Patents - Well Lead Medical Co Ltd v CJ Medical Ltd
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| Kidney Stone Author Robert R Wal Licence Public Domain |
Interim Injunctive Proceedings
I have previously discussed Charlotte May KC's judgment in Well Lead Medical Co Ltd v CJ Medical Ltd [2024] EWHC 951 (IPEC) (26 April 2024) in which Well Lead applied unsuccessfully for interim injunctive relief (see Interim Injunction Applications in IPEC - Well Lead Medical Co Ltd v CJ Medical Ltd. 5 May 2024).
The Invention
Judge Hacon described the invention for which the patent was granted as a "device for removing stone fragments from a patient." Kidney stones and gallstones have plagued humankind for ages. Complications resulting from the presence of such stones in the urinary tract or biliary tract often require surgical intervention resulting in several days in hospital. Although advances have been made in lithotripsy, there had been little progress in removing the stone fragments before this invention.
The following shows an embodiment of the invention:
The obturator (90) is inserted into the sheath (20) which is in two parts, proximal and distal and may be rigid, semi0rigid or flexible with a length of between 15 and 56 centimetres, There us a sidearm (50) extending from the sheath which is connected by tubing (70) to a negative pressure system by a collection container (80).
The distal end of the sheath is thereby introduced into the patient’s body either via the ureter or through an incision in the skin and positioned close to the stone. The obturator is removed from the sheath and a cap is placed on the sheath's proximal end to block the passage of air. The negative pressure system is activated. Lithotripsy is performed on the stone. The stone fragments created are drawn by the suction effect from the site of the stone into the collection container.
The claims
The claims
S125 (1) of the Patents Act 1977 provides that for the purposes of that Act an invention for which a patent has been granted shall be taken to be that specified in a claim as interpreted by the description and any drawings contained in that specification. The disputed claims in this case were 1 and 3. Judge Hacon broke them down into the following integers in para [25] of his judgment:
| Claim 1 | |
| 1 | A device for removing a stone, a stone fragment or a foreign body from a patient comprising: |
| 2 | (i) a suction evacuation assembly (10) which includes a sheath (20) and one or more side arms (50, 60); |
| 3 | said sheath (20) having a proximal end (21) and a distal end (22) |
4 | (ii) an obturator (90) having a straight or tapered distal end (92) which is inserted into a proximal end (21) of the sheath (20) and which extends beyond the distal end (22) of the sheath (20) |
| 5 | and is releasably secured to the proximal end (21) of said sheath (20); |
| 6 | (iii) a side arm (50) emanating from the outer surface (24) of said sheath (20), |
| 7 | wherein said side arm (50) further comprises a pressure regulating mechanism (110) in the form of a longitudinal slit in respect of the axis of the side arm (50) |
| 8 | which allows a person using the suction evacuation assembly (10) to increase the negative pressure within the suction evacuation assembly (10) by covering the pressure regulating mechanism (110) or decrease the negative pressure within the suction evacuation assembly (10) by uncovering the pressure regulating mechanism (110); |
| 9 | (iv) optionally, an accessory side arm (60) emanating from the outer surface (34) of said sheath (20); |
| 10 | (v) said sheath (20) having a lumen (23) which is the same diameter as a lumen (53) of said side arm (50) and if present as a lumen (63) of said accessory side arm (60) |
| 11 | (vi) a flexible cap (100) releasably secured to the proximal end (21) of the sheath (20); |
| 12 | (vii) a proximal end of a primary tube (76) releasably secured to said side arm (50) or if present said accessory side arm (60) and a distal end (72) of said primary tube (76) releasably secured to a collection container (80); |
| 13 | (viii) a proximal end of a secondary tube (78) releasably secured to said collection container (80) and a distal end of said secondary tube (78) releasably secured to a negative pressure system (120) |
| 14 | (ix) wherein said obturator (90) can be withdrawn from said sheath (20) and a scope can be inserted into the sheath (20) through the flexible cap (100) and into said patient in order to visualize said stone or foreign body using said scope; and |
| 15 | (x) wherein the negative pressure system (120) can be activated in order to remove said stone or foreign body from said cavity if a diameter of said stone or foreign body is narrower than an inside diameter of said sheath (20) and said side arm (50), |
| 16 | or lithotripsy can be performed on said stone or said foreign body in order to create fragments with a decreased diameter which allow the passage of said fragments within the inside diameter of said sheath (20) and said side arm (50); |
| 17 | and the stone, foreign body and/or fragments can be collected in said collection container (80) |
| Claim 3 | |
| 1 | The device of claim 1 further comprising: a flexible, deflectable tip secured to the distal end (42) of the distal sheath (40) which will enable the user to adjust the direction of suction, irrigation, instrument placement, or removal of a stone, stone fragment or any other foreign body or tissue from a patient |
The Judgment
Judge Hacon considered first whether the patent was valid and, secondly, whether it had been infringed,
Grounds of Revocation
S.72 (1) of the Patents Act 1977 enables the Intellectual Property Enterprise Court to revoke a patent for an invention on the grounds listed in paragraphs (a) to (e). One of those grounds is that the invention is not a patentable invention (s.72 (1) (a)). Another is that the matter disclosed in the patent extends beyond that disclosed in the application as filed (s.72 (1) (d)),
Patentable Invention
The conditions for the grant of a patent are set out in s.1 (1). One of those conditions is that the invention involves an inventive step (s.1 (1) (b)), Another is that the grant of a patent is not excluded by s.4A (s.1 (1) (d)). S.4A (1) precludes the grant of a patent for the invention of a method of treatment of the human body by surgery or therapy.
