The person skilled in the art
12.Mostly there was agreement about the skilled team. It would be led by a developer of catheters. Such an individual would be assisted by a clinician who would inform the developer about the needs of patients. 13.The disagreement concerned whether the developer would have had knowledge and experience of indwelling catheters as well as intermittent catheters. 14.The addressees of a patent specification are “those likely to have a practical interest in the subject matter of [the] invention”, such individuals being “persons with practical knowledge and experience of the kind of work in which the invention was intended to be used” per Lord Diplock in Catnic Components Ltd v Hill & Smith Ltd [1982] R.P.C. 183, at p.242-3. 15.The skilled team has an interest in, together with knowledge and experience of the invention as claimed. This raised the question whether the invention here claimed extended to indwelling catheters. If so, necessarily the skilled team would be familiar with them. 16.Dr Baran submitted in his skeleton argument that the claims covered only intermittent catheters. The trial went ahead on an unspoken basis that these were what mattered most, which is possibly why Dr Baran did not develop reasons for the limited scope of the claims as a formal matter of construction. MacGregor did not raise this as a point of construction either, possibly because it had reasons not to argue for a broad scope. Nonetheless, I must deal with it. 17.The effect of Coloplast’s case was that the word ‘catheter’ in the claims should be construed to mean ‘intermittent catheter’. Yet it was not in doubt that the addressee would have known that catheters come in two varieties and the words of the claims did not specify just one of them. Of course, claims must be construed in the context of the specification as a whole. Had there been, for instance, a definition of ‘catheter’ in the specification, that would have been decisive. There was none. Moreover, this is not an instance in which a term of the claims is ambiguous. It would take a strong indication in the specification for the addressee to understand that ‘catheter’ in the claims meant only one type of catheter. 18.Paragraph [0002] of the specification makes an early statement as to the catheters covered by the invention: “Urinary catheters of the kind to which the invention pertains are known, inter alia from [14 identified items of prior art].” It was not suggested by Coloplast that all 14 disclosed only intermittent catheters. If they do not, this would severely undermine the contention that the scope of claims 1, 3 and 5 is limited to intermittent catheters. 19.There is no doubt that the problem said to be overcome by the invention related to intermittent catheters. Paragraph [0004] states: “[0004] An important feature of any urinary catheter used for intermittent catheterisation of the bladder of an incontinent user is the ability of the catheter to slide easily through the urethra without exposing the urethral walls to any risk of damage. Catheters of the kind to which the inventions pertains [sic] have been developed to meet this need by imparting an extremely low friction character to at least part of the surface of the catheter which is actually introduced into the urethra. …” 20.The reader is here informed that catheters of the invention meet a need arising in the context of intermittent catheterisation. But that is not a statement limiting their use exclusively to intermittent catheterisation. Similarly, paragraph [0006] tells the reader that the catheters as claimed have particular advantages when administered by the patient, but does not limit the potential application of such catheters: “[0006] When catheters of this kind are used directly by end users outside the medical environment of a hospital or a clinic, e.g. by or [sic] tetraplegic patients who often have a very poor dexterity, and therefore need a very simple insertion procedure, the most common liquid swelling medium used for preparation of the catheter immediately prior to use would be normal tap water.” 21.The specification goes on to say that the tap water available, e.g. in public toilets, may not be of a sufficiently clean standard. Hence the advantage of having a ready-wetted hydrophilic layer or alternatively a means of wetting the layer using water contained within the catheter packaging. Again, this does not imply that the catheter assemblies claimed exclude indwelling catheters used in a hospital. 22.The closest that the specification comes to indicating a narrow construction of ‘catheter’ is at paragraph [0008]: “[0008] On this background, it is the object of the invention to improve and facilitate the performance of the intermittent urinary catheterisation in any type of environment by providing a ready to use urinary catheter assembly comprising a catheter which can be withdrawn from its package and is prepared for direct insertion in the urethra and in a substantially sterile condition, whereby the general quality of life for users of intermittent catheterisation would be greatly improved.” 23.‘On this background’ indicates that what is being said in this paragraph follows from what was said before: the advantage conferred by the invention will be felt by users of intermittent catheters. That is not the same as saying that the invention cannot be used for indwelling administration. None of the evidence suggested a technical reason why the invention could not apply to indwelling catheters. 24.I therefore take the view that the term ‘catheter’ in claims 1, 3 and 5 should be given its usual meaning and that those claims encompass assemblies comprising catheters for both intermittent and indwelling administration. 25.The team referred to above was therefore skilled in both types of catheter and included a developer and clinician familiar with each of them.