Dynamic Pressure Support for Cheyne-Stokes Respiration

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Solution Overview

Problem

Patients with congestive heart failure often experience Cheyne-Stokes respiration, a breathing disorder characterized by rhythmic waxing and waning periods of respiration, which disrupts sleep and stresses the cardiovascular system, and existing treatments like bi-level positive airway pressure therapy may increase cardiac and respiratory workload.

Innovation Solution

A system that delivers a flow of breathing gas with a controller that adjusts pressure support based on monitored flow characteristics, providing baseline positive pressure during inspiration and reducing it during hyperneic phases of Cheyne-Stokes respiration to minimize workload, using a gas flow generator, sensor, and patient circuit to ensure effective treatment while maintaining patient comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bi-level positive airway pressure therapy is applied to treat Cheyne-Stokes respiration, then respiratory support is improved, but cardiac and respiratory workload increases

Engineering Contradiction:
Improverespiratory supportVSAvoidcardiac and respiratory workload
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by transitioning from static bi-level pressure therapy to dynamic pressure support that continuously adapts to the patient's respiratory phase. The system monitors instantaneous flow rate and adjusts pressure support in real-time, providing higher pressure during inspiration and lower pressure during expiration, thereby supporting respiratory function while reducing overall cardiac and respiratory workload compared to constant bi-level therapy

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the pressure support level based on the patient's instantaneous flow rate and respiratory phase. The controller dynamically adjusts the pressure parameter throughout the respiratory cycle, providing baseline positive pressure support during inspiration and reducing it during hyperneic phases, thereby optimizing respiratory support while minimizing energy expenditure

Inventive Principle:
Principle #35Parameter changes

2Productivity

If pressure support is increased during inspiration, then respiratory efficiency is improved, but pressure provided during expiration increases

Engineering Contradiction:
Improverespiratory efficiencyVSAvoidpressure during expiration
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The patent applies periodic action by delivering pressure support in a cyclic manner synchronized with the patient's respiratory rhythm. The system provides elevated pressure support during the inspiratory phase when respiratory efficiency benefits from positive pressure, and reduces pressure during the expiratory phase, thereby maintaining respiratory efficiency while avoiding excessive expiratory pressure

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts pressure levels based on real-time detection of respiratory phase through flow rate monitoring. By making pressure support variable rather than constant, the system optimizes respiratory efficiency during inspiration while minimizing pressure during expiration, resolving the contradiction between improved productivity and reduced stress

Inventive Principle:
Principle #15Dynamics

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 system effectively reduces Cheyne-Stokes respiration events by adjusting pressure support, improving sleep quality and reducing cardiac workload, thereby alleviating symptoms and stress on the cardiovascular system.

Implementation Method 1

the pressure support system uses the monitored flow rate to determine an instantaneous average inspiratory flow and uses the instantaneous average inspiratory flow and a target flow rate to determine an amount of CSR treatment to be delivered to the patient. The pressure support system delivers the determined amount of CSR treatment by enabling negative pressure support during the CSR event.

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP2523714B1Servo ventilation using pressure drop from baseline
Publication Date: 2019.06.19 KONINKLIJKE PHILIPS NV
  • EP2523714B1 patent drawingFigure 1~2B
  • EP2523714B1 patent drawingFigure 3
  • EP2523714B1 patent drawingFigure 4A~4B

AI summary

A system and method for delivering a flow of breathing gas to an airway of a patient that includes a gas flow generator and a patient circuit that communicates the flow of gas to an airway of a patient. A sensor measures a characteristic associated with the flow of gas, such as flow rate. A controller determines a first characteristic based on the measured characteristic and a target of the flow of gas to be delivered to the patient. The controller controls the delivery of gas to the patient by 1) providing a baseline positive pressure support amount to the patient and 2) providing a modified pressure support amount by reducing the baseline amount by a given amount if the first characteristic is above the target. The baseline pressure includes a pressure provided during inspiration that is higher than a pressure provided during expiration.