Friday, 26 February 2010

T 244/07 – What May Be Taken From Schematic Drawings

It is well known that one cannot extract dimensional parameters from schematic drawings. The present decision adds an interesting consideration.

Claim 1 of the main request read:

Stent (1) having an extensible stent body (2) wherein the stent body (2) has at least two different wall thicknesses (4,5) and wherein the stent body (2) has at least one end region (3,4) the wall thickness (WE) of which is smaller than a wall thickness (WH) of a main region (5), characterised in that the main region (5) has a constant wall thickness (WH) and in that the end region (3,4) has a constant wall thickness (WE).

[...] The preamble of claim 1 results from claims 1 to 3 as filed ; the additional feature of extensibility, which is known as such, has its origin in paragraphs [0001] and [0002] of the original description as published. The feature of constant wall thickness of the main region and the end region in the characterising part is implicitly disclosed, as the expression “wall thickness” in the description is always used with the definite article in the description. That the wall thicknesses are constant also follows from paragraph [0013] of the original description, and in particular from the ratio of wall thicknesses WE/WH cited in line 47. Such an indication is only meaningful if the wall thicknesses of the respective domains are constant.

Moreover the symbols WH and WE, which are provided with arrows in Figures 1 to 3, tell the skilled person unambiguously and without any doubt that each of the wall thicknesses represented in the drawings corresponds to one single and therefore constant wall thickness of the marked regions. The fact that figures are as a rule only schematic and are explicitly identified as such in the description does not alter this fact because what is taken from the figures is not a concrete dimension (such as in the cases underlying decisions T 857/91 and T 272/92) but only a property (Eigenschaft), i.e. the fact that the respective wall thicknesses are constant. The required manufacturing steps for obtaining constant wall thicknesses, which may be in the micrometer domain in the case of stents, are known to the person skilled in this field and do not have to be mentioned.

Therefore, the requirements of A 123(2) are satisfied. [2] 

To read the whole decision (in German), click here.