The European Patent Convention (EPC) was drafted with the intention of prohibiting patent protection of surgical, therapeutic and diagnostic methods.

In particular, Article 53(c) EPC stipulates that “European patents shall not be granted in respect of… methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body”. The reasoning behind this exclusion is that a medical or veterinary professional, faced with the task of administering potentially life-saving treatment to a patient or animal, should not be concerned with whether the treatment would infringe patent rights and therefore open him or her up to litigation.

In our article of October 2019 we explored how the exclusion of Article 53(c) EPC applies to methods of therapy and surgery and to diagnostic methods. In this latest article we take a closer look at the relevance of the exclusion to the protection of medical devices.

A patent application for a medical device may include one or more different types of claim drafted to protect the underlying inventive concept of the device, including: an apparatus claim to the medical device per se; a method claim to the process of manufacturing the medical device; a method or use claim to the operation of the medical device; and/or a computer program claim to a program that causes a computer to perform a method of manufacturing/operating the medical device. In this article we will examine how the European Patent Office (EPO) applies the Article 53(c) EPC exclusion to each of these types of claim.

Apparatus claims

An example of an apparatus claim would be “A medical device comprising: feature X and feature Y”.
Article 53(c) EPC specifically refers to the exclusion of “methods” from patentability, and states that the exclusion “shall not apply to products, in particular substances or compositions, for use in any of these methods”. The term “products” encompasses medical devices such as surgical, therapeutic or diagnostic instruments or apparatuses for use in such methods and therefore, on the face of it, apparatus claims would always appear to fall outside of the exclusion. However, apparatus claims can actually be excluded from patentability if the patent application implies that the apparatus can only be produced by performing a surgical or therapeutic step. This potential pitfall was highlighted in EPO Board of Appeal case T1731/12 (which is a continuation of principles previously established in T775/97).

T1731/12
This case concerned an apparatus for the treatment of neurological conditions caused by abnormal synchronisation of different areas of the brain, such as Parkinson’s disease. Claim 1 (abridged) defined a “Device for the desynchronization of activity of pathologically active brain areas comprising… at least two electrodes… and… control means which are designed such that, during operation, they control the at least two electrodes such that the at least two electrodes emit stimuli to in each case one of at least two subpopulations of a neuron population to be desynchronized, with the stimuli emitted from different electrodes being offset in time, and the stimuli causing the neural activity of the at least two subpopulations to be phase-reset, such that the at least two subpopulations have different neural-activity phases after the phase resets produced by the stimuli.”

In essence, the claimed apparatus comprises two electrodes that are implanted into the brain and a control means that controls the electrodes to perform the functional steps outlined above in order to desynchronise the different areas of the brain. Crucially, the Board held that certain functional features of the claim could only be achieved after the electrodes have been implanted, i.e. after a surgical step had been performed, and the Board noted that this was stated throughout the description. For example, the final feature of the claim “the at least two subpopulations have different neural-activity phases after the phase resets produced by the stimuli” must take into account the position of the implanted electrodes, but the position of the electrodes can only be determined after implantation and thus the control means prior to implantation cannot be designed so that this feature is fulfilled. The Board concluded that the claimed apparatus is therefore defined by at least one feature which can only be achieved following a surgical step and thus the claim contravenes Article 53(c) EPC.

Care should therefore be taken when drafting the patent application to ensure that it is not implied that a therapeutic or surgical step is necessary to arrive at the medical device (even if such a step is not explicitly recited in the claims). The exclusion could potentially be avoided by describing how measurements that are obtained following a surgical step could instead be derived using other means, for example, computer modelling.

Claims to a method of manufacturing a medical device

It is also possible to obtain patent protection to a method of manufacturing a medical device. For example, a claim may recite “A method of manufacturing a medical device, the method comprising: manufacturing step X and manufacturing step Y”.

Interestingly, such a method claim may be allowable even if the method involves interaction with the human body, providing that this is not surgical or therapeutic in nature. For example, the EPO Guidelines for Examination, chapter G-II-4.2, gives the example of a method of manufacturing insoles for correcting posture involving taking an imprint of the footplate, and also the example of manufacturing an artificial limb involving taking a moulding of the stump on which an artificial limb is fitted. The EPO considers that in both examples taking the imprint/moulding is not surgical in nature and, furthermore, the insole/artificial limb would be manufactured outside of the body. Therefore, such methods would not fall within the exclusion of Article 53(c) EPC. In contrast, if a surgical or therapeutic step is necessary in order to carry out the method of manufacture then the claim would fall within the exclusion, as shown in T1005/98.

T1005/98
This case concerned a method of manufacture of an artificial knee joint replacement. Claim 1 (abridged) defined a “Process for the production of an endoprosthesis as a joint replacement for knee joints, whereby the prosthesis requires an operative intervention in the femur, the tibia and the patella of a damaged knee joint, consisting of the following stages: a) production of a preoperative tomographic image of the damaged knee joint; b) production of a corrected preoperative tomographic image of the damaged knee joint… c) production of a postoperative tomographic image of the damaged knee joint; d) production of a tomographic comparison image as a tomographic subtraction image… and… e) Production of at least one femoral and one tibial component of an endoprosthesis on the basis of the tomographic subtraction image.”

In brief, a first (preoperative) image of the damaged joint is produced by means of a computer tomograph. Next, a surgical intervention is performed on the bone parts surrounding the damaged knee joint, during which a minimum of the adjacent healthy bone is removed in order to prepare for the subsequent implantation of the prosthesis. Only after this surgical intervention, a second (postoperative) image of the joint is produced. The preoperative and postoperative images are then further processed and compared in order to manufacture an endoprosthesis of the correct dimensions.

