Overmolded Sensor Diaphragm for Patient Comfort and Light Sealing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Reusable pulse oximeter sensors are uncomfortable for patients due to inadequate compliance and structural issues, and they are difficult to clean thoroughly, which can lead to errors in physiological measurements due to environmental light interference and bio-debris accumulation.

Innovation Solution

A reusable sensor assembly with an overmolded design featuring a skeletal frame coated with a flexible material, including diaphragm structures for conformability and easy cleaning, which provides a secure fit and prevents environmental light infiltration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If a reusable sensor is made with rigid structural features for durability, then the sensor can be reused multiple times, but the patient comfort deteriorates due to inadequate compliance and edges

Engineering Contradiction:

Improvesensor reuse lifeVSAvoidpatient discomfort

Core Design Contradiction:

Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies a flexible coating material over the rigid frame to create a compliant surface that contacts the patient's skin. This flexible layer eliminates harsh edges while preserving the underlying rigid structure for durability and reuse. The coating material is specifically chosen to be soft and conformable to patient anatomy.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sensor combines rigid frame materials with flexible coating materials to create a composite structure. The rigid frame provides structural integrity and reuse capability, while the flexible coating provides patient comfort and compliance. This composite approach resolves the contradiction between durability and comfort.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If the sensor is made loose for patient comfort, then patient comfort improves, but measurement precision deteriorates due to environmental light interference

Engineering Contradiction:

Improvepatient comfortVSAvoidphysiological measurement accuracy

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The flexible coating material forms a light-tight seal between the sensor and patient's skin, creating an optical barrier that prevents environmental light from reaching the photodetector. This allows the sensor to fit comfortably without compromising measurement precision, as the flexible layer blocks stray light paths.

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of manufacture

If the sensor has a multi-part construction for ease of assembly, then manufacturing ease improves, but ease of operation deteriorates due to difficulty in thorough cleaning

Engineering Contradiction:

Improvesensor assembly easeVSAvoidsensor cleaning ease

Core Design Contradiction:

Ease of manufactureVSEase of operation

Solution Approach 1:

The patent merges the frame and coating into a integrated structure where the coating is applied directly over the frame surface. This combination creates a smooth, continuous surface without crevices or gaps where bio-debris could accumulate, making the sensor easy to clean while maintaining the manufacturing advantages of modular components.

Inventive Principle:

Principle #5Merging (Combining)

4Measurement precision

If the sensor fits tightly for measurement precision, then measurement precision improves, but patient comfort deteriorates due to excessive tightness

Engineering Contradiction:

Improvelight detection accuracyVSAvoidpatient discomfort

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The flexible coating material allows the sensor to conform closely to the patient's anatomy, creating a tight seal that prevents light leakage while distributing pressure evenly across the contact surface. This flexibility enables accurate light detection without creating pressure points or discomfort.

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 overmolded sensor assembly offers improved patient comfort, secure and conformable fit, and ease of cleaning, reducing measurement errors by minimizing environmental light interference and bio-debris accumulation.

Implementation Method 1

The pulse oximeter sensor emits light and photoelectrically senses the absorption and/or scattering of the light after passage through the perfused tissue

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

a flexible material, including diaphragm structures for conformability

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS7657294B2Compliant diaphragm medical sensor and technique for using the same

Publication Date: 2010.02.02 COVIDIEN LP

AI summary

A unitary sensor is provided that includes a frame upon which electrical and optical components may be disposed and a coating, such as an overmolded coating provided about the frame. The unitary sensor includes one or more diaphragm structures formed from thin regions of the coating material and disposed generally about at least one of the optical components. The diaphragm structure or structures allow the optical components to be separated, such as by application of an opposing force to the lateral sides of the sensor, such that the sensor may be placed on a patient. The sensor may thereby be placed on a patient's finger, toe, and so forth to obtain pulse oximetry or other physiological measurements.