Inventive Step
S.3 of the Patents Act 1977 provides that an invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art by virtue only of s.2 (2) of the Act and disregarding s.2 (3). S.2 (2) includes within the state of the art all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way.
Pozzoli Test
At para [23] of his judgment in Pozzoli Spa v BDMO SA and another [2007] BusLR D117, [2007] EWCA Civ 588, [2007] 1 Bus LR D117, [2007] FSR 37, [2007] Bus LR D117, Lord Justice Jacob suggested the following test to determine whether an invention involves an inventive step:
"(1) (a) Identify the notional "person skilled in the art"
(b) Identify the relevant common general knowledge of that person;
(2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;
(3) Identify what, if any, differences exist between the matter cited as forming part of the "state of the art" and the inventive concept of the claim or the claim as construed;
(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?"
"(1) (a) Identify the notional "person skilled in the art"
(b) Identify the relevant common general knowledge of that person;
(2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;
(3) Identify what, if any, differences exist between the matter cited as forming part of the "state of the art" and the inventive concept of the claim or the claim as construed;
(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?"
Person Skilled in the Art
The judge noted at para [5] of his judgment that the parties had agreed that the skilled person would be a urologist familiar with the use of a ureteroscope, that is to say, a specialist endoscope used in the ureter for finding and removing kidney stones.
Common General Knowledge
Save for stating that shockwave lithotripsy, ureteroscopy and percutaneous nephrolithotomy are known procedures for treating kidney stones and that progress has been made in shattering such stones but less in removing their fragments, the judgment touches on the skilled addressees' common general knowledge only obliquely in the context of construing claims 1 and 3 and considering differences between those claims and the prior art.
Inventive Concept
Instead of identifying their inventive concepts, the judge construed claim 1 between paras [26] and [40] and claim 3 between [41] and [59] of his judgment.
Prior Art
CJ Medical relied on US patent 6,997,867 B2 for a flexible sleeve slidingly transformable into a large suction sleeve ("Soble") and CN 203042329 U (‘Wan’). Wan was a Chinese utility model that had been invented by the same inventor as the inventor of the patent in suit.
Differences between Claims 1 and 3 and Soble
Soble referred to US Patent No. 5,730,727 for a thumb-conformable suction control regulator (‘Russo’). The judge considered Soble and Russo between para [62] and para [70]. He held at [72] that where the cited prior art refers to more than one document and the party relying on the prior art alleges that just one of those documents would have been considered, there is an evidential burden on that party to show that the skilled person at the priority date would have consulted that document as opposed to any of the others referred to in the cited prior art and would have selected particular information from within the supplementary disclosure if selection is alleged. His Honour found at [78] that CJ Medical had not discharged that evidential burden. For that reason he held that none of the claims of the patent in suit lacked an inventive step over Soble plus Russo.
(1) The cover in Soble was a sleeve and not the sheath as in claim 1.
(2) Soble did not teach the use of an obturator.
(3) Soble had a clamp upstream of the side arm and not a flexible cap as in claim 1.
