Well Lead Medical Co Ltd v CJ Medical Ltd [2025] EWHC 492 (IPEC) (07 March 2025)

This judgment was handed down remotely at 10.30am on 7 March 2025 by circulation to the parties or their representatives by e-mail and by release to the National Archives.

.............................

HIS HONOUR JUDGE HACON

Judge Hacon:

Introduction

1. European Patent No. 3 760 143 B1 (‘the Patent’) claims a device for removing stone fragments from a patient. Towards the start of the Patent it indicates the main purpose of the invention: ‘Kidney stones and gallstones have plagued mankind for ages’.

2. The Patent concerns an advance in the technique of endoscopic lithotripsy. Lithotripsy is the application of energy to break a kidney stone or gallstone into fragments. The device claimed uses suction to draw out the fragments, the suction being applied via a sheath which has been inserted into the urinary tract to reach the stone.

3. The Patent is owned by the claimant (‘Well Lead’). The defendant (‘CJ Medical’) is alleged to have infringed by marketing its products. CJ Medical denies infringement and says that the Patent is invalid.

4. Richard Davis KC and Nick Zweck appeared for Well Lead, Guy Tritton and Laura Adde for CJ Medical.

The skilled person

5. It was agreed that the skilled person is a urologist who would be familiar with the use of a ureteroscope, a specialist endoscope used in the ureter for finding and removing kidney stones. The ureter is the tube that carries urine from the kidney to the bladder.

6. CJ Medical made the point that the invention as claimed has a purpose wider than just dealing with kidney stones and that the CGK of the skilled person should reflect that. I agree, but it did not seem to make a difference to the issues and arguments.

The expert witnesses

7. Well Lead’s expert was Kasra Saeb-Parsy. Mr Saeb-Parsy is a consultant urologist surgeon at Cambridge University Hospitals NHS Foundation Trust. CJ Medical’s expert was Bhaskhar Somani. He is a consultant urologist surgeon at University Hospitals Southampton and Editor in Chief of the Journal of Clinical Urology. Both Mr Saeb-Parsy and Professor Somani were knowledgeable in the field of endoscopic removal of kidney stones and were mostly helpful witnesses.

8. Well Lead raised an issue about Professor Somani. There was in evidence a transcript of a short video on YouTube in which Professor Somani explains the virtues of the Seplou Access Sheath, which is CJ Medical’s sheath alleged to infringe the Patent. He begins:

‘My name is Professor Bhaskar Somani and I’m going to share with you the advantage of using the suction ureteral access sheath and I’ve used the Seplou Access Sheath which I think is brilliant. And I think suction sheaths are quite revolutionary and will change the game of endourology.’

9. Professor Somani did not mention this endorsement in his written evidence for the court. It was raised in cross-examination. He said that he engages in education of a wide audience, not specifically CJ Medical, and that he has in the past promoted products marketed by others, including Well Lead. More dubiously, he said that in the YouTube video concerned he was not promoting a particular product.

10. It is well established that an expert must disclose any matter which may give rise to a material conflict of interest to the solicitors acting for the party for which the expert is giving evidence. The solicitors must then disclose the matter to the other parties in the case and to the court, see Zuber Bux v The General Medical Council [2021] EWHC 762 (Admin) at [23] to [47], in which Mostyn J summarised the applicable authorities.

11. Professor Somani stated in oral evidence that he did not inform CJ Medical’s patent attorneys about his YouTube presentation of the Seplou Access Sheath. He undoubtedly should have done. Well Lead was fully entitled to raise concerns. But I have no reason to believe that CJ Medical retained Professor Somani its expert in order to exploit a perceived bias in its favour. It was not suggested that Professor Somani has any commercial relationship with CJ Medical regarding the recommendation of its products or anything else.

12. Well Lead pointed to two instances where Professor Somani had modified his view in cross-examination, although both seem to me probably to have been reasonable corrections. I believe that notwithstanding his enthusiasm for CJ Medical’s product Professor Somani was endeavouring to state his honest views and that I should give his evidence equivalent weight to that of Mr Saeb-Parsy.

Technical Background

13. At the priority date there were three alternative procedures for treating kidney stones:

(1) Shockwave lithotripsy. This a non-invasive technique. Shockwaves in the form of pressure waves are applied to the exterior of the body, close to the kidney. The stone is broken by the treatment, typically over 45-60 minutes. The fragments are excreted naturally.

(2) Ureteroscopy. A ureteroscope is inserted into the ureter. Usually the ureteroscope is contained in a ureteral access sheath. The flexible scope is extended beyond its sheath into the entrance to the kidney and in the case of some patients a little beyond the entrance, depending on the size and dilation of the kidney’s structure. An instrument which applies local lithotripsy is passed along a channel in the ureteroscope to reach the stone and to fragment it. The fragments are either removed mechanically by further instruments or are excreted.

(3) Percutaneous nephrolithotomy (PCNL). PCNL is more invasive than URS. One or more incisions are made in the patient’s back to gain access to the kidney by keyhole surgery. A fine needle is inserted to pierce the kidney, then a dilator is passed along the opening made by the needle to make it large enough for a sheath to be inserted. The sheath is used by the surgeon as a conduit for a nephroscope, another specialist endoscope, this one used specifically for kidney stones.

The Patent

14. The background section of the specification provides an indication of the acknowledged prior art and the nature of the inventive concept intended by the patentee. It explains that although advances had been made in lithotripsy, there had been little progress in removing the stone fragments.

15. Paragraph [0003] says that great strides have been made in the treatment of patients suffering from a stone, but not in every aspect of treatment:

‘… all the inventions focus on the access and fragmentation of the stones. Extracorporeal shock wave lithotripsy uses pressure waves to crush the stone, but then requires the patient to pass the stone fragments on their own. Amplatz percutaneous nephrostomy sheaths and various ureteral sheaths allow access to the stones for lithotripsy.

However, they require either the patient to pass the stone fragments on their own or to have the stone removed at the time of lithotripsy using pressure irrigation, stone basket, and/or stone forceps.’

16. The specification describes known techniques for removal and concludes the background section by saying:

‘While the stone retrieval devices known in the prior art performed adequately, there is significant room for improvement. The stone retrieval device disclosed below is an improvement over those known in the art.’

17. Paragraph [0017] says that use of the invention goes beyond the treatment of kidney and other stones and that it may also be used for tissue ablation and morcellation. Morcellation is the cutting of tissue into smaller pieces to allow removal.

18. Figure 10 shows an embodiment of the invention:

A diagram of a pipe with numbers and a pipe

Description automatically generated with medium confidence

19. Among the key components is the obturator 90, shown separately on the right. Another is the sheath 20. The sheath is in two parts, proximal (the upper part as represented in the figure) and distal. The sheath may be rigid, semi-rigid or flexible and has a length of about 15 to 65cm. There is a side arm 50 emanating from the proximal sheath. This is connected by tubing 70 to a negative pressure system 120 via a collection container 80. At the proximal end of the proximal part of the sheath is a flexible cap 100 which is releasably secured to the sheath.

