Engineering
Lensed Row-Column Probes: Fix the Travel-Time Model First
A short engineering review of lens-aware ray-traced beamforming for row-column ultrasound arrays, separating travel-time accuracy from attenuation, reverberation and runtime.
By ALEVA | California, USA
Can an acoustic lens widen a volumetric ultrasound probe's field of view without leaving the beamformer behind?
The method
A peer-reviewed 2025 study by Salari and colleagues couples a diverging lens on a row-column array with ray-traced beamforming. Instead of treating the lens as infinitely thin, the method accounts for its geometry and the different sound speeds in the lens and surrounding medium. It finds minimum travel time, not simply the shortest geometric path.
The authors compared predicted travel times with hydrophone measurements and evaluated reconstructed phantom images using spherical and bicylindrical lenses. Their evidence concerns those experimental configurations, not every probe or tissue condition.
The trade-off
A better delay model does not remove lens attenuation or reverberation. Lens material, shape and alignment still affect the usable imaging region. The paper leaves an optimized GPU implementation to future work; it does not establish real-time GPU performance.
A proposed OEM acceptance test
Our engineering recommendation is to evaluate lens and reconstruction as one controlled configuration:
Record lens geometry, material properties, alignment and the assumed propagation model.
Replay the same captured data through the reference and candidate; compare target position, point-spread width and contrast on-axis and off-axis.
Measure timing residuals, attenuation, reverberation and complete reconstruction time separately. Define acceptance limits before testing.
Bottom line: a lens change should trigger review of the beamformer's travel-time model, not only an enclosure or probe-interface update.
For project context, see ALEVA's custom probe design checklist. This is public research analysis, not measured ALEVA performance or a commercial implementation claim.
Source
Salari A, Audoin M, Tomov BG, Yiu BYS, Thomsen EV, Jensen JA. Beamformer for a Lensed Row-Column Array in 3-D Ultrasound Imaging. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. February 2025;72(2):238-250. DOI: 10.1109/TUFFC.2025.3526523 · DTU research record and accepted manuscript.
No research figures or clinical images reproduced.