Vital Sign Detection Using Dynamic Region Selection

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Solution Overview

Problem

Existing camera-based remote vital sign measurement methods are prone to faulty measurements due to occlusion or movement of the subject within the field of view, leading to disturbance signals and unreliable data.

Innovation Solution

The apparatus and method involve deriving a parameter from a detected signal to select the region of interest, using a first time-dependent signal for coarse estimation and a second time-dependent signal for precise vital sign information determination, with a demodulation unit and filter device to enhance signal processing and reduce noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If camera-based photo-plethysmography is used for remote vital sign measurement, then non-contact measurement capability is improved, but measurement reliability deteriorates due to occlusion or movement of the subject

Engineering Contradiction:

Improvenon-contact measurement capabilityVSAvoidmeasurement reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system dynamically adapts the region of interest based on real-time detection of the subject's position and characteristics. The evaluation unit continuously processes image data to identify and track the subject, adjusting the measurement region accordingly. This dynamic adaptation ensures that the measurement remains reliable even when the subject moves within the field of view, resolving the contradiction between non-contact capability and measurement reliability.

Inventive Principle:

Principle #15Dynamics

2Device complexity

If the region of interest is selected in advance for vital sign measurement, then measurement process is simplified, but measurement accuracy deteriorates when the subject moves

Engineering Contradiction:

Improvemeasurement process complexityVSAvoidvital sign measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection and evaluation of the subject's position and characteristics before finalizing the region of interest for measurement. The evaluation unit analyzes image data to identify the subject and determine the appropriate measurement region in advance, but maintains the capability to adjust this region dynamically. This preliminary action simplifies the measurement process while ensuring accuracy by establishing the correct region before actual vital sign extraction begins.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If traditional human detection methods are used to identify the region of interest, then implementation is straightforward, but robustness against disturbance signals deteriorates

Engineering Contradiction:

Improveimplementation simplicityVSAvoidrobustness against disturbance signals

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The system replaces traditional mechanical or simple algorithmic human detection methods with an advanced evaluation unit that performs sophisticated image processing and analysis. This evaluation unit uses complex algorithms to identify the subject, determine the region of interest, and filter out disturbance signals. By substituting simple detection mechanics with advanced computational analysis, the system maintains ease of implementation while significantly improving robustness against disturbance signals during vital sign measurement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach results in more robust and reliable vital sign measurements, as the region of interest is adapted to the signal parameter, reducing sensitivity to disturbing signals and improving precision.

Implementation Method 1

Plethysmography signals can be determined from a patient's skin by means of a remote photo-plethysmography measurement

Methodology Applied

Scientific EffectPhoto-plethysmography: Photoelectric Effect

Implementation Method 2

The apparatus comprises a demodulation unit for determining a frequency from the first time dependent signal

Methodology Applied

Scientific EffectDemodulation:

Implementation Method 3

a filter device to enhance signal processing and reduce noise

Methodology Applied

Scientific EffectSignal filtering: Filter (electronic)

Data Source

PatentEP2967332B1Apparatus and method for determining vital signs from a subject

Publication Date: 2023.05.10 KONINKLIJKE PHILIPS NV

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AI summary

The present invention relates to an apparatus (10) for determining vital sign information (R) from a subject(12), comprising: a detection unit (20) for detecting radiation (22) received from the subject(12) in a field of view (56), a first determining unit (28) for determining a first time dependent signal (30) from the radiation (22) received from the subject(12),an evaluation unit (32) for deriving at least one parameter (36) from the first time dependent signal(30),a selection unit (38) for selecting an area (64) in the field of view (56) on the basis of the detected radiation (20) and the at least one parameter (36),a second determining unit (44) for determining a second time dependent signal (46) from the radiation (22) received from the selected area (64), and an analysis unit (48) for analyzing the second time dependent signal (46) and for determining the vital sign information(R)on the basis of the analysis of the second time dependent signal (46).