CN-114796785-B - Flow path sensing for flow therapy devices

Abstract

The present invention provides flow path sensing for a flow therapy device that includes a sensing chamber that measures the flow of gas provided to a patient. The sensing chamber may be located after the blower and/or mixer. The sensing chamber may include an ultrasonic transducer, a temperature sensor, a heated temperature sensing element, and/or a gas concentration sensor. The gas flow path used in conjunction with the sensor system prevents the creation of undesirable vortices in the gas flow that can create anomalies in the flow measurement.

Inventors

• Russell William Burgers
• Jess edward donnelly
• Dean Anthony Buck
• PHILIP JOHN DICKINSON
• Andrei Van Schalkwick
• Joel Michael Lawson

Assignees

• 费雪派克医疗保健有限公司
• 费雪派克医疗保健有限公司

Dates

Publication Date

20260421

Application Date

20161202

Priority Date

20161202

Claims (20)

1. 1. A flow therapy device, comprising: A main housing including a flow generator to generate an airflow for delivery to a patient; A humidifier to humidify and/or heat the generated airflow; A sensing chamber comprising a flow path configured to receive a generated gas flow and a plurality of sensors configured to measure a property of the gas flow flowing through the flow path, wherein the plurality of sensors comprises: A first ultrasonic transducer positioned at a downstream portion of the flow path, A second ultrasonic transducer positioned at an upstream portion of the flow path, A heating type temperature sensing element configured to determine a gas flow rate of the gas flow flowing through the flow path, A temperature sensor configured to determine a temperature of the gas flow flowing through the flow path, A humidity sensor configured to determine a humidity of the airflow flowing through the flow path, A first pressure sensor configured to determine an absolute pressure within the flow path, an A second pressure sensor disposed within the main housing and configured to be exposed to an ambient temperature, the second pressure sensor configured to determine an estimate of the ambient pressure, and A controller configured to receive the outputs from the plurality of sensors and to operate the flow generator and/or the humidifier based on the outputs from the plurality of sensors, Wherein the sensing chamber further comprises a sensing circuit board, wherein a first portion of the sensing circuit board is positioned at least partially within the flow path of the sensing chamber, and wherein the sensing circuit board comprises at least a second portion of the sensing circuit board positioned outside the flow path, Wherein the plurality of sensors of the sensing chamber are configured to be placed within the first portion of the sensing circuit board, and Wherein the first and second ultrasonic transducers are positioned on opposite ends of the sensing circuit board.
2. 2. The flow therapy apparatus of claim 1, wherein the sensing chamber is positioned downstream of the flow generator.
3. 3. The flow therapy device of claim 1 or 2, wherein the flow therapy device further comprises an inlet port that receives gas from at least two different gas sources, the flow generator receiving gas from the inlet port to generate the gas flow.
4. 4. A flow therapy apparatus according to claim 3, wherein the flow generator is configured to mix gases from the gases of the at least two different gas sources to produce a mixed gas.
5. 5. The flow therapy device of claim 1, wherein the first and second ultrasonic transducers are positioned such that a space between the first and second ultrasonic transducers at least partially coincides with the flow path of the sensing chamber.
6. 6. The flow therapy device of claim 1 or 2, wherein the first and second ultrasound transducers are configured to determine a gas concentration of the gas flow flowing through the flow path.
7. 7. The flow therapy device of claim 1 or 2, wherein the first and second ultrasound transducers are configured to determine a flow rate of the airflow through the flow path.
8. 8. The flow therapy device of claim 1, wherein the sensing circuit board comprises a cutout around the heated temperature sensing element.
9. 9. The flow therapy device of claim 1 or 2, wherein the temperature sensor is a thermistor.
10. 10. The flow therapy device of claim 1 or 2, wherein the humidity sensor and the temperature sensor are combined humidity and temperature sensors configured to monitor a dew point of the airflow.
11. 11. The flow therapy device of claim 1 or 2, wherein the plurality of sensors further comprises a temperature and humidity sensor configured to monitor a dew point of the airflow.
12. 12. The flow therapy device of claim 11, wherein the temperature sensor is configured to be closer to an inlet of the flow path of the sensing chamber and the temperature and humidity sensor is closer to an outlet of the flow path of the sensing chamber.
13. 13. The flow therapy device of claim 11, wherein the sensing circuit board includes a curved finger to position the temperature sensor and the humidity and temperature sensor closer to a center of the flow path to improve accuracy of readings.
14. 14. The flow therapy device of claim 11, wherein the temperature sensor and the temperature and humidity sensor are each configured to be placed in close proximity to one of the first and second ultrasound transducers.
15. 15. The flow therapy device of claim 1, wherein the sensing circuit board includes traces arranged to reduce thermal conduction between a chamber wall and the sensing circuit board.
16. 16. The flow therapy device of claim 1, wherein the second portion of the sensing circuit board includes circuitry for the first and second ultrasound transducers.
17. 17. The flow therapy device of claim 1, wherein the sensing chamber includes a seal separating the first portion of the sensing circuit board from the second portion of the sensing circuit board.
18. 18. The flow therapy device of claim 1 or 2, wherein the plurality of sensors further comprises a gas concentration sensor configured to determine an oxygen concentration or other gas concentration of the gas in the flow path.
19. 19. The flow therapy device of claim 17, wherein the seal is configured to enclose a high pressure region of the flow path, wherein a sensor on the first portion of the sensing circuit board measures a characteristic of the gas flow, the seal preventing gas from escaping from the high pressure region of the flow path and moving toward electronics of the flow therapy device, and preventing water from contacting the second portion of the sensing circuit board.
20. 20. The flow therapy device of claim 1 or 2, wherein the controller is configured to use the output from the heated temperature sensing element and the output from the first and second ultrasonic transducers to provide redundancy for flow measurements, the redundancy including rapid flow measurements of the first and second ultrasonic transducers at low flow rates, and accurate flow measurements by the heated temperature sensing element at low flow rates.

