# US 7,607,435 B2 · Gas or liquid flow sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,435 B2 - Document ID: US7607435B2 - Status: Granted - Kind: B2 - Application number: 10/763,040 - Filed: 2004-01-21 - Published: 2005-07-21 - Granted: 2009-10-27 - Earliest claimed: 2004-01-21 - Assignees: Battelle Memorial Institute - Inventors: Brian A. Lipp - Web page: https://patentgrep.com/patent/US7607435B2 ## CPC - G01F 1/28: by drag-force, e.g. vane type or impact flowmeter - A61M 15/0065: {Inhalators with dosage or measuring devices (A61M15/0028 takes precedence; dosage devices incorporated in aerosol cans B65D83/52)} - A61M 15/02: with activated or ionised {fluids, e.g. electrohydrodynamic [EHD] or electrostatic devices}; Ozone-inhalators {with radioactive tagged particles} - A61M 2016/0021: {with a proportional output signal, e.g. from a thermistor} - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - 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 An air flow sensor comprises a flexible resistive element permanently affixed to a flexible substrate. The air flow sensor is positioned in an inlet for airway to be monitored such that the sensor covers the inlet at all times other than during inhalation. When a vacuum is applied to the airway, a resulting drop in air pressure within the airway causes air to flow through the inlet and airway, causing the sensor's substrate to flex. Flexure of the substrate also causes a resistive element to flex, resulting in a change in the electrical resistance of the resistive element, such as an increase in resistance. Flexure of the sensor is enhanced by flexible leads, which serve as a hinge point. An air shield may be positioned around the periphery of the air flow sensor to channel and restrict the movement of air flowing through the air inlet, thereby enhancing movement of the sensor. ## Claims ### Claim 1 A gas or liquid flow sensor, comprising: (i) a non-conductive flexible substrate; (ii) a flexible transducer formed on the substrate, wherein said transducer consisting of a resistive ink or resistive elastomer; (iii) at least one flexible lead connecting the substrate to a mounting portion of the sensor; and (iv) first and second electrical contacts in electrical communication with the transducer; wherein the substrate and the flexible lead are displaceable in the presence of a stream of moving gas or liquid causing flexure of the transducer and changing an electrical value of the transducer and wherein said sensor is disposed in a pulmonary medication delivery device. ### Claim 2 (depends on 1) The sensor according to claim 1 wherein a protective covering covers at least a portion of the flexible transducer. ### Claim 3 (depends on 1) The sensor according to claim 1 wherein said gas is air. ### Claim 4 (depends on 1) The sensor according to according to claim 1 wherein at least one of the first and second electrical contacts are affixed to the mounting portion. ### Claim 5 (depends on 1) The sensor according to according to claim 1 wherein the electrical value of the flexible transducer changes relative to the flexure of at least the flexible substrate. ### Claim 6 (depends on 1) The sensor according to according to claim 1 wherein the flexible substrate substantially returns to an original orientation when a bending force impinging the flexible substrate is removed. ### Claim 7 (depends on 1) The sensor according to according to claim 1 wherein the sensor forms at least a portion of a one-way valve in a stream of moving gas. ### Claim 8 (depends on 1) The sensor according to claim 1 wherein said resistive transducer is a resistive ink. ### Claim 9 (depends on 8) The sensor according to claim 8 wherein said resistive ink comprises conductive carbon particles in a binder. ### Claim 10 (depends on 8) The sensor according to claim 8 wherein said non-conductive flexible substrate is made of a material selected from the group consisting of a polyester, polyimide and a fluoropolymer. ### Claim 11 (depends on 10) The sensor according to according to claim 10 wherein said non-conductive flexible substrate is made of polyimide. ### Claim 12 (depends on 1) The sensor according to claim 1 wherein the flexible transducer includes a portion formed on the flexible lead. ### Claim 13 (depends on 1) The sensor according to claim 1 wherein the flexible substrate and the flexible lead are integral to one another. ### Claim 14 (depends on 1) The sensor according to claim 1 wherein the electrical value of the flexible transducer changes relative to the flexure of the flexible substrate and the flexible lead. ### Claim 15 (depends on 1) The sensor according to claim 1 wherein said pulmonary medication delivery device is an electrohydrodynamic aerosolization device. ### Claim 16 (depends on 15) The sensor according to claim 15 wherein said electrohydrodynamic aerosolization device is a hand-held device. ### Claim 17 (depends on 1) The sensor according to claim 1 wherein the first and second electrical contacts are affixed to the first side of the flexible substrate; wherein a third electrical contact and a fourth electrical contact are affixed to the second side of the flexible substrate; and wherein said third electrical contact is in electrical communication with said first electrical contact and said fourth electrical contact is in electrical communication with said second electrical contact. ### Claim 18 (depends on 1) The sensor according to claim 1 wherein the body of the sensor is generally rectangular, circular, triangular, elliptical, polygonal, trapezoidal, U-shaped, and parallelogram in shape. ### Claim 19 (depends on 1) The sensor according to claim 1 wherein the body of the sensor is generally rectangular in shape.