Portable Pulse Oximeter AF Rhythm Classification

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Solution Overview

Problem

Current methods for diagnosing Atrial Fibrillation (AF) are unreliable due to reliance on symptoms, intermittent monitoring, and bulky devices that interfere with daily activities, leading to low patient compliance and delayed detection, which can result in missed opportunities for timely therapy.

Innovation Solution

A portable blood oxygenation level monitoring device acquires short-term plethysmographic waveforms to classify heart rhythms as AF, Normal Sinus Rhythm, or other irregularities using a three-state traffic-light indicator, employing parametric modeling, coefficient of variation, Shannon entropy, and Mahalanobis distance to differentiate between rhythms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If intermittent 24-hour Holter monitoring or long-term monitoring is used, then the ability to diagnose and quantify AF is improved, but the device becomes bulky and interferes with daily activities, reducing patient compliance

Engineering Contradiction:
ImproveAF diagnosis accuracyVSAvoidpatient compliance
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent extracts the essential AF detection functionality from complex monitoring systems, using only a pulse oximeter to obtain plethysmographic waveforms. This eliminates the need for bulky Holter monitors or external recorders while maintaining diagnostic capability through automated analysis of pulse interval variability and waveform morphology

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs automated classification of AF episodes using embedded algorithms that analyze plethysmographic data without requiring patient intervention. The device automatically detects beats, calculates pulse intervals, applies classification rules, and generates results, eliminating the need for patient skill or compliance in operating complex monitoring equipment

Inventive Principle:
Principle #25Self-service

2Ease of operation

If symptom-based AF diagnosis is used, then the diagnostic process is simple, but the reliability of AF diagnosis is low because symptoms may not correspond to genuine AF episodes

Engineering Contradiction:
Improvediagnostic simplicityVSAvoidAF diagnosis reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary automated classification system that bridges simple pulse oximetry and reliable AF diagnosis. The system uses objective criteria including pulse interval variability, plethysmographic waveform morphology, and beat-to-beat interval analysis to mediate between easy-to-obtain data and accurate diagnosis, eliminating reliance on subjective symptom reporting

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/symptom-based diagnostic approach with an automated computational system. Instead of relying on patient-reported symptoms, the system uses algorithmic analysis of physiological signals (pulse intervals, waveform shape) to objectively determine AF status, substituting human judgment with automated classification rules

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Duration of action of stationary object

If delayed information from 7-day or 30-day Holter monitoring is used, then comprehensive monitoring is achieved, but immediate reaction with therapy is not possible, missing the optimal 48-hour treatment window

Engineering Contradiction:
Improvemonitoring durationVSAvoidtherapy response time
Core Design Contradiction:
Duration of action of stationary objectVSLoss of time

Solution Approach 1:

The patent enables preliminary detection and classification of AF episodes in real-time, allowing immediate therapeutic intervention during the critical first 48 hours. The automated system continuously monitors and instantly classifies rhythm status, providing timely alerts that enable prompt treatment before blood clots form in the atria

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system provides continuous real-time monitoring and immediate classification of AF episodes, eliminating the delayed information feedback inherent in traditional Holter monitoring. The automated analysis continuously processes plethysmographic data without interruption, ensuring uninterrupted detection and immediate therapy initiation when AF is detected

Inventive Principle:
Principle #20Continuity of useful action

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 provides high sensitivity and specificity (>95%) in discriminating AF episodes, enabling prompt and accurate detection directly at home, improving patient monitoring and therapy optimization with minimal disruption to daily life.

Implementation Method 1

performs short term acquisition of the plethysmographic waveform of a patient from a portable blood oxygenation level monitoring device

Methodology Applied
Scientific EffectPhotoplethysmography:

Data Source

PatentEP2587991B1A portable pulseoximeter for a direct and immediate automated evaluation of the cardiac rhythm (regularity)
Publication Date: 2021.08.18 M I R SPA
  • EP2587991B1 patent drawingFigure 1
  • EP2587991B1 patent drawingFigure 2~3
  • EP2587991B1 patent drawing

AI summary

The present invention relates to the field of patient monitoring. More particularly the invention relates to a system that performs short term acquisition of the plethysmographic waveform of a patient from a portable blood oxygenation level monitoring device and establishes whether the patient has an episode of Atrial Fibrillation (AF) or has a Normal Sinus Rhythm (NSR) or any other not-specific rhythm irregularity. Such classification is implemented directly in the device, suitable for at home use, and the result of the classification is displayed automatically using a three-state, traffic-light indicator.