It is notable that the surgical intervention is not recited in the claim. Nevertheless, the Board of Appeal held that it was clear from the description that the surgical step was necessary so that the second (postoperative) image could be obtained and therefore the claimed method implies a surgical step. Therefore, despite the fact that the actual manufacture of the knee joint was performed outside of the human body, the requirement that a surgical step needed to be carried out to produce the second image meant that the claimed invention was excluded under Article 53(c) EPC (at the time Article 52(4) under the previous provisions of the EPC).

The exclusion could potentially have been avoided if the application disclosed a method of manufacturing the prosthesis that did not involve a surgical step. In this regard, the applicant argued that the prosthesis could alternatively be produced by comparing images obtained virtually using a computer, and that therefore surgical intervention was not indispensable for the claimed procedure. However, the Board was not persuaded by this, noting that the application did not make any reference to this alternative, and instead repeatedly referred to performing an operative intervention prior to capturing the second image.

Claims to a method of operating a medical device

Another category of claim is that to a method of using a medical device. Such a claim may read “A method of operating a medical device, the method comprising: operation step X and operation step Y”.

At first glance it may appear that such a claim would always contravene Article 53(c) EPC. After all, the exclusion explicitly prohibits the patenting of surgical, therapeutic or diagnostic methods, and therefore a claim to a method of operating a medical device would seem to fall within the scope of the exclusion. However, the case law states that a method concerning the functioning of an apparatus associated with a living human or animal body is not excluded from patentability if no functional relationship exists between the steps related to the apparatus and the therapeutic effect of the apparatus on the body, and this legal principle has been confirmed by EPO Enlarged Board of Appeal in G1/07. Two cases with contrasting outcomes, T44/12 and T82/93, are explored below.

T44/12
T44/12 concerned a method of detecting a blockage in a medical pumping system. Claim 1 (abridged) defined “A method of automatically detecting an occlusion in a downstream fluid line of a medical pumping system… comprising: during a pumping sequence, determining a first force value indicative of force in the downstream fluid line at time T1 [and] a second force value indicative of force in the downstream fluid line at time T2; providing an indication of an occlusion in the downstream fluid line… if a relationship between the first and second force values departs from an expected relationship”.

Notably, claim 1 recites that the force values are determined “during a pumping sequence” and therefore requires that the method is carried out whilst medicament is being delivered. However, the Board held that essentially the method involves no more than determining and comparing two force values in order to give an indication of a possible occlusion, and that this does not have a functional link with the medicament being injected into the patient for the therapy (for example, there was no influence on the quantity, frequency or speed of the delivery of the medicament). The Board also found that the experimental and mathematical determination of an occlusion in the fluid line does not result in the medical practitioner being given any indication as to what should be done in the ongoing therapeutic treatment of the patient. In view of this, claim 1 was not found to contravene Article 53(c) EPC.

T82/93
T82/93 concerned adjusting the rate of a pacemaker during exercise. Claim 1 (abridged) defined “A method of operating a pacer in accordance with the required cardiac output while a person is exercising, said pacer being adapted to be implanted in a human body and comprising a pulse generator and control circuitry therein… characterized in that… pressure sensing means is used to sense the right ventricular systolic pressure and this pressure value and/or its time derivative are used to control the pacer rate.”

The Board held that the use of a sensed pressure value derived from a particular part of the human body for quantitatively controlling the output of the pacer, which is applied to the human body in order to obtain a therapeutic effect, contravened Article 53(c) EPC (at the time Article 52(4) EPC). This is because there was a functional link between the value which is measured and the therapeutic treatment which is applied.

Computer program claims

Until recently, it was generally thought that a claim of the form “A computer program which, when running on a computer, causes the computer to perform a method comprising steps X, Y and Z” was not objectionable under Article 53(c) EPC irrespective of whether a claim to the method itself would be objected to. In fact, the EPO Guidelines for Examination, chapter G-II-4.2.1, explicitly state that this is the case. However, as mentioned in our round-up of recent Board of Appeal decisions, this has been thrown into doubt by T944/15, published by the EPO in February 2021.

T944/15
The claims in T944/15 initially related to a data processing method that the Board decided was excluded under Article 53(c) EPC. In order to overcome this, the appellant reformulated the claims to instead define a computer program (of the form outlined above), and pointed to the Guidelines at G-II-4.2.1 in support of the argument that the reformulated claims were not excluded under Article 53(c) EPC. However, in a decision that will be surprising to some, the Board came to the conclusion that the reformulated claims were still excluded from patentability under Article 53(c) EPC. In doing so, the Board directly contradicted the Guidelines for Examination on this point.

While the Boards of Appeal are not bound by these Guidelines, this is still likely to be seen as a controversial decision and there is a good chance that the reasoning behind the decision will be challenged in future cases. In view of this, despite the negative view from the Board in T944/15, it still appears advisable to include computer program claims in European patent applications, at least until this matter becomes settled by updated Guidelines for Examination and/or further case law.

Conclusion

The application of Article 53(c) EPC to medical device claims can at times appear counter-intuitive, and care should be taken to ensure that a claim does not unintentionally fall within the scope of the exclusion. As we have seen, even apparatus claims to a medical device can be excluded from patentability, as can method claims directed to the manufacture of a device, and therefore if possible the application should be drafted in a manner that does not imply that a therapeutic or surgical step is necessary to arrive at the device. Paradoxically, claims to a method of operating a medical device are not necessarily excluded, if it can be shown that there is no functional relationship between the steps related to the device and the therapeutic effect of the device on the body.