Spatiotemporal Reconstruction of Vascular Pulse Waves
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Solution Overview
Problem
Current methods for reconstructing cardiac frequency phenomena in the brain lack sufficient temporal resolution to isolate single vascular pulse waves, and existing technologies struggle with motion alias and frequency alias artifacts, limiting the ability to accurately image and separate arterial and venous pulse waves.
Innovation Solution
A method and device utilizing wavelet transforms to extract cardiac frequency phenomena from angiographic data acquired at faster than cardiac frequency, employing complex valued wavelet transforms, high temporal resolution wavelet transforms, and cross-correlation to attenuate motion and frequency alias, allowing for spatiotemporal reconstruction of moving vascular pulse waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cardiac gated methods are used to reconstruct vascular pulse waves, then the imaging can be performed at cardiac frequency, but the temporal resolution is insufficient to isolate single vascular pulse waves
Solution Approach 1:
The patent segments the cardiac cycle into multiple phases by acquiring angiographic data at multiple time points faster than cardiac frequency. This allows isolation and reconstruction of individual vascular pulse waves (arterial, capillary, venous phases) separately, achieving the temporal resolution needed to distinguish single pulse waves while maintaining imaging capability through the segmentation of the cardiac cycle into reconstructable phases
Solution Approach 2:
The patent employs dynamic acquisition by capturing angiographic data at variable time points within the cardiac cycle, using wavelet transforms to dynamically reconstruct images at different temporal resolutions. This dynamic approach allows the system to adaptively resolve single vascular pulse waves while maintaining overall imaging productivity through selective reconstruction of relevant cardiac phases
2Measurement precision
If high temporal resolution wavelet transforms are applied to extract cardiac frequency phenomena, then single vascular pulse waves can be isolated, but motion alias and frequency alias artifacts occur
Solution Approach 1:
The patent converts the harmful motion alias artifact into useful information by analyzing the aliasing pattern itself. The wavelet transform detects and characterizes the motion-induced aliasing, then uses this information to reconstruct images that compensate for the motion effects. The aliasing that was originally harmful becomes a source of temporal resolution information that helps isolate single vascular pulse waves
Solution Approach 2:
The patent changes the temporal sampling parameters by acquiring data at multiple time points faster than cardiac frequency, then uses wavelet transforms to reconstruct images at optimized temporal resolutions. This parameter change allows the system to achieve sufficient temporal resolution to isolate single pulse waves while managing motion alias through multi-parameter reconstruction
3Measurement precision
If angiographic data is acquired at faster than cardiac frequency, then sufficient temporal resolution is achieved, but the data complexity and processing requirements increase
Solution Approach 1:
The patent extracts only the relevant cardiac frequency components from the high-rate angiographic data using wavelet transforms. By filtering and reconstructing only the cardiac-related temporal frequencies, the system reduces the complexity of processing the full high-speed data stream while maintaining the temporal resolution needed to isolate single vascular pulse waves
Solution Approach 2:
The patent applies partial action by selectively reconstructing only the cardiac phases of interest (arterial, capillary, venous) from the excessive high-rate data. Rather than processing all acquired frames equally, the wavelet transform identifies and reconstructs only the relevant cardiac frequency components, reducing processing complexity while achieving sufficient temporal resolution
Data Source
AI summary
The brain appears to have organized cardiac frequency angiographic phenomena with such coherence as to qualify as vascular pulse waves. Separate arterial and venous vascular pulse waves may be resolved. This disclosure states the method of extracting a spatiotemporal reconstruction of the cardiac frequency phenomena present in an angiogram obtained at faster than cardiac frequency. A wavelet transform is applied to each of the pixel-wise time signals of the angiogram. If there is motion alias then instead a high frequency resolution wavelet transform of the overall angiographic time intensity curve is cross-correlated to high temporal resolution wavelet transforms of the pixel-wise time signals. The result is filtered for cardiac wavelet scale then pixel-wise inverse wavelet transformed. This gives a complex-valued spatiotemporal grid of cardiac frequency angiographic phenomena. It may be rendered with a brightness-hue color model or subjected to further analysis.