# US 11,433,210 B2 · Gases mixing and measuring for a medical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,433,210 B2 - Document ID: US11433210B2 - Status: Granted - Kind: B2 - Application number: 15/313,836 - Filed: 2015-05-27 - Published: 2017-07-13 - Granted: 2022-09-06 - Earliest claimed: 2014-05-27 - Assignees: Fisher & Paykel Healthcare Limited - Applicants: Fisher & Paykel Healthcare Limited - Inventors: Andre Van Schalkwyk; Anthony James Newland; Rachael Glaves; Wenjie Robin Liang; Winnie Yong Jiang-Foo - Web page: https://patentgrep.com/patent/US11433210B2 ## CPC - A61M 16/1005: {with O2 features or with parameter measurement} - A61M 16/0066: {Blowers or centrifugal pumps} - A61M 16/024: {including calculation means, e.g. using a processor} - A61M 16/12: by mixing different gases - A61M 16/122: {with dilution} - A61M 16/16: Devices to humidify the respiration air {(A61M16/1045 takes precedence)} - G01F 1/66: by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters - G01F 1/662: {Constructional details} - G01F 25/10: of flowmeters - G01F 25/15: {specially adapted for gas meters (G01F25/11 - G01F25/14, G01F25/17 take precedence)} - G01H 5/00: Measuring propagation velocity of ultrasonic, sonic or infrasonic waves {, e.g. of pressure waves} - G01N 29/024: by measuring propagation velocity or propagation time of acoustic waves - G01N 29/036: by measuring frequency or resonance of acoustic waves - G01P 5/245: {by measuring transit time of acoustical waves (measuring propagation velocity of acoustical waves per se G01H5/00)} - A61M 16/161: {with means for measuring the humidity} - A61M 2016/1025: {the O2 concentration} - A61M 2202/0208: Oxygen - A61M 2205/3334: Measuring or controlling the flow rate - A61M 2205/3368: Temperature - A61M 2205/3375: Acoustical, e.g. ultrasonic, measuring means - A61M 2205/50: with microprocessors or computers - A61M 2206/14: Static flow deviators in tubes disturbing laminar flow in tubes, e.g. archimedes screws - A61M 2206/20: having means for promoting or enhancing the flow, actively or passively - G01N 2291/0212: Binary gases - G01N 2291/0215: Mixtures of three or more gases, e.g. air - G01N 2291/02809: Concentration of a compound, e.g. measured by a surface mass change - G01N 2291/02836: Flow rate, liquid level - 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)} - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract A gases humidification system includes a measuring chamber and a mixing chamber. The mixing chamber has one or more mixing elements that improve a mixing of gases before reaching the measuring chamber. Ultrasonic sensing is used to measure gases properties or characteristics within the measuring chamber. A baffle or a vane may be used to control and direct the gases flow through the mixing chamber as the gases flow moves into the measuring chamber. ## Claims ### Claim 1 A gases measurement apparatus comprising: a gases measuring chamber comprising a gases flow path from a first end of the gases measuring chamber to a second end of the gases measuring chamber, wherein a downstream direction is defined along the gases flow path from the first end to the second end and an upstream direction is defined along the gases flow path from the second end to the first end; an upstream gases flow path configured to connect a gases source to the gases measuring chamber, the upstream gases flow path comprising a gases mixing chamber coaxial with the gases measuring chamber, and further comprising a gases flow guide configured to improve laminar flow of the gases prior to entering the gases flow path of the gases measuring chamber, the gases flow guide located downstream of the gases source; a controller; the gases measuring chamber further comprising: a first ultrasonic sensor positioned at the first end of the gases measuring chamber, the first ultrasonic sensor configured to transmit a downstream acoustic pulse train in a first measurement phase, to detect an upstream acoustic pulse train in a second measurement phase, and to send a signal to the controller; a second ultrasonic sensor positioned at the second end of the gases measuring chamber, the second ultrasonic sensor configured to transmit the upstream acoustic pulse train in the second measurement phase, to detect the downstream acoustic pulse train in the first measurement phase, and to send a signal to the controller; a first temperature sensor at an inlet of the gases measuring chamber, the first temperature sensor configured to measure temperature of the gases flowing in the gases flow path at the inlet; a second temperature sensor at an outlet of the gases measuring chamber, the second temperature sensor configured to measure temperature of the gases flowing in the gases flow path at the outlet; and at least one pressure sensor configured to measure a pressure of the gases flowing in the gases flow path; and wherein the controller is configured to determine a characteristic of the gases based at least in part on the signal received from the first ultrasonic sensor, the signal received from the second ultrasonic sensor, and signals received from the first and second temperature sensors. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the gases comprise gases from two sources of gases. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the two sources of gases comprise a concentrated source of oxygen and room air. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the downstream acoustic pulse train or the upstream acoustic pulse train comprises a plurality of acoustic pulses. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the downstream acoustic pulse train or the upstream acoustic pulse train comprises a single acoustic pulse. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the characteristic of the gases comprises at least one of gases concentration, flow rate, or velocity. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the first and second ultrasonic sensors are configured to be excited at a natural resonant frequency. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the controller is configured to determine a downstream time of flight for the downstream acoustic pulse train, the controller is configured to determine an upstream time of flight for the upstream acoustic pulse train, and the controller is configured to determine the characteristic of the gases based at least in part on the downstream time of flight and the upstream time of flight. ### Claim 9 (depends on 1) The apparatus of claim 1, further comprising heat transfer features that increase heat transfer from the gases flowing through the measurement apparatus to a housing of the measurement apparatus and reduce heat transfer from the gases to an environment. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the heat transfer features are tracks formed on a surface of a printed circuit board or a moulded component, or a conductive path assembled into the measurement apparatus. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the gases measuring chamber is a part of a blower assembly of a gases delivery apparatus, the blower assembly comprising a blower, wherein the blower is the gases source. