Well Lead Medical Co, Limited v CJ Medical Limited

In construing a patent claim, the court gives the words their natural meaning in the context of the specification, while allowing only such technical tolerance as the skilled person would understand. Descriptions of material as an “embodiment” or “embodiment of the disclosure” do not necessarily bring it within the invention as finally claimed.

For inventive step, a document cross-referred to in prior art is not automatically available as supplementary disclosure. Where several documents are mentioned, the party relying on one must show that the skilled person would have consulted it and selected the particular information relied upon.

A product patent is not excluded as a method-of-treatment patent merely because its description explains a surgical use. Under the third Actavis question, disclosed but unclaimed variants may indicate that strict compliance with the claim is essential.

Well Lead owned a patent for a suction evacuation device used to remove stones and stone fragments. CJ Medical denied infringement and challenged validity on grounds including construction, lack of inventive step, added matter and exclusion of methods of treatment or diagnosis.

The construction issues concerned the meaning of “the same” diameter in claim 1 and whether the flexible, deflectable tip in claim 3 required active deflection. The inventive-step attacks relied principally on Soble, considered with Russo, and Wan. The court also considered whether the patent was excluded under section 4A(1) of the Patents Act 1977, and whether certain product sizes infringed as equivalents.

1. Construction. “The same” diameter in claim 1 meant the same diameter, subject to a limited manufacturing tolerance. A variation of about 5% was appropriate. References in the specification to an “embodiment of the disclosure” or merely “an embodiment” were not embodiments of the invention as finally settled upon by the patentee.
2. Claim 3 did not require active deflection. The flexible tip could be actively or passively deflected, but had to be flexible enough to enable the user to adjust the direction of suction, irrigation or similar functions to a significant extent.
3. Inventive step. A cross-referred document is not automatically available to supplement cited prior art. Where several documents are referred to, the party relying on one must establish that the skilled person would have consulted that document and selected the information relied upon. CJ Medical failed to establish that Russo should be combined with Soble. Nor would it have been obvious to add the pressure-regulating mechanism or use an obturator. Claims 1 and 3 therefore lacked no inventive step over Soble.
4. Wan disclosed an access sheath and its “piercing stylus” would have been understood as a kind of obturator. Claim 1 consequently lacked inventive step over Wan. CJ Medical did not establish that a flexible, deflectable tip was common general knowledge or obvious over Wan, so claim 3 remained valid.
5. The added-matter objection failed. The skilled person would understand the optional accessory side arm to emanate from the proximal sheath.
6. The product claims were not excluded by section 4A(1) of the Patents Act 1977 or article 53(c) EPC merely because the description disclosed a surgical method of using the device.
7. Applying the third question in Actavis, the disclosed but unclaimed variants with 5–20% diameter variation did not infringe as equivalents. Size 14 infringed claims 1 and 3 on normal construction; sizes 10–13 did not infringe.
8. Claim 1 was invalid for lack of inventive step. Claim 3 was valid and was infringed by sales of size 14 only.