Sensor Assembly Contamination Removal via Piezoelectric Vibration

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Solution Overview

Problem

Respiratory therapy systems face contamination issues with sensors in the patient circuit, leading to inaccurate measurements and potential safety hazards due to the accumulation of particles and residual water on sensing elements, which can cause erratic operation and unsafe delivery of gases.

Innovation Solution

A sensor assembly with a mechanically coupled actuator that applies high-frequency oscillations to break away particles and contaminants from the sensing element, using a piezoelectric actuator to create shockwaves and maintain a clean surface for accurate parameter measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are positioned within the airway to measure gas parameters, then measurement capability is improved, but contamination accumulation on the sensing element occurs

Engineering Contradiction:

Improvegas parameter measurementVSAvoidcontamination accumulation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies high-frequency mechanical vibrations to the sensing element to prevent contamination accumulation. The vibrations create forces that repel particles and prevent them from adhering to the sensing element surface, thereby maintaining measurement precision while the sensor remains positioned in the airway.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces passive sensor surfaces with actively vibrated surfaces. Instead of using mechanical cleaning mechanisms that would require contact and complex structures, the solution uses vibrational fields to achieve contamination removal, substituting a simple mechanical vibration source for complex mechanical cleaning systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Duration of action of stationary object

If residual water and particulates form a film on the sensor surface, then sensing capability is impeded, but the sensor remains in use for inter and intra sessions

Engineering Contradiction:

Improvesensor usage durationVSAvoidsensing capability

Core Design Contradiction:

Duration of action of stationary objectVSMeasurement precision

Solution Approach 1:

The patent implements continuous vibration of the sensing element throughout sensor operation. This continuous vibrational action maintains the sensing surface free from contamination buildup over extended periods, ensuring both prolonged sensor usage duration and sustained measurement precision without requiring periodic cleaning interruptions.

Inventive Principle:

Principle #20Continuity of useful action

3Extent of automation

If contamination shifts the signal threshold of the sensor, then control system operation becomes erroneous, but the sensor provides feedback for system control

Engineering Contradiction:

Improvecontrol system feedbackVSAvoidsignal threshold accuracy

Core Design Contradiction:

Extent of automationVSReliability

Solution Approach 1:

The sensing element performs self-cleaning through its own vibrational motion. The high-frequency vibrations generated by the actuator attached to the sensing element create forces that continuously prevent contamination from adhering to or shifting the sensor surface, thereby maintaining signal threshold accuracy while the sensor provides automated feedback for control system operation.

Inventive Principle:

Principle #25Self-service

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 solution effectively reduces contamination buildup, ensuring reliable, repeatable, and accurate sensing of gas parameters, thereby enhancing patient safety and system control by maintaining calibrated response limits and preventing thermal overshoots or incorrect medication dosages.

Implementation Method 1

using a piezoelectric actuator to create shockwaves

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

applies high-frequency oscillations to break away particles and contaminants from the sensing element

Methodology Applied

Scientific EffectMechanical vibration: Vibration

Data Source

PatentUS9022946B2Contamination removal from sensors placed in an airway

Publication Date: 2015.05.05 ZOLL MEDICAL CORPORATION

AI summary

A sensor assembly includes a sensing element and an actuator. The sensing element measures a parameter associated with gas in an airway. The actuator actuates the sensing element to prevent contamination build up on the sensing element.