CO2 Sensor for Respiratory Circuit Integrity Detection
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Solution Overview
Problem
Current lung ventilators face challenges in reliably detecting disconnection of the patient interface due to complex algorithms that fail in scenarios with significant leaks or high-resistance tubes, leading to potential harm from loss of breathing support.
Innovation Solution
Incorporating carbon dioxide sensors fluidly coupled to both the inspiratory and expiratory ports to measure exhaled gas and compare the CO2 levels to a threshold, providing an indication of the patient interface's fluid coupling to the patient, and triggering an alarm if the levels remain below the threshold for a specified period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex algorithms based on pressure and flow measurements are used to detect breathing circuit disconnection, then the detection capability is improved, but the system reliability deteriorates in scenarios with significant leaks or high-resistance tubes
Solution Approach 1:
The patent replaces mechanical/physical measurement systems (pressure and flow sensors) with a chemical measurement system (CO2 sensor). The CO2 sensor detects the presence of exhaled carbon dioxide to determine circuit integrity, which is not affected by mechanical issues like tube resistance or circuit leaks that plague pressure and flow-based systems.
Solution Approach 2:
The patent changes the measurement parameter from physical quantities (pressure, flow) to a chemical parameter (CO2 concentration). This parameter change enables reliable detection because CO2 is a direct byproduct of respiration and its presence in the circuit is independent of mechanical circuit conditions.
2Measurement precision
If complex algorithms are used to detect breathing circuit integrity, then the detection sensitivity is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex algorithmic processing of multiple physical parameters with a simple chemical detection approach. The CO2 sensor provides direct information about circuit integrity through a single measurement, eliminating the need for complex algorithms to interpret multiple signals.
Solution Approach 2:
The patent extracts the essential information needed for detection (presence of exhaled CO2) from the complex mixture of signals that would otherwise require algorithmic processing. By focusing on this single extracted parameter, the system achieves high sensitivity without complexity.
3Reliability
If CO2 sensors are used to detect patient interface disconnection, then the system reliability is improved, but the device complexity increases
Solution Approach 1:
The patent replaces unreliable mechanical detection methods with a chemical sensing approach. The CO2 sensor provides robust, reliable detection that is insensitive to mechanical variations in the breathing circuit, achieving high reliability with relatively simple implementation.
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
This method provides a reliable and sensitive detection of breathing circuit integrity, ensuring timely alerts and preventing harmful disconnections by utilizing CO2 sensors to differentiate between inhaled and exhaled gases, thus maintaining patient safety.
Implementation Method 1
a carbon dioxide sensor fluidly coupled to an expiratory port to measure an amount of carbon dioxide from exhaled gas
Data Source
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AI summary
A carbon dioxide sensor for use in a respiratory therapy system. The carbon dioxide sensor determines whether a patient interface is fluidly coupled to a patient.