# US 10,307,559 B2 · Humidifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,307,559 B2 - Document ID: US10307559B2 - Status: Granted - Kind: B2 - Application number: 13/980,196 - Filed: 2012-01-24 - Published: 2013-10-31 - Granted: 2019-06-04 - Earliest claimed: 2011-01-24 - Assignees: ResMed Limited - Applicants: Roger Mervyn Lloyd Foote; Ronald James Huby; Andrew Roderick Bath - Inventors: Roger Mervyn Lloyd Foote; Ronald James Huby; Andrew Roderick Bath - Web page: https://patentgrep.com/patent/US10307559B2 ## CPC - A61M 16/16: Devices to humidify the respiration air {(A61M16/1045 takes precedence)} - A61L 9/00: Disinfection, sterilisation or deodorisation of air (body deodorants A61Q15/00; purifying air by respirators A62B, A62D9/00; separating dispersed particles from gases or vapours B01D45/00 - B01D51/00, B03C3/00; chemical or biological purification of waste gases B01D53/34; production of ozone C01B13/10; air-conditioning systems incorporating sterilisation F24F3/16, F24F8/20) - A61M 16/024: {including calculation means, e.g. using a processor} - A61M 16/0833: {T- or Y-type connectors, e.g. Y-piece} - A61M 16/1075: {by influencing the temperature (A61M16/1045 takes precedence)} - A61M 16/109: {the humidifying liquid or the beneficial agent} - A61M 16/1095: {in the connecting tubes} - A61M 16/142: {with semi-permeable walls separating the liquid from the respiratory gas} - A61M 16/161: {with means for measuring the humidity} - H05B 3/42: non-flexible - A61M 16/162: {Water-reservoir filling system, e.g. automatic} - A61M 2016/0024: {with an on-off output signal, e.g. from a switch} - A61M 2016/0027: {pressure meter} - A61M 2016/0036: {in the breathing tube and used in both inspiratory and expiratory phase} - A61M 2205/3368: Temperature - A61M 2205/3653: by Joule effect, i.e. electric resistance - A61M 2205/50: with microprocessors or computers - A61M 2205/702: automatically during use - F04C 2270/041: Controlled or regulated - H05B 2203/021: Heaters specially adapted for heating liquids - H05B 2203/022: Heaters specially adapted for heating gaseous material - 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)} - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS ## Abstract A humidifier includes a heating element including a porous structure of electrically resistive and thermally conductive material configured to substantially vaporise liquid that is passed through the porous structure. The porous structure has a liquid inlet and a vapour outlet. The humidifier further includes an outer housing surrounding at least a portion of the porous structure for containing the liquid and vapour within the porous structure. The porous structure includes a first electrical connector and a second electrical connector, the first and second connectors being configured for receiving electrical power and applying a voltage across the porous structure to generate heat. ## Claims ### Claim 1 A humidifier for increasing a humidity of a supply of air, the humidifier comprising: an enclosed gas flow path for the supply of air; a heating element including a porous structure of electrically resistive and thermally conductive material configured to substantially vaporise liquid that is passed through the porous structure, the porous structure having a liquid inlet and a vapour outlet; and an outer housing surrounding at least a portion of the porous structure for containing the liquid and vapour within the porous structure, an enclosure of the enclosed gas flow path surrounding the outer housing so that the enclosed gas flow path is between the outer housing and the enclosure of the enclosed gas flow path and the heating element and the outer housing are immersed within the supply of air in the enclosed gas flow path; wherein the porous structure includes a first electrical connector and a second electrical connector, the first electrical connector and the second electrical connector being configured for receiving electrical power and applying a voltage across the porous structure so that the porous structure generates heat; and the vapour outlet is arranged to expel heated vapour for delivery into the enclosed gas flow path to increase the humidity of the supply of air. ### Claim 2 (depends on 1) The humidifier according to claim 1, wherein the first electrical connector is located at or near the liquid inlet and the second electrical connector is located at or near the vapour outlet. ### Claim 3 (depends on 1) The humidifier according to claim 1, further comprising a connector fitting configured to deliver liquid from a supply of liquid to the liquid inlet. ### Claim 4 (depends on 3) The humidifier according to claim 3, wherein the connector fitting comprises a connection spigot, and the humidifier further comprises a sealing tube configured to form a sealed connection between the connection spigot and the outer housing. ### Claim 5 (depends on 3) The humidifier according to claim 3, wherein the connector fitting comprises a liquid inlet spigot configured to receive liquid from the supply of liquid, and wherein the humidifier further comprises a liquid supply tube connected to the liquid inlet spigot. ### Claim 6 (depends on 1) The humidifier according to claim 1, wherein the porous structure and the outer housing are each elongate, and the vapour outlet of the porous structure extends beyond the outer housing and is configured to be exposed to a flow of breathable gas to be humidified through an open end of the outer housing. ### Claim 7 (depends on 1) The