Cardiac Image Synchronization via Non-Linear Time Warping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cardiac imaging methods fail to accurately synchronize image sequences acquired at different heart rates, leading to time-distorted representations of heart behavior during medical procedures.
Innovation Solution
The method employs non-linear time warping to synchronize image sequences based on the non-linear dependence of cardiac cycle phases on heartbeat rates, using a piecewise linear function to adjust presentation times and ensure accurate alignment along the cardiac cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If linear synchronization methods are used to align image sequences acquired at different heart rates, then the synchronization process is simple and fast, but time distortions occur in the representation of heart behavior
Solution Approach 1:
The patent transforms the synchronization approach by changing from linear time scaling to non-linear time warping. The system divides the cardiac cycle into multiple phases (e.g., isovolumetric contraction, ejection, isovolumetric relaxation, filling) and applies different time scaling factors to each phase based on the relationship between heart rate and phase duration. This allows accurate representation of heart behavior at different rates while maintaining computational feasibility.
Solution Approach 2:
The patent segments the cardiac cycle into distinct physiological phases, each with its own time-duration characteristics. By identifying key events (e.g., valve openings/closings, peak contraction) and dividing the cycle accordingly, the system can apply phase-specific time warping functions. This segmentation enables precise control over time alignment in each phase while preserving the overall cardiac cycle structure.
2Manufacturing precision
If non-linear time warping is applied to accurately synchronize cardiac phases, then time alignment accuracy improves, but computational complexity increases
Solution Approach 1:
The patent pre-computes time warping functions based on established physiological relationships between heart rate and cardiac phase durations. These functions are derived offline and stored for rapid application during synchronization. By performing the complex non-linear transformation calculations in advance, the system reduces real-time computational burden while maintaining high accuracy during actual image sequence synchronization.
Solution Approach 2:
The patent implements a dynamic synchronization approach where time scaling factors are adjusted based on the instantaneous heart rate and the specific cardiac phase being synchronized. Rather than applying a fixed global scaling factor, the system dynamically modifies time parameters for each phase according to the measured heart rate, allowing accurate adaptation to varying cardiac conditions while using computationally efficient lookup tables and interpolation methods.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for performing a medical procedure includes holding a non-linear dependence between the duration of a given phase within a cardiac cycle and a respective heartbeat rate. First and second image sequences of the dynamic activity of the heart of a patient, acquired at respective different first and second heartbeat rates of the heart, are received. Synchronization between the first and second image sequences is performed based on the non-linear dependence, on the first and second heartbeat rates, and on a given common heartbeat rate. The first and second image sequences are played in synchronization with the common heartbeat rate.