The ranking covers 71 companies, with the top-ranked assignee holding 31 records against 24 at fifth place and 12 at tenth. That gap shows real concentration at the top but not a monopoly — a meaningful share of the ranked leaders hold double-digit filings, so competitive and licensing analysis needs to look well past the single leader. Major dialysis equipment manufacturers and research-focused university and government holders both appear among the ranked names, reflecting the mix of commercial device development and academic sorbent-chemistry research in this field.

Completed filings fell from 7 in 2021 to 2 in 2024, a 71% drop over that window, which is the most recent period not distorted by publication lag. Filing lags roughly 18 months behind the actual application date, so 2025 and 2026 figures in any dataset will always look artificially low and should not be read as confirming a further decline. The 2021–2024 drop most plausibly reflects consolidation of claim space already staked out around 2017–2018, when filings peaked at 30 in a single year, rather than declining interest in the underlying technology.

Devices for handling body fluids (IPC class A61M) appear in 84.6% of the 221 records in scope, making it the near-universal core claim category. Sorbent and separation chemistry — B01J and B01D — sit at 24.4% and 21.7% respectively, and these two classes overlap heavily with A61M rather than standing as separate filing tracks. Water treatment (C02F) and medicinal preparation classes (A61K) appear in smaller shares, around 8.6% and 7.2%, indicating secondary but real claim territory around dialysate chemistry.

Battery weight reduction, dialysate volume minimisation and wear-comfort harness design all show thinner filing density relative to the core device and sorbent claims that dominate this dataset. These are engineering constraints named directly in the field's own search terminology, which suggests they are recognised as important but not yet heavily claimed. A first filing describing a specific mechanism — for example, a sorbent regeneration cycle-control method tied to a defined dialysate volume reduction — would sit in comparatively open claim space relative to the dense A61M and B01J overlap.

US8404091B2, granted to Baxter International in March 2013, claims a dialysis treatment device with a three-cell architecture: a first cell with an electrodialysis unit, a second cell with a urease compartment and/or sorbent compartment, and a third cell with a second electrodialysis unit, all in fluid communication. It specifically targets urea removal from dialysis waste streams using electrodialysis combined with enzymatic or sorbent processing. Anyone designing a urea-removal subsystem using a comparable multi-cell electrodialysis-plus-urease or sorbent arrangement should review this claim scope closely, since it predates and may read onto more recent wearable-system urea-handling designs.