20. In use the obturator is inserted into the proximal end of the sheath and extends beyond the distal end. Figure 16 largely illustrates this arrangement, although not showing the obturator 90 extending beyond the end of the sheath. This is part of Figure 16:

A drawing of a device

Description automatically generated

21. The assembly as a whole is marked 10 (which includes the negative pressure system and the collection container, not shown here). The two parts of the sheath 20, the proximal sheath and the distal sheath are marked 30 and 40 respectively. Also shown is an optional side arm 60.

22. Just visible in Figure 16 but not marked is a slit in the side arm 50. This is shown in plan view in Figure 14:

A black and white drawing of a line with numbers and a circle

Description automatically generated

23. The slit in the side arm is marked 110. The surgeon can increase the suction pressure of the system by covering the slit with his or her finger and decrease the pressure by wholly or partly uncovering the slit. 23 represents the lumen of the sheath, 53 is the lumen of side arm and 63 is the lumen of the optional side arm 60.

24. The specification explains how the product claimed would be used in the typical instance of treating a patient suffering from a kidney stone using lithotripsy. The obturator is introduced into, and then secured to, the proximal end of the sheath. The function of the obturator is to allow the surgeon to manoeuvre and guide the sheath more easily. The distal end of the sheath is thereby introduced into the patient’s body. This could be via the ureter or percutaneously, i.e. through an incision in the skin. The distal end of the sheath is positioned close to the stone. The obturator is disengaged from the sheath and removed. A flexible cap is attached to the proximal end of the sheath to block air access. The side arm is connected, via a collection container, to the negative air pressure system. A scope is inserted into the sheath at the proximal end, through the flexible cap and into the patient. The scope is used to visualise the stone. 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 via the gap between the endoscope and the sheath lumen, or alternatively through the entire sheath lumen after the endoscope has been retracted. The fragments move into the side arm and then along a connecting tube into the collection container.

The claims

25. Claims 1 and 3 were the claims in issue, set out here with claim 1 divided into 17 integers:

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

Construction

Claim 1 - sheath lumen and the side arm lumen have ‘the same’ diameter

26. Integer 10 requires ‘said sheath having a lumen which is the same diameter as a lumen of said side arm and if present as a lumen of said accessory side arm’. The optional accessory side arm can be left to one side. The issue is what ‘the same diameter’ means, as between the sheath and the main side arm.

27. Paragraph [0020] of the specification states:

‘In one embodiment, the diameter of the lumen 53 of the side arm 50 is up to 20% smaller than the diameter of the lumen 33, 43 of the proximal 30 and the distal sheath 40. In another embodiment, the diameter of the lumen 53 of the side arm 50 has a diameter which is the same or up to 20% larger than the diameter of the lumen 33, 43 of the proximal 30 and the distal sheath 40. According to the present invention, the diameter of the lumen 53 of the side arm 50 is the same as the diameter of the lumen of the sheath 23, 33, 43 to facilitate the efficient evacuation of stones, stone fragments or other foreign bodies.’

28. Paragraph [0015] says:

‘One important feature of the current invention is a sheath 20 that has a side arm 50 that has an identical or nearly identical luminal circumference.’

29. The same paragraph says more about this, explaining the reason for identical or nearly identical luminal circumferences (and therefore diameters):

‘When the stone fragments are larger, but still small enough to enter the sheath lumen 23, the endoscope can be withdrawn to a location that is just proximal to the distal end 52 of the side arm 50. … With the scope in this position, the sheath 20 and the side arm lumens now have a similar caliber channel with the side port channel equal or slightly larger than the sheath channel. The stone fragments or foreign body have an unimpeded evacuation route. This allows a continuous evacuation channel for the stone fragments to reach the collection container 80.’

30. Well Lead submitted that the first two embodiments referred to in paragraph [0020] must be taken to be embodiments of the invention and therefore the same lumen diameter means that the diameter of the side arm lumen may be + 20% the dimension of the sheath lumen.

31. The difficulty with this submission is that the word ‘embodiment’ is used in confusingly different ways in the specification. Sometimes the description speaks of an ‘embodiment of the present invention’, which is clear. Elsewhere it refers to an ‘embodiment of the disclosure not forming part of the present invention’, equally clear. But there is also discussion of matter which is either an ‘embodiment of the disclosure’, just an ‘embodiment’ or a ‘preferred embodiment’.

32. Well Lead referred to the current Guidelines for Examination in the EPO (March 2024), Part F, Chapter IV-17, which includes this at 4.3:

‘An inconsistency between the description and the claims cannot be removed by introducing at the beginning of the description a generic statement such as "embodiments not falling under the scope of the appended claims are to be considered merely as examples suitable for understanding the invention" without indicating which parts of the description are no longer covered. To remove the inconsistency, such a statement has to refer to specific embodiments (e.g. "Embodiments X and Y are not encompassed by the wording of the claims but are considered as useful for understanding the invention").

The terms "disclosure", "example", "aspect" or similar, on their own, do not necessarily imply that what follows is not encompassed by an independent claim. Unambiguous expressions have to be adopted to mark an inconsistent embodiment (e.g. by adding "not encompassed by the wording of the claims", "not according to the claimed invention" or "outside the subject-matter of the claims") instead of merely replacing the terms "embodiment" or "invention" by one of the aforementioned terms.

As long as the resulting text of the description does not present conflicting information to the reader, an inconsistent embodiment may also be remedied by ensuring that it is not referred to as being "according to the invention" throughout the description and by complementing the reference to it with an explicit statement to the effect that it is retained due to being useful for understanding the invention (e.g. "embodiment useful for understanding the invention", "comparative example from background art".’

33. I do not know that the Guidelines current during the period of prosecution of the Patent were the same as the current version. Even if they were, the Guidelines do not advance matters much.

34. My impression is that during prosecution some effort was made to make the specification consistent with the claim, but not overmuch. By comparing the Patent with the application for the Patent it appears that the words ‘according to the present invention’ were added to paragraph [0020] and placed before the words ‘the diameter of the lumen of the side arm is the same as the lumen of the sheath’. It suggests that the draftsperson wished at this stage to clarify that having the diameters the same was central to the invention as finally settled upon.

35. It is possible that at the time the examiner took a relaxed view about other parts of the specification: provided that no embodiment in which the respective lumen sizes are not substantially the same was expressly stated to be an embodiment according to the invention, any references simply to ‘an embodiment’ or ‘an embodiment of the disclosure’ where such embodiments were, by the time of grant, no longer part of the invention, could be left alone.

