Ventilation Device for Filtering Mask with Dynamic Fan Control

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Solution Overview

Problem

Existing filtering masks suffer from pressure imbalances, humidity, and temperature issues due to non-coordinated exhalation valves and continuous extraction fans, leading to reduced breathing comfort and ineffective air exchange, with potential contamination from external airflows.

Innovation Solution

A ventilation device with a detachable design, featuring an inlet port, outlet port, exhalation valve, extraction fan, and sensors that activate the fan based on detected pressure, temperature, or humidity thresholds, and a command and control unit to regulate airflow dynamically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a continuous extraction fan is used to guarantee air exchange, then air exchange is improved, but vacuum conditions are created within the filter cup that hinder normal breathing

Engineering Contradiction:
Improveair exchangeVSAvoidnormal breathing
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The extraction fan operates periodically rather than continuously, being activated during exhalation phases and deactivated during inhalation phases. This periodic operation maintains effective air exchange while preventing vacuum conditions that would hinder normal breathing, as the fan is synchronized with the respiratory cycle detected by pressure sensors.

Inventive Principle:
Principle #19Periodic action

2Object-affected harmful factors

If the extraction fan is positioned inside the filtering cup to limit contamination, then contamination is reduced, but the useful volume for breathing is reduced by 15-45%

Engineering Contradiction:
ImprovecontaminationVSAvoiduseful breathing volume
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The extraction fan is extracted from the interior of the filtering cup and positioned in an external housing attached to the outer face of the cup. This relocation eliminates the fan's occupation of breathing space, maintaining 100% of the cup's internal volume for respiration while preventing unfiltered air from entering through the fan inlet, thus solving both contamination and volume issues simultaneously.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If the exhalation valve operates based on pressure threshold alone, then valve operation is simplified, but air exchange is insufficient when pressure remains below threshold despite humidity and temperature issues

Engineering Contradiction:
Improvevalve operationVSAvoidair exchange
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

Pressure sensors provide feedback about the respiratory cycle to the control system, which then activates the extraction fan during exhalation phases. This feedback mechanism enables the system to coordinate fan operation with breathing patterns, ensuring adequate air exchange and preventing humidity accumulation without requiring complex manual controls, as the system automatically responds to detected pressure changes.

Inventive Principle:
Principle #23Feedback

4Productivity

If the extraction fan operates continuously to extract air from the cup, then air exchange is guaranteed, but the fan is not capable of avoiding possible opposite airflows from the outside toward the inside of the filter cup

Engineering Contradiction:
Improveair exchangeVSAvoidopposite airflow contamination
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The extraction fan operates periodically during exhalation phases when airflow direction is outward, preventing opposite airflows from entering the cup during inhalation phases. This periodic operation synchronized with the respiratory cycle maintains effective air exchange while eliminating the risk of unfiltered air being drawn into the cup through the fan inlet.

Inventive Principle:
Principle #19Periodic action

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

Ensures optimal air exchange and comfort by adapting to respiratory rhythm and environmental conditions, preventing contamination while maintaining a large inner volume for breathing, even during strenuous activities.

Implementation Method 1

an exhalation valve arranged between the inlet port and the outlet port to allow an airflow from the inlet port to the outlet port when a pressure difference across the exhalation valve exceeds a predefined threshold value

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

at least one sensor arranged at the inlet port to locally detect the value of a physical quantity

Methodology Applied
Scientific EffectPressure detection:

Implementation Method 3

the value of the physical quantity detected by the sensor exceeds a predefined threshold value

Methodology Applied
Scientific EffectTemperature detection:

Implementation Method 4

the value of the physical quantity detected by the sensor exceeds a predefined threshold value

Methodology Applied
Scientific EffectHumidity detection:

Data Source

PatentEP4142887B1Ventilation device for a filtering mask
Publication Date: 2025.12.10 POLITECNICO DI MILANO
  • EP4142887B1 patent drawingFigure 1~2
  • EP4142887B1 patent drawingFigure 1a~2a
  • EP4142887B1 patent drawingFigure 3~4

AI summary

A ventilation device is disclosed for a filter mask engageable with the outer face of the cup of the filter mask. The device comprises: an inlet port which removably engages an opening of the cup of the mask; an outlet port in fluid communication with the inlet port; an exhalation valve arranged between the inlet port and the outlet port; an extraction fan arranged between the inlet port and the exhalation valve; a sensor arranged at the inlet port to detect the value of a physical quantity; a command and control unit in signal communication with the sensor and with the extraction fan. The command and control unit activates the extraction fan when the value of the physical quantity detected by the sensor exceeds a predefined threshold value.