humidifier according to claim 1, wherein the porous structure has a cylindrical shape or a tapered shape. ### Claim 8 (depends on 1) The humidifier according to claim 1, wherein the porous structure is formed of an open pore metal foam and the open pore metal foam comprises a chromium alloy, the chromium alloy comprising MCrAlX, where M is one or more of Nickel (Ni), Cobalt (Co) or Iron (Fe) contributing at least 50% by weight, Chromium (Cr) contributing between 8% and 35% by weight, Aluminium (Al) contributing greater than 0% but less than 8% by weight, and X contributing less than 25% by weight, with X including zero or more other elements, including Molybdenum (Mo), Rhenium (Re), Ruthenium (Ru), Titanium (Ti), Tantalum (Ta), Vanadium (V), Tungsten (W), Niobium (Nb), Zirconium (Zr), Boron (B), Carbon (C), Silicon (Si), Yttrium (Y) and Hafnium (Hf). ### Claim 9 (depends on 8) The humidifier according to claim 8, wherein the open pore metal foam is formed by pyrolysis and/or metallisation of a polymer foam. ### Claim 10 (depends on 1) The humidifier according to claim 1, wherein the porous structure comprises a body of carbon fibres bundled in a form of tow-, twist-, knit-, braid-, felt-, woven fabric- or tape- structures, the body of carbon fibres having precursors of Poly Acyrlic Nitrile, rayon and/or pitch. ### Claim 11 (depends on 1) The humidifier according to claim 1, wherein the porous structure is formed of ceramic material. ### Claim 12 (depends on 1) The humidifier according to claim 1, wherein the porous structure has a substantially uniform porosity or has a porosity that varies along its length and/or diameter. ### Claim 13 (depends on 1) The humidifier according to claim 1, wherein the outer housing is formed of electrically and thermally insulating material. ### Claim 14 (depends on 13) The humidifier according to claim 13, wherein the outer housing is formed of alumina, fused quartz, or a polymer. ### Claim 15 (depends on 1) The humidifier according to claim 1, wherein the humidifier is adapted for mounting within an air delivery tube, and further comprises a mounting structure for mounting the humidifier within the air delivery tube, the mounting structure being adapted to space the humidifier from an internal wall of the air delivery tube. ### Claim 16 (depends on 15) The humidifier according to claim 15, wherein the mounting structure includes a coil structure adapted to mount the humidifier substantially parallel to a longitudinal axis of the air delivery tube, the coil structure comprising a resistance heater configured to heat air flowing through the air delivery tube. ### Claim 17 (depends on 1) The humidifier according to claim 1, further comprising a power supply configured to supply the voltage across the porous structure, and a controller configured to control the power supply such that vapour is delivered only during a portion of a phase of a patient's breathing cycle. ### Claim 18 (depends on 1) The humidifier according to claim 1, wherein the heating element is configured so that the liquid flowing through the porous structure is heated predominantly by the heat generated by the porous structure. ### Claim 19 (depends on 1) The humidifier according to claim 1, wherein the heating element is oriented so that the liquid passes through the porous structure in a direction substantially parallel to the flow of air through the gas flow path. ### Claim 20 (depends on 1) The humidifier according to claim 1, wherein the heating element and the outer housing are arranged so that the liquid is centrally dispersed into the heating element and the vapor is outwardly dispersed into the gas flow path. ### Claim 21 (depends on 1) A respiratory apparatus for delivering a flow of breathable gas to a patient, comprising: a flow generator configured to generate the flow of breathable gas; a liquid supply; and the humidifier according to claim 1 configured to receive a volume of liquid from the liquid supply, vapourize the volume of liquid and deliver the vapour into the flow of breathable gas to create a humidified flow of breathable gas. ### Claim 22 (depends on 21) The respiratory apparatus according to claim 21, wherein the liquid supply comprises a micro-pump or a piezo-electric pump. ### Claim 23 A respiratory device configured to deliver breathable gas to a patient, the respiratory device comprising: an air delivery tube with a longitudinal axis; and an air heater coil adapted to heat an airflow within the air delivery tube, the air heater coil comprising a plurality of loops or petals, each loop or petal arranged to overlap an adjacent loop or petal in a direction along the air delivery tube longitudinal axis to form a rosette configuration adapted to cover substantially all or most of a cross-sectional area of an air flow path within the air delivery tube. ### Claim 24 (depends on 23) The respiratory device according to claim 23 further comprising: a flow generator configured to pressurize a flow of breathable gas, the flow generator being in pneumatic communication with the air delivery tube; a humidifier configured to humidify the pressurized breathable gas; and a patient interface connected to the air delivery tube. ### Claim 25 (depends on 23) The respiratory device according to claim 23, wherein the plurality of loops or petals are formed of resistive wire. ### Claim 26 (depends on 23) The respiratory device of claim 23, wherein at least some of the plurality of loops or petals extend radially from the air delivery tube longitudinal axis.