36. Taking a purposive approach to this point of construction does not help much. The only identified purpose in having the two diameters the same or about the same is to facilitate the efficient evacuation of stones, fragments or foreign bodies. Neither of the experts in this case has expertise in fluid dynamics such as to confirm that a close similarity in diameters is necessary for that purpose. Nor would the skilled person. It is to be noted, though, that this stated purpose is in a sentence within paragraph [0020] which says that the lumen diameters are the same ‘according to the invention’.

37. CJ Medical submitted that ‘the same’ in integer 10 of claim 1 should be given its natural meaning, subject to some limited leeway indicated in paragraph [0015], such as + 5% manufacturing tolerance.

38. The words ‘the same as’ in claim 1 are, as used in the claim itself, clear and not ambiguous. They are consistent with a statement in the one sentence of paragraph [0020] which explicitly refers to what is covered by the invention and are also consistent with the words of paragraph [0015], again unambiguously referring to the claimed invention.

39. In my view the skilled reader of the Patent would have understood that ‘the same’ means what it says, subject to a limited tolerance. It seems to me that a manufacturing tolerance of + 5% is probably about right.

40. In the patent specification, references to an ‘embodiment of the disclosure’ or to ‘an embodiment’ are not to be taken as embodiments of the invention as finally settled upon by the patentee.

Claim 3 - a flexible, deflectable tip

41. Paragraph [0025] of the Patent discusses flexibility and deflection. I will separate the relevant part of the paragraph into two parts for reasons that will become apparent:

[0025] In one embodiment of the present invention, the distal end 42 of the distal sheath 40 includes a flexible tip 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 flexible tip has a length in the range of 4 to 10 cm. The flexible tip is deflectable to any angle desired by the user of the device. The flexible tip may have memory which is to say that the flexible tip may be configured into a specific angle or form and retain that configuration. It can be inserted into the body in another configuration, i.e., straight, until it is manipulated into a specific location by the user of the device. The flexible tip can then be reverted back to the original shape.

The distal portion of the distal sheath can also be deflected either actively or passively. In the active mold, the distal sheath is straight. A cable or some other mechanism along the inner (lesser) curvature of the bend can be either withdrawn or shortened gradually thus bending the distal portion 42 of the distal sheath 40 to a maximum of 360 degree. In the passive mold, the distal portion 42 of the distal sheath 40 has an inherent bend up to 360 degrees. The bendable portion can either be gradually straightened by withdrawing or shortening a cable or some other mechanism along the outer (greater) curvature of the bend or by using the rigid/semi-rigid obturator. In the preferred embodiment the bending section is about 4-6 cm. The flexible distal segment 42 is deflected by active mode.’

42. It was agreed that the two uses of the word ‘mold’ are probably mistakes and that substituting ‘mode’ gives the right meaning.

43. The first six sentences of paragraph [0025] are about the tip. The remainder is about the distal portion of the distal sheath. It is clear that the two are not the same. Claim 1 speaks of the sheath and that it has a proximal and distal end. There is no mention of a flexible tip. Claim 3 says ‘The device of claim 1 further comprising: a flexible, deflectable tip secured to the distal end of the distal sheath …’ (my emphasis).

44. The second section of paragraph [25] begins: ‘The distal portion of the distal sheath can also be deflected either actively or passively’. I think that on a more natural reading, the idea being communicated is that like the tip the distal portion of the distal sheath can be deflected by active or passive means, though it could be read to distinguish the tip from the distal portion of the distal sheath in this regard. It is clear, however, that paragraph [0025] treats the deflection of the tip and the deflection of the sheath as two distinct features.

45. I have not found CJ Medical’s case on this easy to follow. It appears, or at least appeared, to be that deflection of the tip must be active, i.e. achieved by a cable or other means pulling in one direction or another under the direction of the surgeon. In its opening written submissions CJ Medical said that there were three possible constructions of claim 3. Having rejected the first two, CJ Medical set out the third, which it adopted. I read it to mean that ‘deflection’ in claim 3 means active deflection only:

‘Construction Three: That the tip of the sheath may be deflected by the surgeon using cables or other mechanism running along respectively the inner or outer curvature of the sheath as described in the Patent at [0025]. This interpretation has much to commend itself for the following reasons:

i. It obviously does have considerable support in [0025];

ii. A preferred embodiment is that the flexible distal segment (i.e. the tip) is deflected by active mode. The draftsman may thus have thought this active mode worthy of a separate claim to Claim 1;

iii. Instinctively, one can see that a surgeon being able to use a cable or other mechanical means to actively deflect or straighten a sheath (and its tip) might have something inventive about it if in the prior art, CGK sheaths had been flexible but did not have such an active control means available to the surgeon. Indeed, Professor Somani’s view is that if the third interpretation is right, Claim 3 is inventive over traditional prior art CGK sheaths i.e. was not inherently obvious over CGK [1].

iv. The wording of Claim 3 “…which will enable the user to adjust the direction..” is consonant with the idea of a surgeon being empowered to adjust the direction of the tip of a sheath through means put at his or her disposal (e.g. cables).’

46. In CJ Medical’s closing argument, its case on the construction of claim 3 was put this way (counsel’s italics):

‘Claim 3 is about disclosing a flexible, deflectable tip which will enable the user (surgeon) to adjust the direction of e.g. an endoscope (instrument). A merely flexible tip (however flexible) cannot do that. The endoscope can adjust the direction of the sheath but the sheath cannot adjust that do that but not the other way around. A truly passive flexible tip (hyperflexible or otherwise) cannot “adjust” the direction of an instrument such an endoscope.

Construction Three is taught (enabled) in [0025]. Using the cable or other means along the curvature of the bend (inner curve when sheath is straight (active) and outer curvature when sheath is pre bent (passive) is clearly taught. It is these means that enable the use to adjust the direction of the sheath. The wording of the claim and the teaching are entirely consonant with each.’

47. The emphasis here is on flexibility enabling the user to adjust direction. I agree, but not that it enables the surgeon to adjust the direction of the endoscope itself, rather the direction of suction etc. Direction of suction etc. may be assisted by the separate adjustment of the endoscope but this is not what claim 3 is concerned with. This aside, the submission seems again to be that claim 3 requires active deflection.

48. In oral closing submissions CJ Medical’s counsel gave some attention to the part of paragraph [0025] which refers to the mode in which the tip has a memory. It is pre-bent upon insertion and then straightened using a cable or some other mechanism.

49. The embodiment with the memory discussed in paragraph [0025] is inserted straight and if required manipulated into another shape which, unless further manipulated, it will retain. This seems to me to have nothing to do with whether the manipulation, the deflection, is active or passive.

50. Well Lead submitted that deflection may be active or passive. According to Well Lead, passive deflection involves pressing the tip against a structure within the kidney or other part of the body so as to deflect the tip in one direction or another. In my view this construction better fits the words of the claim and the specification as a whole.

