Breath-Actuated Nebulizer Circuit for Humidified Ventilation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Challenges in administering nebulized drugs to patients on a mechanical ventilator include inefficient drug delivery, unpredictable dosing, and interference from humidification, which can lead to aerosol losses and interruption of breathing.
Innovation Solution
A ventilator circuit design that minimizes the influence of duty cycle, bias flow, and humidification by using a breath-actuated nebulizer with a pressure sensor, allowing nebulization only during inspiration, and incorporating a humidifier or heat and moisture exchanger to maintain efficient drug delivery without interrupting breathing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a nebulizer is incorporated into a breathing circuit, then nebulized drugs can be delivered to patients, but humidification interferes with droplet formation and transfer
Solution Approach 1:
The breathing circuit is segmented into distinct zones: a first section that provides humidification and a second section that receives nebulized drugs. This spatial separation allows humidified air to be generated without interfering with droplet formation, as the humidification occurs in a separate pathway from the nebulizer output.
Solution Approach 2:
A three-way valve serves as an intermediary device that controls the flow paths between the humidifier, nebulizer, and patient. It enables selective routing of humidified air away from the nebulizer output while maintaining proper drug delivery, thus mediating between the conflicting requirements of humidification and nebulization.
2Ease of repair
If the nebulizer is removed to refill or clean it, then maintenance can be performed, but breathing gas flow must be interrupted
Solution Approach 1:
The breathing circuit is divided into isolated sections with the nebulizer positioned in a removable location. This segmentation allows the nebulizer to be detached for maintenance while the rest of the circuit remains intact and operational, enabling service without complete system shutdown.
Solution Approach 2:
The circuit is designed with pre-configured connection points and isolation mechanisms that allow the nebulizer to be removed or installed without requiring disassembly of other circuit components. This preliminary preparation of the circuit architecture enables quick maintenance operations.
3Ease of operation
If humidification is provided during nebulization, then patient comfort is maintained, but aerosol losses increase and drug output decreases
Solution Approach 1:
The system separates the humidification function from the nebulization function by providing humidified air through a dedicated pathway that does not intersect with the nebulized drug stream. This ensures that patient comfort is maintained through humidification while aerosol losses are minimized by preventing humid air from interfering with droplet formation.
Solution Approach 2:
The humidification function is extracted from the nebulization pathway and placed in a separate section of the breathing circuit. This extraction allows humidified air to be supplied to the patient without being mixed with the nebulized drug aerosol, thereby eliminating the harmful interaction between humidity and aerosol stability.
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
Enhances drug delivery to the lungs, reduces aerosol losses, and allows nebulizer removal without interrupting ventilation, improving drug delivery efficiency and patient comfort.
Implementation Method 1
a pressure sensor interposed between the nebulizer and the ventilator, wherein the pressure sensor controls a pressurized air supply to the nebulizer required for nebulization to occur, such that nebulization only occurs during a pressure increase on the inspiratory limb caused by an increase in air pressure from the ventilator to force an inhalation by the patient
Implementation Method 2
a nebulizer on the inspiratory limb interposed between a T-fitting and a three-way valve such that the nebulizer can be removed from the inspiratory limb without interrupting the flow of breathing gases to the patient
Implementation Method 3
a humidifier or heat and moisture exchanger (HME) on the inspiratory limb interposed between the nebulizer and the endotracheal tube
Data Source
AI summary
A ventilator circuit apparatus is disclosed for the administration of an aerosolized drug from a nebulizer through an endotracheal tube to a patient on a mechanical ventilator with humidification of the breathing gases. In an embodiment, the nebulizer can be disconnected without interrupting the airflow to the patient. In an embodiment, a T-fitting and three-way valve in the ventilator circuit permits the nebulizer to be bypassed by the airflow, allowing the nebulizer to be removed from the apparatus without interrupting the flow of breathing gases to the patient. In an embodiment, the nebulizer is breath-enhanced jet nebulizer. In an embodiment, the jet nebulizer is breath-actuated, by use of an air pressure sensor that toggles the flow of pressurized air to the nebulizer that drives the jet required for nebulization. A related method is also disclosed.