Surgical Complications: T1631/17 and implicit surgical steps

It is well known that “methods of treatment of the human or animal body by surgery” are not patentable at the EPO in accordance with Article 53(c) EPC.  What may not be so well known is that method claims that do not comprise any explicit surgical steps may still be excluded from patentability under Article 53(c) EPC, if one or more surgical steps are considered to be implicit. 
 
A recent¹ decision by the EPO’s Technical Board of Appeal (BOA), T1631/17, addresses the question of when an unclaimed surgical step is considered to be implicit to a claimed method.
 
In this article of two halves, we first set out a brief summary of the decision and some practical tips to consider when drafting and prosecuting patent applications containing methods which require a preceding surgical step. For those readers interested in a deeper dive, we then take a look at the background to this decision and examine the findings of the BOA in more detail.
 

Part 1: What this decision means for patent applicants

Summary of the decision

The decision in T1631/17 supports previous case law which states that an unclaimed step may be considered essential and thus implicitly part of a claimed method, if it represents “the contribution of the invention over the art”. In other words, the step may be considered implicit if it is at the heart of the advantage that the claimed method provides over the prior art.
 
However, the BOA also set out another set of circumstances under which an unclaimed surgical step may be considered implicit.
 
In the present case, the claimed steps of the method were considered to be preceded by two unclaimed preparatory steps; the first of which was non-surgical and the second of which was surgical. The first preparatory step was considered implicit to the claimed method as it represented the contribution of the invention over the art. The second preparatory step was considered implicit merely because it fell “in time and space” between the first preparatory step and the claimed steps of the method. As this second preparatory step was surgical, it resulted in the exclusion of the claim from patentability.
 
Therefore, an unclaimed surgical step which doesn’t represent the contribution of the art, but which falls “in time and space” between another unclaimed but essential step and the claimed steps of the method, can also be considered implicit to that method.
 

Practise points

The EPO’s approach to claims relating to methods that are preceded by an unclaimed surgical step is still unsettled and very case-specific. However, the present case, in combination with existing case law (discussed in more detail in Part 2 of this article) suggests that the risk of receiving an objection under Article 53(c) EPC might at least be reduced by taking the following precautions in such cases:

• Where possible, avoid the explicit inclusion of any steps in the claims that might be considered surgical in nature (e.g. simply leave out the surgical step from the claim or, if necessary, use wording which implies that the step has already been conducted, for example “pre-delivered”)

• If appropriate, indicate in the description that any steps that entail a physical intervention with the human or animal body involve only an insubstantial physical intervention that entails little health risk (such that the intervention should not be considered “surgical” at all), or argue that this is the case during prosecution

• If appropriate, indicate in the description that these “physical intervention” steps are commonly carried out in the prior art (i.e. even when the claimed method is not being performed), or argue that this is the case during prosecution

• Emphasise in the description that any contributions that the invention makes over the prior art are not directly related to these “physical intervention” steps (i.e. that the advantages provided by the claimed method steps are above and beyond those that follow directly from the “physical intervention” steps), or argue that this is the case during prosecution

• Emphasise in the description that any contributions that the invention makes over the prior art are not directly related to any steps that precede these “physical intervention steps”, to avoid an objection of the type raised in T1631/17, or argue that this is the case during prosecution

• If an objection under Article 53(c) EPC does arise and previous case law is cited, take advantage of the fact that the EPO case law in this area appears to be very case-specific. In particular, try to distinguish the case in question from that in the cited case law based on the facts of the case. For instance, in T429/12, the BOA stated that T836/08, which deals with the operation of a device, was not applicable to the case in question, which concerned the production of an aligning plate.

 
For a more detailed analysis of the decision, please read on…..
 

Part 2: A deep dive into the decision

Before considering the decision in T1631/17 in more detail, we’ll briefly consider some existing case law illustrating how the BOA have previously addressed the issue of implicit surgical steps, in order to put the new decision into context.
 

When an unclaimed surgical step is implicit: conflicting case law

In G1/07, the Enlarged BOA stated that:
 
" Under Article 84 EPC, whether or not a step being or encompassing a surgical step excluded from patentability can be omitted either by using positive wording for such omission like “pre-delivered” or by simply leaving it out from the claim depends on whether the claimed invention is fully and completely defined by the features of the claim without that step. That requires an assessment of the individual case under consideration” (point 4.3.1)
 
Therefore, any unclaimed surgical step that is considered to be necessary for the invention to be fully and completely defined will be considered essential and thus implicitly “read into” the claimed method. As a result, such a method will be excluded from patentability.
 
