Breathing Circuit Temperature Control via Internal Resistance Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing temperature control systems for heated breathing-circuits in medical equipment suffer from temperature-drift errors and inherent errors in electronic components, leading to inaccuracies in resistance value measurements and subsequent temperature control.
Innovation Solution
A method and apparatus that utilize a temperature-sampling circuit with a short-circuit loop and a microprocessor to continuously heat the breathing-circuit, sample temperature signals, and calculate actual temperature values by accounting for internal resistances and resistance values of the temperature sensor, thereby correcting for temperature-drift errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If resistance values of NTC thermistors are obtained by sampling systems directly, then the temperature control system is simple, but temperature-drift errors and inherent errors of electronic components cause inaccuracies in resistance value measurements
Solution Approach 1:
The patent applies preliminary action by measuring and storing the internal resistance values of the sampling system at different temperatures before actual temperature measurement. The system pre-characterizes the temperature-drift characteristics of electronic components and creates correction data that is applied during operation to compensate for measurement errors.
Solution Approach 2:
The patent implements feedback by using the measured internal resistance values to calculate correction factors that are applied to subsequent temperature measurements. The system continuously monitors and adjusts for the temperature-drift errors of electronic components based on feedback from resistance measurements at known reference temperatures.
2Ease of operation
If temperature-drift errors of electronic components are not corrected, then the system operation is straightforward, but the temperature control effect is affected due to errors in resistance values
Solution Approach 1:
The patent applies self-service by enabling the temperature control system to automatically measure, calculate, and apply its own correction factors without external intervention. The system performs self-calibration by measuring internal resistances at reference temperatures and uses these measurements to correct subsequent temperature readings autonomously.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting the resistance value parameters used in temperature calculations based on measured temperature-drift characteristics. The system changes the effective resistance parameters to account for electronic component variations, thereby maintaining measurement accuracy across different operating conditions.
3Measurement precision
If a short-circuit loop is added to measure internal resistance of the temperature-sampling circuit, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing the short-circuit loop and function-selection circuit to serve multiple purposes: they are used both for measuring the internal resistance of the sampling system and for controlling the overall temperature measurement process. The same circuitry performs both calibration and operational functions, reducing the need for separate dedicated components.
Solution Approach 2:
The patent implements periodic action by alternating between different circuit configurations through the function-selection circuit. The system periodically switches between the short-circuit loop configuration (for measuring internal resistance) and the normal temperature sensing configuration, enabling sequential calibration and measurement operations using shared circuitry.
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 approach enhances the accuracy of temperature control by eliminating the influence of temperature-drift errors, ensuring precise temperature monitoring and control within the heated breathing-circuit.
Implementation Method 1
a gas-temperature sampling device, like a negative temperature coefficient (NTC) thermistor, needs to be provided on a heated breathing-circuit to monitor gas temperature
Implementation Method 2
a heating device needs to be heat the gas delivered from the breathing circuit to users
Data Source
AI summary
A temperature control method for a heated breathing-circuit includes steps of: continuously controlling the heated breathing-circuit to be heated continuously in a first predetermined time period; obtaining a sampling temperature signal of the heated breathing-circuit in a second predetermined time period; obtaining a resistance value of a temperature sensing loop by converting the sampling temperature signal; controlling the temperature-sampling circuit to be electrically connected with the short-circuit loop in a third predetermined time period, to obtain an internal resistance value of the temperature-sampling circuit; obtaining a resistance value of the temperature sensor thought the resistance value of the temperature sensing loop, a resistance value of the resistance wire, and the internal resistance; and calculating the resistance value of the temperature sensor and the temperature of the temperature sensor, to obtain an actual temperature value of the heated breathing-circuit. A temperature control system for a heated breathing-circuit is also provided.