Minimum Pd/Pa Ratio Analysis for Phase-Independent Stenosis Detection

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Solution Overview

Problem

Existing cardiovascular diagnostic techniques face challenges in accurately diagnosing coronary artery diseases without unnecessary complications and assumptions, particularly in identifying stenosis and other cardiac system phenomena, as they often rely on complex imaging and pressure data that can be unreliable due to assumptions about cardiac cycle phases.

Innovation Solution

The method involves determining a minimum ratio of distal pressure (Pd) to proximal pressure (Pa) (MCR) using intravascular data collection probes, which are sampled at high rates to identify minimum cycle ratios (MCR) on a per cardiac cycle basis, independent of cardiac cycle phases, and displaying these ratios to facilitate accurate diagnosis of stenosis and other cardiac conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex imaging and pressure data techniques are used to diagnose coronary artery diseases, then diagnostic capability is improved, but reliability deteriorates due to assumptions about cardiac cycle phases

Engineering Contradiction:

Improvediagnostic capabilityVSAvoidreliability of pressure data

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent extracts only the essential information needed for diagnosis by calculating a simplified pressure ratio (Pd/Pa) from the complex pressure data, eliminating the need for complex imaging and phase-specific assumptions while maintaining diagnostic accuracy

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the complex pressure data into a different parameter form (minimum pressure ratio) that is independent of cardiac cycle phase assumptions, thereby improving reliability while preserving diagnostic capability

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If phase-specific assumptions are made in pressure data analysis, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improvepressure data accuracyVSAvoidcomplexity of analysis method

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent removes the complex phase-specific analysis requirements by extracting only the minimum pressure ratio value, simplifying the measurement approach while maintaining precision through the robust MCR metric

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of analyzing pressure data within specific cardiac phases, the patent inverts the approach by identifying the minimum pressure ratio across all phases, eliminating the need for phase identification while preserving measurement accuracy

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP4032467B1System for evaluating a cardiac system by determining minimum ratio pd/pa (distal pressure/arterial pressure)

Publication Date: 2025.07.09 ST JUDE MEDICAL SYST

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AI summary

In part, the disclosure relates to computer-based methods, and systems suitable for evaluating a cardiac system using a diagnostic metric such as a pressure value-based ratio. Selection of a subset or portion of a cardiac cycle is avoided in one embodiment to increase reliability and usability of a diagnostic ratio and parameters described herein. In one embodiment, a minimum or a relative extrema of a series of diagnostic metrics plotted on a per cycle basis are used to inform diagnosis of a stenosis or other intravascular event or phenomena.