Description

Flow path sensing for flow therapy devices Description of the divisional application The application is a divisional application of Chinese patent application with the application date of 2016, 12 and 2, the application number of 201680079350.9 and the name of flow path sensing of flow treatment equipment. Technical Field The present disclosure relates to methods and systems for flow path sensing in a flow therapy device for delivering gas to a patient. Background Breathing assistance devices are used in a variety of different environments, such as hospitals, medical facilities, home care, or home environments, to deliver a flow of gas to a user or patient. The breathing assistance apparatus or flow therapy apparatus may include valves for delivering oxygen and gas flow, and/or humidification apparatus for delivering heated and humidified gases. Flow therapy devices may allow for the regulation and control of characteristics of the gas flow, including flow rate, temperature, gas concentration, humidity, pressure, etc. Sensors such as heated temperature sensing elements and/or thermistors are used to measure these properties of the gas. Disclosure of Invention The present disclosure describes a flow therapy device in which the gas flow is measured through at least a portion of a flow path. The portion of the flow path may be configured to continuously curve such that there is no significant angle. The flow path may include an inlet, a horizontal portion, and an outlet, wherein the inlet and the outlet may be positioned in vertically opposite directions, and the horizontal portion is positioned between the inlet and the outlet. The horizontal portion may have a smooth curve along the entire length of the horizontal portion. The flow path may further include one or more sensors positioned within the flow path and configured to measure a flow of gas through the portion of the flow path. The one or more sensors may include one or more of an ultrasonic transducer or a gas concentration sensor. The one or more sensors may be configured to sense a flow rate and/or an oxygen concentration. The one or more sensors may be located in a sensor module. The flow path may be further configured to have a total flow distance between 50mm and 150 mm. The flow path may also be further configured to have an average cross-sectional diameter of between 10mm and 20mm. The flow path may further include a first cross-sectional area at a first end of the flow path, a second cross-sectional area at a second end of the flow path, and an intermediate cross-sectional area between the first end and the second end of the flow path, wherein the intermediate cross-sectional area may be less than the first cross-sectional area, and wherein the intermediate cross-sectional area may be less than the second cross-sectional area. The one or more sensors may be located after the blower. The blower may be a mixer. The one or more sensors may further include a heated temperature sensing element configured to measure a flow rate of the gas, and/or a temperature, humidity, and temperature, and/or a pressure sensor. A gas flow path is also described for preventing unwanted vortices in the gas flow that may create anomalies when measuring flow rates. The flow path may be used with an ultrasonic sensor system. The present disclosure describes a flow therapy device that may include an inlet port that receives gas flows from at least two different gas sources, a blower that receives gas flows from the inlet port, wherein the blower is configured to mix the gas flows from the different gas sources to produce a mixed gas, a gas flow path that receives the mixed gas from the blower and directs the gases through a sensor chamber, and one or more sensors, wherein the sensors are configured to measure one or more properties of the gas flows through the gas flow path. The one or more sensors may be located after the blower. The blower may be a mixer. The one or more sensors may be located in a sensor module. The different gas sources may include oxygen, and the inlet port may include a valve configured to deliver a flow of oxygen to the blower. The valve may comprise a proportional valve. The one or more sensors may include two or more ultrasonic transducers. The one or more sensors may also include a gas concentration sensor. The ultrasonic transducers may be configured to determine a gas concentration. The ultrasonic transducers may be configured to determine a flow rate. The one or more sensors may include a heated temperature sensing element configured to measure a gas flow rate. The present disclosure describes a sensing chamber in a flow therapy device that may include a flow path configured to accommodate a flow of gas, and one or more sensors configured to measure a property of the flow of gas flowing through the flow path, wherein the sensors may include a first ultrasonic transducer positioned at a downstream portion of the flow path and a second ultras