Spectral Doppler Detection Using Spatial Sub-Gate Diversity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Spectral Doppler ultrasound imaging is limited in sensitivity due to electronic and acoustic noise, and existing noise reduction methods, such as oversampling, are not effective in all cases, especially when fast flow or deep sample volumes restrict sampling rates.
Innovation Solution
The method involves dividing the Doppler gate into sub-gates and using different spatial content or receive apertures to acquire samples, estimating multiple spectra, and combining them to reduce noise variance, thereby improving detectability without requiring oversampling in time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If oversampling is used to reduce speckle noise, then spectral variance is reduced, but sampling rate requirements increase which is not achievable for fast flow or deep sample volumes
Solution Approach 1:
The patent transitions from temporal oversampling to spatial oversampling by dividing the Doppler gate into multiple sub-gates at different spatial locations. Instead of acquiring multiple samples at the same location over time (temporal dimension), the system acquires samples from multiple different spatial positions within the gate simultaneously or in rapid succession, thereby reducing spectral variance without increasing the temporal sampling rate requirement.
Solution Approach 2:
The Doppler gate is segmented into multiple sub-gates or spatial regions, each providing independent spectral estimates. By combining spectra from these spatially separated sub-gates, the system achieves reduced spectral variance through spatial diversity, avoiding the need for temporal oversampling that would be required to achieve the same noise reduction at a single location.
2Object-affected harmful factors
If post-processing non-linear filters are used to reduce noise, then some noise reduction is achieved, but speckle and other variance are not sufficiently reduced
Solution Approach 1:
Instead of applying filters in the temporal or frequency domain, the patent introduces spatial diversity by acquiring spectral estimates from multiple spatial locations within the Doppler gate. This spatial dimension provides additional independent information that, when combined, reduces spectral variance more effectively than temporal filtering alone.
Solution Approach 2:
The patent combines spectral estimates from multiple spatial sub-gates to produce a composite spectrum with reduced variance. By merging independent spectral measurements from different spatial locations, the system achieves superior noise and speckle reduction compared to applying non-linear filters to a single spectral estimate.
3Object-affected harmful factors
If better quality electronic components and transducers are used to reduce noise, then noise is reduced, but system cost and complexity increase
Solution Approach 1:
The system uses existing hardware components to acquire signals from multiple spatial locations within the Doppler gate, leveraging the inherent spatial diversity already present in the ultrasound beam. By processing these spatially separated signals, the system achieves noise reduction without requiring additional specialized hardware or higher-quality components.
Solution Approach 2:
The patent changes the processing approach from improving hardware quality to exploiting spatial parameter diversity. By varying the spatial position of sub-gates within the Doppler gate and combining their spectral estimates, the system achieves noise reduction through parameter variation rather than hardware improvement.
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
This approach reduces spectral variance and noise, enhancing the ability to distinguish flow from noise, and improves the detectability of flow in ultrasound imaging without the temporal sampling constraints.
Implementation Method 1
By transmitting a plurality of pulses (e.g., pulsed wave (PW)) at a location, a Doppler response is generated
Data Source
AI summary
In spectral pulsed wave Doppler imaging, spatial variance in signal and/or noise are reduced by combination of multiple spectra with at least partially decorrelated noise. Rather than requiring oversampling in time, the multiple spectra for one Doppler gate are created from different spatial signals. The Doppler gate is divided into sub-gates, the beamformed sample locations in the Doppler gate are grouped into two or more groups using any selection criterion, and/or different receive apertures are used to simultaneously sample the Doppler gate. Spectra for the gate are estimated from the samples with the different spatial content and then combined.