Segmented Inspiratory Limb Heating Across Distinct Temperature Zones

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Solution Overview

Problem

Existing respiratory humidification systems face challenges in maintaining optimal temperature and humidity levels in gas delivery conduits that traverse through distinct temperature zones, leading to issues like condensation or overheating.

Innovation Solution

A segmented inspiratory limb with dual heater wire circuits and sensors in each segment, controlled by a controller that adjusts power distribution based on feedback from multiple sensors to maintain desired temperature and humidity levels across different zones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single heater circuit is used throughout the inspiratory limb, then the device complexity is reduced, but the temperature control precision deteriorates when passing through distinct temperature zones

Engineering Contradiction:
Improveheater circuit configurationVSAvoidtemperature control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The inspiratory limb is divided into multiple segments (first segment and second segment) with separate heater wire circuits for each segment. This segmentation allows independent temperature control of each zone, enabling precise temperature management when the conduit passes through distinct temperature zones such as incubators or blanket-covered areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each segment of the inspiratory limb is equipped with its own heater wire circuit and temperature sensor, allowing localized heating and temperature control. This ensures that each zone receives appropriate heating based on its specific thermal environment, improving overall temperature control precision.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If multiple heater wire circuits are implemented in separate segments, then the temperature control precision is improved, but the device complexity increases

Engineering Contradiction:
Improvetemperature control precisionVSAvoidheater circuit configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple heater wire circuits from different segments are electrically coupled together through an intermediate connector, allowing them to be controlled by a single controller. This merging approach enables precise temperature control in multiple zones while avoiding the need for separate control systems for each segment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The intermediate connector serves multiple functions: it electrically couples heater wire circuits from different segments, provides a common control interface, and integrates sensor feedback from multiple zones. This multi-functionality reduces the overall system complexity while maintaining precise temperature control.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Temperature

If heating is applied throughout the entire conduit, then the gas temperature is maintained, but condensation or overheating occurs in specific zones

Engineering Contradiction:
Improvegas temperature maintenanceVSAvoidcondensation and overheating
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The heating system transitions from static uniform heating to dynamic zone-specific heating. Each segment can be heated or cooled independently based on real-time temperature sensor feedback, allowing the system to adapt to changing thermal conditions and prevent both condensation and overheating in specific zones.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Temperature sensors are positioned at multiple locations (intermediate connector and patient-end) to provide feedback on the thermal state of different zones. This feedback enables the controller to adjust heating power to each segment independently, preventing harmful effects like condensation in cooler zones or overheating in warmer zones.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If segment-specific sensor feedback is implemented, then the temperature control precision is improved, but the measurement and control complexity increases

Engineering Contradiction:
Improvetemperature sensing accuracyVSAvoidsensor feedback system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Sensor feedback signals from multiple segments are combined and processed through a single controller that receives inputs from temperature sensors positioned at the intermediate connector and patient-end. This merging approach maintains precise temperature measurement across multiple zones while avoiding the complexity of separate control systems for each segment.

Inventive Principle:
Principle #5Merging (Combining)

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

Effectively maintains optimal gas temperature and humidity levels by dynamically adjusting heating in response to sensor feedback, reducing condensation and overheating, and ensuring safe delivery to the user.

Implementation Method 1

a first heater wire circuit positioned within the first segment and a second heater wire circuit positioned within the second segment

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4663223A1Zone heating for respiratory circuits
Publication Date: 2025.12.17 FISHER & PAYKEL HEALTHCARE LTD
  • EP4663223A1 patent drawingFigure 1
  • EP4663223A1 patent drawingFigure 2
  • EP4663223A1 patent drawingFigure 3A~3B

AI summary

Some embodiments provide for an inspiratory limb for a breathing circuit that includes a first segment that comprises a first heater wire circuit and a second segment that comprises a second heater wire circuit. The inspiratory limb can include an intermediate connector that includes a connection circuit that electrically couples the first heater wire circuit to the second heater wire circuit. The inspiratory limb can be configured to operate in two modes wherein, in a first mode, electrical power passes through the first electrical connection to provide power to the first heater wire circuit without providing power to the second heater wire circuit, and in a second mode, electrical power pass through the first electrical connection to provide power to both the first heater wire circuit and the second heater wire circuit.