Transcutaneous Oxygen Patch Using Photoluminescent Film

Solution Overview

Problem

Conventional methods for monitoring transcutaneous oxygen levels require bulky devices with heating elements, making them unsuitable for portable and continuous use, especially in wearable form factors.

Innovation Solution

A wearable transdermal patch using a photoluminescent sensing film that emits light responsive to oxygen presence, with an optical source and photodetector to compute oxygen concentration based on light intensity and lifetime, eliminating the need for heating elements and enabling wireless monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional heating elements are used to measure transcutaneous oxygen levels, then measurement accuracy is improved, but device size and power consumption increase

Engineering Contradiction:

Improvetranscutaneous oxygen measurement accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces the thermal/mechanical heating system with an optical system. Specifically, it uses a photoluminescent sensing film that emits light when excited by an optical source, and oxygen concentration is determined by measuring the intensity and lifetime of this emitted light. This substitution eliminates the need for heating elements while maintaining measurement capability, thereby reducing power consumption and device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from thermal-based to optical-based. Instead of using temperature-dependent oxygen solubility changes (which require heating), the system uses photoluminescence intensity and lifetime changes in response to oxygen concentration. This parameter change enables measurement without thermal input, resolving the contradiction between accuracy and power consumption.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If conventional heating elements are used to measure transcutaneous oxygen levels, then measurement accuracy is improved, but device portability deteriorates

Engineering Contradiction:

Improvetranscutaneous oxygen measurement accuracyVSAvoiddevice weight

Core Design Contradiction:

Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent replaces the thermal/mechanical heating system with an optical system. Specifically, it uses a photoluminescent sensing film that emits light when excited by an optical source, and oxygen concentration is determined by measuring the intensity and lifetime of this emitted light. This substitution eliminates the need for heating elements while maintaining measurement capability, thereby reducing power consumption and device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from thermal-based to optical-based. Instead of using temperature-dependent oxygen solubility changes (which require heating), the system uses photoluminescence intensity and lifetime changes in response to oxygen concentration. This parameter change enables measurement without thermal input, resolving the contradiction between accuracy and power consumption.

Inventive Principle:

Principle #35Parameter changes

3Loss of information

If conventional oxygen saturation measurement is used, then blood oxygen levels are monitored, but tissue oxygen concentration cannot be directly measured

Engineering Contradiction:

Improvetissue oxygen concentration informationVSAvoidoxygen concentration measurement accuracy

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The patent introduces a photoluminescent sensing film as an intermediary between the optical source and the tissue. This film is in direct contact with the epidermal surface and its photoluminescence properties are modulated by the oxygen concentration in the underlying tissue. The film acts as a mediator that translates tissue oxygen concentration into measurable optical signals, enabling direct monitoring of tissue oxygen levels rather than just blood oxygen saturation.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables continuous, accurate, and portable monitoring of transcutaneous oxygen levels, reducing device size and power consumption while improving patient comfort and mobility.

Implementation Method 1

A photoluminescent indicator emits light responsive to an illuminating stimuli in a manner that varies with the presence of the diffused oxygen

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

transcutaneous diffusion through an epidermal surface of a patient

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentUS20230035741A1Transcutaneous gaseous measurement device

Publication Date: 2023.02.02 WOCESTER POLYTECHNIC INST

AI summary

A transdermal patch measures a gaseous concentration based on transcutaneous diffusion through an epidermal surface of a patient. The patch employs an indicator responsive to a gaseous presence for emitting light having an intensity and lifetime (duration) based on the gaseous presence. An optical receptor is in communication with logic for receiving the intensity of emitted light and computing a gaseous concentration based on the received intensity and lifetime (duration). A wireless transmitter conveys the results to a base station or monitoring counterpart for untethered patient monitoring. Low power demands and circuit footprint are amenable to a wearable device such as a patch for continuous use.