FFR Estimation via Composite Transfer Functions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining fractional flow reserve (FFR) in cardiovascular diseases are often computationally expensive and burdensome for patients, relying on invasive measurements and complex, costly equipment.
Innovation Solution
An image processing system that uses geometry-derived transfer functions to simulate FFR by combining local and global effect transfer functions, learned from previous measurements and CFD simulations, allowing for non-invasive FFR estimation without the need for extensive in-situ measurements or expensive equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If invasive FFR measurements are performed using special catheters with pressure probes, then measurement precision is improved, but device complexity and procedural risk increase
Solution Approach 1:
The patent creates a virtual copy of the FFR measurement system using CFD simulations. Instead of using physical catheters with pressure probes, the system generates a computational model that replicates the hemodynamic conditions and calculates FFR values through numerical solutions of the Navier-Stokes equations, thereby eliminating the need for invasive measurement devices
Solution Approach 2:
The patent replaces the mechanical measurement system (catheters, pressure probes, differential pressure transducers) with a computational fluid dynamics system. The mechanical pressure measurements are substituted by calculating pressure fields through numerical simulation, eliminating the need for physical intervention in the vascular system
2Ease of operation
If non-invasive CFD simulations are performed using volumetric data from CT projections, then ease of operation is improved, but computational cost and time increase
Solution Approach 1:
The patent segments the coronary artery tree into multiple regions of interest (ROIs) around the stenosed site, focusing the CFD simulation only on these critical segments rather than the entire vascular system. This segmentation reduces the computational domain size and allows for faster simulations while maintaining accuracy in the stenosis region
Solution Approach 2:
The patent applies local quality by concentrating computational resources on specific regions around the stenosis rather than uniformly across the entire coronary tree. The transfer function is calibrated using local geometric parameters (lumen diameter, wall thickness, curvature) at the stenosed site, allowing for optimized computational efficiency in the most critical areas
3Measurement precision
If 3D coronary angiography is used to generate volumetric models, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the imaging system universal by accepting multiple input formats (2D angiograms, 3D volumetric data, CT projections) and processing them through a unified CFD framework. The system can handle different imaging modalities and reconstruct the necessary geometric parameters for transfer function calculation, making the equipment requirements more flexible and less specialized
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A system (IPS) and related method for fractional flow reserve, FFR, simulation. The simulation for a range of FFR values for a vasculature portion is based on a composite transfer function which is combined from a weighted sum of global effect transfer functions he, each representing a distinct physical effect that causes a pressure drop. The weights we are gotten from a previous training phase against pressure pi versus flow rate fi 5 sample measurements associated with respective vasculature geometries. The simulated range of FFR values is visualized in a graphics display (GD) as a function of pressure and flow rate values within respective intervals.