Well Lead Medical Co, Limited v CJ Medical Limited
Decision date: 7 March 2025
Neutral citation: [2025] EWHC 492 (IPEC)
Overall AI summary confidence: high
Short overview
This short overview is intended to summarise the case, issues and outcome so far as they are supported by the judgment.
AI confidence in this short overview: high
This was a patent infringement and validity trial about a suction evacuation device for removing stones; Well Lead sued CJ Medical over the Seplou Sheath. The court construed key terms (notably that "the same" diameters means equal within a limited manufacturing tolerance and that a "flexible, deflectable tip" may be actively or passively deflectable) and held claim 1 invalid for lack of inventive step over Wan but upheld claim 3, finding CJ Medical's size 14 product infringed claim 3 (and fell within claim 1), while other sizes did not infringe. Added‑matter and the Art.53(c)/s.4 defence failed.
Ratio decidendi
This summary is intended to identify the ratio decidendi, meaning the legal reasons for deciding and the binding part of the decision.
AI confidence in this ratio decidendi summary: high
The decisive legal findings were (1) claim construction: where a claim term (here "the same" diameters) is central to the settled invention it is to be read as requiring equivalence subject to a realistic manufacturing tolerance (about 5% in this case); (2) novelty/obviousness: Wan rendered claim 1 obvious (so claim 1 invalid), whereas Soble (and an unproven cross‑reference to Russo) did not; and (3) infringement: claim 3, properly construed to allow passive as well as active deflection, was valid and infringed by CJ Medical's size 14 product. Also, a cross‑reference in prior art will only be used to supplement disclosure for inventive‑step purposes if it is shown the skilled person would have consulted and applied that document.
Obiter dicta
This summary is intended to identify obiter dicta, meaning observations made by the way that were not necessary to deciding the case and are not binding.
AI confidence in this obiter dicta summary: medium
The judgment suggested (obiter) that inconsistent use of "embodiment" in a specification can limit which disclosed variants the skilled reader treats as part of the claimed invention; a single market example without evidence of market penetration is generally insufficient to establish common general knowledge; and purposive construction of terms like "flexible" should be tied to the functional requirement in the claim (i.e. sufficient flexibility to enable the claimed adjustment), not broader aspirational descriptions.