Respiration Sensor Segmented Cavity Thermal Flow Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current apnea sensors are unreliable in measuring breathing gas flow due to sensitivity to motion artifacts, surrounding air disturbances, and false skin contact, and lack disposability, leading to potential cross-contamination and safety issues.
Innovation Solution
A respiration sensor with a housing featuring separate cavities for nasal and oral gas flow, equipped with a thermistor-based breathing detector and an electronic circuit for signal processing, and a hood to prevent ambient airflow interference, ensuring accurate measurement of gas flow and rate while minimizing re-breathing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If thermistors are suspended in open air to measure breathing gas flow, then the measurement can detect thermal flow of breathing gas, but the device becomes very sensitive to surrounding air flowing by, causing signal disturbances and artifacts
Solution Approach 1:
The device divides the measurement function into separate channels: one for nasal breathing detection and one for oral breathing detection. Each channel has its own thermistor and housing cavity, allowing independent measurement of thermal flow from each source without cross-interference. This segmentation enables the system to distinguish between nasal and oral breathing patterns while maintaining sensitivity to thermal flow.
Solution Approach 2:
The housing acts as an intermediary structure that directs and channels the breathing gas flow toward the thermistors. The housing includes specific flow channels and openings that guide the thermal flow from the nose or mouth to the respective thermistor, while blocking irrelevant ambient air flow. This intermediary structure protects the thermistors from direct exposure to surrounding air disturbances.
2Measurement precision
If housing covers thermistors to minimize signal disturbances from flowing surrounding air or skin contact, then signal sensitivity is improved, but the housing forms a continuous cavity between mouth and nose, causing flow disturbances and errors when patient breathes through both
Solution Approach 1:
The housing is segmented into two separate cavities: a first cavity for nasal breathing detection and a second cavity for oral breathing detection. This segmentation allows the system to independently measure thermal flow from each source without creating a continuous cavity that would cause flow disturbances. Each cavity has its own thermistor and flow path, enabling accurate detection of whether the patient is breathing through the nose, mouth, or both simultaneously.
3Ease of manufacture
If reusable devices are used to reduce cost, then economic efficiency is improved, but cleaning practices are not reliable enough to ensure high level of purity, causing cross-contamination risk between patients
Solution Approach 1:
The device is designed as a disposable single-use sensor that is discarded after one patient measurement. This eliminates the need for cleaning and sterilization processes, completely removing the risk of cross-contamination between patients. The disposable nature ensures that each patient receives a sterile measurement device, improving patient safety while the low cost of the simple disposable sensor makes it economically viable.
4Device complexity
If indirect measurements of respiratory muscle movement or chest movement are used, then device complexity is reduced, but the measurements are unreliable since respiratory muscle or chest movement may occur even when patient is suffering from apnea
Solution Approach 1:
The device replaces mechanical measurement systems (resistive belts, piezo-resistive belts measuring chest or abdominal movement) with a thermal flow measurement system. The thermistor directly measures the thermal flow of breathing gas through the nose or mouth, providing a direct indicator of actual breathing activity. This substitution eliminates the indirect nature of mechanical measurements and provides reliable apnea detection based on actual gas flow through the airways.
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 sensor provides reliable, motion-insensitive apnea detection and measurement, reducing false positives and cross-contamination risks, while being cost-effective and disposable for improved patient safety.
Implementation Method 1
Devices based on measuring the thermal flow of breathing gas are less sensitive to motion
Data Source
Figure 1~2
Figure 3~4
AI summary
A sensor for measuring a respiration is disclosed herein. The sensor includes at least one housing (7) having a first cavity (12) with a first port (11) allowing a respiration gas flow, and a second cavity (22) with a second port (21) also allowing a respiration gas flow. The sensor also includes at least one breathing detector (51) for acquiring a signal indicative of the respiration gas flowing through the first cavity and the second cavity. The at least one housing is equipped with at least one additional port (31) for removing the respiration gas flow coming from the first cavity and the second cavity, which additional port being separate from the first port and the second port.