Curved Sensing Chamber Layout for Stable Respiratory Flow Measurement
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Solution Overview
Problem
Current flow therapy apparatuses face challenges in accurately measuring gas flow rates and oxygen concentrations due to unwanted vorticity in the flow path, which can lead to anomalies in measurement, and require improved sensing systems for precise control and calibration.
Innovation Solution
A flow therapy apparatus with a continuously curved flow path and ultrasonic transducers positioned at both ends, along with a heated temperature sensing element, to measure flow rate and oxygen concentration, and a calibration system that adjusts parameters based on sensor readings to prevent vorticity and ensure accurate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional flow path design is used, then device complexity is reduced, but measurement precision deteriorates due to vorticity and flow anomalies
Solution Approach 1:
The flow path is designed with continuous curvature instead of sharp angles, creating a smooth transition that eliminates vorticity and flow separation. This curved geometry ensures laminar flow conditions throughout the measurement section, directly improving measurement precision while the overall structure remains relatively simple.
Solution Approach 2:
The flow path cross-sectional area is varied along its length, with a smaller middle cross-sectional area between the first and second ends. This parameter change optimizes flow velocity distribution and prevents stagnation zones, thereby improving measurement accuracy without significantly increasing device complexity.
2Measurement precision
If multiple sensors are added to measure flow rate and oxygen concentration, then measurement precision improves, but device complexity increases
Solution Approach 1:
Multiple sensing functions (flow rate measurement and oxygen concentration measurement) are integrated into a single flow path structure. The sensors are positioned within the same continuously curved flow path, allowing simultaneous measurement of multiple gas properties without requiring separate measurement chambers or complex routing.
Solution Approach 2:
The flow path structure serves multiple functions: it guides gas flow, eliminates vorticity, provides a measurement environment for flow rate sensors, and accommodates oxygen concentration sensors. This multi-functionality reduces the need for additional separate components, thereby improving measurement precision without proportionally increasing device complexity.
3Measurement precision
If flow path has sharp angles, then device complexity is reduced, but measurement precision deteriorates due to vorticity
Solution Approach 1:
All angles in the flow path are replaced with continuous curves. The flow path transitions smoothly from the first end through the middle section to the second end, eliminating any sharp corners that would generate vorticity. This geometric modification ensures uniform flow distribution across the measurement section, directly improving measurement precision.
Solution Approach 2:
The cross-sectional area of the flow path is deliberately varied, with the middle cross-sectional area being smaller than at the ends. This parameter variation creates optimal flow velocity profiles that prevent flow separation and reduce vorticity, thereby improving measurement accuracy while maintaining a relatively simple overall geometry.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides precise measurement of gas flow rates and oxygen concentrations, reduces anomalies caused by vorticity, and enables effective calibration for reliable operation, enhancing the accuracy and reliability of the flow therapy apparatus.
Implementation Method 1
The one or more sensors can comprise two or more ultrasonic transducers. The ultrasonic transducers can be configured to determine a flow rate.
Implementation Method 2
The ultrasonic transducers can be configured to determine a gas concentration.
Implementation Method 3
The one or more sensors can comprise a heated temperature sensing element configured to measure gases flow rate.
Implementation Method 4
The flow path can be configured to be continuously curved such that there are no significant angles. The flow path can be further configured to have a total flow distance between 50 mm and 150 mm.
Data Source
AI summary
A respiratory flow therapy apparatus including a sensing chamber which measures a flow of gases provided to a patient. The sensing chamber can be located after a blower and/or mixer. The sensing chamber can include an ultrasonic transducer, a temperature sensor, a heated temperature sensing element, and/or a gas concentration sensor. A flow path of gases used in conjunction with the sensor system prevents unwanted vorticity in the flow of gases that can create anomalies in measuring flow.