51. Well Lead had a point on the construction of ‘flexible’. It submitted that the word should be purposively construed. The tip has to be flexible enough to be suitable for the treatment of any kidney stone a surgeon is liable to come across. This assumes that claim 3 would be understood as being directed solely to ureteroscopy and both sides appeared to take that view. Flexibility according to Well Lead means that the tip must be flexible enough so that it could potentially access any of the calyces in the kidney. This must include the calyx which is the most difficult to reach. The point can be illustrated by this diagram:

A diagram of a kidney

AI-generated content may be incorrect.

52. The eight bulb-shaped structures in the diagram are calyces within a kidney. The tip must be flexible enough to bend into the most awkwardly placed calyx. The diagram illustrates the tip reaching the lowest calyx, which as shown is the most difficult to reach but one.

53. There is support for this construction of ‘flexible’ in paragraph [0025] which says that the tip is deflectable to any angle desired by the user. However, claim 3 is not so specific. In my view, the tip must be flexible enough to enable the user adjust the direction of suction etc. to some significant extent, but nothing more than that.

54. I found the evidence on deflection largely unhelpful. Mr Saeb-Parsy said in his written evidence that the tip in claim 3 can be actively or passively deflected, not on the basis of his technical knowledge, just from reading paragraph [0025] of the specification. Professor Somani in his written evidence blurred the distinction between the tip and the distal portion of the distal sheath and seemed also to blur the difference between active and passive deflection on the one hand and alternative shapes that a tip with memory may have on the other.

55. I was referred to several passages of Professor Somani’s cross-examination which were said to support Well Lead’s construction of claim 3. I will not set them out, partly because they are long and partly because I do not find them of help on points of construction.

56. This is from Mr Saeb-Parsy’s oral evidence to which my attention was drawn:

‘Q. If the tip was merely passive, in other words it just could flex, but there was no control means to bend it, the surgeon could not adjust the direction of the endoscope, could he, using the sheath? It would be the endoscope adjusting the direction of the sheath, not the other way round; correct?

A. Sorry, could you repeat that again?

Q. You have a passively flexible sheath; all right? Something like this, but there is no means for bending it, there is no wire or anything like that to bend it. I cannot use that by inserting, to change the direction, can I, of the endoscope. It is passive. It does nothing. It can follow the way the endoscope changes, but it cannot adjust the direction of the endoscope, can it?

A. Correct.’

57. The first question may have been directed towards whether a tip that is deflected only passively would be of practical use. But the question which Mr Saeb-Parsy understood and answered was about the passive deflection of the sheath, not the tip.

58. I am thrown back on to the words of claim 3. The user must be able to adjust the direction of suction, irrigation, etc. If it were technically possible to do this only by using active deflection, the skilled person would know that active deflection must be implied. But I was not shown any such evidence.

59. The words of claim 3 do not specify active or passive deflection of the tip, one way or the other. I conclude that it could be either. This is consistent with the more natural reading of paragraph [0025]. The tip must be flexible enough to enable the user to adjust the direction of suction etc.

The prior art

60. CJ Medical cited three items of prior art in support of its allegation that the Patent lacks inventive step, of which two were relied on at trial:

(1) US Patent No. 6,997,867 B2 (‘Soble’), and

(2) Chinese Utility Model No. CN 203042329 U (‘Wan’).

61. Soble referred to other patents, including US Patent No. 5,730,727 (‘Russo’). It was agreed that the skilled person should be taken to have read Soble and Russo in combination, although there was a dispute about the relevance of the other patents referred to Soble.

Soble and Russo

62. Soble discloses a sleeve which is placed over a flexible endoscope. The sleeve has a port, i.e. a side arm, which is connected to a vacuum source. In use, the endoscope is substantially withdrawn from the sleeve when the necessary visualisation is complete, the sleeve’s proximal opening (that nearest the surgeon) is sealed off so that the only passage is between the vacuum source and the distal end of the sleeve which will be close to, for instance, a fragmented stone. The entire sleeve becomes what the Patent calls a suction lumen.

63. This is Figure 1:

A drawing of a pipe

Description automatically generated

64. It shows an endoscope 50 over which the sleeve 10 is placed and a port 20 which connects the lumen of the sleeve 30 to a vacuum source.

65. This is Figure 2:

A drawing of a hose

Description automatically generated

66. This figure shows the endoscope withdrawn beyond the opening to the port and the seal 40 closed. The suction via port 20 pulls material from the distal opening 15 of the sleeve.

67. The invention in Russo is entitled ‘Thumb conformable suction control regulator’. The device is used with medical devices. This is Figure 1:

A drawing of a device

Description automatically generated

68. A catheter 13 is connected to the front inlet 14. The body of the device 11 provides a passage from the front inlet to the exit 16. Suction may be applied at the exit 16. Mid-way is a side stem 18 with an interior oval-shaped passage 19 terminating at an outlet 20, with side ledges 24 and 25. In use a boot cover 12 rests on the side ledges. The boot cover has a flexible top diaphragm 30 and two side vent slots 31 and 32.

69. Figures 6 and 7 show the boot cover in place and how the device works:

A diagram of a pipe

Description automatically generated with medium confidence

70. Suction is applied at 16. In the open mode of Figure 6, air may pass through the side vents 31 and 32 reducing or eliminating the suction effect at the front inlet 13. In the closed mode of Figure 7, the surgeon has applied their thumb on to the flexible diaphragm 30, closing the inlets and causing a suction effect to be applied at inlet 13.

The law on inventive step

71. One point of law arose. It is well established that where the cited prior art expressly refers to other material which may be consulted by the reader, that further material becomes in principle available to supplement the cited disclosure when considering inventive step, see Pfizer Ltd’s Patent [2001] FSR 16, at [66]. However, there is no unqualified assumption that the information contained in a cross-referred document can always be taken to supplement the cited disclosure. As Laddie J said in the paragraph of Pfizer just referred to:

‘When any piece of prior art is considered for the purposes of an obviousness attack, the question asked is “what would the skilled addressee think and do on the basis of this disclosure?”’

72. Where the cited prior art refers to more than one document which can be consulted by the reader and the party relying on the prior art alleges that just one such document would have been considered, there is an evidential burden on that party to show that the skilled person at the priority date (a) would have consulted that document as opposed to any of the others referred to in the cited prior art and (b) would have selected particular information from within the supplementary disclosure if selection is alleged.

Inventive step over Soble

Combining Soble and Russo

73. Russo is referred to in columns 7 and 8 of Soble:

‘Whether the suction port is linked to a source of positive pressure, negative pressure or both, the suction port may be further connected to a switch or valve that turns the pressure on and off (e.g. a trumpet valve), and/or a pressure-regulator. Examples of such control devices are described in publications such as U.S. Pat. No. 5,882,348 to Winterton et al., U.S. Pat. No. 5,938,589 to Wako et al., and U.S. Pat. No. 5,730,727 to Russo, all incorporated herein by reference.’

