Variable Sampling Beamforming for Ultrasound Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-frequency ultrasound imaging systems face challenges in achieving high-resolution images due to increased data sampling rates and processing requirements, which are prohibitively expensive and computationally intensive, especially when using conventional beamforming techniques.
Innovation Solution
The modified variable sampling beamforming technique, which spaces adjacent samples by a quarter of an odd number of wavelengths, allowing for reduced data transfer rates and lower processing requirements by using a single sample per pixel, effectively reducing the ADC sampling frequency and processing power needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional beamforming techniques are used with high-frequency ultrasound, then image resolution is improved, but data sampling rate and processing requirements increase prohibitively
Solution Approach 1:
The patent segments the traditional uniform sampling approach into variable sampling intervals. Instead of sampling at fixed regular intervals across all depths, the system uses finer sampling intervals at shallow depths and coarser intervals at greater depths, dividing the sampling strategy into depth-dependent segments that match the actual information requirements at different ranges.
Solution Approach 2:
The patent applies local quality by adapting the sampling density to the local requirements at different depths. Regions closer to the transducer use higher sampling density where fine detail is more critical, while deeper regions use lower sampling density, optimizing the overall data quality while reducing total data volume and processing requirements.
2Measurement precision
If higher analog-to-digital sampling rates are used, then beamforming accuracy is improved, but hardware cost and processing power requirements increase
Solution Approach 1:
The patent implements dynamic sampling where the sampling rate is not fixed but varies according to depth. The system dynamically adjusts the sampling interval based on the round-trip time of flight calculations, using faster sampling for shallow targets and slower sampling for deeper targets, thereby optimizing accuracy where needed while reducing hardware burden overall.
Solution Approach 2:
The patent changes the sampling rate parameter as a function of depth rather than maintaining a constant high sampling rate. By calculating variable sampling intervals based on the round-trip time of flight for each depth position, the system achieves adequate beamforming accuracy at each depth while significantly reducing the average sampling rate and associated hardware requirements.
3Measurement precision
If more samples per wavelength are captured, then quantization error is reduced, but data transfer rate increases
Solution Approach 1:
The patent applies partial action by capturing only the necessary number of samples per wavelength at each depth position rather than uniformly capturing excessive samples throughout the entire depth range. The variable sampling interval ensures adequate sampling for beamforming at each depth while avoiding the waste of capturing more samples than needed, thereby reducing total data transfer requirements.
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 enables high-frequency ultrasound imaging with a lower number of sample acquisitions at a reduced data transfer rate, cutting the total data captured in half and allowing for lower frequency ADCs, thereby reducing the cost and processing requirements while maintaining image quality and resolution.
Implementation Method 1
short bursts of radio frequency (RF) sound are emitted and received from small electromechanical transduction elements
Implementation Method 2
the detected echoes are used to map the acoustic properties of the tissues from which the sound waves were reflected
Implementation Method 3
a time delay is applied to the excitation pulses for each element such that the wave-fronts constructively interfere along a line at a specific angle, and destructively interfere elsewhere
Implementation Method 4
the first sample time along the selected A-line for a given ultrasound element, relative to its respective transmit time, is determined by calculating a round-trip time-of-flight delay
Data Source
AI summary
The present disclosure provides systems and methods for ultrasound imaging using a modified variable sampling beamforming technique. Unlike conventional methods of variable sampling beamforming, in which in-phase and quadrature samples are obtained for each pixel location, in various example embodiments of the present disclosure, the pixel locations are quadrature-spaced such that for each 5 sample point, an adjacent sample point along an A-line is employed as the quadrature sample. The samples at each array element may be triggered according to the time of flight between a first pixel location and the location of the array element, such that successive samples, corresponding to successive pixel locations along the selected A-line, are obtained such that adjacent samples are spaced by a 10 time interval corresponding to a quarter of an odd number of wavelenghths of the beamformed transmit pulse, and such that only one sample is acquired per pixel.