The judge could find no difference between a sheath and a sleeve and held that a cap would have been an obvious alternative to a clamp. However, the use of an obturator would not have been obvious in his view. He decided at [88] that it would not have been obvious to a skilled person to modify Soble by using an obturator. It followed that neither claim 1 nor claim 3 lacked an inventive step over Soble.
Wan
Wan disclosed the depicted surgical instrument with an irrigation and suction mechanism for washing and expelling fragments following lithotripsy. It is used in percutaneous nephrolithotomy, gallbladder surgery and the fragmentation of bladder stones in women.
As it can be used percutaneously it has a ‘piercing sleeve tube’ which the judge referred to as "piercing stylus". The piercing sleeve tube (3) is connected to a main tube (9) which has a side arm.
The piercing stylus (6) is slightly longer than the combined length of the connected piercing sleeve tube and the main tube. A sealing cap (7) is removed and the piercing stylus is inserted into the main/piercing tube. The stylus and tube are inserted into a pre-cut opening at the surgical site and moved into the patient until the distal end reaches the stone or other target. The piercing stylus is then withdrawn from the tube, the sealing cap is replaced, and an endoscope is inserted into the tube via an aperture (8).
Attachments to the endoscope are used to carry out irrigation and fragmentation at the target site. The side arm is connected to an external suction pump. The suction applied is controlled using a narrow slot in the side arm. Small fragments are removed from the fragmentation site by suction via the narrow space between the inside of the tube and the endoscope. Larger fragments can be removed if the endoscope is withdrawn, presumably to a point proximal to the side arm.
Differences between Claim 1 and Wan
Judge Hacon noted two differences between claim 1 of the Patent and Wan:
- Wan disclosed a ‘piercing stylus’ rather than an obturator; and
- Wan has no collection container.
Differences between Claim 3 and Wan
Added Matter
Integer 9 of claim 1 claimed ‘… optionally, an accessory side arm (60) emanating from the outer surface (34) of said sheath (20);’ CJ Medical argued that the additional matter was that the additional side arm may also emanate from the distal sheath. The judge found that the skilled person reading the -atent would have understood that the additional side arm must emanate from the proximal sheath. The objection of added matter therefore failed.
Method of Treatment
S.130 (7) of the Patents Act 1977 declares that s.2 to s.6 are so framed as to have, as nearly as practicable, the same effects in the United Kingdom as the corresponding provisions of the European Patent Convention ("EPC") have in the territories to which the EPC applies. The provision of the EPC that corresponds to s.4A of the Patents Act is art 53 (c):
"European patents shall not be granted in respect of:
..............
(c) methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body;
"European patents shall not be granted in respect of:
..............
(c) methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body;
this provision shall not apply to products, in particular substances or compositions, for use in any of these methods."
Even though all the claims of the patent were product claims, CJ Medical submitted that the patent nevertheless amounted to a patent for a method of treatment of the human body by way of surgery because the description set out such a method. It argued that a surgeon carrying out that method would infringe the patent. Judge Hacon rejected that submission at [130]:
"It was not established on the evidence that performing the method disclosed in the Patent would necessarily require the use of the device claimed. Even if it had been, I do not accept that the Patent falls within prohibition of s.4A (1) (a) of the 1977 Act and art.53 (c) EPC. The words of art.53(c) reveal that the policy behind the provision is to prohibit only the patenting of certain kinds of methods, those identified. In my view there was no intent to place any restriction on the patenting of any sort of product. Although the expressly excluded products of art.53 (c) are substances and compositions, they are stated to be exemplars."
"It was not established on the evidence that performing the method disclosed in the Patent would necessarily require the use of the device claimed. Even if it had been, I do not accept that the Patent falls within prohibition of s.4A (1) (a) of the 1977 Act and art.53 (c) EPC. The words of art.53(c) reveal that the policy behind the provision is to prohibit only the patenting of certain kinds of methods, those identified. In my view there was no intent to place any restriction on the patenting of any sort of product. Although the expressly excluded products of art.53 (c) are substances and compositions, they are stated to be exemplars."
Infringement
Well Lead objected to the marketing by CJ Medical of a device called the "Selou Sheath". Ar trial the dispute on infringement came down to whether the Selou Sheath had a diameter which was the same as the diameter of the lumen of the side arm in the patent. If the diameters were not the same, Well Lead had a further argument on equivalence. The "Selou Sheath" came in several different sizes but size 14 was within the tolerances specified in claim 1. It followed that the Selou Sheath fell within claims 1 and 3 of the patent.
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