74. Russo is relied on by CJ Medical in support of a necessary part of the argument on inventive step that it was obvious to modify the device in Soble to include the feature in integer 7 of the Patent: ‘wherein 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’.

75. The relevant passage in Soble cross-refers to two other US patents in addition to Rosso. They were not in evidence and were not shown to the experts. All that can be said about them is that apparently they disclose ‘a switch or valve that turns the pressure on and off (e.g. a trumpet valve), and/or a pressure-regulator’. It is possible that one or both disclose more than one alternative type of device. It is therefore not possible to say how many alternative pressure control devices there were from which the skilled person would have had to make a selection.

76. It is also entirely possible that the skilled person would have thought that one or other of the devices disclosed in the two other US patents would be significantly more suitable for attachment to the Soble device than that disclosed in Russo. Were that the case, it may well not have been obvious to use the Russo device. I cannot know.

77. CJ Medical submitted that this ship had sailed because the court approved an order at the CMC in which Soble incorporating Russo by reference was listed as a citation in respect of which lack of inventive step could be argued. I reject this submission. The judge who heard the CMC would have had no reason to consider the merits of any aspect of the proposed argument on inventive step and she certainly made no ruling on the matter.

78. The evidential burden on CJ Medical has not been met with regard to combining the disclosure of Russo with Soble. For that reason alone I find that none of the claims of the Patent lack inventive step over Soble plus Russo. There were other arguments but given my finding that Russo cannot be taken into account I will consider only those directed to the content of Soble.

Differences between claim 1 and Soble

79. Well Lead submitted that there are three relevant differences between Soble taken alone and claim 1:

(1) The cover in Soble is a sleeve, not the sheath of claim 1.

(2) Soble does not teach the use of an obturator.

(3) Soble has a clamp upstream of the side arm, not the flexible cap of claim 1.

Sleeve v sheath

80. The experts were agreed that the terms ‘sleeve’ and ‘sheath’ are sometimes used interchangeably. The skilled reader of the Patent would not rely on ‘sheath’ as a term of art to distinguish such a thing from a sleeve. Whether there is a relevant difference between the sleeve of Soble and the sheath of the Patent depends on the respective ways in which each is used.

81. Mr Saeb-Parsy for Well Lead identified three distinctive features of the Soble sleeve that would not make it suitable for use as a sheath in the invention of the Patent: the Soble sleeve covers the scope completely, it moves in tandem with the scope and it fits the scope snugly. None of these distinctions survived in cross-examination. Professor Somani said that there was no relevant distinction between the Soble sleeve and the sheath of the Patent and he maintained this in cross-examination. I accept Professor Somani’s evidence on this.

No obturator in Soble

82. The patented device uses the obturator to push the sheath through the ureter towards the kidney (in a kidney stone application). Soble does not mention any obturator.

83. CJ Medical argued that Soble is not concerned with how the sheath gets into the ureter. The starting point for the description in Soble has the sheath already in the ureter. It was acknowledged CGK that an obturator could be used to push the sheath into and along the ureter.

84. Mr Saeb-Parsy gave unchallenged evidence that obturators are supplied with pre-packaged access sheaths. He said that it was highly unlikely, if not impossible, that as of the priority date an obturator could be found to fit a sheath that was designed and shaped for an endoscope as in Soble. None of the obturators available for the commonly used access sheaths at the priority date would have fitted the Soble sheath. The skilled person would also have thought that if an attempt was made to use an obturator there would be difficulties with (i) releasably securing the obturator to the sheath, (ii) avoiding wrinkling of the sheath, (iii) fitting a sheath adapted for an obturator on to an endoscope and (iv) maintaining the sheath in position when the obturator is removed if the sheath is made from a flexible, soft material, one of the options in Soble.

85. It was common ground that the sleeve/sheath discussed in Soble could be manoeuvred through a ureter to reach a kidney using the endoscope without having to go to the trouble of prior insertion with an obturator. Because of this and Mr Saeb-Parsy’s evidence, I find that it would not have been obvious to use an obturator.

A clamp in Soble instead of a flexible cap

86. Well Lead argued that a clamp was required in Soble because when it was undone it allowed the withdrawal of the scope to be sufficiently free of friction.

87. Soble is clear that other known means can be used to seal off the proximal opening of the sheath against the enclosed scope aside from a clamp, among them a rubber band. It was an agreed part of the CGK that flexible caps were commonly used to achieve a seal between a sheath and a scope by the time of the priority date. CJ Medical argued that using a flexible cap instead of a clamp would have been seen by the skilled person as an obvious alternative. That was Professor Somani’s view, which I find persuasive.

Conclusion on Soble and inventive step

88. CJ Medical have not met the evidential burden required to show that the skilled person would in addition have considered the disclosure of Russo regarding a pressure regulating mechanism. It would not have been obvious to the skilled person to modify Soble by adding a pressure regulating mechanism or by using an obturator. Neither claim 1 nor claim 3 of the Patent lacks inventive step over Soble.

Wan

89. Wan is a Chinese utility model with the same inventor as the Patent. It discloses a surgical instrument with an irrigation and suction mechanism for washing and expelling fragments following lithotripsy. It is used in PCNL (see above), gallbladder surgery and cystolithotripsy (fragmentation of bladder stones) in women. Because it can be used percutaneously it has a ‘piercing sleeve tube’ and what was alternatively translated as a ‘piercing stylus’ or ‘piercing needle’. The alternatives made no difference so I will call it a ‘piercing stylus’.

90. Figure 5 shows an embodiment:

A drawing of a pipe

Description automatically generated

91. 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. In use, the 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 to 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.

92. Two embodiments of the invention are described. The principal difference is that in embodiment 2 the piercing sleeve tube 3 and the main tube 9 are glued together, whereas in embodiment 1 they are connected via a connecting structure. The parties were agreed that an attempt to connect the sleeve tube to the main tube during the course of their use in the body would be dangerous and that embodiment 2 would be seen as the sole workable alternative.

93. The evidence of both experts was that Wan disclosed a sheath for an endoscope which could be used either for PCNL or for ureteroscopy.

Piercing stylus, obturator and trocar

94. There was debate about the function of the piercing stylus in Wan as the skilled person would have perceived it to be.

95. Mr Saeb-Parsy discussed what he said would have been seen by the skilled person as puzzles in his or her attempt to understand Wan. I will quote the relevant paragraph of his first report in full:

‘113. There are, however, a number of errors and points in the specification that the Skilled Urologist would find difficult to understand why they have been written in the way they have:

(a) The most significant issue is the description of item 6 as a “stylus”. From the way that it is drawn in Figures 3 and 5, it appears to be a very large needle. I also understand from Clyde & Co that Well Lead considers that the correct translation of the Chinese words used for item 6 is “piercing needle”. However, the Skilled Urologist would be puzzled as to why a needle would be necessary. Paragraph [0004] says that an opening has already been made at the surgical site when the “stylus” is inserted. I take this to mean that the patient’s skin has been punctured. This suggests that Wan is contemplating the “stylus” being used as a needle to puncture a passageway into the organ being operated on (the kidney, gall bladder or bladder).