Since G1/07, the case law from the Technical BOA has provided varied and sometimes conflicting guidance regarding when an unclaimed surgical step will be considered “essential” to a claimed method.  
 
For example, in T923/08 and T836/08, the BOA came to opposing decisions regarding whether methods which inherently require the fixation of a so-called “reference system” to a bone, prior to the claimed method steps, are excluded from patentability.
 
In T 923/08, the BOA found the fixation of the reference system to the bone to be an indispensable requirement for carrying out the claimed method. It was considered to represent an essential feature of the method because it was required for solving the problem underlying the claimed method. In contrast, the BOA in T836/08 noted that the fixation of the reference system to the bone was not part of the claimed method, which related only to the operation of a device. The BOA stated that the fact that the method was carried out after or even during a surgical procedure on the body does not mean that the claimed method is surgical as such. Therefore, the fixation of the reference system to the bone was not considered to be an essential feature that was implicit to the claimed method.
 
In other cases, the BOA have stated that whether or not an unclaimed surgical step is “essential” depends upon whether that surgical step represents the contribution of the invention over the art.
 
T992/03 related to a magnetic resonance method for imaging pulmonary and cardiac vasculature using dissolved polarised ¹²⁹Xe gas. While such a method necessarily requires a preceding step in which the ¹²⁹Xe gas is delivered to the patient, for example by injection into the heart, the BOA concluded that this unclaimed surgical step was not essential to the claimed method. This is because the contribution of the invention over the art was not characterised by the delivery of the ¹²⁹Xe gas to the patient. Instead, it was characterised by the manner in which the dissolve-phase gas was excited once it had been delivered.
 
A later case, T429/12, supports this definition of an “essential” feature. T429/12 related to a method for producing an aligning plate for drilling a hole in the bone of a jaw, where the location of an anatomical structure of the jaw relative to at least one reference element fixed to the bone is determined. The BOA noted that:
 
“The provision of a reference element fixed to the bone, preferably in the form of a screw, is not only required for the claimed method, which uses this element to determine the location of anatomical structures of the jaw, but represents the gist of the invention, since it makes possible to achieve the advantages over the prior art acknowledged in the patent. Moreover, the step of fixing the reference element to the bone serves the sole purpose of using this element in the production of the aligning plate. In other words, this step would not be carried out if no aligning plate were to be produced” (point 3.4; emphasis added)
 
Accordingly, the fact that the description or claims imply that a surgical step may have previously taken place, or even that a surgical step is necessary for the claimed method to be carried out, might not mean that the surgical step will be considered essential and read into the claimed method.
 
Instead, one must assess the relevance of that previous surgical step to the contribution the claimed method makes over the art. If the unclaimed surgical step is at the heart of the advantage that the claimed method provides over the prior art, it is likely to be considered an essential step (as in T429/12).
 
In contrast, surgical steps that are necessary for a claimed method to be performed may not be considered essential, if they would have been carried out anyway or if they are not directly related to the particular advantage that the invention provides over the art (as in T992/03).
 
As an aside, it is notable that the BOA in T429/12 stated that the decision in T836/08, which deals with the operation of a device, was not applicable to the case in question, which concerned the production of an aligning plate. This highlights the extent to which decisions concerning this particular exclusion depend on the facts of the case.
 
At first glance, the new decision in T1631/17 would appear to closely follow the decisions in T992/03 and T429/12. However, a closer examination suggests another divergence from previous case law.
 

Where we are now: T1631/17

T1631/17 is an appeal of a decision to revoke European Patent No. 1 901 676 following opposition proceedings before the EPO².
 
Claim 1 recited a method for producing tooth replacement parts. This method makes use of two impressions of the patient’s teeth. In order to create these two impressions, the claimed method requires preparatory steps which can be summarised as follows: 

1. The missing tooth substance is replaced and the first impression is taken

2. The replaced tooth substance is removed, the teeth are prepared to receive the final dental prosthesis and the second impression is taken.

These two preparatory steps were not recited in the claimed method. Therefore, the Appellant argued that the claim does not explicitly contain a surgical step. The BOA agreed.
 
The Appellant also argued that the claim does not implicitly contain a surgical step, as the preparatory steps take place “completely separately” from the claimed method (the steps of which make use of the pre-made impressions and do not require the presence of the patient).
 
