and begin increasing the negative pressure when the target pressure has reached the minimum target pressure. ### Claim 29 (depends on 28) The system of claim 28, wherein said controller is further adapted to increment the target pressure toward a maximum target pressure when the negative pressure has risen to or is greater than the target pressure. ### Claim 30 (depends on 29) The system of claim 29, wherein said controller is further adapted to decrease the negative pressure when the target pressure has reached the maximum target pressure, whereby the negative pressure oscillates over time between the maximum target pressure and the minimum target pressure.