(b) However, if item 6 is a needle, it is a very sizeable one that would only be suitable for puncturing in a straight line directly into a hollow organ making sure that there are no other structures or organs in its path that could be pierced or damaged by it. This would make even an experienced urologist very hesitant about using the device, especially in the kidney. In contrast to this, the PCNL procedure that is used in practice to get access to the kidney, involves making a small incision in the skin and passing a very small, fine needle into the kidney. A guidewire for a serial dilator or balloon dilator is then passed into the kidney. Once the urologist is happy the guidewire is in the kidney and the collecting system, the dilator is inserted following the guidewire and is used to serially dilate the hole in the kidney until it is large enough to be able to insert the access sheath (or sleeve tube as it is called in Wan). This is not, though, a procedure that the Skilled Urologist would carry out as it is a sub-specialist area of surgery (though the Skilled Urologist would be aware of it from their training).

(d) The procedures that Wan says its device can be used for are also somewhat puzzling. These are “percutaneous nephroscopic surgery, gall bladder-preserving surgery, and cystolithotrity in women” (paragraph [0001]). My understanding is that Wan’s device is essentially for percutaneous surgery only. As indicated above, by percutaneous nephroscopic surgery, I take Wan to mean PCNL. “Cystolithotrity” is incorrect terminology and should be “cystolithalopaxy” (the treatment of bladder stones normally via the urethra). I can see no reason why Wan says that this procedure is for women and not for men as well. The procedure is routinely used in the treatment of both men and women. But more importantly, the Skilled Urologist would not want to use a rigid (see below) access sheath with a large, sharp “stylus” in the urethra due to the risk of repeatedly puncturing the urethra’s walls.

(e) In addition to the above points, “lithotrity” in paragraph [0003] should be “lithotripsy”.

(f) Overall, these points and the way in which Wan is written generally suggest that it may have been drafted by a product engineer, who is not fully familiar with how urological procedures are carried out or the correct terminology to use for them rather than being written by a clinician or by a product engineer working in conjunction with a clinician.’

96. Mr Saeb-Parsy explained his assumption in sub-paragraph (d) that the piercing sheath in Wan is rigid:

‘Wan does not say what materials its tubes are made of but the assumption from its specification is that they would be hard, rigid ones. This is partly from the need for Embodiment 1 to push the sleeve tube into the piercing tube during an operation (which would require rigidity of materials) and partly from the comment in paragraph [0011] on sterilisation. This is another passage that the Skilled Urologist would be puzzled by - there is no reason why having a control slit in the branch tube would assist in sterilisation - but the fact that Wan envisages its device undergoing sterilisation would suggest to the Skilled Urologist that is intended to be reusable and made of a robust material. Generally urological devices that are reusable are made of stainless steel.’

97. This reading of Wan by Mr Saeb-Parsy was not disputed by Professor Somani save with regard to Mr Saeb-Parsy’s view that the piercing sheath would be taken by the skilled person to be rigid. Professor Somani had three reasons why it may not be: (i) embodiment 2 does not require the sleeve to be pushed into the piercing tube, (ii) flexible items can be sterilised and (iii) the reference to use in cystolithotrity (probably better: cystolithalopaxy) in women implies use of the sheath in the urethra.

98. In his written evidence Mr Saeb-Parsy introduced the device known as a ‘trocar’, part of the CGK at the priority date:

‘A trocar was a device used to create a channel into a cavity such as the abdomen to allow passage of instruments such as a laparoscope into that cavity. A trocar typically consisted of three main components: a sharp-tipped obturator, a cannula, and a valve mechanism. The obturator was a rigid, pointed instrument used for the initial puncture of the abdominal wall or hollow organ.’

99. Mr Saeb-Parsy stated that a better term for the stylus in Wan was a trocar. The reason for this was the similarity in appearance between the piercing stylus 6 shown in Wan and a trocar. This view seems to have developed only after Mr Saeb-Parsy was shown the Patent and asked about differences between Wan and the Patent. As appears from his paragraph 113, quoted above, before then he thought that, notwithstanding the use of the adjective ‘piercing’, the stylus is similar to an obturator for use in ureteroscopy.

100. Mr Saeb-Parsy reinforced his revised view by stating that no urologist would insert a trocar into a kidney. He went further, saying that no urologist would consider using a trocar for any ureteral procedure because they are made of stiff material such as stainless steel rather than flexible material. The implication of this evidence is that the device disclosed in Wan is paradoxically unsuitable for any of the procedures which Wan states in paragraph [0001] to be the very procedures for which it is to be used: PCNL, gallbladder preserving surgery and cystolithalopaxy in women. Professor Somani agreed that a trocar would not be used for any such procedure.

101. Mr Saeb-Parsy offered no explanation for the paradox he implied except to say that the skilled person would wonder whether the writer of Wan knew what they were talking about. That would assume that Dr Wan himself had had no input in the writing of Wan: in cross-examination Mr Saeb-Parsy stated that Dr Wan, also the inventor of the Patent, is a urologist who would know the steps of urological procedures.

102. Professor Somani’s evidence was simpler. Mr Saeb-Parsy’s first impression was right: the skilled person would understand that the stylus in Wan is an obturator. He pointed out that Mr Saeb-Parsy’s stated reason for the change of heart, that the Wan stylus looks like a trocar in figure 3 of Wan, is unconvincing because it looks almost the same as the obturator shown in the figures of the Patent.

103. Professor Somani went on give other reasons. First, trocars are typically used in keyhole surgery and Wan says nothing about that procedure. Secondly, trocars are never used in any of the procedures expressly identified in Wan as those for which its device is intended. Third, as Mr Saeb-Parsy said, no urologist would insert a trocar into a kidney. Fourth, as Mr Saeb-Parsy also said, the skilled person would believe that the sheath in Wan is an access sheath which uses suction to remove stones and fragments. Wan describes the use of the stylus: it is inserted into the sheath, both are introduced into the surgical site via a pre-cut opening, the stylus is withdrawn and replaced by an endoscope. This is fully consistent with how an obturator is used.

Inventive step of claim 1 over Wan

104. There are two differences between claim 1 of the Patent and Wan: Wan discloses a ‘piercing stylus’ rather than an obturator and has no collection container. At the trial Well Lead conceded that there would have been nothing inventive about adding a collection container.