The BOA disagreed and found that the claimed method did implicitly include both of these preparatory steps. The BOA referred to the teaching of G1/07 and argued that, if essential features of the invention are missing from the claim, these must be read when interpreting the claim.
 
The BOA noted that the claimed method provides a simplified way of designing a replacement tooth part by allowing the desired external shape of the tooth replacement part to be designed directly on the patient by the dentist. The first preparatory step of replacing the missing tooth substance and taking the first impression of the “finished” teeth are what facilitate this. Indeed, claim 1 recited that the method was “characterised in that the impression of a human dentition in which missing tooth substance is replaced is used as the first impression”, indicating that this is the feature that is considered to distinguish the invention over the prior art³. The BOA concluded:
 
“2.2. It follows that the replenishment of the missing tooth substance is an essential feature of the invention. In the present case, in particular, because this step represents precisely the contribution that goes beyond the state of the art. This process set must therefore be read when interpreting the claim” (translated from the original German; emphasis added).
 
Therefore, as the replacement of the missing tooth substance and the taking of the first impression represent the contribution of the invention over the art, the first preparatory step was considered to be an essential feature of the present invention and thus implicit to the claimed method.
 
This would appear to accord with the decisions in T992/03 and T429/12. However, there is no assertion that either the replacement of the missing tooth substance or the taking of the first impression constitute surgical steps.
 
Instead, the surgical step was considered to be found in the second preparatory step, in particular the preparation of the teeth to receive the final dental prosthesis. In accordance with G1/07, a step is considered surgical if it represents “a substantial physical intervention on the body…when entails a substantial health risk even when carried out with the required professional care and expertise” (headnote 1). The BOA asserted that the second preparatory step:
 
“is carried out directly on the patient and represents a surgical procedural step because body tissue is removed invasively and to a considerable extent” (point 2.4; translated from the original German).
 
With regard to whether this second preparatory step is also an essential feature of the claimed method, the BOA state:
 
“The preparation of the teeth, which takes place after the first impression (see paragraph [0027] of the description) is therefore also within the claimed method in terms of time and space. The claimed method cannot be carried out without the immediate implementation of the intermediate step of preparing the teeth, because otherwise the second impression could not be taken. Without this process step, the invention within the meaning of G 1/07 would therefore not be described completely and comprehensively. It is therefore also implicitly contained in the claimed method” (point 2.3; translated from the original German)
 
Therefore, despite the fact that this second preparatory step does not represent the contribution of the invention over the art, the BOA considered it to be essential and thus implicit to the claimed method because it falls (in time and space) between an essential, earlier step and the claimed steps of the method. As the method was now considered to begin with the first preparatory step, the second
preparatory step must also be read into the claim in order for the method to be completely and comprehensively described.
 
In summary, T1631/17 does appear to support the decisions in T992/03 and T429/12, insofar as an unclaimed step may be considered essential and thus implicit if it represents the contribution of the invention over the art.
 
However, T1631/17 also suggests that simply arguing that the unclaimed surgical step does not represent the contribution of the invention over the art may not be sufficient to avoid this step being read into a method claim. If a preceding, unclaimed step is considered to be essential, such that the claimed method is deemed to implicitly begin earlier in the procedure than originally claimed, any surgical steps falling within the temporal scope of that new, extended procedure may also be implicitly incorporated into the method claim (as illustrated in Figure 1, below). As a result, that claim may receive an objection under Article 53(c) EPC. 
 

 
In conclusion, T1631/17 adds to the varied (and sometimes conflicting) case law surrounding the exclusion of the patenting of surgical methods, and in particular to the question of when unclaimed surgical steps are considered to be essential and therefore implicit to a claimed method. The case does provide a confirmation of the approach taken in T992/03 and T429/12, but also identifies another set of conditions under which an unclaimed surgical step may be considered implicit to a claimed method. Given the BOA’s tendency to argue that decisions on this matter are highly case-specific, it remains to be seen the extent to which this decision will influence the EPO’s approach to such methods going forward.

For further information or assistance, please get in touch with Julia or your usual Kilburn & Strode adviser. 

Edited by: James Snaith

1. Decided 31 July 2020
2. The original opponent did in fact withdraw their opposition, but the Opposition Division decided to go ahead with opposition proceedings anyway, which is allowed if it is likely that the patent will be limited or revoked “without further assistance from the opponent(s)”.
3. In the two-part form of claim preferred by the EPO, the “preamble” sets out features known in combination in the prior art, and the “characterising portion” sets out those features of the invention that are novel and inventive over the art.