Capacitive Sensor with Dielectric Foam for Wearable Pressure Monitoring

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Solution Overview

Problem

Current methods for monitoring weight-bearing pressure on limbs, particularly after surgeries like hip replacements, lack effective tools to ensure compliance with weight-bearing instructions, leading to prolonged healing times and increased costs due to unmonitored weight-bearing.

Innovation Solution

A capacitive sensor system with a flexible, non-toxic dielectric foam that measures pressure or vacuum, integrated with microminiaturized electronics in a vacuum-sealed housing, providing accurate and non-intrusive feedback for rehabilitation and wound care, and capable of being worn next to the skin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a sensor system is designed to be flexible and wearable next to the skin, then ease of operation and patient compliance improve, but measurement precision and reliability may deteriorate due to movement and environmental interference

Engineering Contradiction:

ImprovewearabilityVSAvoidpressure measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The sensor system employs flexible printed circuit boards (FPC) and thin-film encapsulation layers that allow the device to conform to skin contours while maintaining structural integrity. The flexible substrate enables the sensor to move with the patient without compromising measurement accuracy, resolving the contradiction between wearability and measurement precision.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sensor components are nested within a protective flexible housing that contains multiple functional layers. The FPC board is embedded within the flexible structure, allowing the sensitive measurement elements to be protected while maintaining flexibility for skin contact, thus preserving both ease of operation and measurement precision.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Device complexity

If microminiaturized electronics are integrated into the sensor, then device complexity is reduced and ease of manufacture improves, but reliability may worsen due to miniaturization challenges

Engineering Contradiction:

Improveelectronics integrationVSAvoidsensor reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Traditional mechanical wiring and connection methods are replaced with flexible printed circuit board technology, which provides more reliable electrical connections while maintaining miniaturization. The FPC technology enables compact integration of electronics without the reliability issues associated with miniaturized mechanical connectors, resolving the contradiction between device complexity and reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the sensor uses a vacuum-sealed housing to protect internal components, then reliability improves, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvecomponent protectionVSAvoidvacuum sealing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of rigid vacuum-sealed housings, the patent employs flexible encapsulation films and conformal coating techniques that provide protection while being compatible with flexible substrates. These thin-film barriers offer environmental protection without requiring complex vacuum sealing processes, resolving the contradiction between reliability and ease of manufacture.

Inventive Principle:

Principle #30Flexible shells and thin films

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 enables precise monitoring of pressure and vacuum, reducing healing time and hospitalization duration by ensuring compliance with weight-bearing instructions, and can be used in various clinical applications beyond limb load monitoring.

Implementation Method 1

A capacitive sensor with a flexible, non-toxic dielectric foam that measures pressure or vacuum

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

A capacitive sensor with a flexible, non-toxic dielectric foam

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS10912513B2Pressure and vacuum sensors, systems, and associated methods with a plurality of layers of a dielectric material

Publication Date: 2021.02.09 WEARSENSE LLC

AI summary

A system includes a housing, a capacitive sensor, and an electronics module. The housing has an interior and is configured to be maintained at a first pressure that is lower than a pressure external of the housing the interior under a vacuum pressure. The capacitive sensor is disposed within the housing and includes a plurality of layers of a dielectric material. The electronics module is coupled to the capacitive sensor and includes a processor configured to receive a raw capacitance value from the capacitive sensor and to output a signal identifying a pressure exerted on the capacitive sensor.