105. Whether claim 1 embodies an inventive step over Wan in the end turned on the short issue of whether the skilled person would take the piercing stylus to be an obturator or not.

106. Professor Somani accepted in cross-examination that the use of the Wan device as explained in Wan was more consistent with a percutaneous procedure than ureteroscopy via the urethra.

107. Mr Saeb-Parsy maintained his modified view that the obturator would be taken to be a trocar but provided no further reason to explain the paradox apparently presented by Wan. Professor Somani was not challenged in his criticisms of Mr Saeb-Parsy’s modified view. I find those criticisms convincing.

108. It seems to me that although use of the word ‘piercing’ to describe the stylus is odd, it is no odder than describing the sheath as piercing. Neither expert suggested that the sheath would be used to pierce the patient’s skin. On the other hand, piercing in the sense of entering the patient would make sense of the word in both contexts.

109. In my view, at the priority date the skilled person would have understood the part of the Wan device described as a piercing stylus to be a kind of obturator. Accordingly claim 1 lacks inventive step over Wan.

Inventive step of claim 3 over Wan

110. The issue in relation to claim 3 is whether it was obvious to secure a flexible, deflectable tip to the distal end of the sheath.

111. To avoid mischaracterisation of CJ Medical’s position, I will quote the relevant part of its written closing argument, which returned to its three constructions of claim 3:

‘As discussed in our opening, the answer to Pozzoli 4 depends on the correct construction of Claim 3. If either Construction One or Two is correct, the Defendant contends that both were CGK, and thus obvious over Wan. But neither party contends that these constructions are correct.

If, as the Defendant asserts, Construction Three is correct (i.e. Claim 3 requires the active or passive means taught at [0025]), then the Defendant’s position is that this would not have been obvious to the Skilled Person over Wan as at the Priority Date.’

112. This is not clear. As I have said, Construction Three was presented as requiring active deflection only. I have rejected that construction, although with regard to ‘flexible’, I have not accepted Well Lead’s interpretation of that word.

113. As appears from CJ Medical’s closing argument, there was a concession that claim 3 is not obvious over Wan of Construction Three is correct, but it also refers to active or passive means taught in paragraph [0025]. That may be a reference to the point made by counsel in oral submissions that passive deflection is concerned with whether the mode in which the tip has a memory, an argument I have rejected. I have gone back to the transcript taken at the trial, but nothing said in oral closing submissions makes matters clearer.

114. Well Lead’s point was that since Wan does not disclose a flexible tip, CJ Medical had to rely on CGK to fill in that gap. CJ Medical produced just one item of prior art, known as the UroPass, which had a sheath with a flexible tip. Professor Somani said that it was part of the CGK. Mr Saeb-Parsy said that it was not, that he had not previously been aware of it and that it had not been used in either of the high profile hospitals in which he was a consultant before the priority date.

115. I take the view that to make good a case on CGK where it is disputed between the experts, the party relying on it will generally have to do better than to produce one example that was on the market with no figures to indicate how widespread sales were before the priority date or other evidence to establish that it was part of the CGK.

116. I leave aside CJ Medical’s concession on the obviousness of claim 3, which may not stand when taken with my findings on construction. I find that CJ Medical did not establish on the evidence that it was obvious at the priority date to secure a flexible, deflectable tip to the distal end of the sheath. Claim 3 does not lack inventive step over Wan.

Added matter

117. The device claimed has ‘one or more side arms’ (integer 2). So far I have discussed only what could be viewed as the principal side arm, that which is connected to the negative air pressure system via the collection container. This is integer 9:

‘… optionally, an accessory side arm (60) emanating from the outer surface (34) of said sheath (20);’

118. The function of the optional accessory side arm is to provide additional irrigation, or the passage of a guide wire or any other device that may be needed during the removal of stone fragments or other foreign bodies, or as an additional channel for the removal of foreign bodies.

119. CJ Medical’s argument on added matter at the trial (others were not pursued) was that whereas in the parent PCT Application (WO 2016/018479 A1) the accessory side arm is only disclosed as emanating from a proximal sheath, claim 1 discloses that the accessory side arm emanates from the sheath, not necessarily the proximal sheath. Put another way, the additional matter said to be disclosed in the Patent is that the additional side arm may also emanate from the distal sheath.

120. CJ Medical did not submit that the Patent expressly states anywhere that the additional side arm may emanate from the distal sheath. Whenever any part of the sheath is specified in the description it is the proximal sheath, e.g. in paragraphs [0023] and [0027].

121. The figures of the Patent which include a depiction of the accessory side arm show it only emanating from the proximal sheath.

122. In their written closing submissions CJ Medical acknowledged that the skilled person reading the Patent would have understood that the additional side arm must emanate from the proximal sheath because of the functions it may perform:

‘The Skilled Person would therefore understand that the accessory side arm is a functionally distinct sub-class of the more general “one or more side arms” disclosed on page 2 of the Patent, and that the requirement that it emanates from a proximal sheath is necessary for it to perform these functions.’

123. This assertion was not made by reference to anything the experts said. The experts seem not to have directly addressed the point at all. However, for the reasons I have given I think that CJ Medical is right about how the skilled person would have addressed the matter.

124. I find that the skilled person reading the Patent would have understood that the additional side arm must emanate from the proximal sheath. The objection of added matter fails.

Method of treatment or diagnosis

125. CJ Medical relied on section 4A(1) of the Patents Act 1977. It provides:

‘4A. (1) A patent shall not be granted for the invention of –

(a) a method of treatment of the human or animal body by way of surgery or therapy, or

(b) a method of diagnosis practised on the human or animal body.’

126. Section 4A is among those which must be interpreted, as nearly as practicable, in the same way as the corresponding provision in the European Patent Convention, art.53(c), which states:

‘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.’

127. The meaning of ‘a method of treatment of the human or animal body by way of surgery’ in art 53(c) was considered in detail by the Enlarged Board of Appeal of the European Patent Office in Case G1/07 MEDI-PHYSICS/Treatment by surgery [2010] EPOR 25. I need not explore that decision since Well Lead accepted CJ Medical’s contention that the method for using the device claimed set out in the Patent would amount to a treatment by surgery.

128. All the claims of the Patent are product claims. CJ Medical argued that the Patent nevertheless amounts to a patent for a method of treatment of the human body by way of surgery because the description sets out such a method. A surgeon carrying out that method would infringe the Patent.

129. Well Lead’s argument was simply that the application of s.4A(1) is confined to patents with method claims.

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.

131. With regard to CJ Medical’s point that a surgeon using the device of the Patent would infringe, it seems to me that the policy of art.53(c) is to accept such a possibility. For instance, a patent for a substance or composition suitable for use in a method of treatment of the human body by way of surgery would lead to exactly that result: a surgeon using the substance or composition in the course of the relevant treatment would infringe. However, it was apparently assumed by those who framed art.53(c), no doubt correctly, that any action for infringement would be directed against the party making or disposing of the product concerned, not the surgeon. This is to be contrasted with a claim for a method of treatment. In relation to such a claim it may be difficult to prove infringement by parties supplying a product used in the method, depending on the facts. The only clear infringer may be the surgeon.

