Within this 282-record dataset, one assignee leads with 45 records, well ahead of the fifth-ranked assignee at 15. The top five assignees together account for 131 records, or 46.5% of all records in scope. Beyond the tenth-ranked assignee (8 records), the field spreads into a long tail of companies with only a handful of filings each, typically tied to specific probe or materials niches.

Filing peaked at 19 records in 2021 and had fallen to 9 by 2024, a 53% decline over that three-year span. However, publication typically lags filing by around 18 months, so the 2025 and 2026 figures in any dataset are necessarily incomplete and should not yet be read as confirming a continued decline. A clearer read on the current trend will only be possible once those years finish publishing.

The A61B subclass (diagnosis and surgery) covers 78.0% of the 282 records, and B06B (mechanical vibration generation) covers 37.9%, reflecting the medical-imaging core of this field. Because a single record can carry multiple IPC codes, these percentages overlap and sum to more than 100%. Adjacent classes tied to materials and solid-state integration, such as H10N and H01L, sit far lower at 10.3% and 6.7% respectively, indicating comparatively less claim density there.

The clearest under-claimed areas relative to the imaging core are piezoelectric composite fabrication, backing material damping profiles, element crosstalk suppression geometry and kerf-fill acoustic isolation — branches that sit in the thinner H10N and H01L classes rather than the dominant A61B and B06B classes. This does not mean these branches are unclaimed, only that filing density is lower there than in core imaging-system claims. Any new filing in these areas should still run a targeted prior-art search rather than assume open ground.

US20170172543A1, assigned to Olympus and filed in 2017, claims an ultrasound transducer array built by stacking an acoustic lens on a laminated body containing a transducer section with first acoustic matching layers, plus a second acoustic matching layer, where the groove width of the transducer section's groove portion is equal to or greater than that of the second matching layer's groove portion. That specific groove-width relationship between the two layers is the operative constraint. A design that inverts that relationship, or removes one of the matching layers entirely, would sit outside this specific claim, though it should still be checked against the wider matching-layer prior art in this dataset.