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein the gases flow guide comprises a vane. ### Claim 13 (depends on 1) The apparatus of claim 1, further comprising a first humidity sensor located upstream of the gases source. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the gases measuring chamber further comprises a second humidity sensor configured to measure humidity of gases flowing in the gases flow path. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the controller is further configured to determine the characteristic of the gases based at least in part on signals received from the first and second humidity sensors. ### Claim 16 (depends on 1) The apparatus of claim 1, wherein the inlet of the gases measuring chamber comprises an oxygen inlet and an air inlet, the at least one pressure sensor comprising a first pressure sensor at the oxygen inlet and a second pressure sensor at the air inlet. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the at least one pressure sensor further comprises a third pressure sensor at the outlet. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the controller is further configured to determine the characteristic of the gases based at least in part on signals received from the first, second, and third pressure sensors. ### Claim 19 A method for determining a characteristic of gases flowing through an apparatus along a gases flow path from a first end of the apparatus to a second end of the apparatus, the apparatus comprising a first ultrasonic sensor positioned at the first end and a second ultrasonic sensor positioned at the second end, a downstream direction defined along the gases flow path from the first end to the second end and an upstream direction defined along the gases flow path from the second end to the first end, the method comprising: transmitting a downstream acoustic pulse train from the first ultrasonic sensor and detecting the downstream acoustic pulse train at the second ultrasonic sensor; determining a downstream time of flight based at least in part on the downstream acoustic pulse train; transmitting an upstream acoustic pulse train from the second ultrasonic sensor and detecting the upstream acoustic pulse train at the first ultrasonic sensor; determining an upstream time of flight based at least in part on the upstream acoustic pulse train; determining a temperature of the gases flowing along the gases flow path at an inlet of the apparatus using a first temperature sensor; determining a temperature of the gases flowing along the gases flow path at an outlet of the apparatus using a second temperature sensor; determining the characteristic of the gases based at least in part on the downstream time of flight, the upstream time of flight, and the temperature of gases flowing along the gases flow path at the inlet and outlet of the apparatus; and determining a pressure of the gases flowing in the flow path using a pressure sensor, wherein the gases are configured to flow from a portion of the gases flow path upstream of the apparatus, the portion of the gases flow path comprising a gases flow guide configured to improve laminar flow of the gases prior to entering the apparatus, the gases flow guide located downstream of a gases source, wherein the apparatus comprises a single gases measuring chamber defined by a housing of the apparatus, wherein the first and second ultrasonic sensors, the first and second temperature sensors, and the pressure sensor are located at the single gases measuring chamber, and wherein the single gases measuring chamber is coaxial with a gases mixing chamber. ### Claim 20 A gases delivery apparatus comprising: a gases mixing chamber configured to receive gases from a gases source, the gases mixing chamber comprising a gases flow path from a first end of the gases mixing chamber to a second end of the gases mixing chamber and at least one mixing element situated within the gases flow path; a humidification system; and a gases measurement apparatus comprising: a gases measuring chamber configured to receive the gases from the gases mixing chamber, wherein the gases measuring chamber and the gases mixing chamber are coaxial, the gases measuring chamber comprising a gases flow path from a first end of the gases measuring chamber to a second end of the gases measuring chamber, wherein a downstream direction is defined along the gases flow path from the first end to the second end and an upstream direction is defined along the gases flow path from the second end to the first end; a controller; and the gases measuring chamber further comprising: a first ultrasonic sensor positioned at the first end of the gases measuring chamber, the first ultrasonic sensor configured to transmit a downstream acoustic pulse train in a first measurement phase, to detect an upstream acoustic pulse train in a second measurement phase, and to send a signal to the controller; a second ultrasonic sensor positioned at the second end of the gases measuring chamber, the second ultrasonic sensor configured to transmit the upstream acoustic pulse train in the second measurement phase, to detect the downstream acoustic pulse train in the first measurement phase, and to send a signal to the controller; a first temperature sensor at an inlet of the gases measuring chamber, the first temperature sensor configured to measure temperature of the gases flowing in the gases flow path at the inlet; a second temperature sensor at an outlet of the gases measuring chamber, the second temperature sensor configured to measure temperature of the gases flowing in the gases flow path at the outlet; and at least one pressure sensor configured to measure a pressure of the gases flowing in the gases flow path; wherein the controller is configured to determine a characteristic of the gases based at least in part on a signal received from the first ultrasonic sensor, a signal received from the second ultrasonic sensor, a signal from the first temperature sensor, and a signal from the second temperature sensor, wherein the at least one mixing element is configured to mix gases in the gases flow path of the gases mixing chamber and to improve laminar flow of the gases before the gases enter the gases flow path of the gases measuring chamber, the at least one mixing element located downstream of the gases source. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the gases measurement apparatus is a separate component that is selectively removable from the gases delivery apparatus and is configured to be located between the gases source and the humidification system. ### Claim 22 (depends on 20) The apparatus of claim 20, further comprising a blower assembly that includes a blower, wherein the blower is the gases source and the gases measurement apparatus is a part of the blower assembly. ### Claim 23 (depends on 22) The apparatus of claim 22, further comprising a humidity sensor is at an intake of the blower. ### Claim 24 (depends on 20) The apparatus of claim 20, further comprising a valve to regulate the contribution of at least one of the gases to the gases mixture. ### Claim 25 (depends on 20) The apparatus of claim 20, wherein the controller is adapted to control a blower or a valve in response to the determined characteristic.