Mid-Wave Infrared Camera for Non-Contact CO2 Breath Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current respiratory monitoring methods are invasive and interfere with patient convalescence, making it difficult to accurately assess carbon dioxide concentration and respiration rate, as patients become aware of being monitored and alter their breathing patterns.
Innovation Solution
A non-contact, minimally invasive system using a mid-wave infrared camera with a narrow band-pass filter to capture images of exhaled breath, processing pixel intensity values with a calibration curve to determine CO2 concentration and respiration rate, allowing for reliable assessment without patient participation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If invasive monitoring methods (wires and electrodes) are used to monitor respiratory function, then measurement precision is improved, but patient comfort and natural breathing behavior deteriorate due to physical contact and awareness of monitoring
Solution Approach 1:
The patent replaces mechanical invasive monitoring systems (wires and electrodes that physically contact the patient) with an optical non-contact system using infrared imaging. The system captures images of the patient's face and analyzes breath condensations or facial movements through optical detection, eliminating physical contact while maintaining monitoring capability and preserving natural breathing behavior.
Solution Approach 2:
The patent introduces an intermediary medium (infrared light or optical field) to transmit respiratory information without direct contact. Instead of electrodes directly contacting the skin, the system uses infrared images as an intermediary carrier to detect respiratory parameters through breath condensations or facial changes, enabling remote monitoring.
2Object-affected harmful factors
If non-contact monitoring methods are used to avoid patient interference, then patient comfort is improved, but measurement precision may deteriorate due to lack of direct contact with respiratory gases
Solution Approach 1:
The patent changes the detection parameter from direct gas sampling to optical detection of breath condensations or facial thermal patterns. By detecting the condensation of breath or temperature changes on the face caused by exhaled CO2-rich air, the system maintains non-contact monitoring while achieving sufficient measurement precision through these alternative physical parameters.
Solution Approach 2:
The patent creates an optical copy or image of the respiratory process rather than directly sampling the gas. By capturing infrared images of the breath condensations or facial movements caused by respiration, the system creates a visual representation that can be analyzed to derive CO2 concentration and respiratory rate without direct contact with the exhaled gases.
3Reliability
If invasive monitoring apparatus are placed on the patient, then reliable respiratory data can be obtained, but device complexity and physical burden increase
Solution Approach 1:
The patent extracts the monitoring function from the patient's body by removing invasive apparatus. Instead of having wires and electrodes attached to the patient, the system extracts respiratory information remotely through optical detection of breath condensations or facial patterns, simplifying the device profile to a non-invasive imaging system.
Solution Approach 2:
The patent employs a multi-functional optical system that can detect multiple respiratory parameters simultaneously through a single imaging device. The same infrared camera and image processing system can measure CO2 concentration, respiration rate, and breath pattern characteristics, eliminating the need for multiple separate invasive sensors and reducing overall system complexity.
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
Enables accurate, non-invasive monitoring of carbon dioxide concentration and respiration rate, reducing patient awareness and interference, thereby providing reliable respiratory function assessment.
Implementation Method 1
a mid-wave infrared camera to capture images of a patient's exhalation airstream utilizing a narrow band-pass filter set at an IR absorption wavelength of CO2
Data Source
AI summary
What is disclosed is a system and method for image-based determination of carbon dioxide (CO2) concentration in exhaled breath. In one embodiment, an image of the exhaled airstream of a subject of interest is received. The image is captured using a mid-wave infrared camera system having an optical filter tuned to the infrared absorption band of CO2. The image is preprocessed to isolate a region of pixels containing the exhaled airstream and intensity values of pixels in the identified region are normalized by a value of a known radiance such as that of the subject's nose or face. The image is analyzed to determine CO2 concentration levels of the exhaled airstream using a calibration curve which relates pixel intensity to CO2 concentrations. The calibration curve is derived using a physics-based parameterized model. The CO2 concentration levels are determined and communicated to a computer workstation. Various embodiments are disclosed.