132. I reject CJ Medical’s argument under s.4A(1)(a).

Infringement

133. The product alleged to infringe, the Seplou Sheath, is a kit of parts. Well Lead relies on s.60(2) of the Patent Act 1977 but reliance on that subsection of itself raised no issue. By the time of the trial the dispute on infringement came down to a single point on normal construction, namely whether the sheath of CJ Medical’s products have a diameter which is the same as the diameter of the lumen of the side arm. If the diameters are not the same, Well Lead had a further argument on equivalence.

134. The Seplou Sheath comes in five different sizes. This table produced by Well Lead was accepted to be factually accurate:

*Product* *Size*	Diameter of sheath lumen (mm)	*Diameter of side arm lumen (mm)*	*Differences (%)*
10	3.33	4.57	37.2
11	3.67	4.69	27.8
12	4.00	4.79	19.8
13	4.33	4.68	8.1
14	4.67	4.68	0.2

Normal construction

135. I have found that ‘the same’ in claim 1 requires a variation between the two diameters of no more than 5%. Size 14 of the Seplou Sheath infringes on a normal construction, the other sizes do not.

Sizes 10-13 as equivalents

136. It was common ground that whether sizes 10-13 infringe as equivalents of the claimed invention turns only on the third question identified by Lord Neuberger in Actavis UK Ltd v Eli Lilly & Co. [2017] UKSC 48, at [66]. It was therefore agreed that (1) the variants - each of sizes 10-13 - all achieve the same result in substantially the same way as the inventive concept of the Patent and (2) it would have been obvious to the skilled person reading the patent at the priority date, a person who knows that all the variants achieve substantially the same result, that they do so in substantially same way as the inventive concept.

137. This is Lord Neuberger’s third question:

‘Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?’

138. CJ Medical relied on the passages from paragraphs [0015] and [0020] of the Patent which I have set out above.

139. In paragraph [0015] ‘identical or nearly identical’ lumen sizes are stated to be ‘one important feature of the current invention’.

140. Paragraph [0020] first discusses three possibilities: (i) the diameter of the side arm lumen is up to 20% smaller than that of the sheath and (ii) the diameters are the same and (iii) the diameter of the side arm lumen is up to 20% smaller than that of the sheath. These three options are said to be ‘embodiments’ but not embodiments of the invention. Paragraph [0020] goes on, however, to say that ‘according to the present invention’ the diameters are the same.

141. CJ Medical submitted that this was an instance of the principle of ‘disclosed but not claimed’. In Akebia Therapeutics Inc v Fibrinogen, Inc [2020] EWHC 866 (Pat) Arnold LJ (sitting as a High Court Judge) discussed the principle in the context of the third Actavis question, pointing out that it has an established history in the case law of the German Federal Supreme Court (BGH):

‘[456] Again, this is an instance of a principle recognised by the BGH that, where the specification discloses several ways in which a particular technical effect can be achieved but only one way is claimed, the conclusion that use of the other (disclosed but not claimed) ways to achieve the technical effect cannot amount to infringement as an equivalent extends to further undisclosed ways in which the technical effect can be achieved where the further ways operate in a manner more similar to the disclaimed than the claimed methods: see Case X ZR 69/10 – Diglyzidverbindung (Diglycid compound) at [45]-[46].’

142. I accept CJ Medical’s submission. In my view the skilled person would have recognised the distinction between (a) an embodiment in which the lumen sizes are the same and (b) embodiments in which there is 5-20% variation. The latter are disclosed but not claimed in claim 1. This is an instance where the principle of ‘disclosed but not claimed’ falls to be applied.

143. Further, the latter embodiments include one in which the lumen of the side arm is 20% smaller in diameter than the lumen of the sheath, which does not seem to accord with the purpose behind the requirement of respective lumen sizes.

144. CJ Medical also relied on a comparison between a sentence in paragraph [0020] of the Patent and its equivalent in the application for the Patent as filed. In Actavis Lord Neuberger said:

‘[88] While it would be arrogant to exclude the existence of any other circumstances, my current view is that reference to the file would only be appropriate where (i) the point at issue is truly unclear if one confines oneself to the specification and claims of the patent, and the contents of the file unambiguously resolve the point, or (ii) it would be contrary to the public interest for the contents of the file to be ignored. The first type of circumstance is, I hope, self-explanatory; the second would be exemplified by a case where the patentee had made it clear to the EPO that he was not seeking to contend that his patent, if granted, would extend its scope to the sort of variant which he now claims infringes.

145. In my judgment Lord Neuberger’s condition (i) is not met. For the reasons I have given I do not believe that the point in issue is truly unclear taking into account the specification and claims. However, I would add that the comparison which CJ Medical makes is supportive of my finding in relation to (i).

146. The relevant sentence in the Patent is one I have already referred to and quoted. Its equivalent in the PCT Application is:

‘In yet another embodiment, the diameter of the lumen 53 of the side arm 50 is the same or larger than the diameter of the lumen of the sheath 23, 33, 43 to facilitate the efficient evacuation of stones, stone fragments or other foreign bodies.’

147. As appears from paragraph [0020] of the Patent, this sentence was amended during prosecution. Marked up, the amendments were as follows:

‘According to the present invention, ~~In yet another embodiment,~~ the diameter of the lumen 53 of the side arm 50 is the same as ~~or larger than~~ the diameter of the lumen of the sheath 23, 33, 43 to facilitate the efficient evacuation of stones, stone fragments or other foreign bodies.’

148. This amendment is fully consistent with an intent to narrow the invention to one in which the two lumen sizes are the same or nearly identical.

149. I find that the size 14 of the Seplou Sheath falls within claim 1 and 3 of the Patent. None of the other sizes fall within the claims.

Conclusion

150. Claim 1 of the Patent is invalid for lack of inventive step. Claim 3 is valid. Claim 3 is infringed by sales of the Seplou Sheath in size 14 but not any of the other sizes.

	WELL LEAD MEDICAL CO., LIMITED	Claimant
	- and -
	C J MEDICAL LIMITED	Defendant

	[Home] [Databases] [World Law] [Multidatabase Search] [Help] [Feedback]
	Intellectual Property Enterprise Court
You are here: BAILII >> Databases >> Intellectual Property Enterprise Court >> Well Lead Medical Co Ltd v CJ Medical Ltd [2025] EWHC 492 (IPEC) (07 March 2025) URL: http://www.bailii.org/ew/cases/EWHC/IPEC/2025/492.html Cite as: [2025] EWHC 492 (IPEC)

Intellectual Property Enterprise Court